Thiele D L, Geissler G H, Williams F H, Lipsky P E
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235.
Transplantation. 1992 Jun;53(6):1334-40. doi: 10.1097/00007890-199206000-00030.
Treatment of murine spleen cells (SpC) with L-leucyl-L-leucine methyl ester (Leu-Leu-OMe) depletes L3T4(+) and Lyt2(+) cytotoxic T lymphocyte precursors and the capacity to generate lethal graft-versus-host disease in semiallogeneic class I + II MHC and multiple non-MHC-disparate recipient mice, whereas T helper cell function is preserved. In the present studies the role of Leu-Leu-OMe-sensitive CTL in skin graft rejection was examined. C57BL/6J (B6) mice were serially thymectomized, lethally irradiated, reconstituted with T cell-depleted bone marrow, and treated with intraperitoneal injections of anti-L3T4 and anti-Lyt2 monoclonal antibodies. These adult thymectomized, bone marrow-reconstituted, T cell-depleted (ATXBM, TCD) mice were unable to reject B6xDBA/2F1 (B6D2F1) skin grafts. When such ATXBM, TCD mice were reconstituted with 7 x 10(7) control B6 SpC, acute rejection of B6D2F1 skin was observed. When B6 donor SpC were Leu-Leu-OMe-treated prior to transfer to ATXBM, TCD mice, uniform rejection of B6D2F1 skin grafts was still observed, although a significant delay in the time to rejection was observed. More rigorous T cell depletion of ATXBM, TCD host mice by infusion of antithymocyte globulin did not prevent delayed rejection of B6D2F1 skin initiated by transfer of Leu-Leu-OMe-treated B6 SpC. Despite the lack of complete prevention of skin allograft rejection, Leu-Leu-OMe treatment of B6 donor cells prevented lethal GVHD even in thymectomized B6D2F1 recipients. Precursors of anti-B6D2F1-specific CTL were greatly reduced or undetectable in unreconstituted ATXBM, TCD mice or in irradiated B6D2F1 recipients of Leu-Leu-OMe-treated B6 SpC. By contrast, ATXBM, TCD recipients of Leu-Leu-OMe-treated B6 SpC were found to contain a population of anti-class I MHC-specific CTL precursors of host origin within 28 days of reconstitution. These findings have indicated a number of features of the cells involved in skin graft rejection. First, Leu-Leu-OMe-sensitive CTL play a major role in acute rejection of class I + II MHC and multiple non-MHC antigen-disparate skin grafts. Moreover, the thymus-independent expansion of host-derived CTL precursors in ATXBM, TCD mice reconstituted with syngeneic Leu-Leu-OMe-resistant T helper cells also appears to play a role in mediating rejection of allogeneic skin grafts.
用L-亮氨酰-L-亮氨酸甲酯（Leu-Leu-OMe）处理小鼠脾细胞（SpC），可耗尽L3T4(+)和Lyt2(+)细胞毒性T淋巴细胞前体，并消除在半同种异体I类+ II类主要组织相容性复合体（MHC）以及多个非MHC不相合受体小鼠中产生致死性移植物抗宿主病（GVHD）的能力，而T辅助细胞功能得以保留。在本研究中，检测了Leu-Leu-OMe敏感的细胞毒性T淋巴细胞（CTL）在皮肤移植排斥反应中的作用。对C57BL/6J（B6）小鼠进行连续胸腺切除、致死性照射，用去除T细胞的骨髓进行重建，并用腹腔注射抗L3T4和抗Lyt2单克隆抗体进行处理。这些成年胸腺切除、骨髓重建、T细胞耗竭（ATXBM，TCD）的小鼠无法排斥B6xDBA/2F1（B6D2F1）皮肤移植。当用7×10⁷对照B6 SpC重建此类ATXBM，TCD小鼠时，观察到B6D2F1皮肤的急性排斥。当B6供体SpC在转移至ATXBM，TCD小鼠之前用Leu-Leu-OMe处理时，仍观察到B6D2F1皮肤移植的一致排斥，尽管排斥时间有显著延迟。通过输注抗胸腺细胞球蛋白对ATXBM，TCD宿主小鼠进行更严格的T细胞耗竭并不能阻止由Leu-Leu-OMe处理的B6 SpC转移引发的B6D2F1皮肤的延迟排斥。尽管未能完全预防皮肤同种异体移植排斥，但对B6供体细胞进行Leu-Leu-OMe处理即使在胸腺切除的B6D2F1受体中也能预防致死性GVHD。在未重建的ATXBM，TCD小鼠或接受Leu-Leu-OMe处理的B6 SpC的照射B6D2F1受体中，抗B6D2F1特异性CTL的前体大大减少或无法检测到。相比之下，发现接受Leu-Leu-OMe处理的B6 SpC的ATXBM，TCD受体在重建后28天内含有一群宿主来源的抗I类MHC特异性CTL前体。这些发现揭示了参与皮肤移植排斥反应的细胞的一些特征。首先，Leu-Leu-OMe敏感的CTL在I类+ II类MHC以及多个非MHC抗原不相合皮肤移植的急性排斥中起主要作用。此外，在用同基因Leu-Leu-OMe抗性T辅助细胞重建的ATXBM，TCD小鼠中，宿主来源的CTL前体的非胸腺依赖性扩增似乎也在介导同种异体皮肤移植的排斥中起作用。
