FIGURE 3. SKAP1 deficiency delays allograft rejection but does not influence CD8⁺ effector T cell migration.

(A) BALB/c islet allograft survival in wildtype (WT) or SKAP1^−/− (KO) B6 recipients that were either untreated or received limited immunosuppression immediately after transplantation (CTLA-4-Ig 200 μg on days 0 and 2). (B) B6.OVA islet graft survival in WT or KO B6 recipients that were not immunosuppressed but received 5 × 10⁶ naïve SKAP1^+/+ or SKAP1^−/− OT-I cells, respectively, immediately after transplantation. (C) B6.OVA islet grafts were transplanted to B6 mice and the migration of co-transferred, PTx-treated SKAP1^+/+ and SKAP1^−/− OT-I effector T cells to the grafts was imaged and enumerated by two-photon intravital microscopy as described in Fig. 1 (N = 3 mice, 10 movies). In these experiments, SKAP1^−/− OT-I cells transferred were from B6 OT-I.SKAP1^−/−.RAG^+/− donors; however, the transfer of B6 SKAP1^−/−. RAG^−/− OT-I effectors yielded the same results (n = 2 mice, 4 movies; data not shown). Representative, volume-rendered images are shown. Blood vessel and islet channels were subtracted from right panel to better visualize infiltrating T cells. Scale bar = 50 μm. (C) Motility parameters of SKAP1^+/+ and SKAP1^−/− OT-I cells detected in the total image volume. *p<0.05 compared to each of the other groups; ***p<0.0001; n.s. = not significant.