RESUMEN

The NYVAC poxvirus vector is used as vaccine candidate for HIV and other diseases, although there is only limited experimental information on its immunogenicity and effectiveness for use against human pathogens. Here we defined the selective advantage of NYVAC vectors in a mouse model by comparing the immune responses and protection induced by vectors that express the LACK (Leishmania-activated C-kinase antigen), alone or with insertion of the viral host range gene C7L that allows the virus to replicate in human cells. Using DNA prime/virus boost protocols, we show that replication-competent NYVAC-LACK that expresses C7L (NYVAC-LACK-C7L) induced higher-magnitude polyfunctional CD8(+) and CD4(+) primary adaptive and effector memory T cell responses (IFNγ, TNFα, IL-2, CD107a) to LACK antigen than non-replicating NYVAC-LACK. Compared to NYVAC-LACK, the NYVAC-LACK-C7L-induced CD8(+) T cell population also showed higher proliferation when stimulated with LACK antigen. After a challenge by subcutaneous Leishmania major metacyclic promastigotes, NYVAC-LACK-C7L-vaccinated mouse groups showed greater protection than the NYVAC-LACK-vaccinated group. Our results indicate that the type and potency of immune responses induced by LACK-expressing NYVAC vectors is improved by insertion of the C7L gene, and that a replication-competent vector as a vaccine renders greater protection against a human pathogen than a non-replicating vector.

Asunto(s)

Vectores Genéticos/inmunología , Leishmania major/efectos de los fármacos , Vacunas contra la Leishmaniasis/administración & dosificación , Leishmaniasis Cutánea/prevención & control , Linfocitos T/efectos de los fármacos , Proteínas Virales/genética , Animales , Antígenos de Protozoos/genética , Antígenos de Protozoos/inmunología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Vectores Genéticos/química , Células HeLa , Humanos , Inmunización Secundaria , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-2/genética , Interleucina-2/inmunología , Leishmania major/genética , Leishmania major/inmunología , Vacunas contra la Leishmaniasis/biosíntesis , Vacunas contra la Leishmaniasis/genética , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/parasitología , Proteínas de Membrana de los Lisosomas/genética , Proteínas de Membrana de los Lisosomas/inmunología , Ratones , Ratones Endogámicos BALB C , Proteínas Protozoarias/genética , Proteínas Protozoarias/inmunología , Linfocitos T/inmunología , Linfocitos T/parasitología , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología , Virus Vaccinia/genética , Virus Vaccinia/inmunología , Proteínas Virales/inmunología , Replicación Viral