Vaccination with Plasmids Encoding the Leishmania Major GP63 Glycoprotein and CD40L Results in a Partial Suppression of the Inflammatory Reaction after Experimental Infection

Abstract

The development of an effective vaccine against leishmaniasis is the aim of an intensive research effort, to bring relief to thousands of people worldwide. DNA vaccination is a promising approach in this direction, since it is able to generate a strong cellular immune response. We tested whether the co-administration of a plasmid encoding a truncated gp63 gene, that allows extracellular secretion of the encoded protein, and a plasmid encoding for CD40L could induce a protective response in genetically susceptible BALB/c mice and reduce the local inflammatory swelling after infection with Leishmania major. We document that vaccination with the combination of plasmids for gp63 and CD40L reduced inflammatory swelling, while vaccination with the truncated gp63-encoding plasmid resulted in an exacerbation of the local inflammatory reaction. These preliminary data indicate that the CD40L expression plasmid is consequently an efficient adjuvant for the induction of protective responses in the context of a DNA vaccination against leishmaniasis.