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Updated: Oct 2, 2026

Identification of Mediators of T-cell Receptor Signaling via the Screening of Chemical Inhibitor Libraries
Published on: January 22, 2019
Neisserial binding to CEACAM1 arrests the activation and proliferation of CD4+ T lymphocytes
Ian C Boulton1, Scott D Gray-Owen
1Department of Medical Genetics and Microbiology, University of Toronto, Medical Sciences Building Rm. 4381, 1 Kings College Circle, Toronto, Ontario M5S1A8, Canada.
Abstract:
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.
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