Antigen-presenting cell receptors and processing machinery (APC-RPM) (APC-RPM)

Antigen-presenting cell (APC) receptors and processing machinery refer to the integrated system of proteins that capture, process, and present antigens to T cells to initiate adaptive immunity (Janeway et al., Immunobiology, 2016). This machinery includes pattern recognition receptors (PRRs) like Toll-like receptors (TLRs) for pathogen sensing, intracellular enzymes like the proteasome for protein degradation, and transporters like TAP for peptide delivery to the endoplasmic reticulum (UniProt, 2024). The central components are the Major Histocompatibility Complex (MHC) Class I and II molecules, which display processed peptides on the cell surface for recognition by T-cell receptors (NCBI, 2023). Additionally, costimulatory receptors such as CD80 and CD86 are essential for providing the secondary signals required for full T-cell activation (StatPearls, 2023). In cancer, this machinery is frequently impaired—for instance, through the loss of MHC expression—allowing tumors to evade the immune system (Nature Reviews Cancer, 2019). Conversely, overactivity or misdirected presentation of self-antigens can lead to autoimmune diseases. Therapeutic strategies targeting this system include the use of TLR agonists as vaccine adjuvants, proteasome inhibitors like bortezomib to modulate peptide pools, and checkpoint inhibitors that target receptors like PD-L1 expressed on APCs (PubChem, 2024).

Other names

Antigen processing and presentationMHC presentation pathwayAPC machinery

TLR agonism, costimulation blockade, proteasome inhibition, immune checkpoint inhibition, and antigen loading.