Comparative study of American cutaneous leishmaniasis and diffuse cutaneous leishmaniasis in two strains of inbred mice

Abstract

Two Leishmania strains, AZV (isolated from a typical case [human] of American cutaneous leishmaniasis) and AMP (from a case of diffuse cutaneous leishmaniasis), were studied in C57BL/6 and BALB/c mice. After infection with 104 amastigotes of either strains, C57BL/6 mice developed self-resolving lesions lasting 20-23 wk and showed delayed hypersensitivity response to leishmanial antigen and specific agglutinating antibodies. BALB/c mice infected with 104 AZV or AMP amastigotes developed chronic, large, ulcerated lesions and showed impaired cellular and humoral responses to the parasite. When BALB/c and C57BL/6 mice received 102 AMP amastigotes, patterns of infection were similar to those observed after inoculation of 104 amastigotes. In vitro studies revealed that spleen cells from AZV- or AMP-infected C57BL/6 mice showed an increased DNA-synthetic response to leishmanial antigen, concanavalin A and phytohemagglutinin. Spleen cells from AZV- or AMP-infected BALB/c mice showed an increased response to concanavalin A and diminished responses to leishmanial antigen, phytohemagglutinin and lipopolysaccharide.