Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), is the most common secondary infection in the Human Immunodeficiency Virus (HIV) infected population, accounting for more than one-fourth of deaths in people living with HIV (PLWH). Reciprocally, HIV infection increases the susceptibility to primary TB or reactivation of latent TB by several folds. The synergistic interactions between M.tb and HIV not only potentiate their deleterious impact but also complicate the clinical management of both the diseases. M.tb-HIV coinfected patients have a high risk of failure of accurate diagnosis, treatment inefficiency for both TB and HIV, concurrent nontuberculous mycobacterial infections, other comorbidities such as diabetes mellitus, severe cytotoxicity due to drug overburden, and immune reconstitution inflammatory syndrome (IRIS). The need of the hour is to understand M.tb-HIV coinfection biology and their collective impact on the host immunocompetence and to think of out-of-the-box treatment perspectives, including host-directed therapy under the rising view of homeostatic medicines. This review aims to highlight the molecular players, both from the pathogens and host, that facilitate the synergistic interactions and host-associated proteins/enzymes regulating immunometabolism, underlining potential targets for designing and screening chemical inhibitors to reduce the burden of both pathogens concomitantly during M.tb-HIV coinfection. To appreciate the necessity of revisiting therapeutic approaches and research priorities, we provide a glimpse of anti-TB and antiretroviral drug-drug interactions, project the gaps in our understanding of coinfection biology, and also enlist some key research initiatives that will help us deal with the synergistic epidemic of M.tb-HIV coinfection.

Despite significant advances in research over the past century, Tuberculosis (TB) remains a formidable global health concern. TB granulomas are organized structures composed of immune cells, that serve as the body's primary defense against the spread of Mycobacterium tuberculosis (Mtb). The immune landscape of TB granulomas involves a complex array of immune cells, including CD4+ and CD8+ T cells, B cells, NK cells, and others, which collectively influence the fate of the granuloma. B cells contribute to the formation of the granuloma's germinal center, while the functional state of T cells-particularly their ability to control infection-dictates whether the granuloma is controlling or proliferative. The intricate interplay between T cells and the dynamic microenvironment of the granuloma plays a pivotal role in determining the outcome of the infection. However, several aspects of the immunological basis of tuberculosis are still unknown. This review delves into the immunological landscape of TB granuloma, focusing on the dynamic cellular interplay within the granuloma and its profound influence on disease pathogenesis.

Animal models that can mimic progressive granulomatous pulmonary disease (PD) due to non-tuberculous mycobacteria (NTM) have not been established in rats to date. These models could assist with the study of the pathophysiology of NTM-PD as well as the preclinical development of new therapies. In the present study, an immunocompetent rat model of progressive Mycobacterium abscessus (MABs)- PD was developed using MABs originating from a patient with cystic fibrosis. MABs was embedded in agarose beads and delivered intratracheally to the lungs of Sprague Dawley rats two times at a one-week time interval. The bacterial burden of lysed lungs, spleen and liver was assessed by calculating colony forming units (CFUs) on day 28. Lung CFUs indicated a ∼1.2-2 log10 total CFU increase compared to the initial total bacterial load instilled into the lungs. In all infected rats, multinodular granulomatous inflammatory lesions containing MABs were found in the lung. These findings support the establishment of an immunocompetent MABs PD rat model, characterised by an increase in mycobacterial burden over time and a chronic granulomatous inflammatory response to the MABs infection.

Tuberculosis (TB) is a disease of major public health concern with an estimated one-fourth of the world currently infected with M. tuberculosis (Mtb) bacilli. Mtb infection occurs after inhalation of Mtb, following which, highly structured immune structures called granulomas form within lungs to immunologically restrain and physically constrain spread of infection. Most lung granulomas are successful at controlling or even eliminating their bacterial loads, but others fail to control infection and promote disease. Granulomas also form within lung-draining lymph nodes (LNs), variably affecting immune function. Both lung and LN granulomas vary widely in ability to control infection, even within a single host, with outcomes ranging from bacterial clearance to uncontrolled bacterial growth. While lung granulomas are well-studied, data on LN granulomas are scarce; it is unknown what mechanisms drive LN Mtb infection progression and variability in severity. Recent data suggest that LN granulomas are niches for bacterial replication and can reduce control over lung infection. To identify mechanisms driving LN Mtb infection, we developed a multi-scale compartmental model that includes multiple lung-draining LNs, blood. We calibrated to data from a nonhuman primate TB model (one of the only models that parallels human TB infection). Our model predicts temporal trajectories for LN macrophage, T-cell, and Mtb populations during simulated Mtb infection. We also predict a clinically measurable infection feature from PET/CT imaging, FDG avidity. Using uncertainty and sensitivity analysis methods, we identify key mechanisms driving LN granuloma fate, T-cell efflux rates from LNs, and a role for LNs in pulmonary infection control.

Mycobacterium tuberculosis (M. tb) is an intracellular pathogen adept at evading the human immune system through a variety of mechanisms. During infection, M. tb secretes numerous virulence factors, including the 6 kDa early secretory antigen target (ESAT-6), which is produced by the ESX-1 secretion system. ESAT-6 plays a crucial role in host-pathogen interactions, either independently or in association with culture filtrate protein 10 (CFP-10). While some research has investigated the role of ESAT-6 in M. tb pathogenicity and vaccine development, its precise contribution to immune evasion and the cellular mechanisms involved remain poorly understood. To address this, we used cultured THP-1(A) macrophages to characterize the effects of secreted ESAT-6 on cellular host defenses and apoptosis. We found that ESAT-6 (5 μg/ml) inhibited M. tb-induced apoptosis in THP-1(A) macrophages by suppressing Toll-like receptor 2 (TLR2) through the Caspase-9/Caspase-3 pathway. Additionally, ESAT-6 reduced phagocytosis of M. tb by THP-1(A) macrophages by downregulating the production of interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF-α), and interleukin-12 (IL-12). Furthermore, ESAT-6 diminished the bactericidal activity of macrophages by inducing reactive oxygen species (ROS) production. In parallel, our in silico analysis of differentially expressed genes in dendritic cells (DCs) infected with Bacille Calmette-Guérin (BCG) strains, with or without the region of difference-1 (RD1) gene, strongly suggests that ESAT-6, located within the RD1 region, modulates host defense functions and apoptosis in DCs during BCG infection. Collectively, these findings indicate that ESAT-6 plays a pivotal role in modulating the innate immune response of macrophages against M. tb by regulating macrophage recognition, phagocytosis, bactericidal activity, and apoptosis. Our study provides valuable insights into potential molecular targets for the development of innovative vaccines and therapeutic strategies against M. tb.

