Scientists have discovered how the immune system fights Toxoplasma gondii, a parasite that causes the disease toxoplasmosis in humans, according to a paper online in Nature Immunology.
Immune cells called CD8+ T lymphocytes are required to fight T. gondii, which can cause severe disease in humans with weak immune systems. These cells recognize parasite-derived protein fragments displayed on the surface of infected cells. Nilabh Shastri and colleagues show that a fragment of the T. gondii protein called GRA6 is a target of CD8+ T lymphocytes and induces a protective immune response in mice. They also showed that the host cell protein ERAAP, which acts as a scissor to 'clip' proteins into fragments, is required for the production of this protective GRA6 fragment. This is the first time ERAAP has been shown to have a specific and protective role in the immune response to pathogens. Author contact: Nilabh Shastri (University of California, Berkeley, CA, USA)
E-mail: nshastri@berkeley.edu Abstract available online. (C) Nature Immunology press release.
Message posted by: Trevor M. D'Souza
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