CD4+ T-cell-independent rejection of corneal allografts

Transplantation. 2006 Apr 27;81(8):1171-8. doi: 10.1097/01.tp.0000203140.70742.cb.

Abstract

Background: Several studies suggest that a significant number of corneal allografts undergo rejection in the absence of CD4 T cells. This study examined the role of CD4 T cell-independent mechanisms of corneal allograft rejection.

Methods: BALB/c corneal allografts were transplanted to C57BL/6 beige nude mice that received either CD8 or CD8 T cells from C57BL/6 CD4 knockout (KO) mice that had rejected BALB/c corneal allografts. Immune effector functions of CD8 or CD8 T cells from C57BL/6 CD4 KO mice were assessed using delayed-type hypersensitivity assays and Annexin V apoptosis assays respectively. RESULTS.: Both CD8 and CD8 T cells from CD4 KO corneal allograft rejector mice mediated corneal allograft rejection following adoptive transfer to nude mice. CD8 T cells, but not CD8 T cells, from CD4 KO mice adoptively transferred donor-specific DTH and induced apoptosis of BALB/c corneal endothelial cells in vitro. Apoptosis of BALB/c corneal endothelial cells was mediated by double negative (DN) T cells, as treatment of CD8 cells from CD4 KO mice with anti-Thy 1.2 plus complement abolished their effector function.

Conclusion: The results support the proposition that CD4 T cell-independent rejection of corneal allografts can be mediated by either CD8 or CD8 T cells. The CD8 T cells represent a unique DN T cell population that might mediate rejection by either direct cytolysis or by inducing apoptosis of the donor corneal endothelium.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adoptive Transfer
  • Animals
  • Apoptosis
  • CD4-Positive T-Lymphocytes / physiology*
  • CD8-Positive T-Lymphocytes / physiology
  • Corneal Transplantation / immunology*
  • Epithelium, Corneal / pathology
  • Graft Rejection / etiology*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • T-Lymphocytes, Cytotoxic / immunology
  • Transplantation, Homologous