Genetic vaccine can protect against Chagas disease.(Brief Article)

2002 OCT 9 - (NewsRx.com & NewsRx.net) -- by Michael Greer, senior medical writer - A genetic vaccine against the parasite responsible for Chagas disease can protect animals from infection, researchers in the United States report.

"Immunity to Trypanosoma cruzi requires elicitation of humoral and cell-mediated immune responses to extracellular trypomastigotes and intracellular amastigotes," explained Nisha Garg and colleagues working at the University of Georgia in Athens.

Mice immunized with a key T. cruzi gene showed robust T-cell and antibody responses to infection, suggesting that a DNA-based approach can produce an effective vaccine for humans, Garg and coauthors reported.

The researchers inoculated mice with DNA plasmids containing the trans-sialidase family genes, which code for key T.cruzi surface glycoproteins. Unfortunately, immunization with these plasmid vectors provided only limited protection to study animals, they said.

Vaccine performance was significantly improved with the addition of cytokine adjuvants - interleukin-12 and granulocyte-macrophage colony-stimulating factor (GM-CSF) plasmids, delivered with the antigen-encoding vectors.

Cytokine-enhanced DNA immunization produced comprehensive cytotoxic T lymphocyte (CTL) and antibody responses to T. cruzi infection, according to the report, with up to 80% of treated animals surviving otherwise lethal challenge with the parasite.

While ...