Immune system (Antigen-presenting cells, B cells, and T cells)

The immune system components mentioned—antigen-presenting cells (APCs), B cells, and T cells—constitute the fundamental units of the adaptive immune response. APCs, including dendritic cells and macrophages, capture and process antigens to present them to T cells via MHC molecules, initiating a specific immune response (StatPearls: Physiology, Antigen Presenting Cells). T cells are responsible for cell-mediated immunity, including the direct killing of infected or cancerous cells and the coordination of other immune cells, while B cells mediate humoral immunity through the production of highly specific antibodies (NIH: Overview of the Immune System). Although this entry describes a collection of cell types rather than a single molecular target, these cells express a wide array of therapeutic targets such as CD20, PD-1, and CTLA-4. Drugs interacting with these cells range from immunosuppressants used in transplantation to checkpoint inhibitors and CAR-T cell therapies used in oncology (PubMed: PMC7358244). Dysregulation of these cells is a hallmark of numerous pathologies, including autoimmune diseases, chronic inflammation, and various malignancies.

Other names

Adaptive immune systemCellular and humoral immunityLymphocytes and APCs

Modulation of immune cell activity through binding of specific surface antigens, checkpoint inhibition, or suppression of intracellular signaling pathways.