Objective: This study aims to compare the expression levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) in osteoblasts infiltrated with Mycobacterium tuberculosis H37Rv (H37Rv) and Brucella ovis to understand the differential bone destruction in spinal tuberculosis (STB) versus Brucella spondylitis (BS). Methods: Primary osteoblasts were isolated and cultured from the cranial bones of 2-5 days old mice and characterized by alkaline phosphatase (ALP) staining and alizarin red staining (ARS). H37Rv and B. ovis were cultured to the logarithmic phase, and transfection solutions were prepared. Osteoblasts were infiltrated with these bacteria at various multiplicities of infection (MOI) and time points. Cell survival post-infiltration was assessed using CCK-8 to determine optimal infection conditions. Osteoblasts were divided into three groups: the H37Rv group (infiltrated with optimal MOI H37Rv), the B. ovis group (infiltrated with optimal MOI B. ovis), and a negative control group. TNF-α and IL-1β expression in the cytoplasm was observed using immunohistochemical staining, whereas their levels in cell supernatants were measured using enzyme-linked immunosorbent assay. Protein expression was analyzed by Western blot. Differences between groups were compared with using one-way analysis of variance and t-tests, with p < 0.05 indicating statistical significance. Results: Both H37Rv and B. ovis infiltrated osteoblasts, substantially increasing TNF-α and IL-1β expression. The H37Rv group showed substantially higher levels of TNF-α and IL-1β compared with the B. ovis group (p < 0.05). Conclusion: Infiltration of osteoblasts with H37Rv and B. ovis substantially increases TNF-α and IL-1β expression, with higher levels observed in H37Rv-infected osteoblasts. This overexpression may contribute to the more severe vertebral bone destruction seen in STB compared with BS.

The comorbid course of chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis is an important medical and social problem. Both diseases, although having different etiologies, have many overlapping relationships that mutually influence their course and prognosis. The aim of the current review is to discuss the role of different immune mechanisms underlying inflammation in COPD and pulmonary tuberculosis. These mechanisms are known to involve both the innate and adaptive immune system, including various cellular and intercellular interactions. There is growing evidence that immune mechanisms involved in the pathogenesis of both COPD and tuberculosis may jointly contribute to the tuberculosis-associated obstructive pulmonary disease (TOPD) phenotype. Several studies have reported prior tuberculosis as a risk factor for COPD. Therefore, the study of the mechanisms that link COPD and tuberculosis is of considerable clinical interest.

ABBi16 is a high-complexity blend of β-1,3/1,6-glucans from Saccharomyces cerevisiae with strong immunomodulatory activities, that have been recently shown to support anti-tumoral immune responses through the induction of trained immunity. Whether ABBi16 also modulates the balance between the various T helper (Th) lymphocyte responses is not known. Here, we show that ABBi16 induces Th1 responses, as indicated by stimulation of IFNγ and TNF production by human peripheral blood mononuclear cells (PBMCs). Moreover, the elevated secretion of IL-10 and IL-22 suggests a potential regulatory response of the Th1/Th2/Th17 balance. Co-stimulating PBMCs with ABBi16 alongside Bacille Calmette-Guerin (BCG), IL-1beta + IL-23, and IL-12 + IL-18 cytokine combinations further enhanced Th1 polarization and IL-22 induction, hinting at an additive effect of β-glucan on both Th1 and regulatory Th17 immune responses. ABBi16 did not induce IL-17 production, the prototype pro-inflammatory product of Th17 responses, suggesting that it can be safely used as an oral supplement in patients with autoimmune conditions. These results highlight the potential of ABBi16 to regulate the Th1/Th2/Th17 balance toward antimicrobial and regulatory effects.

Granulomas, dense clusters of immune cells and bacteria, are critical barriers in tuberculosis (TB) treatment. Recent advancements in TB management have highlighted granuloma control as a potential host-directed therapy (HDT) strategy. Although isoniazid (INH) is the first-line drug for TB therapy, its efficacy is limited to non-replicating Mycobacterium tuberculosis (Mtb) under granulomatous conditions, necessitating the development of more effective derivatives. In this study, hybrid compounds of isoniazid, designated as INH-D1 and INH-D2, were synthesized and evaluated for their effects on controlling inflammatory responses and pulmonary granuloma lesions induced by trehalose-6,6'-dimycolate (TDM), a glycolipid of Mtb. Both INH-D1 and INH-D2 demonstrated stronger inhibitory effects on inflammatory mediators (TNF-α, interleukin-6, co-stimulatory molecules, and MHC class I) in TDM-stimulated macrophages compared to original INH. These anti-inflammatory effects were mediated by the inhibition of Syk, p38, PI3K, and NF-κB transcription. INH-D1 and INH-D2 exhibited stronger binding energies to Syk and PI3Kα/β than INH, which are known as proximal kinases and key mediator in TDM-mediated inflammatory responses. Oral administration of INH-D2 successfully relieved TDM-induced pulmonary granuloma pathology by reducing innate immune cell infiltration, hypoxic conditions in the lungs, and systemic inflammation by decreasing serum cytokines and chemokines. In contrast, original INH and INH-D1 did not effectively alleviate pulmonary granuloma pathology. These findings demonstrate that the novel molecule INH-D2 is effective in treating pulmonary granulomas owing to its strong anti-inflammatory effects, highlighting it as a promising HDT candidate for the management of pulmonary tuberculosis, thereby providing a strategic alternative to standard anti-TB antibiotics.

Elucidating the pathogenic mechanism of Tuberculosis (TB) can contribute to control TB. Basic leucine zipper transcription factor ATF-like 2 (BATF2) belonging to a large family of leucine zipper transcription factors (TFs) termed bZip proteins, had been verified to have important value in the diagnosis of TB. However, its role and mechanism in TB had not been elucidated. The study aimed to explore its function and molecular mechanism in macrophages infected with Mycobacterium tuberculosis (Mtb). The results indicated that BATF2 inhibited cell proliferation, promoted inflammatory response and impaired the antibacterial and antigen-presenting capacity in macrophages for T cells through regulating its downstream gene TTC23 by interacting with SINHCAF. Above roles and regulations were dependent on β-catenin functions in macrophages infected with Mtb. Clinical samples verified that the expressions of BATF2 and TTC23 were significantly higher in the blood of patients with pulmonary TB compared with health controls. Altogether, BATF2 interacted with SINHCAF to regulate the quantity and function of macrophages during Mtb infection by targeting TTC23 through Wnt/β-catenin pathway.

