α-Galactosylceramide (α-GalCer) is a synthetic glycolipid with antitumorial and immunostimulatory. α-Galactosylceramide is a very potent NKT cell agonist and binds effectively to CD1d. The complex of α-Galactosylceramide plus CD1d binds the NKT cell TCR (T cell antigen receptor)^[1][2][3][4]. IC50 & Target: NKT cell^[3] In Vitro: Culture supernatants of activated Vα24+NKT-cell cultures stimulated with α-Galactosylceramide pulsed monocyte-derived dendritic cells (Mo-DCs) exhibits antiproliferative activities against melanoma cells. This effect is predominantly due to release of IFN-γ, and to a lesser extent IL-12. Other cytokines, including IL-4 and IL-10, are released but these cytokines have less antiproliferative effects. Vα24+NKT-cells stimulated by α-Galactosylceramide-pulsed Mo-DCs have anti-tumour activities against human melanoma through antiproliferative effects exerted by soluble mediators^[3]. In Vivo: α-Galactosylceramide treatment can protect against spontaneous, carcinogen-, or oncogene-induced primary tumor formation in mice. Consistent with a prime role for IFN-γ in NKT cell-mediated tumor responses, a C-glycoside analog of α-Galactosylceramide that preferentially stimulated IFN-γ production is even more effective than α-Galactosylceramide at preventing metastases of the B16 melanoma^[1].
Since α-Galactosylceramide shows a potent antitumor activity and stimulates the lymphocyte proliferation (LP) on allogeneic mixed lymphocyte reaction (MLR) in the mouse, α-Galactosylceramide is considered to be a nonspecific immunostimulating agent which is a biological response modifier^[4].