Immune system via antigen-presenting cells and T lymphocytes

The interaction between antigen-presenting cells (APCs) and T lymphocytes is the fundamental mechanism of the adaptive immune response. APCs, including dendritic cells, macrophages, and B cells, process exogenous and endogenous antigens into peptides and present them on Major Histocompatibility Complex (MHC) molecules (StatPearls, 2023). T lymphocytes recognize these MHC-peptide complexes via their specific T-cell receptors (TCR), which, when combined with co-stimulatory signals like the CD80/86-CD28 interaction, leads to T-cell activation and clonal expansion (Janeway's Immunobiology, 2017). This system is a primary focus of immunotherapy; for instance, checkpoint inhibitors like Pembrolizumab block inhibitory signals (PD-1/PD-L1) to enhance T-cell activity against tumors, while drugs like Abatacept block co-stimulation to treat autoimmune diseases (Nature Reviews Drug Discovery, 2020). Because this 'target' represents a complex biological system rather than a single molecule, it is typically addressed in drug development through specific receptors or ligands within the APC-T cell synapse.

Other names

Antigen presentation pathwayAPC-T cell axisAdaptive immune responseCell-mediated immunity

Modulation of the interaction between antigen-presenting cells and T lymphocytes through co-stimulatory blockade, checkpoint inhibition, or interference with T-cell receptor signaling and cytokine production.