Follicular helper T lymphocytes in health and disease

Figure 3 Inhibitory receptor programmed cell death 1, its ligands and their role in humoral response. In the absence of an operative programmed cell death 1 (PD-1)/PD-1 Ligand axis, follicular helper T lymphocytes (T_FH) increase and autoimmunity may develop (A); memory B cells are formed normally (B); reduced plasma cells (PC) are found (C); Foxp3⁺ CXCR5⁺ Bcl-6⁺ regulatory T cells (T_FR) increase and have higher suppressive ability on T_FH function leading to impaired antibody responses (D). PD-1: Programmed cell death-1; CXCR5: Chemokine (C-X-C motif) receptor; Bcl: B cell lymphoma.