IN-VIVO PREFERENTIAL USAGE OF TCR V-BETA-8 IN TORPEDO ACETYLCHOLINE-RECEPTOR IMMUNE-RESPONSE IN THE MURINE EXPERIMENTAL-MODEL OF MYASTHENIA-GRAVIS

The aim of our study was to determine the T cell receptor (TCR) V beta gene usage involved in the T cell response to Torpedo AChR in C57BL/6 mice. The specific proliferation towards AChR was found to be blocked by anti-V beta 8.1,2,3 and to a lesser extent by anti-V beta 5 mAbs, but not by the other antibodies used (anti-V beta 2, V beta 6, V beta 9). In addition, a significant expansion of CD4(+)V beta 8(+) cells wa s observed when lymph node cells from these primed mice were stimulate d in vitro with purified AChR. Involvement of V beta 8 subfamilies was also explored in vivo. After 7 days of treatment, there was a strikin g inhibition of the proliferative response of cells from anti-V beta 8 .1,2,3-treated mice and a moderate inhibition when using anti-V beta 8 .1,2 and anti-V beta 8.2 antibodies. Thus our in vitro and in vivo ana lysis indicate that in C57Bl/6 mice, T cell response to AChR is restri cted to few Vp TCR, mostly belonging to the V beta 8 sub-families.