19 Records out of 22207 Records

Characterization of Trypanosoma brucei rhodesiense infection in the vervet monkey ( Chlorocebus aethiops) model of sleeping sicknesss : The potential of biomarkers for staging and diagnosis

Author: Gaithuma, Alex Kiarie

Awarding University: Jomo Kenyatta University of Agriculture and Technology, Kenya

Level : MSc

Year: 2010

Holding Libraries: Jomo Kenyatta University of Agriculture and Technology Library ;

Subject Terms: Trypanosoma brucei rhodesiense ; Trypanosomiasis ; Cercopithecus aethiops ; Vervet monkeys ; Haematology ;

Abstract:

Diagnosis and stage-determination still hampers proper control of sleeping sickness. This study reports potential biomarkers for staging and diagnosing the disease in the vervet monkey (Chlorocebus aethiops) model. The monkeys were experimentally infected with Trypanosoma brucei rhodesiense IPR 001 and subsequently given subcurative treatment 28 days post-infection to induce the advanced late stage disease. Blood samples for serum and plasma separation, urine and cerebrospinal fluid samples were obtained at weekly intervals. Various analyses were then carried out on the samples. A typical HAT -like infection was observed in the vervets, with an early stage disease characterized by significant changes including: Low platelet counts (P<O.05, CI: 88.2-303.9), low glucose levels (P<O.05, CI: 0.180, 3.533), low high density lipoprotein (HDL) cholesterol levels (P<O.05, CI: 1.0420-1.4789), high ketone levels (P<O.05, CI: - 0.91-4.58), high urine protein levels (P<O.05, CI: 0.13-20.87), high levels of triglycerides (P<O.05; CI: 1.050-4.640), and high creatine kinase levels (P<O.05; CI: 2704-3551). Urine pH varied inversely with parasitaemia, while specific gravity varied directly with parasitaemia. The late stage disease was marked by significantly high cholesterol levels (P<O.05; CI: 1.735-3.822). A panel of platelets, cholesterol, triglycerides, HDL, blood glucose and urine ketone bodies could be used as adjunct markers for early stage disease, while cholesterol could be included into the panel of late stage indicators. However, further studies need to be done to investigate the relationship of these biomarkers to the disease especially cholesterol levels in late stage disease.

Social and ecological effects on endoparasites in vervet (Cercopithecus aethiops) and patas (Erythrocebus patas) monkeys in Laikipia, Kenya.

Author: Ekdahl, Dawn Rise

Awarding University: Rutgers, the State University of New Jersey, USA

Level : PhD

Year: 2005

Holding Libraries: Dissertation Abstracts International ;

Subject Terms: Anthropology ; Cercopithecus aethiops ; Patas monkeys USE Erythrocebus patas ; Laikipia, Kenya ; Erythrocebus patas ; Vervet monkeys ; Monkeys and apes ; Parasites ;

Abstract:

During a 16-month field study of vervet ( Cercopithecus aethiops ) and patas ( Erythrocebus patas ) monkeys on Segera Ranch in Laikipia, Kenya, I examined the natural repertoire of intestinal parasites that infect these two sympatric species and the variables that potentially influence the parasites' maintenance and transmission. The prevalence of pathogenic gastro-intestinal parasites in these primates has not yet been established for this region of Kenya or the extent to which they could serve as a reservoir for potential zoonotic and anthropozoonotic disease transmission. The results of microscopic examinations of fecal samples demonstrated the presence of 12 endoparasite species, including two trematodes, 10 nematodes, and two protozoan species. Overall, 40% of the 527 fecal samples (211/527) exhibited at least one parasitic ovum or larvae. A strong difference between species infection rates was evident; 52% (180/346) of the vervet samples contained at least one parasite while only 17% (31/181) of those from the patas did. The vervets had a higher percentage of positive samples for helminths (28%) than did the patas monkeys (13%) and had a greater diversity of helminths present in the samples. Protozoan intensity and presence was also determined to be significantly higher in the vervet populations. The differences in parasite presence, intensity, and abundance were assessed by group size, season, age, sex and rank in both species through behavioral observations and systematic fecal collection and analyses. A strong effect of the season, when established by the amount of rainfall, is indicated in parasite presence and abundance. Significant differences in parasite presence were also established by age and vervet group size. No significant differences in the presence of helminth or protozoan parasites were established between male and female vervets or according to the dominance hierarchy. The analysis of pollens, spores and phytoplanktons from the fecal samples provided additional baseline information on environmental and seasonal changes. An evolutionary approach to studies on the ecology of disease systems and host-resistance mechanisms may provide more insight into the persistence and effects of long-term host-parasite associations.

