In vivo Bdep results in a normalization of platelet counts in a murine model of T-cell–mediated ITP. Platelet counts in transferred recipient SCID mice after 21 days post-engraftment of 3 × 104 splenocytes. SCID mice were either transferred with phosphate-buffered saline or with ND splenocytes from platelet-immunized CD61 KO mice (ND), splenocytes from ND KO mice but depleted of CD19+ B cells in vitro (ND Bdep in vitro), or splenocytes from platelet-immunized CD61 KO mice depleted in vivo with anti-CD20 antibody before platelet immunization (Bdep in vivo, pre), or after platelet immunization (Bdep in vivo, post). Each data point represents 1 SCID mouse. Data were analyzed using one-way analysis of variance with a Tukey’s posttest (*P < .05; ***P < .001).