α-galcer

α-Galactosylceramide (KRN7000) is a synthetic glycolipid with antitumorial and immunostimulatory and is a very potent NKT cell agonist and binds effectively to CD1d. The complex of α-Galactosylceramide and CD1d can bind to the T cell antigen receptor of NKT cells.

α-Galactosylceramide analog 8 (α-GalCer analog 8) is a triazole derivative of α-galactosylceramide. [1] It increases IL-2 secretion by DN32.D3 NKT hybridoma cells when co-cultured with CD1d-transfected RBL cells pre-loaded with α-GalCer analog 8 at a concentration of 32 ng/ml. α-GalCer analog 8 (32 ng/ml) induces IL-4 secretion to a greater extent than the synthetic α-GalCer KRN 7000 in mouse splenocytes in vitro and in mouse serum following administration of a 1 µg per animal dose, indicating a Th2 response.

KRN7000 analog 3 (Compound 14), an α-GalCer analog featuring a 4-phenoxy substituent, acts as an iNKT agonist. This compound induces higher levels of IL-2 cytokine secretion in mNK1.2 cells (ranging from 49.2 to 62.6 ng mL) compared to α-GalCer (44.1 ng mL). KRN7000 analog 3 shows potential for research in anti-tumor agents and vaccine adjuvants.

KBC-007 is a synthetic branched chain-containing analog of α-galactosylceramide (α-GalCer). It induces IL-4 and IFN-γ secretion by mouse splenocytes when used at a concentration of 0.5 ng/ml and IL-2 secretion by DN32.D3 NKT hybridoma cells co-cultured with CD1d-transfected RBL cells pre-loaded with KBC-007 at a concentration of 8 ng/ml. KBC-007 (1 μg per animal) increases levels of IL-4, but not IFN-γ, to a similar degree as α-GalCer in mouse serum. KBC-007 (0.5 μg per animal) increases the survival rate of mice immunized with the inactivated influenza A virus A/PR/8/34 in a model of influenza infection.