Pattern recognition and uptake pathways on dendritic cells and B cells

Pattern recognition and uptake pathways on dendritic cells and B cells refer to the integrated biological systems used by professional antigen-presenting cells (APCs) to sense and internalize pathogens and danger signals (Mellman and Steinman, 2001). These pathways are primarily mediated by a variety of germline-encoded Pattern Recognition Receptors (PRRs), including Toll-like receptors (TLRs), C-type lectin receptors (CLRs), and scavenger receptors, which identify conserved molecular patterns known as PAMPs and DAMPs (Iwasaki and Medzhitov, 2004). Upon ligand binding, these receptors trigger intracellular signaling cascades and uptake mechanisms such as phagocytosis and receptor-mediated endocytosis, facilitating the processing of antigens for presentation on MHC molecules. B cells also utilize these pathways, often in synergy with B-cell receptor (BCR) signaling, to enhance their capacity for antigen presentation and to drive antibody production (Bekeredjian-Ding and Jego, 2009). These pathways are critical therapeutic targets; for example, TLR agonists like imiquimod and monophosphoryl lipid A are employed as vaccine adjuvants or immunotherapies to stimulate robust immune responses against infections and malignancies. However, the overactivation or dysregulation of these pathways can lead to severe safety concerns, such as cytokine release syndrome or the development of autoimmune diseases, requiring precise pharmacological control.

Other names

Pattern recognition receptorsAntigen uptake pathwaysInnate immune sensing pathwaysPRR signalingEndocytic pathways in professional APCs

Activation of pattern recognition receptors (PRRs) and endocytic machinery to promote antigen internalization, processing, and presentation, thereby initiating or modulating adaptive immune responses.