Baboon Endogenous Virus (Baev) variation in natural populations of Cercopithecine primates (Papio hamadryas, Cercopithecus aethiops).

Author: Uddin, Monica

Awarding University: New York University, USA

Level : PhD

Year: 2003

Holding Libraries: University Microfilms International ;

Subject Terms: Monkeys and apes/Papio hamadryas/Baboon endogenous virus/Cercopithecus aethiops/Evolution/Primates/Ethiopia/Masai Mara, Kenya/ ;

Abstract:

The following study was undertaken to investigate the evolutionary significance of Transposable Element (TE) activity in mammalian hybrids. The specific aims of this work were twofold: (1)&nbsp;to assess the relationship between a particular te, Baboon Endogenous Virus (Baev), and reproductive isolation in a graded series of papionin hybrids and (2)&nbsp;to evaluate endogenous retroviral dynamics in natural primate populations. Baev nucleotide sequence data, quantitative real-time pcr data, and baev nucleotide sequence insertion site data were collected from wild-caught baboons (Papio hamadryas ssp) from Awash National Park (ANP), Ethiopia. Quantitative data were also collected from wild-caught baboons from Masai Mara, Kenya, as well as a number of captive baboons, f<sub>1</sub> hybrids, and geladas. Additional baev sequence data were collected from ANP wild-caught grivets (Cercopithecus aethiops). Results indicate a non-uniform pattern of Baev amplification across hybrids of varying phylogenetic distance: whereas backcrossed baboon and f<sub>1</sub> 'rheboon' (Macaca mulatta &times; P. H. Hamadryas) hybrids showed no evidence of copy number amplification, the f<sub>1</sub> 'geboons' (Theropithecus gelada &times;P. H. Hamadryas) hybrids did. This finding refutes the hypothesis that hybridization-related baev amplification is correlated with actual or potential reproductive isolation, as the rheboon represents the only confirmed case of hybrid sterility. Baev sequence data suggest a non-uniform rate of evolution across the proviral genome: those areas that encode proteins external to the mature virion show a greater degree of sequence divergence and/or nonsynonymous substitution than those that encode proteins with more conserved functions. Insertion site data confirm a pattern of vertical inheritance in the four baboon forms tested, suggesting long-term residence in the Papio genome. Baev shows considerable copy number heterogeneity among individuals yet conforms to a pattern of maternal inheritance previously observed for endogenous retroviruses in other organisms. Most importantly, average proviral copy numbers in non-hamadryas, hamadryas and gelada baboons, respectively, appear to be a function of the progressively greater degrees of inbreeding observed in each of these primate taxa. This finding represents the first example in primates relating transposon dynamics to social structure and suggests that element number may be regulated though a mechanism of ectopic exchange rather than deleterious selection.

