CD4 cell.

Pam2Cys (Dipalmitoyl-S-glyceryl-cysteine; S-[2,3-Bis(palmitoyloxy)propyl]cysteine) is a TLR2 agonist and immunostimulant. Pam2Cys binds to TLR2 to activate dendritic cells and trigger the TLR2-dependent NF-κB signaling pathway. Pam2Cys also induces dendritic cell maturation by upregulating the expression of cell surface MHC II molecules. Pam2Cys activates innate immune signaling pathways, drives pro-inflammatory and antimicrobial responses, enhances the expression of macrophage activation markers, increases phagocytic activity, induces the release of IL-12 and pro-inflammatory cytokines, and polarizes macrophages into a pro-inflammatory, antimicrobial phenotype without interfering with IL-10-induced macrophage polarization. Pam2Cys also serves as the lipid moiety in synthetic lipopeptide vaccines and possesses self-adjuvant properties. Pam2Cys enhances the immunogenicity of conjugated peptide segments and induces cellular and humoral immune responses. However, it does not activate CD4 T cells in mouse splenocyte cultures when used alone. Pam2Cys activates pulmonary TLR2 signaling pathways, triggers innate immune responses, recruits neutrophils and macrophages, induces the secretion of various cytokines, alleviates symptoms and damages associated with influenza A virus infection in mice without impairing adaptive immunity. Pam2Cys can be used in studies related to tuberculosis and influenza A virus infection .