Tuberculosis (TB) remains a global health concern despite decreasing incidence. Delayed TB diagnosis can exacerbate patient outcomes and lead to broader public health issues such as mass infections. Differentiation between TB and bacterial pneumonia is often complicated by variable clinical and radiological manifestations of TB, leading to diagnostic delays.

An 89-year-old, Japanese male patient with a history of diabetes mellitus, hypertension, and hypothyroidism presented with right-sided chest pain. Based on the elevated inflammatory response, right pleural effusion, and infiltrating shadow in the lung field, the diagnosis of right pleurisy was made and the antibiotic, ampicillin/sulbactam, was administered. The patient’s condition, inflammatory reaction, and right pleural effusion temporarily improved. However, persistent low-grade fever and malaise prompted further evaluation, revealing repeated right pleural effusion and inflammatory response. A right thoracentesis was performed; the patient was diagnosed with tuberculous pleurisy as a result of exudative effusion with lymphocyte predominance, elevated adenosine deaminase levels, and positive Mycobacterium TB polymerase chain reaction test. Anti-TB treatment, including isoniazid, rifampicin, and ethambutol was initiated, leading to significant clinical improvement. The patient successfully completed a 12-month course of TB therapy without recurrence or deterioration.

There are cases of TB wherein temporary improvement apparently could be shown through treatment with antimicrobial agents other than anti-TB drugs, necessitating careful evaluation in atypical cases of bacterial pneumonia.

• Antibiotics
• Ampicillin/sulbactam
• Pneumonia
• Tuberculosis
• Tuberculous pleuritis
• Case report

• cancer immunotherapy
• concomitant immunity
• increasing cancer immunogenicity
• modulating the class of the anti-cancer response
• monitoring of the anti-cancer response
• vaccination against cancer

• RGPIN 04117-2018 Natural Sciences and Engineering Research Council of Canada

• biomarkers
• immunomics
• model-informed precision dosing
• multi-omics
• personalized medicine
• tuberculosis

• TB immunotherapy
• TB latency
• TB vaccination
• lung inflammation
• mycobacteria and host gene expression
• tuberculosis

• Bacterial infections
• Immunology
• Infectious disease
• T cells

• CD4-Positive T-Lymphocytes/immunology
• CD4-Positive T-Lymphocytes/pathology
• Female
• Humans
• Interleukin-17/immunology
• Interleukin-1beta/immunology
• Interleukin-2/immunology
• Lung/immunology
• Lung/pathology
• Male
• Mycobacterium tuberculosis/immunology
• Nitric Oxide/immunology
• Tuberculosis, Pulmonary/immunology
• Tuberculosis, Pulmonary/pathology

• 210662/Z/18/Z Wellcome Trust
• NC/L001039/1 National Centre for the Replacement, Refinement and Reduction of Animals in Research
• R01 AI106725 NIAID NIH HHS
• Wellcome Trust
• 202485/Z/16/Z Wellcome Trust

• Anti-tubercular drugs
• Pharmacokinetics
• Therapeutic drug monitoring

• HIV
• biomarkers
• diagnostics
• treatment monitoring
• tuberculosis

The Mycobacterium bovis Bacillus Calmette-Guerin (BCG) vaccine is administered parenterally to infants and young children to prevent tuberculosis (TB) infection. However, the protection induced by BCG is highly variable and the vaccine does not prevent pulmonary TB, the most common form of the illness. Until improved TB vaccines are available, it is crucial to use BCG in a manner which ensures optimal vaccine performance. Immunization directly to the respiratory mucosa has been shown to promote greater protection from TB in animal models. γδ T cells play a major role in host defense at mucosal sites and are known to respond robustly to mycobacterial infection. Their positioning in the respiratory mucosa ensures their engagement in the response to aerosolized TB vaccination. However, our understanding of the effect of respiratory BCG vaccination on γδ T cell responses in the lung is unknown. In this study, we used a calf model to investigate the immunogenicity of aerosol BCG vaccination, and the phenotypic profile of peripheral and mucosal γδ T cells responding to vaccination. We observed robust local and systemic M. bovis-specific IFN-γ and IL-17 production by both γδ and CD4 T cells. Importantly, BCG vaccination induced effector and memory cell differentiation of γδ T cells in both the lower airways and peripheral blood, with accumulation of a large proportion of effector memory γδ T cells in both compartments. Our results demonstrate the potential of the neonatal calf model to evaluate TB vaccine candidates that are to be administered via the respiratory tract, and suggest that aerosol immunization is a promising strategy for engaging γδ T cells in vaccine-induced immunity against TB.

