(A) Migration of CXCR2 RNA-transfected T cells into the peritoneal cavity. PBMCs were stimulated for 11 days in vitro with autologous DCs pulsed with pp65 mRNA as described in Materials and Methods. Cells were harvested and transfected with CXCR2 RNA (2 μg/106 cells). Forty-eight hours later, untransfected and CXCR2 RNA-transfected cells were harvested and differentially labeled with CFSE (1 μM for untransfected cells and 10 μM for CXCR2 RNA-transfected cells) for 5 min in PBS, washed, mixed, and injected intravenously into SCID mice (2 × 107 cells per mouse, n = 3 per group). Mice were injected intraperitoneally with PBS only or with chemokines (GRO-a, IL-8, or UL146) at 1 μg/ml in PBS every 8 hr for 24 hr after injection of T cells. Lymphocytes were harvested after sacrifice by peritoneal lavage and centrifuged, and the relative accumulation of untransfected and CXCR2 RNA-transfected cells was evaluated by flow cytometric analysis. Accumulation of CFSEhigh cells (CXC2 RNA-transfected T cells) and CFSElow cells (untransfected T cells) in PBS-treated animals was used as a baseline for comparison with the accumulation of cells in cytokine-treated animals. Data are displayed as fold change compared with PBS-treated animals. (B) Migration of CXCR2 RNA-transfected T cells into the CNS. PBMCs were stimulated for 11 days in vitro with autologous DCs pulsed with pp65 mRNA as described in Materials and Methods. Cells were harvested and transfected with CXCR2 RNA (2 μg/106 cells). Forty-eight hours later, un-transfected and CXCR2 RNA-transfected cells were harvested and labeled with CFSE (5 μM) for 5 min in PBS, washed, and injected intravenously into SCID mice (1 × 107 cells per mouse, n = 3 per group). Anesthetized mice were subsequently injected via the right parietal lobe with the CMV chemokine UL146 (1 μg in 5 μl of PBS) and via the left parietal lobe with PBS only. The accumulation of CFSE-labeled cells in the right and left parietal lobes was assessed 6 hr later by flow cytometry after dissection of the cerebral hemispheres and single-cell digest preparation from the parietal lobes. A representative flow cytometric dot plot of a mouse injected with CXCR2 RNA-transfected T cells shows greater accumulation of lymphocytes within the right parietal lobe injected with the CXCR2 ligand UL146. (C) In vivo migration of CXCR2-transfected T cells. The accumulation of T cells within the right (UL146-injected) and left (PBS-injected) parietal lobes was assessed by flow cytometry and human T cells per 100,000 events were plotted. Results demonstrated significant accumulation of CXCR2 RNA-transfected T cells within the CNS in response to UL146, whereas untransfected T cells did not exhibit any preferential accumulation (*p < 0.05; t test).