A Laboratory Strain of Leishmania major: Protective Effects on Experimental Leishmaniasis.

PURPOSE: Leishmaniasis, as one of the most important vector-borne and zoonotic diseases, can be seen in different forms and is more prevalent in developing countries worldwide. Due to the absence of effective strategies in its prevention, treatment, and control, investigation of effective control strategies against the disease is necessary. In this research, we evaluated the immunogenicity of a cold-adapted laboratory strain of Leishmania major (LMC) in the mouse model. METHODS: Twenty BALB/c mice were divided into two groups. LMC group received 4 × 106 of LMC strain in 0.5 ml DMEM, and VLM group, as the control group, received 0.5 ml Dulbecco's modified Eagle's medium. Both groups were challenged with virulent L. major 3 weeks after inoculation. RESULTS: The data obtained from the analysis of immune responses and histopathological changes interestingly revealed protection against L. major in immunized mice. Compared with the VLM group, the mice immunized with LMC strain of L. major in the LMC group showed a significant increase in IFN-γ and IgG2a levels (P < 0.05) which are important indexes for Th1-related immune responses. Additionally, significant differences in concentration of IgG1 and IgG total before and after the challenge was observed in LMC group (P < 0.05). Furthermore, the immunized mice showed a significant reduction in mean sizes of skin lesion and liver damage compared to the VLM group. CONCLUSION: Based on the present findings on immunogenicity of LMC strain, it seems this strain is able to induce both humoral and cellular immunity and a significant protection against L. major in the mouse model.

Study on Theileria lestoquardi antigens as potential vaccine candidates.

Theileria lestoquardi is the causative agent of malignant theileriosis of sheep and goats, causing morbidity and mortality in these animals worldwide. Western blot analysis based on T. lestoquardi schizont antigens was carried out using sera collected from Iranian sheep, which had been immunized with T. lestoquardi schizont-infected cells. The results of Western blot analysis demonstrated that schizont-immunized animals produced antibodies reacting with protein bands at 73, 42, 20, 14, and 12 kDa. Comparison of the results of the current Western blotting test with earlier studies of Theileria spp. revealed two immunogenic schizont proteins with molecular weights of 73 and 42 kDa shared between T. annulata and T. lestoquardi. Two other proteins with molecular weights of 14 and 12 kDa have not been previously found in other Theileria species. Our results suggest that the 73-kDa protein could be a potential vaccine candidate and that the 14- and 12-kDa proteins could be considered as diagnostic antigens.