Résumé
Protamine sulphate/DNA complexes have been shown to protect DNA from DNase digestion in a lipid system for gene transfer. A DNA-based vaccine complexed to protamine sulphate was used to induce an immune response against Schistosoma mansoni anchored-glycosylphosphatidylinositol tegumental antigen in BALB/c mice. The protection elicited ranged from 33 to 44 percent. The spectrum of the elicited immune response induced by the vaccine formulation without protamine was characterized by a high level of IgG (IgG1> IgG2a). Protamine sulphate added to the DNA vaccine formulation retained the green fluorescent protein encoding-plasmid longer in muscle and spleen. The experiments in vivo showed that under protamine sulphate effect, the scope of protection remained unchanged, but a modulation in antibody production (IgG1= IgG2a) was observed.
Sujets)
Animaux , Femelle , Souris , Anticorps antihelminthe/immunologie , Antigènes d'helminthe/immunologie , Glycosylphosphatidylinositols/immunologie , Antagonistes de l'héparine/immunologie , Protamine/immunologie , Schistosoma mansoni/immunologie , Vaccins à ADN/immunologie , Anticorps antihelminthe/sang , Antigènes d'helminthe/administration et posologie , Glycosylphosphatidylinositols/administration et posologie , Antagonistes de l'héparine/administration et posologie , Immunoglobuline G/immunologie , Souris de lignée BALB C , Protamine/administration et posologie , Schistosomiase à Schistosoma mansoni/prévention et contrôle , Facteurs temps , Vaccins à ADN/administration et posologieRésumé
The 18-kDa protein from Mycobacterium leprae is a major target for the immune response in leprosy. We have developed a system to express this antigen in yeast as a fusion protein with the C-terminal region of the yeast membrane protein GAS1, which would render the recombinant protein anchored to the plasma membrane by a glycosylphosphatidylinositol (GPI) anchor. Cells lacking the GAS1 gene and transformed with the hybrid 18-kDa-GAS1 construct express a polypeptide that reacts with an 18-kDa-specific monoclonal antibody. In addition, these cells react with an alpha-CRD antibody after GPI-PLC treatment. The non-transformed cells are negative. These data indicate that our system may be suitable for the expression of foreign proteins in yeast in a GPI-anchored form