Dectin-1 is a receptor for beta-glucan recognizing beta1,3 and beta1,6-linked glucans on yeast, mycobacterial, and plant cell walls and plays a role in innate immune responses [137, 138]. Zymosan, a beta-glucan and mannan-rich ligand binds to Dectin-1 , and Dectin-1 interacts with the tetraspanin molecule CD37. Dectin-1 binds to Saccharomyces,
Candida, Pneumocystis, Coccidiodes, Penicillium, and Aspergillus, but not Cryptococcus fungal species, leading to Inhibitors,research,lifescience,medical activation of Dectin-1+ cells and elimination of fungal pathogens by activating inflammatory responses, such as TNF-alpha, CDCL1, IL-1beta, GM-CSF, and IL-6, by the presence of an ITAM in its cytoplasmic tail . In fact, Dectin-1 Inhibitors,research,lifescience,medical knockout mice are highly susceptible to pathogenic infections due to inflammatory defects and reduced fungal killing . Furthermore, Dectin-1 binds to bacteria resulting in TNF-alpha, IL-6, RANTES, G-CSF, and IL-12 secretion . The stimulation of inflammatory and Th1 cytokines leads to the proposal of Dectin-1 targeting of soluble GS-1101 in vitro antigens by appropriate ligands
to stimulate Inhibitors,research,lifescience,medical cellular immunity. Anti-Dectin-1 and anti-Dectin-2 monoclonal antibodies conjugated to OVA [142, 143] and induced significant expansion of T cells in the draining lymph nodes of mice and IFN-gamma secretion by T cells [142, 143]. Purified beta1,3-d-glucan from Saccharomyces cerevisiae cell wall, free from mannan and other proteins, binds to Dectin-1 receptor on DCs. Beta1,3-d-glucan conjugated to OVA matures bone marrow derived DCs was rapidly phagocytosed and stimulated
Inhibitors,research,lifescience,medical >100-fold more efficiently CD8+ OT-I and CD4+ OT-II T cells, compared to OVA alone . Immunization of mice with beta1,3-d-glucan stimulated IgG2c antibodies, CD4+ T cells, IFN-gamma, and Th17 biased responses . Thus, robust stimulation of humoral and cellular Inhibitors,research,lifescience,medical immune responses results following immunization with vaccine candidates that target Dectin-1 receptor. DNGR-1. DNGR-1 (NK lectin group receptor-1, Clec9A) is a group V C-type lectin-like type II membrane protein located close to Dectin-1 STK38 encoded within the NK gene complex. DNGR-1 is expressed on murine CD8+ DCs not on CD4+ DCs, on CD11c+ DCs but not by CD11c− cells (B cells, T cells, NK cells, NKT cells, macrophages, and granulocytes), on plasmacytoid DCs, and on a small subset of human blood DCs (BDCA-3+ DCs) and monocytes (CD14+CD16−) and induces proinflammatory cytokines [145, 146]. DNGR-1 is also not expressed by interstitial DCs, in skin epidermis, and on GM-CSF derived bone marrow DCs but highly expressed on Flt3 ligand bone marrow derived CD8+ DCs (CD11blowCD24hiB220−) .