Figure 4.

CD4⁺IL-7Rα⁺ T cells infiltrate the tissue allograft. Frozen kidney biopsies from transplant recipients with chronic rejection were stained with IL-7Rα and CD4 or CD25. (A, top) IL-7Rα⁺ T cells (green) and CD4⁺ T cells (red) are indicated by the arrowheads and are present in the interstitial compartment. Double-positive CD4⁺IL-7Rα⁺ T cells (yellow arrowheads) are colored in orange as a result of the merging of the two single-color images. (middle) IL-7Rα⁺ T cells (green) and CD25⁺ T cells (red) are also present in the interstitial compartment. Double-positive CD25⁺IL-7Rα⁺ T cells (yellow arrowheads) are colored in orange as a result of the merging of the two single-color images. (bottom) CD25⁺ T cells (green) and CD4⁺ T cells (red). Double-positive CD4⁺CD25⁺ T cells (yellow arrowheads) are colored in orange as a result of the merging of the two single-color images. (B, top) CD4⁺ T cells (green) infiltrating the kidney of a patient with documented chronic rejection are FOXP3 negative (red). (middle and bottom) CD25⁺ T cells (green) and IL-7Rα⁺ T cells (green) are also negative for FOXP3 (red). (C) CD4⁺ T cells (yellow) in the lymph node are FOXP3 positive (green). Bars, 10 μm.