Leishmania Aehiopica Infections in Cercopithecus Aethiops: Initiation of Infection and Immune Profiles.
No Thumbnail Available
Date
2000-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
In the search of vaccines and dmgs for the control of diseases the availability of animal
models is vital. Cutaneous leishmaniasis, caused by L. aethiopica is an endemic disease in
Ethiopia. Availability of an animal model for L. aethiopica could be useful for studying the
different aspects of the disease. In this study, monkeys were infected with an isolate of L.
aethiopica to develop the primate experimental model of the disease. Twelve grivet
monkeys (Cercopithecus aethiops) were trapped from cutaneous leishmaniasis (CL) nonendemic
areas. Experimental infections were initiated in these animals after they were
screened for natural infection. Inoculation of grivet monkeys with L. aethiopica parasite
resulted either in lesion or symptomless infection. One grivet monkey produced clinical
lesions following inoculation with promastigotes of diffuse cutaneous leishmaniasis (DCL)
strain of L. aethiopica. Another grivet monkey produced nodules following inoculation
with promastigotes of localized cutaneous leishmaniasis (LCL) strain of L. aethiopica. In
addition to tlus, loss of hair at the infection site was seen in two of these animals after
inoculation with LCL strain of Eo' aethiopica promastigotes. In order to. assess whether
grivet monkeys have similar immune responses as humans following infection with
leishmaniasis, we investigated the ill vivo and ill vitro immune responses of these animals
to leishmanial antigens. Delayed type hypersensitivity (DTH) response as measured by skin
testing indicated no significant response in the experimental animals. Monkeys were bled
and the proliferative response of their peripheral blood mononuclear cells (PBMC) as well
as IFN-y and interleukin IL-IO production were tested ill vitro in response to leishmanial
antigens. The finding indicated that ill vitro lymphocyte proliferative response of infected
animals to live localized cutaneous leishmaniasis strain L. aethiopica promastigotes was significantly higher than controls. However, ill vitro lymphocyte proliferative response of
infected animals to live DeL strain of L. aethiopica promastigotes and killed parasites was
not significantly higher compared to controls. Low level of IFN-y was produced after
stimulation with leishmanial antigen. There was no detectable level ofIL-lO production
after ill vitro stimulation
Description
Keywords
Biology