• clinical trials
• desired attributes
• developmental trajectory
• natural immunity
• new TB vaccines
• tuberculosis

It is generally thought that Mycobacterium tuberculosis (Mtb)-specific CD4⁺ Th1 cells producing IFN-γ are essential for protection against tuberculosis (TB). In some studies, protection has recently been associated with polyfunctional subpopulation of Mtb-specific Th1 cells, i.e., with cells able to simultaneously secrete several type 1 cytokines. However, the role for Mtb-specific Th1 cells and their polyfunctional subpopulations during established TB disease is not fully defined. Pulmonary TB is characterized by a great variability of disease manifestations. To address the role for Mtb-specific Th1 responses during TB, we investigated how Th1 and other immune cells correlated with particular TB manifestations, such as the degree of pulmonary destruction, TB extent, the level of bacteria excretion, clinical disease severity, clinical TB forms, and “Timika X-ray score,” an integrative parameter of pulmonary TB pathology. In comparison with healthy Mtb-exposed controls, TB patients (TBP) did not exhibit deficiency in Mtb-specific cytokine-producing CD4⁺ cells circulating in the blood and differed by a polyfunctional profile of these cells, which was biased toward the accumulation of bifunctional TNF-α⁺IFN-γ⁺IL-2⁻ lymphocytes. Importantly, however, severity of different TB manifestations was not associated with Mtb-specific cytokine-producing cells or their polyfunctional profile. In contrast, several TB manifestations were strongly correlated with leukocyte numbers, the percent or the absolute number of lymphocytes, segmented or band neutrophils. In multiple alternative statistical analyses, band neutrophils appeared as the strongest positive correlate of pulmonary destruction, bacteria excretion, and “Timika X-ray score.” In contrast, clinical TB severity was primarily and inversely correlated with the number of lymphocytes in the blood. The results suggest that: (i) different TB manifestations may be driven by distinct mechanisms; (ii) quantitative parameters and polyfunctional profile of circulating Mtb-specific CD4⁺ cells play a minor role in determining TB severity; and (iii) general shifts in production/removal of granulocytic and lymphocytic lineages represent an important factor of TB pathogenesis. Mechanisms leading to these shifts and their specific role during TB are yet to be determined but are likely to involve changes in human hematopoietic system.

• Th1 cells
• band neutrophils
• neutrophils
• polyfunctional lymphocytes
• pulmonary destruction
• tuberculosis

Understanding human immunity to Mycobacterium tuberculosis (Mtb) during different stages of infection is important for development of an effective tuberculosis (TB) vaccine. We aimed to evaluate immunity to Mtb infection by measuring immune responses to selected Mtb antigens expressed during different stages of infection over time and to observe sustainability of immunity.

In a cohort study comprising East Greenlanders aged 17–22 years (2012 to 2014) who had either; undetectable Mtb infection, ongoing or prior Mtb infection at enrolment, we measured immunity to 15 antigens over a one-year period. Quantiferon-TB Gold testing (QFT) defined Mtb infection status (undetected/detected). The eligible study population of East Greenlanders aged 17–22 years was identified from the entire population using the Civil Registration System. From the source population 65 participants were selected by stratified random sampling according to information on Mtb infection stage. Retrospective and prospective information on notified TB (including treatment) was obtained through the mandatory TB notification system and was used to characterise Mtb infection stage (ongoing/prior). Immunity to 15 antigens including two QFT antigens, PPD and 12 non-QFT antigens (representing early, constitutive and latent Mtb infection) was assessed by measuring immune responses using whole-blood antigen stimulation and interferon gamma measurement.

Of 65 participants, 54 were considered Mtb-infected. Immunity to Mtb infection fluctuated with high annual risk of conversion (range: 6–69%) and reversion (range: 5–95%). During follow-up, five (8%) participants were notified with TB; neither conversion nor reversion was associated with an increased risk of progressing to TB.

Our findings suggest that human immunity to natural Mtb infection over time is versatile with fluctuations, resulting in high levels of conversion and reversion of immunity, thus human immunity to Mtb is much more dynamic than anticipated. The study findings suggest future use of longitudinal assessment of immune responses when searching for TB vaccine candidate antigens.