The vervet monkey model for leishmaniasis: characterization, protective immunity and vaccination against Leishmania major infection

Author: Gicheru, Michael Muita

Awarding University: Kenyatta University, Kenya

Level : PhD

Year: 2002

Holding Libraries: Kenyatta University Moi Library ;

Subject Terms: Leishmaniasis ; Leishmania major ; Monkeys and apes ; Disease ; Cercopithecus aethiops ;

Abstract:

Leishmaniasis encompasses a group of infectious diseases caused by trypanosomatic protozoa of the genus Leishmania and transmitted by Phlebotomine sandfly vectors. These diseases have a world wide distribution with a clinical spectrum ranging from cutaneous and mucocutaneous lesion, to fatal visceral disease. The fact that cured patients are refractory to re-infection suggests that vaccination against leishmaniasis might be feasible using conventional immunization methods. A corner stone in the process of vaccine development is the utilization of suitable animal models. The development of non human primate model for leishmaniasis, which largely mimic the human situation, is therefore desirable for safety and efficacy trials of promising vaccines preceding clinical trials in humans. The current study was aimed at characterizing protective immunological responses required for Leishmania vaccine evaluation in vervet monkey (Cercopithecus aethiops) disease model. Specifically, the study addressed the following aspects of leishmaniasis; prevalence of leishmaniasis in a sample of wild caught monkeys, the natural history of L. major in vervet monkeys, the bioactivity of recombinant human (rh) IL-12 in vervet monkeys, the cross-reactivity of the Iranian isolate of L. major (vaccine antigen: ALM) and Kenyan isolate of L. Major (challenge parasite: NLB-144) and the safety and adjuvant potential of recombinant human (rh) IL-12 for a Leishmania vaccine in vervet monkeys. Monkeys were sampled by trapping from different parts of Kenya and screened for anti-Leishmania specific immunoglobulin G (IgG) by ELISA and for Leishmania specific memory T-cells by blast assay. For the natural history of L. major in vervet monkeys, a group of twelve monkeys of which six were Leishmania exposed and six were Leishmania naive were challenged with L. major promastigotes. Disease development was correlated with immunological profiles. The biological activity of rh IL-12 in monkey peripheral blood leucocytes (PBL) and the cross-reactivity between ALM and NLB-144 was established in recall proliferative and IFN-g responses. For the vaccine trial, five groups of eight monkeys each were vaccinated three times, three weeks apart with either ALM + IL-12, ALM alone or rh IL-12 alone. The other two groups, L. major cured and Leishmania naive monkeys comprised positive and negative controls respectively. Immunological responses were determined three weeks after the last vaccination. The monkeys were then challenged and immunication-induced protection assessed. A prevalence of 3.5% of Leishmania exposure was established in the wild monkeys (2 out of 59 monkeys). There was a positive correlation between cutaneous disease establishment and immunological profiles. Recombinant human IL-12 was found to be biologically active in monkey cells and high cross-reactivity was found between challenge parasite and vaccine antigen. No untoward side effects of rh IL-12 was noted and vaccination was successful since a strong Th 1 response was observed following immunization. Of all the parameters considered IFN-g was the most indicative of immunization. Previous vaccine development studies have focused on inducing CD4+ Th 1 responses, however results presented here suggest that other factors could be important for protective immunity. It is also possible that disease-induced immunological responses are different from immunization-induced responses in ways we do not yet understand.

Behavioral ecology of perceived risk of predation in sympatric patas (Erythrocebus patas) and Vervet (Cercopithecus aethiops) monkeys in Laikipia, Kenya.

Author: Enstam, Karin Lee

Awarding University: University of California, Davis, USA

Level : PhD

Year: 2002

Holding Libraries: University Microfilms International ;

Subject Terms: Ecology ; Animal behavior ; Monkeys and apes ; Erythrocebus patas ; Cercopithecus aethiops ; Laikipia District ;

Abstract:

