Publications

Abstract

Interactions between B and T cells are critical for germinal center (GC) reactions and subsequent generation of long-lived memory and plasma cells (PCs). This requires Ag presentation to T cells and serial interactions between receptor/ligand pairs belonging to cytokine, chemokine, CD28/B7, and TNF/TNFR superfamilies that co-operate to induce requisite transcriptional programs in each cell type. In addition to BCR activation, B cell differentiation requires signals provided by T follicular helper (Tfh) cells at multiple spatially distinct checkpoints to ensure the quantity and quality of the antibody response. Tfh cells co-ordinately express molecules that allow them to co-localize with B cells in follicles and GCs of secondary lymphoid tissues and provide stage-specific helper signals to cognate B cells. This process is regulated intrinsically by specific transcription factors and extrinsically by T follicular regulatory (Tfr) cells. The importance of molecular interactions between B and T cells is evidenced by immunodeficient and autoimmune diseases that develop when these interactions are perturbed.