• Adolescent
• Adult
• Female
• Greenland
• Humans
• Longitudinal Studies
• Male
• Mycobacterium tuberculosis/immunology
• Tuberculosis/immunology
• Young Adult

• The commission for Scientific Research in Greenland/The Danish research counsil
• Rosalie Petersens Fond
• Ebba Celinders Legat
• Aase og Ejnar Danielsens Fond
• Dagmar Marshalls Fond
• The 17.12.1981 Foundation
• Christian X Foundation
• A.P. Moeller Foundation for the advancement of medical science
• The Danish Lung Association
• Sundhedspuljen, Greenland Self-Government
• Forskningspuljen, Greenlans Self-government
• European Commission

• Causal pathway
• Drug resistance amplification
• Inappropriate therapy
• Misdiagnosis
• Multidrug-resistant tuberculosis
• Re-treatment
• Tuberculosis

Central memory T cell (Tcm) and polyfunctional CD4 T cell responses contribute to vaccine-elicited protection with both human and bovine tuberculosis (TB); however, their combined role in protective immunity to TB is unclear. To address this question, we evaluated polyfunctional cytokine responses by CD4 T cell effector/memory populations from bacille Calmette–Guerin (BCG) vaccinated and non-vaccinated calves by flow cytometry prior to and after aerosol challenge with virulent Mycobacterium bovis. Polyfunctional cytokine expression patterns in the response by Tcm, effector memory, and effector T cell subsets were similar between BCG-vaccinated and M. bovis-infected calves, only differing in magnitude (i.e., infected > vaccinated). BCG vaccination, however, did alter the kinetics of the ensuing response to virulent M. bovis infection. Early after challenge (3 weeks post-infection), non-vaccinates had greater antigen-specific interferon-γ (IFN-γ)/tumor necrosis factor-α (TNF-α) and lesser IFN-γ/TNF-α/IL-2 responses by Tcm cells than did vaccinated animals. Importantly, these differences were also associated with mycobacterial burden upon necropsy. Polyfunctional responses to ESAT-6:CFP10 (antigens not synthesized by BCG strains) were detected in memory subsets, as well as in effector cells, as early as 3 weeks after challenge. These findings suggest that cell fate divergence may occur early after antigen priming in the response to bovine TB and that memory and effector T cells may expand concurrently during the initial phase of the immune response. In summary, robust IFN-γ/TNF-α response by Tcm cells is associated with greater mycobacterial burden, while IFN-γ/TNF-α/IL-2 response by Tcm cells are indicative of a protective response to bovine TB.

• bovine tuberculosis
• calf model
• central memory T cells
• polyfunctional T cells

• CFP-10
• ESAT-6
• IGRA
• TSPOT
• Tuberculosis

• DosR
• Latent tuberculosis infection
• M. tuberculosis
• RD-1
• Rpf
• T-cell response

• Animals
• Antigens/immunology
• Cell Separation
• Flow Cytometry/methods
• High-Throughput Screening Assays
• Humans
• Immune System Diseases/diagnosis
• Immune System Diseases/immunology
• Immunologic Memory
• In Situ Hybridization, Fluorescence/methods
• Infections/diagnosis
• Infections/immunology
• RNA/analysis
• T-Cell Antigen Receptor Specificity
• T-Lymphocyte Subsets/physiology
• T-Lymphocytes/physiology
• Transcriptome

• R01 AI104615 NIAID NIH HHS
• R01 AI106036 NIAID NIH HHS

• biomarker
• flow cytometry
• immunoassay
• latent tuberculosis infection
• tuberculosis

• CD4+
• CD8+
• HIV co-infection
• IL-10-producing immunosuppressive and Treg cells
• TB
• Th1 and Th17 cells

Mono- and multifunctional specific CD4⁺ and CD8⁺ T-cell responses were evaluated to improve the immune-based detection of active tuberculosis (TB) and latent infection (LTBI). We applied flow cytometry to investigate cytokines profile (IFN-γ, TNF-α, and IL-2) of T cells after stimulation with TB antigens in 28 TB-infected subjects (18 active TB and 10 LTBI) and 10 uninfected controls. Cytokines production by CD4⁺ T cells at single-cell levels was higher in TB-infected subjects than uninfected controls (P < 0.0001). Assigning to activated CD4⁺ T cells, producing any of the three cytokines, a cut-off >0.45%, it was possible to differentiate TB-infected (>0.45%) by uninfected subjects (<0.45%). Among TB-infected subjects, the frequencies of multifunctional CD4⁺ T cells, simultaneously producing all 3 cytokines, are lower in active TB than LTBI subjects (P = 0.003). Thus, assigning to triple-positive CD4⁺ T cells a cut-off <0.182%, TB-infected individuals could be classified as active TB subjects (<0.182%) or LTBI subjects (>0.182%). The magnitude of CD8⁺ T-cell responses showed no differences between active TB and LTBI. Multifunctional CD4⁺ T-cell responses could have the potential to identify at single time point subjects without TB infection and patients having active or latent TB.

