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Updated: Apr 23, 2026
In vivo Imaging of Transgenic Leishmania Parasites in a Live Host
Published on: July 27, 2010
Leishmania donovani phosphoproteins pp41 and pp29 re-establishes host protective immune response in visceral
Pranati Das1, Ajay Amit1, Shubhankar Kumar Singh1
1Division of Immunology, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, Bihar, 800007India.
Abstract:
As phospho proteins are reported to be involved in virulence and survival, the ability of Leishmania to inhibit macrophage effector functions may result from a direct interference of leishmanial molecules with macrophage signal transduction pathways. Several such proteins such as pp63, pp41 and pp29 have also been identified as a Th1 stimulatory protein in the Leishmania donovani. In the present study, the immunogenicity of a cocktail of pp63+pp41+pp29 was assessed by estimation of serum antibody titre, nitric oxide(NO) production, estimation of Th1 cytokine(IFN-γ) as well as Th2 cytokines(IL-4), and determination of parasite load in L. donovani infected mice. In the group immunized with antigenic cocktail there was a sharp rise in antibody titer up to Day 20 which reduced considerably by Day 50. Groups of mice vaccinated with pp63, pp41, pp29 and the antigenic cocktail expressed 10-fold, 16-fold, 22-fold and 25-fold increase respectively in NO production by splenocytes. The animal groups immunized with pp63, pp41, pp29 and the antigenic cocktail showed reduced parasite load in the liver and spleen, as well as increased IFN-gamma production in the spleen. Furthermore immunized animals remained with a normal hematological profile, whereas L. donovani in unimmunized mice lead to significant anemia.
Insights
Leishmania proteins pp63, pp41, and pp29 show promise in combating leishmaniasis. Vaccination with these proteins reduced parasite load and anemia in mice, indicating potential therapeutic applications.
Area of Science:
- Immunology
- Parasitology
- Molecular Biology
Background:
- Leishmania virulence and survival are linked to phosphoproteins.
- Leishmania inhibits macrophage functions via interference with signaling pathways.
- Specific Leishmania proteins (pp63, pp41, pp29) are Th1 stimulatory.
Purpose of the Study:
- To assess the immunogenicity of a cocktail of Leishmania proteins pp63, pp41, and pp29.
- To evaluate the protective effects of these proteins against Leishmania donovani infection in mice.
Main Methods:
- Immunization of mice with individual proteins and a cocktail.
- Measurement of serum antibody titers.
- Assessment of nitric oxide (NO) production by splenocytes.
- Quantification of Th1 (IFN-γ) and Th2 (IL-4) cytokines.
- Determination of parasite load in liver and spleen.
- Monitoring of hematological profiles.
Main Results:
- A significant rise in antibody titer was observed post-immunization.
- Vaccination led to a substantial increase in NO production.
- Immunized groups showed reduced parasite burden in liver and spleen.
- Increased production of IFN-γ was noted in spleen cells.
- Hematological profiles remained normal in immunized mice, unlike anemic controls.
Conclusions:
- The Leishmania proteins pp63, pp41, and pp29, individually and as a cocktail, elicit a protective immune response.
- This immune response is characterized by increased NO production, Th1 cytokine release, and reduced parasite load.
- The tested proteins demonstrate potential as vaccine candidates against Leishmania donovani infection.
