Phagocytic and scavenger pathways on antigen-presenting cells

Phagocytic and scavenger pathways on antigen-presenting cells (APCs) represent a complex network of receptors and intracellular signaling events dedicated to the internalisation of extracellular materials, including pathogens, apoptotic cells, and modified self-molecules (Canton et al., 2013 [PMID: 23928573]). These pathways are primarily mediated by a diverse array of receptors such as scavenger receptors (e.g., MSR1, CD36, MARCO), Fc receptors, and complement receptors expressed on macrophages and dendritic cells (Zani et al., 2015 [PMID: 25871461]). Beyond simple clearance, these pathways are critical for the processing and presentation of antigens to T cells, thereby bridging innate and adaptive immunity (Lim et al., 2011 [PMID: 21904389]). Dysregulation of these pathways is implicated in various pathologies, including atherosclerosis (via foam cell formation), autoimmune diseases (due to defective clearance of apoptotic debris), and cancer (where scavenger receptors can modulate the immunosuppressive tumor microenvironment) (PrabhuDas et al., 2017 [PMID: 29144460]). Therapeutic strategies targeting these pathways often focus on specific receptors to either enhance pathogen clearance or inhibit the uptake of pro-inflammatory ligands, though maintaining systemic immune homeostasis remains a significant challenge (Nimmerjahn & Ravetch, 2008 [PMID: 18193028]).

Other names

Scavenger receptor-mediated endocytosisPhagocytosis and scavenger receptor-mediated uptakeAntigen uptake pathwaysAPC scavenger pathways

Modulation of receptor-mediated endocytosis, enhancement of apoptotic cell clearance (efferocytosis), or inhibition of ligand binding to prevent foam cell formation and inflammatory signaling.