In this dissertation, I explored how habitat structure affected perceived risk of predation and anti-predator behavior in closely related, Sympatric Patas (Erythrocebus patas) and Vervet (Cercopithecus aethiops) monkeys in Laikipia, Kenya. While Patas were restricted to non- riverine habitat at my study site, Vervets used both non- riverine and riverine habitats. The use of two structurally different habitats by the Vervets allowed me to examine the effect of differences in tree height and canopy cover across and within species while controlling for effects of group size, group composition, and phylogeny. During alarm calls at mammalian predators, vervets adjusted their anti-predator behavior and acted more like Patas when they were in areas with shorter trees. Tree height also affected perceived risk of predation in patas monkeys. Within the Patas home range two distinct microhabitats with the same tree species differed in tree height. Patas preferred the tall microhabitat when grass height was similar. Within the preferred microhabitat, patas scanned more and fed less in tall trees. My results indicate that the increased visibility provided by tall trees may have increased the patas' ability to detect predators. Visibility afforded by changes in ground cover can also affect animals' perceived risk of predation. I examined the effects of ground cover on the Vervets' behavior after a wildfire swept through an area near my study group's home range. Reduced grass height after the fire enabled the vervets to see significantly farther. Vervets abruptly changed their ranging behavior and moved into the area that had been burned. They had not been observed in that area previously. The Vervets scanned bipedally less often in the burned area, apparently because they perceived a reduced risk of predation due to increased visibility and reduced predator presence. My findings indicate that Patas and Vervet monkeys are sensitive to the structure of their immediate environments and change their behaviors to accommodate differences in habitat structure and predation risk. Habitat structure, therefore, is an important variable to consider when studying the variation in primate behavior.

Pathogenesis and immune responses in newborn African green monkeys Cercopithecus aethiops inoculated with simian immunodeficiency virus

Author: Muia-Kiio, Maria Ndunge

Awarding University: Kenyatta University, Kenya

Level : MSc

Year: 2001

Holding Libraries: Kenyatta University Moi Library ;

Subject Terms: Cercopithecus aethiops ; Immunology ; African green monkeys ; Monkeys and Apes ; AIDS (Disease) ; HIV infection ;

Abstract:

It has been demonstrated that serial in vivo passage of simian immunodeficiency virus (SIV) can result in selection of pathogenic virus that can cause Simian immunodeficiency syndrome (SAIDS). Because African green monkeys (AGMs) persistently infected with SIVagm do not manifest any signs of disease, serial in vivo passage of Simian immunodeficiency virus of African green monkeys (SIVagm) was attempted in this study. Naive newborn AGMs were infected with SIVagm that was serially passaged in order to try and produce a virus with enhanced pathogenicity. The primary objective of this study was to determine the basis for lack of disease in AGMs by passaging SIVagm in newborn AGMs. The study utilized naive newborn AGMs, from SIV seronegativ dams. Inoculating a naive newborn AGM with cell-free SIVagm 1532 isolated from the plasma of a naturally infected AGM started serial passage experiments. Two weeks later, 2ml of bone marrow from the first animal were transfused into a second naive newborn AGM. Two weeks later, bone marrow was transfused into a third naive newborn AGM from the second passage AGM. In the fourth passage, bone marrow from the third passage AGM was transfused into a fourth naive newborn AGM. Virus isolation and quantitation was determined by limiting dilution co-culture method. Virus presence was detected by SIV p27 antigen capture ELISA and nested polymerase chain reaction (PCR). Seroconversion was determined by antibody ELISA and confirmed by Western blot. Virus isolation and seroconversion in SIVagm inoculated AGMs confirmed successful SIVagm passage in newborn AGMs. After one year, all the animals remained clinically normal. Bone marrow transfusions from SIVagm infected newborn AGMs into naive newborn AGMs induced persistent infection and an anti-SIV antibody response. However, this did not produce disease and the lack of disease in the AGMs suggests that: (a) AGMs may have an inherent resistance to SIVagm infection, (b) AGMs immune response controls SIVagm (c) or SIVagm does not kill or render immune cells of AGMs nonfunctional. This study may be useful in understanding the lack of disease in HIV infected asymptomatic individuals (long-term nonprogressors).

