Antigen-processing and presentation machinery (APM) (APM)

The antigen-processing and presentation machinery (APM) is a complex multi-protein system essential for the immune system's ability to detect and eliminate abnormal cells. It involves the degradation of proteins into peptides by the proteasome, the transport of these peptides into the endoplasmic reticulum by the transporter associated with antigen processing (TAP), and the loading of peptides onto major histocompatibility complex (MHC) molecules with the help of chaperones like tapasin (Rock et al., 2016). This machinery ensures that fragments of viral or tumor-associated proteins are displayed on the cell surface for recognition by T-cell receptors. Defects in the APM, such as the downregulation of MHC Class I or TAP, are common mechanisms of immune evasion in various cancers, leading to reduced tumor immunogenicity (Leone et al., 2013). Therapeutic interventions often target specific components of this machinery, such as proteasome inhibitors (e.g., bortezomib) used in multiple myeloma, or the use of interferons to upregulate APM components in the tumor microenvironment (Seliger, 2005). Understanding the APM is crucial for developing effective cancer immunotherapies and vaccines.

Other names

Antigen processing machineryMHC processing pathwayAntigen presentation pathwayMHC class I antigen processing and presenting machinery

Proteasome inhibition to prevent protein degradation; Upregulation of MHC and TAP expression via cytokine signaling; Enhancement of peptide loading onto MHC molecules.