Nature Immunology3, 229 - 236 (2002)
Published online: 19 February 2002; | doi:10.1038/ni769
Neisserial binding to CEACAM1 arrests the activation and proliferation of CD4+ T lymphocytes
Ian C. Boulton
& Scott D. Gray-Owen
Department of Medical Genetics and Microbiology, University of Toronto, Medical Sciences Building Rm. 4381, 1 Kings College Circle, Toronto, Ontario M5S1A8, Canada.
Infection with Neisseria gonorrhoeae can trigger an intense inflammatory response, yet there is little specific immune response or development of immune memory. In addition, gonorrhea typically correlates with a transient reduction in T lymphocyte counts in blood, and these populations recover when gonococcal infection is resolved. Such observations suggest that the gonococci have a suppressive effect on the host immune response. We report here that N. gonorrhoeae Opa proteins were able to bind CEACAM1 expressed by primary CD4+ T lymphocytes and suppress their activation and proliferation. CEACAM1 bound by gonococcal Opa52 associated with the tyrosine phosphatases SHP-1 and SHP-2, which implicates the receptor's ITIM (immunoreceptor tyrosine-based inhibitory motif) in this effect.
