Motility of naïve, tolerized and primed antigen-specific T cells. Ovalbumin (OVA)-specific T cells from naïve (squares), OVA-fed (tolerized; triangles) or OVA-immunized (primed; circles) DO11.10 severe combined immunodeficiency (SCID) mice were carboxyfluorescein succinimidyl ester (CFSE)-labelled and adoptively transferred into naïve BALB/c mice. Recipients were subsequently challenged with either complete Freund’s adjuvant (CFA) only or OVA/CFA as indicated. T-cell velocity (a, b) and meandering (c, d) were analysed at 8 and 20 hr post-immunization. Data represent the migration of individual cells from several mice, with the mean indicated (#P<0·05; *P<0·005).