Summary:
Visceral leishmaniasis is the most serious form of leishmaniasis, caused by the strains L. donovani and L. infantum. If not treated, it leads to death. Treatment is based on the use of chemotherapeutic formulations, which are characterized by side effects and high costs. For this reason, the development of an effective vaccine is imperative, both for the control of the disease and for the protection of public health. Animal models are useful tools for controlling and selecting pharmaceutical agents or candidate vaccines prior to clinical application, but also for understanding the immunological mechanisms that follow the infection.
This study took place at the Laboratory of Parasitic Immunology of the Hellenic Pasteur Institute. The model of visceral leishmaniasis was developed in three breeds of mice (BALB/c, C57BL/6 transgenic B6.Cg-Tg (HLA-A/H2-D)2Enge/J). Additionally, the prophylactic effect of experimental vaccine (chimeric polyepitope peptides) which was developed in the laboratory, was also evaluated. Finally, the induction of humoral immunity against the soluble antigen and the antigenic components of the vaccine, as well as the cellular immunity after stimulation of spleen cells with each of the chimeric polyepitope peptides in the vaccinated and infected B6.Cg-Tg (HLA-A/H2-D) 2Enge/J mice, were estimated.
From the development of the disease model, a clear conservation of the parasite in the spleen of BALB/c mice was demonstrated, although the liver appeared to be cleansing. In mice of the C57BL/6 strain, the liver as well as the spleen, showed a successful response to the parasite, leading to infection control. Corresponding picture was also seen in the mice of the transgenic sequence of B6.Cg-Tg (HLA/H2-D) 2Enge/J.
For the assessment of the prophylactic effect of the experimental vaccine, the results showed a significant reduction in the parasitic load in the liver and spleen of the immunized mice compared to the mice that had not been immunized. It has also been found that some of the components of the experimental vaccine are capable of inducing, both humoral and cellular immunity.
Keywords:
VISCERAL LEISHMANIASIS, HUMANIZED, TRANSGENIC MOUSE, VACCINATION,
