Figure 5. Adoptive cell therapy with alloprimed CXCR5⁺CD8⁺ T cells into CCR5 KO kidney transplant recipients significantly reduces the proportion of splenic germinal center B cells.

C57BL/6 (WT) and CCR5 KO mice (both H-2^b) were transplanted with A/J (H-2^a) kidney. On posttransplant day 5, a cohort of CCR5 KO recipients underwent ACT with 2×10⁶ CXCR5⁺CD8⁺ T cells. Splenocytes were retrieved for analysis of germinal center (GC) B cells (B220⁺Fas⁺GL-7⁺) on day 14 posttransplant. A) Representative flow cytometric gating on lymphocytes, single cells, and B220⁺ cells are shown. Fluorescent minus one was used as a negative control. B) The proportion of GC B cells (GL-7⁺Fas⁺B220⁺) was significantly higher in CCR5 KO recipients (7.3±0.9%, n=5) compared to WT recipients (0.9±0.1%, n=5; *p<0.0001). Following ACT with 2.0×10⁶ alloprimed CXCR5⁺CD8⁺ T cells, the proportion of splenic GC B cells was significantly reduced in CCR5 KO recipients (4.9±0.4%, n=6; **p=0.002). C) No significant difference in overall quantity of splenic B cells was observed between WT and CCR5 KO recipients (p=ns).