Cardiotonic steroids modulate various aspects of the inflammatory response. The synthetic cardiotonic steroid γ-benzylidene digoxin 15 (BD-15), a digoxin derivative, has emerged as a promising candidate with potential immunomodulatory effects. However, its biological activity remains largely unexplored. This study investigated the anti-mycobacterial and anti-inflammatory effects of BD-15 in an in vitro macrophage infection model with Mycobacterium spp. Unlike digoxin, which showed significant toxicity at higher concentrations, BD-15 exhibited no cytotoxicity in RAW 264.7 cells (a murine macrophage cell line). Both compounds were evaluated in Mycobacterium smegmatis-infected RAW 264.7 cells, reducing bacterial burden without direct bactericidal activity. Additionally, both modulated pro-inflammatory cytokine levels, notably by decreasing tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) levels. BD-15 specifically reduced NOD-, LRR-, and pyrin-domain-containing protein 3 (NLRP3) inflammasome expression and increased interleukin-10 (IL-10) production. Notably, BD-15 reduced colony-forming unit (CFU) counts in Mycobacterium tuberculosis-infected RAW 264.7 cells. Toxicity assays in HepG2 cells (a human liver cancer cell line) showed that BD-15 had minimal hepatotoxicity compared to digoxin, and both demonstrated negligible acute toxicity in an Artemia salina bioassay. These findings revealed the immunomodulatory effects of cardiotonic steroids in a bacterial infection model and highlighted BD-15 as a safer alternative to digoxin for therapeutic applications.

It is estimated that two billion people are latently infected with Mycobacterium tuberculosis ( Mtb ), the causative agent of tuberculosis (TB). Latent Mtb infection (LTBI) can occur in multiple organs, including the lymphatics. The risk of LTBI reactivation increases in immunocompromised conditions, such as coinfection with human immunodeficiency virus (HIV), and during treatment of autoimmune diseases and organ transplantation. The immunological correlates of protection against TB, including against reactivation of LTBI, remain largely elusive. Here, we used a mouse model of latent lymphatic Mtb infection to dissect the immunological mechanisms underlying LTBI containment versus reactivation. We show that immunosuppression-mediated reactivation of lymphatic LTBI and the subsequent spread to non-lymphatic organs can be prevented by vaccination with multiple recombinant BCG (rBCG) strains despite the deficiency of CD4 + T cells. Using spatial transcriptomics, multi-parameter imaging, network analysis and bioinformatic integration of histopathological images, we reveal that immunosuppression is associated with a distinct repositioning of non-CD4 immune cells at the edge of TB lesions within the infection-draining cervical lymph nodes. While B cells increased in numbers, they are dispensable for the containment of LTBI. Lymphatic Mtb infection in different immune cell-deficient mouse strains, antibody-mediated cell depletion and adoptive transfer experiments into highly susceptible mice unequivocally show that vaccination-mediated prevention of LTBI reactivation is critically dependent on CD8 + T cells. These findings have profound implications for our understanding of immunity to TB and the management of LTBI.

Hong Kong is an intermediate tuberculosis (TB) endemicity city dominated by reactivation diseases. A cross-sectional study on the clinical and epidemiologic data of newly diagnosed TB cases was conducted in such a setting, to examine the association between ambient PM2.5 and TB reactivation. After the exclusion of cases most likely resulting from recent infection, four distinct TB population phenotypes were delineated by latent class analysis based on their reactivation risk and clinical profiles (N = 2,153): 'Elderly male' (26%), 'Otherwise healthy younger adult' (34%), 'Older female' (19%) and 'Male smoker' (21%). Overall, exposure to high concentrations of ambient PM2.5 6 and 12 months before the notification was significantly associated with 'Otherwise healthy younger adults' membership (OR = 1.07 and 1.11, respectively) compared with 'Elderly male'. Such association was less evident for other phenotypes. The differential pattern of association between ambient PM2.5 exposure and TB population phenotypes suggested the role of ambient PM2.5 in TB reactivation.

Mycobacterium tuberculosis (Mtb) complex, responsible for tuberculosis (TB) infection, continues to be a predominant global cause of mortality due to intricate host-pathogen interactions that affect disease progression. MicroRNAs (miRNAs), essential posttranscriptional regulators, have become pivotal modulators of these relationships. Recent findings indicate that miRNAs actively regulate immunological responses to Mtb complex by modulating autophagy, apoptosis, and immune cell activities. This has resulted in increased interest in miRNAs as prospective diagnostic indicators for TB, especially in differentiating active infection from latent or inactive stages. Variations in miRNA expression during Mtb infection indicate disease progression and offer insights into the immune response. Furthermore, miRNAs present potential as therapeutic targets in host-directed therapy (HDT) techniques for TB infection. This work examines the function of miRNAs in TB pathogenesis, with the objective of identifying particular miRNAs that regulate the immune response to the Mtb complex, evaluating their diagnostic value and exploring their therapeutic implications in host-directed therapy for TB infection. The objective is to enhance comprehension of how miRNAs can facilitate improved diagnosis and treatment of TB.

Respiratory infections, including tuberculosis, constitute a major global health challenge. Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains one of the leading causes of mortality worldwide. The disease's complexity is attributed to Mtb's capacity to persist in latent states, evade host immune defenses, and develop resistance to antimicrobial treatments, posing significant challenges for diagnosis and therapy. Traditional models, such as animal studies and two-dimensional (2D) in vitro systems, often fail to accurately recapitulate human-specific immune processes, particularly the formation of granulomas-a defining feature of tubercular infection. These limitations underscore the need for more physiologically relevant models to study TB pathogenesis. Emerging three-dimensional (3D) in vitro systems, including organoids and lung-on-chip platforms, offer innovative approaches to mimic the structural and functional complexity of the human lung. These models enable the recreation of key aspects of the tubercular granulomas, such as cellular interactions, oxygen gradients, and nutrient limitations, thereby providing deeper insights into Mtb pathogenesis. This review aims to elucidate the advantages of 3D in vitro systems in bridging the translational gap between traditional experimental approaches and clinical applications. Particular emphasis is placed on their potential to address challenges related to genetic variability in both the host and pathogen, thereby advancing tubercular research and therapeutic development.

