Fig. 5. Induced T_RM cells or CD4⁺ T_RM cells in skin rejected heart allografts.

(A) Animal model: (i) BALB/c mice were immunized by C57BL/6 tail skin; (ii) after BALB/c mice were immunized for 30 days, the skin tissue (2 cm by 2 cm) was taken from immunized BALB/c mice and grafted onto SCID mice; (iii) after SCID mice recovery, C57BL/6 heart grafts were transplanted into SCID mice. (B) C57BL/6 heart graft survival (n = 6 per group). (C) Pathological examination of heart grafts in SCID mice with unimmunized and immunized skin tissues. (D) Flow cytometric analysis and the cell numbers of recipient CD4⁺ and CD8⁺T cells that infiltrated into the heart grafts. (E) Animal model: (i) We transfused 1 × 10⁶ CD4⁺ or CD8⁺ T cells into SCID mice, (ii) immunized these SCID mice with C57BL/6 tail skin, and (iii) transplanted the immunized skin onto another naïve SCID mouse; (4) after SCID mice recovery for 30 days, C57BL/6 heart grafts were transplanted into those SCID mice. (F) C57BL/6 heart graft survival in SCID mice that received skin tissues from either CD4⁺ T cell– or CD8⁺ T cell–reconstituted SCID mice 30 days or so after C57BL/6 skin immunization (n = 5). Data are representative of three independent experiments (n ≥ 3). Data are means ± SD. *P < 0.05, **P < 0.01, and ***P < 0.001, compared between the indicated groups.