Antiplatelet CD61 antibodies in the sera of transferred SCID mice. Anti–CD61-specific antibody production in the sera of SCID mice transferred with either nondepleted (ND) splenocytes (n = 23), CD8⁺ T cell–depleted splenocytes (n = 16), CD19⁺ B cell–depleted splenocytes (n = 7), or CD19 and CD8 double-depleted splenocytes (n = 5). Platelets from either BALB/c mice or CD61 KO mice were incubated with sera from the indicated groups of SCID mice and analyzed by flow cytometry. The data are expressed as fold increase and were calculated by mean channel fluorescence (MCF) of test serum/MCF of naive serum. All the positive sera were not reactive against platelets from CD61 KO mice.