Couper, K N and Roberts, C W and Brombacher, F and Alexander, J and Johnson, L L (2005) Toxoplasma gondii-specific immunoglobulin M limits parasite dissemination by preventing host cell invasion. Infection and Immunity, 73 (12). pp. 8060-8068. ISSN 0019-9567Full text not available in this repository. (Request a copy from the Strathclyde author)
An important role for immunoglobulin M (IgM) during early acute virulent Toxoplasma gondii infection was identified using IgM(-/-) mice that lack surface and secretory IgM but maintain normal B-cell functionality and isotype class switching. Following intraperitoneal inoculation with the virulent RH strain, IgM(-/-) mice displayed significantly fewer peritoneal parasites than wild-type (WT) mice, which correlated with increased tachyzoite dissemination to the liver, lung, and spleen in IgM(-/-) mice compared with WT mice. Early splenic T-cell activation, as measured by CD69 expression, was augmented in IgM(-/-) mice, and serum and peritoneal cavity gamma interferon levels were also elevated in IgM-/- mice compared with WT controls. Consequently, the difference in parasite dissemination was not attributable to an impaired proinflammatory immune response in the IgM-/- mice. Specific IgM was. found to bind to tachyzoites in vivo in WT mice, and this correlated with an increased ability of antiserum collected from WT mice at day 6 postinfection to block tachyzoite cell invasion, compared with comparable serum collected from IgM-/- mice at the same time point. Tachyzoite invasion of host cells was similar if parasites were incubated with WT or IgM(-/-) nonimmune serum, suggesting that natural IgM does not function to limit parasite dissemination during early T. gondii infection. Our results highlight an important role for parasite-specific IgM in limiting systemic dissemination of tachyzoites during early acute T. gondii infection.
|Keywords:||classical complement pathway, major surface protein, CD8+ T-cells, immune-response, natural antibodies, deficient mice, B-cells, infection, resistance, IGM, Pharmacy and materia medica, Infectious Diseases, Immunology, Microbiology, Parasitology|
|Subjects:||Medicine > Pharmacy and materia medica|
|Department:||Faculty of Science > Strathclyde Institute of Pharmacy and Biomedical Sciences|
|Depositing user:||Pure Administrator|
|Date Deposited:||13 Jun 2011 15:28|
|Last modified:||20 May 2016 03:23|