• Biomarkers
• Diagnosis
• Latent tuberculosis infection
• Progression

Cultured IFN-γ ELISPOT assays are primarily a measure of central memory T cell (Tcm) responses with humans; however, this important subset of lymphocytes is poorly characterized in cattle. Vaccine-elicited cultured IFN-γ ELISPOT responses correlate with protection against bovine tuberculosis in cattle. However, whether this assay measures cattle Tcm responses or not is uncertain. The objective of the present study was to characterize the relative contribution of Tcm (CCR7⁺, CD62L^hi, CD45RO⁺), T effector memory (Tem, defined as: CCR7^-, CD62L^low/int, CD45RO⁺), and T effector cells (CCR7^-, CD62L^-/low, CD45RO^-), in the immune response to Mycobacterium bovis. Peripheral blood mononuclear cells (PBMC) from infected cattle were stimulated with a cocktail of M. bovis purified protein derivative, rTb10.4 and rAg85A for 13 days with periodic addition of fresh media and rIL-2. On day 13, cultured PBMC were re-stimulated with medium alone, rESAT-6:CFP10 or PPDb with fresh autologous adherent cells for antigen presentation. Cultured cells (13 days) or fresh PBMCs (ex vivo response) from the same calves were analyzed for IFN-γ production, proliferation, and CD4, CD45RO, CD62L, CD44, and CCR7 expression via flow cytometry after overnight stimulation. In response to mycobacterial antigens, ~75% of CD4⁺ IFN-γ⁺ cells in long-term cultures expressed a Tcm phenotype while less than 10% of the ex vivo response consisted of Tcm cells. Upon re-exposure to antigen, long-term cultured cells were highly proliferative, a distinctive characteristic of Tcm, and the predominant phenotype within the long-term cultures switched from Tcm to Tem. These findings suggest that proliferative responses of Tcm cells to some extent occurs simultaneously with reversion to effector phenotypes (mostly Tem). The present study characterizes Tcm cells of cattle and their participation in the response to M. bovis infection.

• Antibiotics
• Cytokines
• Diagnosis
• Immunomodulation
• Mycobacterium tuberculosis
• Tuberculosis

Mycobacterium tuberculosis continues to be one of the most successful pathogens on earth. Upon inhalation of M. tuberculosis by a healthy individual, the host immune system will attempt to eliminate these pathogens using a combination of immune defense strategies. These include the recruitment of macrophages and other phagocytes to the site of infection, production of cytokines that enhance the microbicidal capacity of the macrophages, as well as the activation of distinct subsets of leukocytes that work in concert to fight the infection. However, being as successful as it is, M. tuberculosis has evolved numerous strategies to subvert host immunity at virtual every level. As a consequence, one third of the world inhabitants carry M. tuberculosis, and tuberculosis continuous to cause disease in more than 8 million people with deadly consequences in well over 1 million patients each year. In this review, we discuss several of the strategies that M. tuberculosis employs to circumvent host immunity, as well as describe some of the mechanisms that the host uses to counter such subversive strategies. As for many other infectious diseases, the ultimate outcome is usually defined by the relative strength of the virulence strategies employed by the tubercle bacillus versus the arsenal of immune defense mechanisms of the infected host.

• Mycobacterium tuberculosis
• immunity
• inflammation
• macrophage

Many and large dumps exist in our knowledge about Mycobacterium tuberculosis infection and disease in infants and children. We still do not understand why some individuals do acquire and others do not acquire the infection in the presence of the same risk factors. We do not understand why some individuals convert from latent to active tuberculosis and why other individuals convert from active to inactive tuberculosis even without treatment.

As a matter of fact the immune system mounts a bouncing, robust and polyedral defence against Mycobacterium tuberculosis, but the bacillus is so much artful and dextrous that it has ahead from this immunological fierce accoutrements. Mycobacterium tuberculosis survival, multiplication, and transmission are largely favoured by the immune mechanisms. The granuloma itself is more bacillus- than host-protective.