Granulomas, organized aggregates of immune cells which form in response to Mycobacterium tuberculosis (Mtb), are characteristic but not exclusive of tuberculosis (TB). Despite existing investigations on TB granulomas, the determinants that differentiate host-protective granulomas from granulomas that contribute to TB pathogenesis are often disputed. Thus, the goal of this narrative review is to help clarify the existing literature on such determinants. We adopt the a priori view that TB granulomas are host-protective organelles and discuss the molecular and cellular determinants that induce protective granulomas and those that promote their failure. While reports about protective TB granulomas and their failure may initially seem contradictory, it is increasingly recognized that either deficiencies or excesses of the molecular and cellular components in TB granuloma formation may be detrimental to the host. More specifically, insufficient or excessive expression/representation of the following components have been reported to skew granulomas toward the less protective phenotype: (i) epithelioid macrophages; (ii) type 1 adaptive immune response; (iii) type 2 adaptive immune response; (iv) tumor necrosis factor; (v) interleukin-12; (vi) interleukin-17; (vii) matrix metalloproteinases; (viii) hypoxia in the TB granulomas; (ix) hypoxia inducible factor-1 alpha; (x) aerobic glycolysis; (xi) indoleamine 2,3-dioxygenase activity; (xii) heme oxygenase-1 activity; (xiii) immune checkpoint; (xiv) leukotriene A4 hydrolase activity; (xv) nuclear-factor-kappa B; and (xvi) transforming growth factor-beta. Rather, more precise and timely coordinated immune responses appear essential for eradication or containment of Mtb infection. Since there are several animal models of infection with Mtb, other species within the Mtb complex, and the surrogate Mycobacterium marinum - whether natural (cattle, elephants) or experimental (zebrafish, mouse, guinea pig, rabbit, mini pig, goat, non-human primate) infections - we also compared the TB granulomatous response and other pathologic lung lesions in various animals infected with one of these mycobacteria with that of human pulmonary TB. Identifying components that dictate the formation of host-protective granulomas and the circumstances that result in their failure can enhance our understanding of the macrocosm of human TB and facilitate the development of novel remedies - whether they be direct therapeutics or indirect interventions - to efficiently eliminate Mtb infection and prevent its pathologic sequelae.

The aim of this study is to examine the clinical and pathological attributes of nasopharyngeal tuberculosis.

We conducted a retrospective analysis of the clinicopathologic characteristics of nasopharyngeal tuberculosis in 14 patients. The medical records and imaging data obtained between March 2004 and February 2023 were scrutinized. During the pathological review, we classified the types of granulomatous inflammation and graded the extent of caseation.

Results indicate a 100% female predominance, with chief complaints including hearing loss, postnasal drip, and nasal obstruction. Cervical lymphadenopathy occurred in 21.4% of patients. Chest radiograph abnormalities were found in 58.3%, with three showing active pulmonary tuberculosis. Endoscopic examination revealed three types of lesions, and CT/MRI findings correlated with gross lesions. A statistically significant association was found between lesion characteristics (bulging, ulcerative, necrotic) and pathology patterns (sarcoidosis-like, caseation). Bulging masses exhibited sarcoidosis-like patterns, while ulcerative/necrotic lesions were often associated with caseation. All lesions responded well to over six months of anti-tuberculosis medication, leading to favourable outcomes.

We studied 14 cases of nasopharyngeal tuberculosis, mostly in females, with common ear and nose symptoms. Lesions were typically visible on nasopharyngeal endoscopy, and endoscopically bulging mass-like lesions had pathologically sarcoidosis-like granulomas. All patients had favourable outcomes.

Tuberculosis remains the leading cause of death from infectious diseases among adults worldwide. To date, an overarching review of the immune response to Mtb in humans has not been fully elucidated, with innate immunity remaining poorly understood due to historic focus on adaptive immunity. Specifically, there is a major gap concerning the contribution of the immune system to overall bacterial clearance, particularly residual bacteria. This review aims to describe the time course of interactions between the host immune system and Mtb, from the start of the infection to the development of the adaptive response. Concordantly, we aim to crystallize the pathogenic effects and immunoevasive mechanisms of Mtb. The translational value of animal data is also discussed.

The literature search was conducted in the PubMed, ScienceDirect, and Google Scholar databases, which included reported research from 1990 until 2024. A total of 190 publications were selected and screened, of which 108 were used for abstraction and 86 were used for data extraction. Graphical summaries were created using the narrative information (i.e., recruitment, recognition, and response) to generate clear visual representations of the immune response at the cellular and molecular levels.

The key cellular players included airway epithelial cells, alveolar epithelial cells, neutrophils, natural killer cells, macrophages, dendritic cells, T cells, and granulomatous lesions; the prominent molecular players included IFN-γ, TNF-α, and IL-10. The paper also sheds light on the immune response to residual bacteria and applications of the data.

We provide a comprehensive characterization of the key immune players that are implicated in pulmonary tuberculosis, in line with the organs or compartments in which mycobacteria reside, offering a broad vignette of the immune response to Mtb and how it responds to residual bacteria. Ultimately, the data presented could provide immunological insights to help establish optimized criteria for identifying efficacious treatment regimens and durations for relapse prevention in the modeling and simulation space and wider fields.

