Antigen-presenting machinery (APM)

The antigen-presenting machinery is a collective term for a cellular system comprising multiple proteins—most notably the proteasome, transporter associated with antigen processing (TAP), endoplasmic reticulum (ER) chaperones, and major histocompatibility complex (MHC) class I and II molecules—that are necessary for processing intracellular or extracellular antigens into peptide fragments and displaying them on the cell surface for recognition by T cells. The effectiveness of this machinery is critical for immune surveillance, especially for the recognition and elimination of cancerous or infected cells. Defects in this system contribute to immune escape in tumors and impaired immunity in infections. Therapeutic strategies aiming to enhance or restore antigen-presenting machinery (such as epigenetic drugs, immunomodulators, or cellular vaccines) are under investigation for improving responses to immunotherapy, but this process is not itself a specific drug target. Instead, it defines a functional property or pathway, not a concrete molecular entity.

Other names

Antigen processing and presenting machineryAntigen processing machinery

Upregulation of antigen-processing genes, Restoration of antigen presentation, Enhancement of MHC expression, Modulation of epigenetic silencing, Reversal of immune escape