Nakano T, Kawamoto S, Lai C-Y, Hsu L-W, Lin Y-C, Sasaki T, Aki T, Shigeta S, Goto T, Ohmori N, Sato S, Goto S, Ono K, Chen C-L
Department of Surgery, Liver Transplantation Laboratory, Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
Transplant Proc. 2005 Jan-Feb;37(1):80-1. doi: 10.1016/j.transproceed.2004.12.290.
In a rat tolerogenic model of orthotopic liver transplantation (OLT), recipient serum after OLT (post-OLT serum) possesses strong immunosuppressive activity. This study aimed to identify immunosuppressive factors present in early post-OLT serum.
Immunosuppressive activity was evaluated in vitro by inhibition of the mixed-lymphocyte reaction (MLR). Autoantigens recognized by MLR-inhibitory IgG were identified by the internal protein sequencing.
Recipient post-OLT serum inhibited MLR, and OLT-inducible IgG was the major immunosuppressive factor. IgG from post-OLT sera (2 to 3 weeks) specifically reacted to 31; 34; and 73-kd autoantigens on spleen cells. The internal sequences of the 31- and 34-kd antigens coincided completely with those of histone H1 molecules. Immunodepletion of anti-histone H1 antibodies (Abs) from early post-OLT serum abolished the MLR-inhibitory activity. Furthermore, rabbit polyclonal Ab-directed histone H1 not only significantly suppressed rat and human MLR but also prolonged survival of heart allografts. Flow-cytometric analysis revealed that some live PVG splenocytes were stained with antihistone H1 Abs, and that these positive cells increased on Con A stimulation. Western blot analysis indicated that several cross-reactive antigens against anti-histone H1 Abs were found in their membrane fraction.
In this study we provide evidence that autoreactive Abs, against histone H1 are a major OLT-induced graft survival factor, and may play at least a part in overcoming the acute rejection phase to establish solid allograft tolerance.
在大鼠原位肝移植（OLT）的致耐受性模型中，OLT后的受体血清（OLT后血清）具有强大的免疫抑制活性。本研究旨在鉴定OLT后早期血清中存在的免疫抑制因子。
通过抑制混合淋巴细胞反应（MLR）在体外评估免疫抑制活性。通过内部蛋白质测序鉴定被MLR抑制性IgG识别的自身抗原。
受体OLT后血清抑制MLR，且OLT诱导的IgG是主要的免疫抑制因子。OLT后血清（2至3周）中的IgG与脾细胞上的31、34和73 kDa自身抗原特异性反应。31 kDa和34 kDa抗原的内部序列与组蛋白H1分子的序列完全一致。从OLT后早期血清中免疫去除抗组蛋白H1抗体（Abs）消除了MLR抑制活性。此外，兔多克隆抗组蛋白H1不仅显著抑制大鼠和人类的MLR，还延长了心脏同种异体移植的存活时间。流式细胞术分析显示，一些活的PVG脾细胞被抗组蛋白H1 Abs染色，并且这些阳性细胞在Con A刺激下增加。蛋白质印迹分析表明，在其膜部分发现了几种与抗组蛋白H1 Abs交叉反应的抗原。
在本研究中，我们提供证据表明，针对组蛋白H1的自身反应性Abs是OLT诱导的主要移植物存活因子，并且可能至少在克服急性排斥期以建立实体同种异体移植耐受性中发挥作用。
