T cell hyporesponsiveness to Mycobacterium tuberculosis induced by CD31: a role for SAP?

M. FLORENCIA QUIROGA; JAVIER O. JURADO; VIRGINIA PASQUINELLI; GUSTAVO J. MARTÍNEZ; ROSA M. MUSELLA; LILIANA CASTRO ZORRILLA; MARÍA M. BRACCO; ALEJANDRO MALBRÁN; EDUARDO ABBATE; H. EDUARDO CHULUYAN; VERÓNICA E. GARCIA.

Cordoba, Argentina.

Congreso; VII Latinamerican Congress of Immunology; 2005

Latin American Association of Immunology (ALAI)

CD31, a glycoprotein expressed by certain T cells, contains an immunoreceptor tyrosine-based inhibitory motif (ITIM) similar to the tyrosine-based switch motif (ITSM) present in SLAM (signaling lymphocytic activation molecule). Since the SLAM-associated protein (SAP) binds to SLAM through its ITSM, it was suggested that SAP might interact with CD31, modulating its signaling. We investigated CD31-SAP interaction, and the effect of CD31 ligation on M. tuberculosis (Mtb)-stimulated T-cells in tuberculosis (TB) patients and healthy donors (HD). Engagement of CD31 by PECAM 1.2 monoclonal antibody inhibited in vitro IFN-g production (as measured by ELISA) from Mtb-stimulated peripheral blood mononuclear cells from TB patients and HD (p