Intramuscular immunization with p36(LACK) DNA vaccine induces IFN-gamma production but does not protect BALB/c mice against Leishmania chagasi intravenous challenge.
Acute visceral leishmaniasis is a progressive disease caused by Leishmania chagasi in South America. The acquisition of immunity following infection suggests that vaccination is a feasible approach to protect against this disease. Since Leishmania homologue of receptors for activated C kinase (LACK) antigen is of particular interest as a vaccine candidate because of the prominent role it plays in the pathogenesis of experimental Leishmania major infection, we evaluated the potential of a p36(LACK) DNA vaccine in protecting BALB/c mice challenged with L. chagasi. In this study, mice received intramuscular (i.m.) or subcutaneous (s.c.) doses of LACK DNA vaccine. We evaluated the production of vaccine-induced cytokines and whether this immunization was able to reduce parasite load in liver and spleen. We detected a significant production of interferon gamma by splenocytes from i.m. vaccinated mice in response to L. chagasi antigen and to rLACK protein. However, we did not observe a reduction in parasite load neither in liver nor in the spleen of vaccinated animals. The lack of protection observed may be explained by a significant production of IL-10 induced by the vaccine.
Marques-da-Silva
Eduardo A
EA
Laboratório de Imunoparasitologia, DECBI/NUPEB-ICEB, Campus Morro do Cruzeiro, Universidade Federal de Ouro Preto, CEP 35400-000, Ouro Preto, MG, Brazil.
Coelho
Eduardo A F
EA
Gomes
Daniel C O
DC
Vilela
Márcia C
MC
Masioli
Cássio Z
CZ
Tavares
Carlos A P
CA
Fernandes
Ana Paula
AP
Afonso
Luis Carlos C
LC
Rezende
Simone A
SA
D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology*; D004195:Disease Models, Animal; D005260:Female; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000276:immunology; D016753:Interleukin-10 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D018314:Leishmania infantum / Q000276:immunology; D007898:Leishmaniasis, Visceral / Q000276:immunology* / Q000517:prevention & control*; D008099:Liver / Q000469:parasitology; D008214:Lymphocytes / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology*; D016052:Protozoan Vaccines / Q000008:administration & dosage / Q000276:immunology*; D013154:Spleen / Q000469:parasitology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*
D000953:Antigens, Protozoan; D015800:Protozoan Proteins; D016052:Protozoan Vaccines; D019444:Vaccines, DNA; D016753:Interleukin-10; C093139:LACK antigen, Leishmania; D015847:Interleukin-4; D007371:Interferon-gamma