These abilities make Mycobacterium tuberculosis one of more successful human pathogens, but dumps in our knowledge and the counterproductive immunity hinder development of new diagnostics, therapies and vaccines. This occurs in front of an infection which engages one third of the world population and a disease which kills in a year about 1.5 million individuals worldwide.

Understanding mechanisms and meaning of immune response in tuberculosis marks out the foundations of strategies with a view to prepare effective vaccines and reliable diagnostic tools as well as to build up therapeutic weapons. To gain these objectives is vital and urgent considering that tuberculosis is a common cause of morbidity and is a leading cause of death.

• Antigens, Bacterial/immunology
• Enzyme-Linked Immunosorbent Assay
• Enzyme-Linked Immunospot Assay
• Humans
• Interferon-gamma/blood
• Interferon-gamma/metabolism
• Interferon-gamma Release Tests/methods
• Interferon-gamma Release Tests/standards
• Latent Tuberculosis/blood
• Latent Tuberculosis/diagnosis
• Latent Tuberculosis/immunology
• Latent Tuberculosis/microbiology
• Mycobacterium tuberculosis/immunology
• Mycobacterium tuberculosis/isolation & purification
• Sensitivity and Specificity
• T-Lymphocytes/immunology
• T-Lymphocytes/metabolism
• T-Lymphocytes/pathology
• Tuberculin Test
• Tuberculosis, Pulmonary/blood
• Tuberculosis, Pulmonary/diagnosis
• Tuberculosis, Pulmonary/immunology
• Tuberculosis, Pulmonary/microbiology

• 08/106/02 Department of Health
• G1001945 Medical Research Council
• HTA/08/106/02 Department of Health

Th1 and Th17 responses are known to play an important role in immunity to pulmonary tuberculosis (PTB), although little is known about their role in extrapulmonary forms of tuberculosis (TB).

To identify the role of Th1, Th17, and Th22 cells in multi-focal TB lymphadenitis (TBL), we examined mycobacteria–specific immune responses in the whole blood of individuals with PTB (n = 20) and compared them with those with TBL (n = 25).

Elevated frequencies of CD4⁺ T cells expressing IFN- γ, TNF-α, and IL-2 were present in individuals with TBL compared with those with PTB at baseline and in response to ESAT-6 and CFP-10. Similarly, increased frequencies of CD4⁺ T cells expressing IL-17A, IL-17F, and IFN-γ were also present in individuals with TBL at baseline and following ESAT-6 and CFP-10 stimulation although no significant difference in frequency of Th22 cells was observed. Finally, frequencies of Th1 (but not Th17) cells exhibited a significantly negative correlation with natural regulatory T cell frequencies at baseline.

Multi-focal TB lymphadenitis is therefore characterized by elevated frequencies of Th1 and Th17 cells, indicating that Th1 and Th17 responses in TB disease are probably correlates of disease severity rather than of protective immunity.

• Adult
• CD4-Positive T-Lymphocytes/immunology
• Female
• Humans
• Male
• Middle Aged
• Th1 Cells/immunology
• Th17 Cells/immunology
• Tuberculosis, Lymph Node/immunology
• Tuberculosis, Lymph Node/microbiology
• Young Adult

• Intramural NIH HHS

New vaccines to prevent tuberculosis are urgently needed. MVA85A is a novel viral vector TB vaccine candidate designed to boost BCG-induced immunity when delivered intradermally. To date, intramuscular delivery has not been evaluated. Skin and muscle have distinct anatomical and immunological properties which could impact upon vaccine-mediated cellular immunity.

We conducted a randomised phase I trial comparing the safety and immunogenicity of 1 × 10⁸ pfu MVA85A delivered intramuscularly or intradermally to 24 healthy BCG-vaccinated adults.

Intramuscular and intradermal MVA85A were well tolerated. Intradermally-vaccinated subjects experienced significantly more local adverse events than intramuscularly-vaccinated subjects, with no difference in systemic adverse events. Both routes generated strong and sustained Ag85A-specific IFNγ T cell responses and induced multifunctional CD4+ T cells. The frequencies of CD4+ T cells expressing chemokine receptors CCR4, CCR6, CCR7 and CXCR3 induced by vaccination was similar between routes.

In this phase I trial the intramuscular delivery of MVA85A was well tolerated and induced strong, durable cellular immune responses in healthy BCG vaccinated adults, comparable to intradermal delivery. These findings are important for TB vaccine development and are of relevance to HIV, malaria, influenza and other intracellular pathogens for which T cell-inducing MVA-based vaccine platforms are being evaluated.