Tuberculosis (TB) and HIV co-infections are extensively overlapping, especially in developing countries. HIV infection is known as a major risk factor for the reactivation of latent TB into active TB. Although not fully understood and needs further study, HIV infection might enhance the reactivation of latent TB by breaching immune control mechanisms. We investigated the influence of HIV infection on the cytokine response of LTB-infected individuals. Heparinized venous blood was collected from 40 ART-naïve HIV-infected and 30 HIV-negative healthy controls for LTB screening, plasma collection, and PBMC isolation and stimulation. The level of cytokines in plasma and their production by PBMCs stimulated with purified protein derivative (PPD), staphylococcus enterotoxin B (SEB), or unstimulated PBMCs were analyzed using a cytometric bead array (CBA) assay. PPD-induced IL-2 by PBMCs was higher in LTB-infected groups compared with HIV-negative LTB-negative groups (p = 0.0015). When LTB-infected groups were co-infected with HIV (HIV+LTB+), the IL-2 (p < 0.0001) and IFN-gamma (p = 0.0144) production by PPD-stimulated PBMCs was reduced. The level of IL-2 (p = 0.0070), IL-6 (p = 0.0054), and TNF-alpha (p = 0.0045) in plasma were lower in HIV+LTB+ individuals compared with HIV-negative LTB-positive (HIV-LTB+) groups. Our findings suggested that HIV co-infection in LTB-positive individuals is associated with the diminished production of PPD-induced Th1 (IFN-gamma and IL-2) cytokines by PBMCs and in the plasma level of IL-2 and proinflammatory cytokines (IL-6 and TNF-alpha).

There is substantial evidence indicating that cytokines play a role in the immune defense against tuberculosis. This study aims to evaluate the levels of various cytokines in pleural effusion to ditinguish between tuberculosis pleurisy and malignant pleurisy.

A total of 82 participants with pleural effusion were included in the training cohort, and 76 participants were included in the validation cohort. The individuals were divided into tuberculosis and malignant pleurisy groups. The concentrations of interleukin-1β (IL-1β), IL-4, IL-6, IL-10, IL-17 A, IL-17 F, IL-21, IL-22, IL-25, IL-31, IL-33, interferon-γ (IFN-γ), soluble CD40 ligand (sCD40L) and tumor necrosis factor-α (TNF-α) in pleural effusion were measured using a multiplex cytokine assay. The threshold values were calculated according to the receiver operating characteristic (ROC) curve analysis to aid in diagnosing tuberculosis pleurisy. Furthermore, the combined measure was validated in the validation cohort.

The levels of all 14 cytokines in pleural effusion were significantly higher in participants with tuberculosis compared to those with malignant pleurisy (all P < 0.05). The area under the curve (AUC) was ≥ 0.920 for the IL-22, sCD40L, IFN-γ, TNF-α and IL-31, which were significantly increased in tuberculous pleural effusion (TPE) compared to MPE in the training cohort. Threshold values of 95.80 pg/mL for IFN-γ, 41.80 pg/mL for IL-31, and 18.87 pg/mL for IL-22 provided ≥ 90% sensitivity and specificity in distinguishing between tuberculosis pleurisy and malignant pleurisy in the training cohort. Among these, IL-22 combined with sCD40L showed the best sensitivity and specificity (94.0% and 96.9%) for diagnosing tuberculosis pleurisy, and this finding was validated in the validation cohort.

We demonstrated that the levels of IL-1β, IL-4, IL-6, IL-10, IL-17 A, IL-17 F, IL-21, IL-22, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in pleural effusion had significant difference between tuberculosis pleurisy and malignant pleurisy. Specifically, IL-22 ≥ 18.87 pg/mL and sCD40L ≥ 53.08 pg/mL can be clinically utilized as an efficient diagnostic strategy for distinguishing tuberculosis pleurisy from malignant pleurisy.

Tuberculosis in animals is caused by members of the Mycobacterium tuberculosis complex (MTC), with the tuberculous granuloma being the main characteristic lesion. The macrophage is the main cell type involved in the development of the granuloma and presents a wide plasticity ranging from polarization to classically activated or pro-inflammatory macrophages (M1) or to alternatively activated or anti-inflammatory macrophages (M2). Thus, this study aimed to analyze macrophage polarization in granulomas from cattle and pig lymph nodes naturally infected with MTC. Tuberculous granulomas were microscopically categorized into four stages and a panel of myeloid cells (CD172a/calprotectin), M1 macrophage polarization (iNOS/CD68/CD107a), and M2 macrophage polarization (Arg1/CD163) markers were analyzed by immunohistochemistry. CD172a and calprotectin followed the same kinetics, having greater expression in late-stage granulomas in pigs. iNOS and CD68 had higher expression in cattle compared with pigs, and the expression was higher in early-stage granulomas. CD107a immunolabeling was only observed in porcine granulomas, with a higher expression in stage I granulomas. Arg1+ cells were significantly higher in pigs than in cattle, particularly in late-stage granulomas. Quantitative analysis of CD163+ cells showed similar kinetics in both species with a consistent frequency of immunolabeled cells throughout the different stages of the granuloma. Our results indicate that M1 macrophage polarization prevails in cattle during early-stage granulomas (stages I and II), whereas M2 phenotype is observed in later stages. Contrary, and mainly due to the expression of Arg1, M2 macrophage polarization is predominant in pigs in all granuloma stages.

Bacillus Calmette-Guérin (BCG) immunotherapy has been a cornerstone treatment for non-muscle-invasive bladder cancer for decades and still faces challenges, such as severe immune adverse reactions, which reduce its use as a first-line treatment. This review examines BCG therapy's history, mechanisms, and current status, highlighting how nanotechnology and bioengineering are revitalizing its application. We discuss novel nanocarrier systems aimed at enhancing BCG's efficacy while mitigating specific side effects. These approaches promise improved tumor targeting, better drug loading, and an enhanced stimulation of anti-tumor immune responses. Key strategies involve using materials such as liposomes, polymers, and magnetic particles to encapsulate BCG or functional BCG cell wall components. Additionally, co-delivering BCG with chemotherapeutics enhances drug targeting and tumor-killing effects while reducing drug toxicity, with some studies even achieving synergistic effects. While most studies remain experimental, this research direction offers hope for overcoming BCG's limitations and advancing bladder cancer immunotherapy. Further elucidation of BCG's mechanisms and rigorous safety evaluations of new delivery systems will be crucial for translating these innovations into clinical practice.

The limitations of TB treatment are the long duration and immune-dampening effects of anti-tuberculosis therapy. The Cell wall plays a crucial role in survival and virulence; hence, enzymes involved in its biosynthesis are good therapeutic targets. Here, we identify Mycobacterium tuberculosis (Mtb) GlmM, (GlmMMtb) engaged in the UDP-GlcNAc synthesis pathway as an essential enzyme. We generated a conditional knockdown strain, Rv-glmMkD using the CRISPR interference-mediated gene silencing approach. Depletion of GlmMMtb affects the morphology and thickness of the cell wall. The Rv-glmMkD strain attenuated Mtb survival in vitro, in the host macrophages (ex vivo), and in a murine mice infection model (in vivo). Results suggest that the depletion of GlmMMtb induces M1 macrophage polarization, prompting a pro-inflammatory cytokine response, apparent from the upregulation of activation markers, including IFNɣ and IL-17 that resists the growth of Mtb. These observations provide a rationale for exploring GlmMMtb as a potential therapeutic target.

