Leishmania braziliensis: Partial Control of Experimental Infection by Interleukin-12 p40 Deficient Mice

• Published in: Memórias do Instituto Oswaldo Cruz 2004-05, Vol.99 (3), p.289-294
• Main Authors: de Souza-Neto, Sebastião Martins, Carneiro, Cláudia Martins, Vieira, Leda Quercia, Afonso, Luís Carlos Crocco
• Format: Article
• Language: English
• Subjects: Animals; cutaneous leishmaniasis; cutaneous leishmaniasis - Leishmania braziliensis - interleukin 12; Disease Models, Animal; Female; Interferon-gamma - biosynthesis; Interferon-gamma - immunology; interleukin 12; Interleukin-12 - biosynthesis; Interleukin-12 - deficiency; Interleukin-12 - immunology; Interleukin-12 Subunit p40; Leishmania braziliensis; Leishmania braziliensis - immunology; Leishmania major; Leishmaniasis, Cutaneous - immunology; Male; Mice; Mice, Inbred C57BL; PARASITOLOGY; Protein Subunits - biosynthesis; Protein Subunits - deficiency; Protein Subunits - immunology; Time Factors; TROPICAL MEDICINE
• ISSN: 1678-8060; 0074-0276; 0074-0276; 1678-8060
• DOI: 10.1590/S0074-02762004000300009

Resistance to infection by Leishmania major has been associated with the development of a Th1 type response that is dependent on the presence of interleukin 12 (IL-12). In this work the involvement of this cytokine in the response to infection by L. braziliensis, a less virulent species in the mouse model, was evaluated. Our results show that while interferon (IFN-γ) deficient (-/-) mice inoculated L. braziliensis develop severe uncontrolled lesions, chronic lesions that remained under control up to 12 weeks of infection were observed in IL-12p40 -/- mice. IL 12p40 -/- mice had fewer parasites in their lesions than IFN-γ-/- mice. Lymph node cells from IL-12p40 -/- were capable of producing low but consistent levels of IFN-γ suggestive of its involvement in parasite control. Furthermore, as opposed to previous reports on L. major-infected animals, no switch to a Th2 response was observed in IL-12p40 -/- infected with L. braziliensis.