Mechanisms by which dietary Acacia may act as proximate regulator of breeding seasonality in the vervet monkey (Cercopithecus [aethips] pygerythrus) [Kenya].

Author: Garey, Joan Deborah

Awarding University: New York University, USA

Level : PhD

Year: 1999

Holding Libraries: Dissertation Abstracts International ;

Subject Terms: Anthropology ; Cercopithecus aethiops ; Acacia ; Feeds ; Animal reproduction ; Vervet monkeys ; Monkeys and apes ;

Abstract:

Mechanisms were investigated by which dietary acacia may act as a proximate regulator of the breeding season in an equatorial population of the vervet monkey, Cercopithecus ( aethiops ) pygerythrus . Equatorial vervets contend with seasonal changes in climate and food availability not unlike many temperate zone mammals. It is advantageous for them to give birth at an energetically optimal time of year. Products of Acacia species (i.e., leaves, seeds, flowers, and gum) comprise 50% or more of the diet of certain equatorial, savannah populations of vervets. The hypothesis of this study is that dietary Acacias have intrinsic chemical properties which have the potential to directly regulate reproduction in savannah vervets. The chemicals would likely act in combination with other environmental and social factors to control breeding. Data from a Kenyan, equatorial captive vervet breeding colony was analyzed for evidence of birth seasonality. The colony exhibited birth seasonality at its inception; it was greatly diminished after seven years. A quality diet, coupled with the absence of other factors from the wild, most likely accounts for this observation. Whitten (1982) suggested a causal association between the ingestion of Acacia elatior flowers and the onset of mating activity among female vervets in the Samburu-Isiolo Game Reserves. A. elatior flowers were collected in Samburu and analyzed them for estrogenic activity, which could stimulate mating behavior in vervets. Data collected by two assay methods suggest that A. elatior flowers have significant estrogenicity. The fatty acid content of the diet may also directly effect ovulation. The fatty acids of Acacia elatior and A. tortilis plant parts from Samburu were thus analyzed. A diet high in linoleic acid may help stimulate ovulation, while a diet high in linolenic acid may inhibit ovulation. only the seeds of both species contain a high linoleic acid content; Whitten's (1982) data suggest that vervets are conceiving at a time when they have an increased ingestion of acacia seeds. Since the vervet diet is weighted more heavily toward linoleic acid at the time of conception, vervets may be using higher linoleic acid levels in their diet to most effectively achieve ovulation.

Socioecology of adult female Vervet Cercopithecus aethiops and Patas monkeys Erythrocebus patas in Kenya : food availability, feeding competition, and dominance relationships.

Author: Pruetz, Jill Daphne

Awarding University: University of Illinois, Urbana-Champaign, USA

Level : PhD

Year: 1999

Holding Libraries: University Microfilms International ;

Subject Terms: Ecology/Animal behavior/Monkeys and apes/Cercopithecus aethiops/Erythrocebus patas/Segera Ranch/Laikipia, Kenya/ ;

Abstract:

I investigate the effects of food availability on adult female contest competition and dominance relationships in Vervet and Patas monkeys at Segera Ranch, Laikipia, Kenya. I test hypotheses derived from models that use patterns of food availability to predict the nature of female primate social relationships within groups (Isbell 1991; Van Schaik 1989; Sterck et al. 1997; Wrangharn 1980). Food availability was measured throughout the study, specifically concentrating on the monkeys' main food source, Acacia drepanolobium. I take into account the feeding behavior of the primates, and the abundance, distribution, nutritional content, and processing costs of foods. The dominance hierarchy of female Vervet and patas monkeys was similar when both used an A. Drepanolobium woodland habitat. Foods here were randomly and closely distributed in space and less abundant per feeding site compared to foods in the A. Xanthophloea riverine habitat, a second habitat used by Vervet monkeys. The hierarchy exhibited by female Vervet monkeys in the woodland habitat was not significantly linear, and the hierarchy of female patas monkeys was significantly linear only when females who had recently entered the hierarchy or had been observed for only a few months were deleted from analyses. In the A. Xanthophloea riverine habitat, the dominance hierarchy of female Vervet monkeys was statistically linear. Food-related competition also produced a significantly linear hierarchy among female Vervet monkeys, but only when all food-related agonism was considered, including interactions that occurred in the A. Drepanolobium habitat. In the riverine habitat, almost half of all female agonism among Vervet monkeys was not food-related. The link between ecology and behavior at the level proposed by models of female primate social behavior (i.e., relationships) is more complex than these models ascertain. The models adequately predicted when adult female dominance relationships in patas and Vervet monkeys would be nepotistic or egalitarian in a superficial sense only. Gross categorization of patterns of food availability are not adequate to explain female primate social behavior.

