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|Title: ||IMMUNOPATHOGENSIS OF EXPERIMENTAL LEISHMANIASIS, BASED ON INFECTIONS BY LOCAL STRAINS OF LEISHMANIA IN GRIVET MONKEYS (CERCOPITHECUS AETHIOPS), SYRIAN HAMSTERS (MESOCRICETUS AURATUS) AND BALB/C MICE|
|Authors: ||Tamrat, Abebe|
|Advisors: ||Prof. Asrat Hailu|
|Keywords: ||Leishmaniasis; low dose; sand fly saliva; lesion size;target organ/tissue;antibody; cytokine.|
|Copyright: ||2005 |
|Date Added: ||23-May-2008 |
|Publisher: ||Addis Ababa university|
Leishmaniasis, a spectrum of diseases, is a global health problem that affects both humans
and other animals. Chemotherapy, immunotherapy and immunoprophylaxis are ideal tools for
the battle against leishmaniasis. Critical assessment of the parasitological, clinical and
immunological spectrum of low dose infection was important to develop live-low dose
vaccine. To this end, CL and VL were induced in experimental animals (BALB/c mice,
hamsters, and grivet monkeys) by intradermal inoculation of different species and doses of
High dose inoculation of L. aethiopica and L. major into the nose tip of the hamsters resulted
in nodular lesion. Significantly greater lesion size and severity was observed in male
hamsters. Low dose infection of the dermotrophic Leishmania together with saliva
exacerbated severity and clinical evolution of lesion. Only 3 out of 30 the hamsters inoculated
with low dose Leishmania developed observable clinical lesion. The failure of the L.
aethiopica and L. major to produce lesion in the 27 hamsters was not due to an effective
immune response, since the DTH reaction was negative.
Infection of Grivet monkeys with varying doses of L. donovani complex was assessed.
Typical infection was established in all groups of monkeys irrespective of the dose. Biopsy
and necropsy findings indicated the dissemination of the parasite to the different target organs
and/or tissues. Analysis of antibody response profile of the monkeys using DAT indicated
gradual development and sustained rise of antibody. Cytokine assay using ELISA showed the
production of mixed Th1 (IFN- , IL-12, & TNF-a) and Th2 (IL-4 & IL-10) like cytokine
profile. One-Way ANOVA followed by LSD test showed significant (P<0.05) differences in
the cytokine production of experimental and control groups. A tendency of a shift towards
Th1 from Th2 cytokine profile was also observed in the later stage of infection.
Notwithstanding the caveats, this study showed the possibility of inducing protective
immunity by low dose leishmanization.|
|Description: ||A THESIS SUBMITTED TO GRADUATE STUDIES PROGRAMME
ADDIS ABABA UNIVERSITY IN PARTIAL FULFILLMENT OF THE
REQUIREMENTS FOR MASTERS OF SCIENCE DEGREE IN
|Appears in:||Thesis - Medical Microbiology|
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