Antigen presentation pathway via antigen-presenting cell

The **antigen presentation pathway via antigen-presenting cell (APC)** refers to the multi-step immunological process by which specialized cells known as antigen-presenting cells (mainly dendritic cells, macrophages, and B cells) process protein antigens and display the resulting peptide fragments on their cell surface bound to major histocompatibility complex (MHC) molecules[1][2][3][4]. This surface presentation allows T cells to recognize these peptides through their T cell receptors (TCRs), initiating tailored adaptive immune responses crucial for the control of infections, response to neoplastic cells, and the regulation of immune tolerance[1][3]. There are two main branches of the pathway: MHC class I (presenting intracellular antigens to cytotoxic T cells) and MHC class II (presenting extracellular antigens to helper T cells); both are essential for the immune system’s ability to distinguish self from non-self and to mount an appropriate defense against pathogens and malignant cells[2][3][4]. Disruptions, defects, or dysregulation in this pathway are implicated in a variety of disease contexts, including infections, cancers, and autoimmune disorders[1][3][4].\n\nNotes on "is_target" and "is_incorrect":\n- **This is not a single molecular target** (such as a receptor or enzyme), but a complex cellular pathway involving multiple proteins (MHC molecules, proteasomes, transporters, co-receptors, etc.) and cell types. Therefore, **it is not considered a "therapeutic target"** in the molecular sense, though many drugs or biologics may modulate components of this pathway or the activity of APCs[1][2][4].\n- The entry is somewhat incorrect as a target: "Antigen presentation pathway via APCs" refers to a process or pathway, not a molecule, receptor, or specific druggable target. Individual proteins within this pathway (such as MHC class I or II molecules) can be considered molecular targets[1][3][4].

Other names

antigen presentation pathwayantigen processing and presentationantigen presentation via APCMHC-mediated antigen presentation