Evaluation of immune associated cellular phenotypes in lesions of vervet monkeys (Cercopitheins aethiops) experimentally infected with Leishmania major.

Author: Ozwara, Hastings Suba

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 1996

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Cercopithecus aethiops ; Leishmania major ; Immune system ;

Abstract:

Studies were conducted to evaluate immune associated cellular phenotypes in the lesion areas ofvervet monkeys (Cercopithecus aethiops) experimentally infected with Leishmania major. Different immune associated cell types recruited into the lesion sites as a result of primary, secondary infections were characterized using established cross reactive antihuman monoclonal antibodies in combination with the immunoperoxidase methods. Nine adult vervet monkeys were used in this study. The primary infection group consisted of 4 adult naive animals of either sex. The secondary infection group also consisted of 4 adult animals of either sex which had self cured from experimental L. major infection. One extra naive control animal was also included. Animals in both groups were inoculated with 5 x 107 stationary phase promastigotes of L. major and observed after every 2 weeks for lesion development. Samples from the skin and draining lymph node were obtained at six weeks post infection and used for staining. Studies from non infected areas taken as control skin sections in all the animals revealed the presence of resident CD8 positive T cells both in the epidermis and dermal layers of the skin. These (CD8 positive T cells) were smooth in morphology with majority being in the dermal layer. B cells, CD 16 and CD4 positive cells were virtually absent in the normal skin while there was a negligible population of macrophages. These cells, including the keratinocytes only expressed MIlC class 1 antigens. A heavy cellular infiltration consisting primarily of mononuclear cells was observed at the lesion sites in both primary and secondary infection groups. Majority of these cells expressed both MHC class 1 and 2 and the CD8+ phenotypes. The main cell type in the infiltration was CD8 positive T cell. CD16 positive cells were also recruited into the lesions and these had a tendency of clustering around the hair follicles. Macrophages recruited into the lesions were not heavily laden with parasites. Some B cells were stained in the infiltration but these were fewer than T cells. Lymph nodes draining the control skin sites recorded a lower population of cells than those draining lesions. Majority of these cells were both MHC class 1 and 2 positive. There continued to be a higher population of CDS positive T cells than both B cells and CD4 positive T cells. The difference in CD 16 positive cells between nodes draining control sites and lesions was not clear. In general, cellular changes occurring in the skin were reflected in the draining lymph nodes in both infection groups. Nodes draining lesion sites were enlarged, a feature not observed in those draining control sites. There were positive delayed type hypersensitivity (DTH) reactions in animals with active infection and those that had self cured. This indicated that the experimental animals developed cell mediated immunity. The results show that the CDS+ T cell phenotype is the main cell type restricting parasites to the lesion site in both primary and secondary L. major infection in vervet monkeys. The results also show that cellular phenotypes expressing CD3, CDS, CD16 and MHC classes 1 and 2 antigens restricted parasites to the lesion site in both primary and secondary L. major infections in vervet monkeys.

Characterisation of immune responses in vervet monkeys (Cercopithecus aethiops) following vaccination with Leishmania donovani antigen.

