RESUMEN
We examined whether plasmids encoding granulocyte-macrophage colony-stimulating factor (pGM-CSF) or CD40-ligand (pCD40L) could modify the immune response to antigen encoded by co-injected plasmid DNA. For this we used as antigen Escherichia coli beta galactosidase (beta-gal), encoded by the plasmid pLacZ. We found that intradermal co-injection of pLacZ with both pGM-CSF and pCD40L enhanced the anti-beta-gal IgG response by approximately two orders of magnitude compared to injections of pLacZ alone. Co-injection of both pGM-CSF and pCD40L with pLacZ significantly enhanced antigen-specific IgG, and in particular IgG(2a), over that of animals co-injected with pLacZ and either pGM-CSF or pCD40L. We found that co-injection of pGM-CSF and pCD40L with pLacZ enhanced the generation of beta-gal-specific cytotoxic T cells, and allowed for a significant expansion of CD8(+) T cells from splenocytes co-cultured with beta-gal expressing stimulator cells. The immunostimulatory effects induced by pGM-CSF or pCD40L required injection of these plasmids to the same site that received pLacZ. 'Priming' experiments, where the site of injection was pre-injected with either plasmid adjuvant, showed that pGM-CSF, but not pCD40L, could enhance the anti-beta-gal immune response induced by subsequently administered plasmid antigen. We conclude that plasmids encoding GM-CSF and CD154 are particularly effective genetic adjuvants when used together to enhance the humoral and cellular immune response to a plasmid-encoded antigen.
Asunto(s)
Ligando de CD40/genética , Factor Estimulante de Colonias de Granulocitos y Macrófagos/genética , Plásmidos/genética , Vacunas de ADN/farmacología , Adyuvantes Inmunológicos/genética , Adyuvantes Inmunológicos/farmacología , Animales , Femenino , Inmunoglobulina G/biosíntesis , Técnicas In Vitro , Operón Lac , Ratones , Ratones Endogámicos BALB C , Linfocitos T Citotóxicos/inmunología , Células Tumorales Cultivadas , Vacunas de ADN/genética , Vacunas de ADN/inmunología , beta-Galactosidasa/genética , beta-Galactosidasa/inmunologíaRESUMEN
Interaction of CD40 with its ligand (CD154) can induce CD40-bearing APCs to express immune stimulatory accessory molecules that facilitate immune recognition. We evaluated whether a plasmid vector encoding CD154 (pCD40L) could influence the immune response to a transgene protein encoded by coinjected plasmid DNA. We found that coinjection of pCD40L in BALB/c mice enhanced the Ab response to beta-galactosidase induced by i.m. or intradermal injection of placZ, a plasmid DNA vector encoding beta-galactosidase. Furthermore, i.m. or intradermal coinjection of pCD40L with placZ enhanced the generation of CTL specific for P815 cells transfected with placZ. This study indicates that pCD40L can serve as a genetic adjuvant capable of augmenting humoral and cellular immune responses to Ags encoded by plasmid DNA expression vectors.
