Leishmania major H-line attenuated under pressure of gentamicin, induces a Th1 response which protects susceptible BALB/c mice against infection with virulent L. major.
An attenuated line of Leishmania major (L. major H-line) has been established by culturing promastigotes in vitro under gentamicin pressure. A modification of the previously described method for the generation of attenuated L. major is described, giving rise to attenuated parasites after 8 rather than 12 subpassages. No lesions developed in BALB/c mice infected with L. major H-line, whereas L. major wild-type (WT) induced a Th2 like response with progressive lesions. Analysis of splenocyte IFN-gamma and IL-4 production following stimulation with promastigotes shows that the L. major H-line preferentially induces Th1-like responses and possibly down-regulates Th2 responses in BALB/c mice. L. major H-line parasites remained localized in the skin and draining lymph node, whereas L. major WT parasites disseminated into the visceral organs of BALB/c mice. Mice infected with L. major H-line acquired some resistance against L. major WT. These results show that the attenuated cell line of L. major is not only avirulent but that it may also modulate the host immune response.
Daneshvar
Hamid
H
Medical School, University of Kerman, Kerman, Iran. hamiddaneshvar@hotmail.com
Burchmore
Richard
R
Hagan
Paul
P
Phillips
R Stephen
RS
D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D005260:Female; D005839:Gentamicins / Q000494:pharmacology; D006801:Humans; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D018320:Leishmania major / Q000187:drug effects / Q000254:growth & development / Q000276:immunology* / Q000472:pathogenicity*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000469:parasitology / Q000473:pathology; D017737:Macrophages, Peritoneal / Q000276:immunology / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D018417:Th1 Cells / Q000276:immunology*; D014611:Vaccination; D014774:Virulence
D000913:Antibodies, Protozoan; D005839:Gentamicins; D015847:Interleukin-4; D007371:Interferon-gamma