First Author | Fischbein MP | Year | 2001 |
Journal | Transplantation | Volume | 71 |
Issue | 8 | Pages | 1146-53 |
PubMed ID | 11374417 | Mgi Jnum | J:69459 |
Mgi Id | MGI:1934690 | Doi | 10.1097/00007890-200104270-00023 |
Citation | Fischbein MP, et al. (2001) CD8+ lymphocytes augment chronic rejection in a MHC class II mismatched model. Transplantation 71(8):1146-53 |
abstractText | Chronic rejection, or cardiac allograft vasculopathy (CAV), remains the leading cause of late death in heart transplant recipients. The precise role and contributions of T lymphocyte subsets to CAV development remains unknown. METHODS: Donor hearts from B6.C-H2bm12 mice were transplanted into T lymphocyte subset knockout recipients and T lymphocyte-reconstituted nude recipients. No immunosuppression was used. Intimal proliferation was measured morphometrically. In vitro studies were performed to analyze the donor-specific activation status of recipient CD8+ lymphocytes by examining cellular proliferation, interleukin-2 secretion, and interleukin-2Ralpha expression. Intracellular cytokine staining assay was performed to determine both the profile and source of intragraft cytokines. RESULTS: Hearts transplanted into wild-type recipients developed severe CAV by 24 days. Intimal lesions were absent in the hearts that were transplanted into nude and CD4-/- knockout mice (containing CD8+ lymphocytes). In contrast, the donor hearts in CD8-/- knockout recipients (containing CD4+ lymphocytes) developed CAV, but significantly less than in wildtype. Adoptive transfer of T lymphocyte subset populations into nude recipients confirmed that CAV was absolutely contingent on CD4+ lymphocytes, and that CD8+ lymphocytes played an additive role in intimal lesion progression in the presence of CD4+ lymphocytes. Although CD8+ lymphocytes alone did not cause CAV in vivo, we demonstrated that MHC class II disparate alloantigens activated CD8+ lymphocytes both in vivo and in vitro. Finally, both CD4+ and CD8+ lymphocytes contributed to the intragraft IL-2 and IFN-gamma production. CONCLUSIONS: In this MHC class II mismatched murine model, CAV is a T lymphocyte dependent event, and absolutely contingent on the presence of CD4+ lymphocytes. Furthermore, CD8+ lymphocytes (1) are activated by MHC class II disparate antigens and (2) play a significant role in the progression of lesion development. Finally, both CD4+ and CD8+ lymphocytes contribute to CAV development via secretion of IFN-gamma, a known mediator of CAV in this model. |