Adhesive interactions of T cells with lymph node vessels studied by epifluorescent IVM on inguinal LNs. (A-B) Rolling fractions. WT and αL-I306A T cells showed comparable rolling fractions in the absence (A) or presence (B) of LFA1 blocking antibody M17/4. (C) Rolling velocity on high-order venules. αL-I306A T cells rolled slower on high-order LN venules than WT. After LFA-1 blockade by M17/4 antibody, both cell types showed comparable rolling velocity. (D) Sticking fractions of WT and KI cells. The fraction of sticking cells was increased for αL-I306A T exclusively on IV and V order venules. Data are expressed as the mean ± SEM of 3 independent experiments. Two-tailed Student t test was used for statistical analyses. Statistical significance was defined as *P < .05 or ***P < .001.
