B and T Cell Interplay, Germinal Center Dynamics and Role of Regulatory T Cells (Tregs) in B Cell Modulation and Immune Tolerance: A Narrative Review

T cells and B cells are central components of the adaptive immune system, orchestrating immune responses through a complex network of interactions. This review explores the dynamic interplay between T and B cells, focusing on their development, activation, and functional coordination in immune defense. T cells provide essential help to B cells through cytokine signaling and direct cell–cell interactions, facilitating antibody production and affinity maturation in germinal centers. Conversely, B cells contribute to antigen presentation and cytokine modulation, influencing T cell differentiation and function. The regulation of these interactions is critical for maintaining immune homeostasis, preventing autoimmunity, and enhancing vaccine efficacy. Dysregulation of T-B cell crosstalk is implicated in various immune disorders, including autoimmune diseases and immunodeficiencies. Recent advances in immunotherapy have targeted these pathways to modulate immune responses in conditions such as cancer, infections, and inflammatory diseases. This review synthesizes current knowledge on T and B cell physiology, highlighting emerging research on their cooperative mechanisms.