Antigen-presenting cells and innate immune sensors (APCs/PRRs)

Montanide ISA 51 is a clinical-grade vaccine adjuvant consisting of a water-in-oil emulsion of highly purified mineral oil and the surfactant mannide monooleate (Seppic, 2023). Its primary biological target is the population of professional antigen-presenting cells (APCs), including dendritic cells, macrophages, and B cells, which are recruited to the injection site following administration (PubMed: 22403483). The adjuvant functions by creating a depot that ensures the slow, sustained release of antigens, protecting them from rapid clearance and providing a persistent stimulus to the innate immune system (PubMed: 23812134). Within these APCs, Montanide ISA 51 engages various innate immune sensors and pattern recognition receptors (PRRs), potentially including the NLRP3 inflammasome, to trigger cellular maturation and the secretion of pro-inflammatory cytokines (PubMed: 21743438). This activation enhances the processing and presentation of vaccine-derived antigens on MHC molecules, leading to the induction of potent Th1-biased T-cell responses and high-titer antibody production. Clinically, it is a key component in therapeutic vaccines for cancer and chronic infections, though its use is frequently associated with local adverse events such as granulomas and sterile abscesses at the site of administration (PubMed: 15163343).

Other names

Professional antigen-presenting cellsInnate immune sensorsPattern recognition receptorsAPCsPRRs

Adjuvant-mediated recruitment and activation of antigen-presenting cells via depot formation and stimulation of innate immune pathways.