EARLY PARASITE CONTAINMENT IS DECISIVE FOR RESISTANCE TO LEISHMANIA MAJOR INFECTION

摘要: We investigated the early spread of Leishmania major in various mouse strains. In BALB/c mice, which are extremely vulnerable to L. infection, parasites disseminated within 10-24 h from site subcutaneous footpad infection popliteal lymph node, spleen, lung, liver and bone marrow. Application recombinant (r)IL-12 prior prevented dissemination into visceral organs animals healed infection. three strains tested, C57BL/6, CBA/J C3H/HeJ, all resistant remained localized draining LN for 3 days without evidence dissemination. C57BL/6 depletion NK1.1+ cells or neutralization interferon (IFN)-gamma led rapid parasite spreading with kinetics similar those seen susceptible animals. Depletion either CD4+ CD8+ T vivo did not alter any strain tested. Experiments severe-combined immunodeficient mice provided further that containment depends on natural killer IFN-gamma, but is independent cells. The finding restrict first 24 after strongly suggests closely associated a phenotype. data show local restriction pre-T cell phase mediated by innate immune system suggest this function plays an important role development protective response.