Antigen-presenting cell machinery (APM)

The antigen-presenting cell (APC) machinery is a complex biological system responsible for the degradation of proteins into antigenic peptides and their subsequent presentation on the cell surface via Major Histocompatibility Complex (MHC) molecules (Rock et al., 2016). This process is essential for the adaptive immune system to monitor cellular health and detect foreign pathogens or mutated proteins. Key components of this machinery include the immunoproteasome, the Transporter associated with Antigen Processing (TAP), and various endoplasmic reticulum-resident chaperones like tapasin and calreticulin (Seliger, 2008). In oncology, tumors often downregulate components of this machinery to evade detection by cytotoxic T lymphocytes, making the restoration of APM function a significant area of therapeutic interest (Leone et al., 2013). Conversely, overactivity or inappropriate presentation of self-peptides can lead to autoimmune disorders where the immune system attacks healthy tissues (Neefjes et al., 2011). Drugs like proteasome inhibitors directly affect the processing stage, while cytokines like interferon-gamma can upregulate the entire pathway to enhance immunogenicity (Seliger, 2014).

Other names

Antigen processing and presentation machineryAPMMHC presentation pathwayAntigen processing pathway

Modulation of the proteasomal degradation of proteins, transport of peptides into the endoplasmic reticulum, and the assembly and surface expression of MHC-peptide complexes to alter T-cell recognition (Rock et al., 2016).