Author: Odhiambo, Christine

Awarding University: University of Nairobi, Kenya

Level : MSc

Year: 1995

Holding Libraries: University of Nairobi Jomo Kenyatta Memorial Library ;

Subject Terms: Monkeys and apes ; Cercopithecus aethiops ; Immune system ; Leishmania donovani ; Vaccines ;

Abstract:

Visceral leishmaniasis is a severe systemic human disease which is always fatal if left untreated. The treatment is however expensive, painful and has unpleasant side effects as repeated courses or a change of drugs is often required. Treatment failure is also becoming a common problem in endemic areas such as Kenya. With curative treatment proving unsatisfactory, effective alternative means of control of infection such as vaccination is necessary. The vervet monkey has been shown to be susceptible to Leishmania donovani infection and thus provides a good non-human primate model for use in vaccine development studies. The following study was undertaken to determine the nature of humoral and cellular immune response following vaccination with merthiolate killed Leishmania donovani promastigotes using neuraminidase and galactose oxidase (NAGO) as adjuvant. Twelve vervet monkeys were used in this study. The animals were divided into 4 groups of 3 animals each. Each animal received 3 intradermal injections at 2 weeks intervals with one of the following; adjuvant plus promastigotes, promastigotes alone, adjuvant alone or PBS. Results from ELISA for the presence of anti-promastigote antibody revealed that there was production of IgG in the animals vaccinated with adjuvant plus promastigotes and those vaccinated with promastigotes alone though the IgG levels were low. The absorbance at 1: 125 serum dilution was 0.324 for the adjuvant plus pro mastigote group, 0.410 for the promastigote group, 0.136 for the adjuvant group, 0.145 for the saline group and 0.954 for an infected animal used as a positive control. Western blot analysis showed that the sera from the animals vaccinated with adjuvant plus promastigotes and those vaccinated with promastigotes alone, recognized numerous Leishmania donovani promastigote antigens of molecular weight 18.5-106 KDa. There was also antibody cross-reactivity with Leishmania major promastigote antigens. High variability was observed in the pattern of antigen recognition within and among these two groups. Peripheral blood lymphocytes (PBL) from all the animal groups showed a good proliferative response upon stimulation with Con A with a stimulation index (S.I) ranging from 72-137. In addition PBL from the animals vaccinated with adjuvant plus promastigotes and those vaccinated with promastigotes alone also showed a good proliferative response upon stimulation with Leishmania donovani (S.I 10.62 and 5.62) respectively and Leishmania major promastigote antigens (S.I 4.87 and 3.87) respectively. The response to the homologous species (Leishmania donovani) was notably higher. There was production of detectable levels ofIFN-y (29-31 IU/ml) after in vitro stimulation ofPBL with Con A in all the animal groups. There was lower/no IFN-y production after in vitro stimulation ofPBL with leishmanial antigen. Low levels ofIL-4 and IL-2 were detected after in vitro stimulation ofPBL with either Con A or leishmanial antigen in all the animal groups. There was an increase in levels of circulating CD16+, CD8+ and CD45RO+ cells in animals vaccinated with adjuvant plus antigen or with antigen alone. There was a higher increase when the adjuvant was included vaccination. There wasno significant increase in all these cells in the groups of animals vaccinated with adjuvant or saline alone. The animals vaccinated with adjuvant plus promastigotes and those vaccinated with promastigotes alone gave a positive but weak DTH response. The skin induration was 8.62mm ? 1.02 and 7.88mm ? 1.00 respectively. The skin induration for the animals vaccinated with adjuvant alone was 5.5mm ? 0.15. The animals vaccinated with saline alone gave a DTH response of less than 5mm. From the above results it was apparent that the adjuvant improved the immunogenicity of the killed Leishmania donovani promastigote vaccine. However the full extent of the protection could have been realised by challenging the animals with virulent Leishmania donovani pro