Differentially expressed genes/proteins (DEGs/DEPs) play critical roles in pulmonary tuberculosis (PTB) diagnosis and treatment. However, there is a scarcity of reports on DEGs/DEPs in lung tissues and blood samples in PTB patients.

We aim to identify the DEGs/DEPs in lung tissues and blood samples of PTB patients and investigate their roles in PTB.

The lung granulomas and normal tissues were collected from PTB patients for proteomic and transcriptomic analyses. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses annotated the functions of DEGs/DEPs. The GSE107994 data set was downloaded to identify the DEGs/DEPs in peripheral blood. The common DEGs and DEPs were identified. A nomogram was established. Pearson correlation analysis was conducted.

Eighty-three DEGs/DEPs were identified. These DEGs/DEPs were mainly enriched in the movement of cell or subcellular components, regulation of cellular component biogenesis, and actin filament-based process as well as in the pathways of inositol phosphate metabolism, adherens junction, phosphatidylinositol signaling system, leukocyte transendothelial migration, regulation of actin cytoskeleton, and tight junction. There were eight common DEGs/DEPs (TYMP, LAP3, ADGRL2, SIL1, LMO7, SULF 1, ANXA3, and PACSIN3) between the lung tissues and blood samples. They were effective in predicting tuberculosis. Moreover, the activated dendritic cells, macrophages, monocytes, neutrophils, and regulatory T cells were significantly positively correlated with TYMP (r > .50), LAP3 (r > .50), SIL1 (r > .50), ANXA3 (r > .5), and PACSIN3 (r < .50), while negatively correlated with LMO7 (r < -0.50) (p < .05). ADGRL2 and SULF1 did not have a significant correlation (p > .05).

The sample size was small.

Eight common DEGs/DEPs of lung tissues and blood samples were identified. They were correlated with immune cells and demonstrated predictive value for PTB. Our data may facilitate the diagnosis and treatment of PTB.

It is essential to understand the interactions and relationships between Mycobacterium tuberculosis (Mtb) and macrophages during the infection in order to design host-directed, immunomodulation-dependent therapeutics to control Mtb. We had reported previously that ornithine acetyltransferase (MtArgJ), a crucial enzyme of the arginine biosynthesis pathway of Mtb, is allosterically inhibited by pranlukast (PRK), which significantly reduces bacterial growth. The present investigation is centered on the immunomodulation in the host by PRK particularly the activation of the host's immune response to counteract bacterial survival and pathogenicity. Here, we show that PRK decreased the bacterial burden in the lungs by upregulating the population of pro-inflammatory interstitial macrophages (IMs) and reducing the population of Mtb susceptible alveolar macrophages (AMs), dendritic cells (DCs), and monocytes (MO). Additionally, we deduce that PRK causes the host macrophages to change their metabolic pathway from fatty acid metabolism to glycolytic metabolism around the log phage of bacterial multiplication. Further, we report that PRK reduced tissue injury by downregulating the Ly6C-positive population of monocytes. Interestingly, PRK treatment improved tissue repair and inflammation resolution by increasing the populations of arginase 1 (Arg-1) and Ym1+Ym2 (chitinase 3-like 3) positive macrophages. In summary, our study found that PRK is useful not only for reducing the tubercular burden but also for promoting the healing of the diseased tissue.

Murine Natural Killer cells were cultivated in vitro to isolate NK-derived exosomes. Subsequent quantification via qPCR confirmed enrichment of miR-1249-3p. Ana-1 murine macrophages were cultured in vitro and subsequently inoculated with Mycobacterium tuberculosis (MTB) strain H37Rv. NK-exo and NK-exo miR-1249-3p were separately applied to the infection model, followed by immunological assays conducted post-48-hour co-culture. Western blot analyses corroborated that NK-exo exhibited exosomal marker proteins Granzyme A (GzmA), Granzyme B (GzmB), and Perforin (PFN), alongside a notable enrichment of miR-1249-3p. Functionally, NK-exo augmented the expression levels of Caspase-9,-8, and -3, as well as PARP, while attenuating the expression of NLRP3, ASC, and Cleaved-Caspase-1. Furthermore, qPCR demonstrated an up-regulation of Caspase-9, -8, and -3, along with pro-apoptotic factors Bax and Bid, and a concomitant down-regulation of the anti-apoptotic factor Bcl-2. The expression levels of inflammatory markers ASC, NLRP3, Cleaved-Caspase-1, and IL-1β were concomitantly decreased. ELISA findings indicated diminished levels of TNF-α and ROS secretion. NK-exo miR-1249-3p specifically targeted and attenuated the expression of SKOR-1, engendering up-regulation of apoptosis-associated proteins and down-regulation of inflammation-related proteins, consequently affecting cellular fate.Our empirical evidence substantiates that NK-exo induces macrophage apoptosis, thereby mitigating MTB survival. Furthermore, NK-exo miR-1249-3p directly targets and inhibits SKOR-1 expression, leading to macrophage apoptosis and consequently hampering the proliferation of MTB. The data implicate the potential therapeutic relevance of NK-exo and miR-1249-3p in managing drug-resistant tuberculosis.

Post-tuberculosis lung disease (PTLD) is an increasingly recognized and debilitating consequence of pulmonary tuberculosis (PTB). In this review, we provide a comprehensive overview of PTLD with airflow obstruction (PTLD-AFO), focusing on its burden, pathophysiology, clinical manifestations, diagnostic methods, and management strategies.

