The combination of DNA vectors expressing IL-12 + IL-18 elicits high protective immune response against cutaneous leishmaniasis after priming with DNA-p36/LACK and the cytokines, followed by a booster with a vaccinia virus recombinant expressing p36/LACK

Microbes Infect. 2003 Feb;5(2):73-84. doi: 10.1016/s1286-4579(02)00077-1.

Abstract

Protocols of immunization based on the DNA prime/vaccinia virus (VV) boost regime with recombinants expressing relevant antigens have been shown to elicit protection against a variety of pathogens in animal model systems, and various phase I clinical trials have been initiated with this vaccination approach. We have previously shown that mice immunized with a DNA vector expressing p36/LACK of Leishmania infantum followed by a booster with VVp36/LACK induced significant protection against Leishmania major infection. To further improve this protocol of immunization, here we investigated whether the cytokines interleukin-12 (IL-12) and IL-18 could enhance protection against L. major infection in BALB/c mice. We found that priming with DNA vectors expressing p36/LACK and either IL-12 or IL-18, followed by a booster with a VV recombinant expressing the same L. infantum LACK antigen, elicit a higher cellular immune response than by using the same protocol in the absence of the cytokines. The cytokine IL-12 triggered a higher number of IFN-gamma-secreting cells specific for p36 protein than IL-18. When immunized animals were challenged with promastigotes, the highest protection against L. major infection was observed in animals primed with DNAp36 + DNA IL-12 + DNA IL-18 and boosted with VVp36. This protection correlated with a Th1 type of immune response. Our findings revealed that in prime/booster protocols, co-expressing IL-12 and IL-18 during priming is an efficient approach to protect against leishmaniasis. This combined prime/booster immunization regime could have wide use in fighting against parasitic and other infectious diseases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies, Protozoan / blood
  • Antigens, Protozoan*
  • Female
  • Genetic Vectors
  • Immunization Schedule
  • Immunization*
  • Immunization, Secondary
  • Interleukin-12 / genetics
  • Interleukin-12 / immunology*
  • Interleukin-12 / metabolism
  • Interleukin-18 / genetics
  • Interleukin-18 / immunology*
  • Interleukin-18 / metabolism
  • Leishmania infantum / immunology
  • Leishmania major / pathogenicity
  • Leishmaniasis, Cutaneous / immunology
  • Leishmaniasis, Cutaneous / parasitology
  • Leishmaniasis, Cutaneous / prevention & control*
  • Mice
  • Mice, Inbred BALB C
  • Protozoan Proteins / genetics
  • Protozoan Proteins / immunology*
  • Protozoan Vaccines / administration & dosage
  • Protozoan Vaccines / immunology
  • Th1 Cells / immunology
  • Vaccines, DNA / immunology
  • Vaccinia virus / genetics*

Substances

  • Antibodies, Protozoan
  • Antigens, Protozoan
  • Interleukin-18
  • Protozoan Proteins
  • Protozoan Vaccines
  • Vaccines, DNA
  • LACK antigen, Leishmania
  • Interleukin-12