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Updated: Aug 14, 2026
In vivo Imaging of Transgenic Leishmania Parasites in a Live Host
Published on: July 27, 2010
Immunization with persistent attenuated Delta lpg2 Leishmania major parasites requires adjuvant to provide protective
Chahnaz Kébaïer1, Jude E Uzonna, Stephen M Beverley
1Department of Pathobiology, University of Pennsylvania, 3800 Spruce Street, Philadelphia, PA 19104, USA.
Abstract:
Leishmania major parasites lacking the GDP-mannose transporter, termed Deltalpg2 parasites, fail to induce disease in mice but persist long-term. We previously found that Deltalpg2 organisms protect BALB/c mice from virulent L. major challenge. In contrast, we report here that Deltalpg2 parasites induce protective immunity in C57BL/6 mice only when administered with CpG-containing oligodeoxynucleotides, indicating that parasite persistence alone is not sufficient to maintain protective immunity to L. major.
Insights
Leishmania major lacking GDP-mannose transporter (Deltalpg2) parasites persist but do not cause disease. Protective immunity in C57BL/6 mice requires Deltalpg2 administration with CpG oligodeoxynucleotides, not just parasite persistence.
Area of Science:
- Immunology
- Parasitology
- Molecular Biology
Background:
- Leishmania major is a protozoan parasite that causes cutaneous leishmaniasis.
- GDP-mannose transporter (Gmt) is essential for parasite survival and virulence.
- Deltalpg2 parasites, lacking Gmt, are attenuated but persist long-term in mice.
Purpose of the Study:
- To investigate the immunoprotective potential of Deltalpg2 parasites in C57BL/6 mice.
- To determine if Deltalpg2 parasite persistence alone is sufficient for protective immunity.
- To evaluate the role of CpG oligodeoxynucleotides in enhancing Deltalpg2-induced immunity.
Main Methods:
- BALB/c and C57BL/6 mice were infected with virulent Leishmania major or Deltalpg2 parasites.
- Deltalpg2 parasites were administered alone or with CpG-containing oligodeoxynucleotides.
- Immune responses and protection against virulent L. major challenge were assessed.
Main Results:
- Deltalpg2 parasites failed to induce disease but persisted in C57BL/6 mice.
- Deltalpg2 parasites alone did not confer protection against virulent L. major challenge in C57BL/6 mice.
- Co-administration of Deltalpg2 parasites with CpG oligodeoxynucleotides induced protective immunity in C57BL/6 mice.
Conclusions:
- Parasite persistence of Deltalpg2 strains alone is insufficient to induce protective immunity against Leishmania major.
- CpG oligodeoxynucleotides are crucial for eliciting protective immunity when combined with attenuated Leishmania parasites.
- These findings highlight the importance of specific immune stimuli for vaccine development against leishmaniasis.
