Ma D, Comerford S, Bellingham D, Sambrook J, Gething M J, Alizadeh H, Anand R, Mellon J, Niederkorn J Y
Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas 75235.
Transplantation. 1994 Mar 15;57(5):718-25. doi: 10.1097/00007890-199403150-00014.
Transgenic mice bearing the simian virus 40 (SV40) large T oncogene developed progressively growing intraocular tumors and displayed characteristics of immunological tolerance to SV40 T antigen. Transgenic mice failed to mount CTL responses to SV40 T antigen-bearing tumor cell lines derived from the transgenic intraocular tumors. Spleen cells from transgenic hosts were able to prevent the in vivo and in vitro generation of CTL responses by lymphocytes from normal syngeneic FVB/N mice. Adoptive transfer of spleen cells from tolerant transgenic donors temporarily inhibited the immunological rejection of SV40 T antigen-positive tumor cells transplanted to normal syngeneic FVB/N recipients. Thus, introduction of SV40 transforming sequences into the mouse germline induced tolerance to SV40 T antigen. However, in normal FVB/N mice, SV40 T antigen-bearing tumor cells failed to experience immune privilege in the anterior chamber and did not elicit systemic down-regulation of delayed-type hypersensitivity responses that characteristically occur when antigens are introduced into the anterior chamber. The results indicate that within the anterior chamber of the eye, SV40 T antigen-bearing cells are perceived by the host's immune system much differently than are other categories of antigen. Thus, SV40 T antigen effectively induces self-immunological tolerance when its gene is introduced into the host's germline but fails to experience immunological privilege in the anterior chamber of the eye in normal hosts.
携带猿猴病毒40(SV40)大T癌基因的转基因小鼠出现了逐渐生长的眼内肿瘤,并表现出对SV40 T抗原的免疫耐受特征。转基因小鼠无法对源自转基因眼内肿瘤的携带SV40 T抗原的肿瘤细胞系产生细胞毒性T淋巴细胞(CTL)反应。转基因宿主的脾细胞能够阻止正常同基因FVB/N小鼠的淋巴细胞在体内和体外产生CTL反应。来自耐受转基因供体的脾细胞的过继转移暂时抑制了移植到正常同基因FVB/N受体的SV40 T抗原阳性肿瘤细胞的免疫排斥。因此,将SV40转化序列引入小鼠种系可诱导对SV40 T抗原的耐受。然而,在正常FVB/N小鼠中,携带SV40 T抗原的肿瘤细胞在前房未能获得免疫赦免,也未引发抗原引入前房时典型出现的迟发型超敏反应的全身下调。结果表明,在眼的前房内,宿主免疫系统对携带SV40 T抗原的细胞的感知与对其他类抗原的感知有很大不同。因此,当SV40 T抗原基因被引入宿主种系时,它能有效诱导自身免疫耐受,但在正常宿主的眼前房中未能获得免疫赦免。