title: A purified GM3 ganglioside conjugated vaccine induces specific, adjuvant-dependent and non-transient antitumour activity against B16 mouse melanoma in vitro and in vivo.
abstract: The presence of substantial amounts of GM3 ganglioside on human melanomas and other tumours, together with its peculiar biological properties, makes this glycolipid a unique target for cancer immunotherapy. B16 mouse melanoma expresses GM3 and constitutes an appropriate model for the development of novel GM3-based vaccines. Recently, we hydrophobically incorporated purified GM3 into the outer membrane protein complex from Neisseria meningitidis to form very small size proteoliposomes (GM3/VSSP). We have examined the antitumour properties of GM3/VSSP vaccine and compared it with GM3 incorporated in very low density serum lipoproteins (GM3/VLDL). Immunization with four doses of GM3/VSSP vaccine (120 microg of ganglioside) plus Freund's adjuvant or Montanide ISA 51 significantly increased the overall survival of mice inoculated in the subcutis with 103 B16-F1 cells, whereas the GM3/VLDL immunogen was ineffective. The non-transient character of tumour protection was confirmed in animals surviving the first challenge and re-inoculated with 5 x 103 cells. GM3/VSSP vaccine also reduced the subcutaneous growth of highly aggressive B16-F10 cells. The importance of ganglioside structure in the tumour-protective effect of GM3/VSSP vaccine was confirmed using GM3 containing N-glycolylneuraminic acid, a ganglioside absent in melanoma cells. Immunostaining and enzyme-linked immunosorbent assay (ELISA) experiments showed a high specificity of immune sera against GM3 and the presence of all four IgG subclasses, with a preponderance of IgG2b and IgG3. In addition, a strong anti-B16 complement-mediated cytotoxicity was induced by vaccination with GM3/VSSP. The present data indicate the molecular specificity of GM3/VSSP vaccine as well as the adjuvant-dependent and non-transient character of tumour protection in the B16 mouse model. These findings suggest that an appropriate GM3 vaccine may be capable of inducing prolonged tumour protection in melanoma patients.
authors.affiliation: Department of Vaccines, Center of Molecular Immunology, PO Box 16 040, Havana 11600, Cuba.
authors.forename: A
authors.initials: A
authors.lastname: Carr
authors.forename: Z
authors.initials: Z
authors.lastname: Mazorra
authors.forename: D F
authors.initials: DF
authors.lastname: Alonso
authors.forename: C
authors.initials: C
authors.lastname: Mesa
authors.forename: O
authors.initials: O
authors.lastname: Valiente
authors.forename: D E
authors.initials: DE
authors.lastname: Gomez
authors.forename: R
authors.initials: R
authors.lastname: Perez
authors.forename: L E
authors.initials: LE
authors.lastname: Fernandez
mesh_terms: D000818:Animals; D002855:Chromatography, Thin Layer; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005679:G(M3) Ganglioside / Q000378:metabolism*; D006736:Horses; D007074:Immunoglobulin G / Q000378:metabolism; D007075:Immunoglobulin M / Q000378:metabolism; D016130:Immunophenotyping; D008546:Melanoma, Experimental / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009438:Neuraminic Acids / Q000378:metabolism; D013997:Time Factors; D019444:Vaccines, DNA
chemical_list: D005679:G(M3) Ganglioside; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D009438:Neuraminic Acids; D019444:Vaccines, DNA