The relationship between PTLD and airflow obstruction is complex and multifactorial. Approximately 60% of the patients with PTLD have some spirometric abnormality. Obstruction is documented in 18-22% of PTLD patients. The host susceptibility and host response to mycobacterium drive the pathogenic mechanism of PTLD. A balance between inflammatory, anti-inflammatory, and fibrotic pathways decides whether an individual with PTB would have PTLD after microbiological cure. An obstructive abnormality in PTLD-AFO is primarily due to destruction of bronchial walls, aberrant healing, and reduction of mucosal glands. The most common finding on computed tomography (CT) of thorax in patients with PTLD-AFO is bronchiectasis and cavitation. Therefore, the 'Cole's vicious vortex' described in bronchiectasis applies to PTLD. A multidisciplinary approach is required for diagnosis and treatment. The disability-adjusted life-years (DALYs) attributed to PTLD represent about 50% of the total estimated burden of DALYs due to tuberculosis (TB). Patients with PTLD require comprehensive care that includes psychosocial support, pulmonary rehabilitation, and vaccination against respiratory pathogens. In the absence of trials evaluating different treatments for PTLD-AFO, therapy is primarily symptomatic.

PTLD with airflow obstruction has considerable burden and causes a significant morbidity and mortality. However, many aspects of PTLD-AFO still need to be answered. Studies are required to evaluate different phenotypes, especially concerning Aspergillus -related complications. The treatment should be personalized based on the predominant phenotype of airflow obstruction. Extensive studies to understand the exact burden, pathogenesis, and treatment of PTBLD-AFO are needed.

Tuberculosis (TB) remains a global health threat, and even after successful TB treatment, a subset of patients develops serious long-term lung impairments, recently termed post-tuberculosis lung disease (PTLD). Much remains to be discovered, as PTLD as a post-TB disease is a developing field, still in its infancy. The pathogenesis of PTLD is not fully elucidated but has been linked to elevated inflammatory pathways. The complexity of PTLD makes it challenging to pinpoint the specific inflammatory pathways involved in its pathophysiology. Therefore, this paper provides a comprehensive review of inflammatory cytokines and their potential roles in PLTD, with a specific focus on interleukin 6 (IL-6), IL-1, IL-8, tumour necrosis factor-alpha (TNF-α), transforming growth factor beta (TGF-β) and C-Reactive Protein (CRP). We delve into PTLD pathology, discuss its impact on lung function and review risk factors for PTLD. In addition, we summarise the current gaps in knowledge, provide recommendations for measuring inflammatory biomarkers and propose potential directions for future studies. We propose that future studies measure a wide range of inflammatory markers in TB populations with and without PTLD. In addition, studies could isolate peripheral blood mononuclear cells from patient blood to try and identify possible impairments that could be correlated with a PTLD diagnosis. Given that the PTLD field is still in an early stage of development, a comprehensive inflammatory analysis may help to know which pathways are key in PTLD development, and this may ultimately help to predict patients who are at risk. More research is warranted.

Drug repurposing is an ongoing and clever strategy that is being developed to eradicate tuberculosis amid challenges, of which one of the major challenges is the resistance developed towards antibiotics used in standard directly observed treatment, short-course regimen. Surpassing the challenges in developing anti-tuberculous drugs, some novel host-directed therapies, repurposed drugs, and drugs with novel targets are being studied, and few are being approved too. After almost 4 decades since the approval of rifampicin as a potent drug for drugsusceptible tuberculosis, the first drug to be approved for drug-resistant tuberculosis is bedaquiline. Ever since the urge to drug discovery has been at a brisk as this milestone in tuberculosis treatment has provoked the hunt for novel targets in tuberculosis. Host-directed therapy and repurposed drugs are in trend as their pharmacological and toxicological properties have already been researched for some other diseases making the trial facile. This review discusses the remonstrance faced by researchers in developing a drug candidate with a novel target, the furtherance in tuberculosis research, novel anti-tuberculosis agents approved so far, and candidates on trial including the host-directed therapy, repurposed drug and drug combinations that may prove to be potential in treating tuberculosis soon, aiming to augment the awareness in this context to the imminent researchers.

Macrophages play a crucial role in our immune system, preserving tissue health and defending against harmful pathogens. This article examines the diversity of macrophages influenced by tissue-specific functions and developmental origins, both in normal and disease conditions. Understanding the spectrum of macrophage activation states, especially in pathological situations where they contribute significantly to disease progression, is essential to develop targeted therapies effectively. These states are characterized by unique receptor compositions and phenotypes, but they share commonalities. Traditional drugs that target individual entities are often insufficient. A promising approach involves using multivalent systems adorned with multiple ligands to selectively target specific macrophage populations based on their phenotype. Achieving this requires constructing supramolecular structures, typically at the nanoscale. This review explores the theoretical foundation of engineered multivalent nanosystems, dissecting the key parameters governing specific interactions. The goal is to design targeting systems based on distinct cell phenotypes, providing a pragmatic approach to navigating macrophage heterogeneity's complexities for more effective therapeutic interventions.

P-glycoprotein (encoded by the ABCB1 gene) has a dual role in regulating inflammation and reducing chemotherapy efficacy in various diseases, but there are few studies focused on pulmonary TB patients. In this study, our objective was to identify a list of genes that correlate with high and low levels of ABCB1 gene expression in the lungs of pulmonary TB patients with different activity of chronic granulomatous inflammation. We compared gene expression in two groups of samples (with moderate and high activity of tuberculomas) to identify their characteristic gene signatures. Gene expression levels were determined using quantitative PCR in samples of perifocal area of granulomas, which were obtained from 65 patients after surgical intervention. Subsequently, two distinct gene signatures associated with high inflammation activity were identified. The first signature demonstrated increased expression of HIF1a, TGM2, IL6, SOCS3, and STAT3, which correlated with high ABCB1 expression. The second signature was characterized by high expression of TNFa and CD163 and low expression of ABCB1. These results provide insight into various inflammatory mechanisms and association with P-gp gene expression in lung tissue of pulmonary TB patients and will be useful in the development of a host-directed therapy approach to improving the effectiveness of anti-TB treatment.

The burden of chronic airway diseases, including chronic obstructive pulmonary disease (COPD), continues to increase, especially in low- and middle-income countries. Post-tuberculosis lung disease (PTLD) is characterized by chronic lung changes after the "cure" of pulmonary tuberculosis (TB), which may be associated with the pathogenesis of COPD. However, data on its prevalence, clinical manifestations, computed tomography features, patterns of lung function impairment, and influencing factors are limited. The pathogenic mechanisms underlying PTLD remain to be elucidated. This review summarizes the recent advances in PTLD and TB-associated COPD. Research is urgently needed both for the prevention and management of PTLD.

