LP CXCR6⁻ but not CXCR6⁺ cells can transfer wasting and colitis upon retransfer into <i>Rag1^−/−</i> recipients.

<p>(<b>A</b>) Schematic transfer protocol. An equal number of CD25⁻CXCR6⁻ cells or CD25⁻CXCR6⁺CD4⁺ T cell isolated from colon LP of colitic mice was retransferred into <i>Rag1^−/−</i> mice. (<b>B</b>) Time course of changes in body weight after retransfer of the two subsets or transfer of CD45RB^high naïve T cells. CXCR6^–transferred <i>Rag1^−/−</i> mice manifested progressive body weight loss to a similar extent to CD45RB^high-transferred <i>Rag1^−/−</i> mice, whereas the cohort that received CXCR6⁺cells did not show wasting. Data are expressed as the mean and s.e.m of two independent experiments. *, <i>P</i> < 0.05 ***, <i>P</i> < 0.001 versus CXCR6⁺-transferred animals. (<b>C</b>) Histopathological analysis of distal colon tissue at 8 weeks post transfer. The transfer of CXCR6⁻CD4⁺ T cells alone induced intestinal inflammation. Scale bars, 50 µm. (<b>D</b>) Number of CD4⁺ T cells in each group were calculated based on the flow cytometric analysis. (<b>E</b>) CXCR6 expression on CD4⁺ T cells in each group was analyzed by flow cytometry using CXCL16-hFc at 8-week post transfer. CXCR6⁻CD4⁺ T cells express CXCR6 upon retransfer. (<b>F</b>) Intracellular cytokine staining was performed in LP CD4⁺ T cells in recipients of CXCR6⁻CD4⁺ T cells at 8 weeks after transfer. The CXCR6⁻ subset produced IFN-γ and IL-17A coincident with the expression of CXCR6 upon retransfer. (<b>G</b>) LP CXCR6⁻ and CXCR6⁺ subsets were purified from CD45RB^high-transferred <i>Rag1^−/−</i> mice at 8-week post transfer, labeled with CFSE and cultured with LP MHC class II⁺CD11c⁺ cells at a 5∶1 ratio in the presence of 5 µg/ml anti-CD3ε Abs and 20 ng/ml IL-23 for 3 days. Proliferation was measured by CFSE dilution. Proliferation by CXCR6⁻ and CXCR6⁺ cells is depicted in the right columns. All data are representative from four independent experiments (mean and s.d.).