In vivo protective effect of the lectin from Canavalia brasiliensis on BALB/c mice infected by Leishmania amazonensis

• Published in: Acta tropica 1996-02, Vol.60 (4), p.237-250
• Main Authors: Barral-Netto, M., Von Sohsten, R.L., Teixeira, M., Conrado dos Santos, W.L., Pompeu, M.L., Moreira, R.A., Oliveira, J.T.A., Cavada, B.S., Falcoff, E., Barral, A.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Canavalia brasiliensis; Experimental leishmaniasis; Female; Human protozoal diseases; Infectious diseases; Interferon-gamma - biosynthesis; Interferon-gamma - pharmacokinetics; Interferon-γ; Lectins - therapeutic use; Leishmania; Leishmania amazonensis; Leishmania mexicana; Leishmaniasis; Leishmaniasis, Cutaneous - immunology; Leishmaniasis, Cutaneous - parasitology; Leishmaniasis, Cutaneous - therapy; Leshmaniasis; Macrophages, Peritoneal - drug effects; Macrophages, Peritoneal - parasitology; Medical sciences; Mice; Mice, Inbred BALB C; Parasitic diseases; Protozoal diseases; Rats; Tegumentary leishmaniasis; Tropical medicine
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/0001-706X(95)00120-4

In vivo administration of Canavalia brasiliensis lectin (at the time of infection, or maintained throughout the infection) reduced the lesions of highly susceptible BALB/c mice infected by Leishmania amazonensis. At the doses used C. brasiliensis lectin (ConBr) does not interfere with penetration or fate of Leishmania in the macrophages in vitro. Since Interferon-γ (IFN-γ) is the major macrophage activating factor, and considered a critical element in the successful immune response against leishmaniasis, we explored its participation in this phenomenon. ConBr either in vivo or in vitro induced IFN-γ production in normal or in leishmania-infected BALB/c mice. However we were unable to change the course of disease by in vivo IFN-γ administration (although IFN-γ preparations were effective in inducing a leishmanicidal effect in vitro on L. amazonensis-infected peritoneal macrophages). Additionally, IFN-γ neutralization with anti-IFN-γ monoclonal antibody did not alter the protection conferred by ConBr administration. These data show that lectin administration in vivo is protective in the otherwise unchecked L. amazonensis infection of BALB/c mice, and suggest that such effect is not mediated by IFN-γ.