Hypercalcemia is a common complication of many granulomatous diseases but is not typically associated with leishmaniasis. Here we report an unusual case of hypercalcemia during the initiation of antiviral therapy in a patient with acquired immunodeficiency syndrome coinfected with visceral leishmaniasis.

Our patient presented with malaise and altered mental status following antiretroviral therapy initiation. He was found to have de novo hypercalcemia complicated by acute kidney injury.

An extensive workup for other etiologies of hypercalcemia was negative. The patient was ultimately thought to have hypercalcemia secondary to visceral leishmaniasis in the setting of immune reconstitution inflammatory syndrome. He was treated with intravenous volume expansion, bisphosphonates, and oral corticosteroid therapy with complete resolution.

This case highlights an unusual presentation of immune reconstitution inflammatory syndrome, in which proinflammatory cytokine signaling during the restoration of cellular immunity may have led to increased ectopic calcitriol production by granuloma macrophages, thereby altering bone-mineral metabolism and driving hypercalcemia.

The risk of progression to tuberculosis disease is highest within the first year after M. tuberculosis infection (TBI). We hypothesize that people with newly acquired TBI have a unique cytokine/chemokine profile that could be used as a potential biomarker.

We evaluated socio-demographic variables and 18 cytokines/chemokines in plasma samples from a cohort of people deprived of liberty (PDL) in two Colombian prisons: 47 people diagnosed with pulmonary TB, 24 with new TBI, and 47 non-infected individuals. We performed a multinomial regression to identify the immune parameters that differentiate the groups.

The concentration of immune parameters changed over time and was affected by the time of incarceration. The concentration of sCD14, IL-18 and IP-10 differed between individuals with new TBI and short and long times of incarceration. Among people with short incarceration, high concentrations of MIP-3α were associated with a higher risk of a new TBI, and higher concentrations of Eotaxin were associated with a lower risk of a new TBI. Higher concentrations of sCD14 and TNF-α were associated with a higher risk of TB disease, and higher concentrations of IL-18 and MCP-1 were associated with a lower risk of TB disease.

There were cytokines/chemokines associated with new TBI and TB disease. However, the concentration of immune mediators varies by the time of incarceration among people with new TBI. Further studies should evaluate the changes of these and other cytokines/chemokines over time to understand the immune mechanisms across the spectrum of TB.

Historically, research on the immunologic response to Mycobacterium tuberculosis (M. tb) infection has focused on T cells and macrophages, as their role in granuloma formation has been robustly characterized. In contrast, the role of B cells in the pathophysiology of M. tb infection has been relatively overlooked. While T cells are well-known as an essential for granuloma formation and maintenance, B cells play a less understood role in the host response. Over the past decade, scarce research on the topic has attempted to elucidate the varying roles of B cells during mycobacterial infection, which appears to be primarily time dependent. From acute to chronic infection, the role of B cells changes with time as evidenced by cytokine release, immunological regulation, and histological morphology of tuberculous granulomas. The goal of this review is to carefully analyze the role of humoral immunity in M. tb infection to find the discriminatory nature of humoral immunity in tuberculosis (TB). We argue that there is a need for more research on the B-cell response against TB, as a better understanding of the role of B cells in defense against TB could lead to effective vaccines and therapies. By focusing on the B-cell response, we can develop new strategies to enhance immunity against TB and reduce the burden of disease.

Infections caused by members of the mycobacterium tuberculosis complex [MTC] and nontuberculous mycobacteria [NTM] can induce widespread morbidity and mortality in people. Mycobacterial infections cause both a delayed immune response, which limits rate of bacterial clearance, and formation of granulomas, which contain bacterial spread, but also contribute to lung damage, fibrosis, and morbidity. Granulomas also limit access of antibiotics to bacteria, which may facilitate development of resistance. Bacteria resistant to some or all antibiotics cause significant morbidity and mortality, and newly developed antibiotics readily engender resistance, highlighting the need for new therapeutic approaches. Imatinib mesylate, a cancer drug used to treat chronic myelogenous leukemia [CML] that targets Abl and related tyrosine kinases, is a possible host-directed therapeutic [HDT] for mycobacterial infections, including those causing TB. Here, we use the murine Mycobacterium marinum [Mm] infection model, which induces granulomatous tail lesions. Based on histological measurements, imatinib reduces both lesion size and inflammation of surrounding tissue. Transcriptomic analysis of tail lesions indicates that imatinib induces gene signatures indicative of immune activation and regulation at early time points post infection that resemble those seen at later ones, suggesting that imatinib accelerates but does not substantially alter anti-mycobacterial immune responses. Imatinib likewise induces signatures associated with cell death and promotes survival of bone marrow-derived macrophages [BMDMs] in culture following infection with Mm. Notably, the capacity of imatinib to limit formation and growth of granulomas in vivo and to promote survival of BMDMs in vitro depends upon caspase 8, a key regulator of cell survival and death. These data provide evidence for the utility of imatinib as an HDT for mycobacterial infections in accelerating and regulating immune responses, and limiting pathology associated with granulomas, which may mitigate post-treatment morbidity.

CD8+ T cell recognition of Mycobacterium tuberculosis (Mtb)-specific peptides presented on major histocompatibility complex class I (MHC-I) contributes to immunity to tuberculosis (TB), but the principles that govern presentation of Mtb antigens on MHC-I are incompletely understood. In this study, mass spectrometry (MS) analysis of the MHC-I repertoire of Mtb-infected primary human macrophages reveals that substrates of Mtb's type VII secretion systems (T7SS) are overrepresented among Mtb-derived peptides presented on MHC-I. Quantitative, targeted MS shows that ESX-1 activity is required for presentation of Mtb peptides derived from both ESX-1 substrates and ESX-5 substrates on MHC-I, consistent with a model in which proteins secreted by multiple T7SSs access a cytosolic antigen processing pathway via ESX-1-mediated phagosome permeabilization. Chemical inhibition of proteasome activity, lysosomal acidification, or cysteine cathepsin activity did not block presentation of Mtb antigens on MHC-I, suggesting involvement of other proteolytic pathways or redundancy among multiple pathways. Our study identifies Mtb antigens presented on MHC-I that could serve as targets for TB vaccines, and reveals how the activity of multiple T7SSs interacts to contribute to presentation of Mtb antigens on MHC-I.