Ghobrial R R, Hamashima T, Wang M E, Wang M, Stepkowski S M, Kahan B D
Department of Surgery, University of Texas Medical School at Houston, 77030, USA.
Transplantation. 1996 Oct 15;62(7):1002-10. doi: 10.1097/00007890-199610150-00020.
Donor-specific transplantation tolerance was induced by administration of chimeric antigens in which four donor immunogenic amino acids (a.a.) were substituted onto the host class I MHC protein. We constructed chimeric rat RT1.Aa cDNA molecules by substituting nucleotides in the alpha1 helical region that encode 10 Lewis (LEW; RT1.A1) a.a., namely Asp58, Arg62, Glu63, Gln65, Lys66, Gly69, Asn70, Asn73, Ser77, and Asn80 ([alpha(1h)1]-RT1.Aa). The chimeric [alpha(1h)1]-RT1.Aa cDNA sequence was verified before transfection into Buffalo (BUF; RT1b) hepatoma cells. Interestingly, the helical regions of LEW rats (alpha(1h)1) and Wistar Furth (WF; RT1u) rats (alpha(1h)u) share four a.a. (Arg62, Glu63, Gln65, and Gly69). Consequently, subcutaneous administration of [alpha(1)1]-RT1.Aa transfectants (20x10(6); day -7) immunized BUF rats to reject in rapid fashion either LEW heart allografts (mean survival time [MST] = 4.2+/-0.4 days vs. 5.6+/-0.5 days in controls; P<0.001) or WF heart allografts (MST=4.4+/-0.6 days vs. 6.0+/-0.0 days in controls; P<0.002). Subcutaneous immunization of ACI (RT1a) rats with [a(1)1]-RT1.Aa transfectants (bearing 10 LEW donor a.a.) accelerated the rejection of LEW hearts (MST=5.0+/-0.8 days vs. 8.2+/-0.4 days in controls; P<0.001). In contrast, the same [a(1)1]-RT1.Aa transfectants (bearing only four WF donor a.a.) injected subcutaneously into ACI rats modestly prolonged the survival of WF hearts to 14.0+/-10.3 days from 5.4+/-0.5 days in controls (P<0.001). Furthermore, ACI recipients were rendered tolerant to WF heart allografts by a single injection via the portal vein of soluble [a(1)1]-RT1.Aa (but not RT1.Aa, RT1.Au, or [a(2)1]-RT1.Aa) antigens in conjunction with brief oral gavage treatment with cyclosporine. Thus, selected donor immunogenic a.a. (Arg62, Glu63, Gln65, and Gly69) of class I MHC antigens become tolerogenic when flanked by host sequences.
通过给予嵌合抗原诱导供体特异性移植耐受，其中四个供体免疫原性氨基酸（a.a.）被替换到宿主I类MHC蛋白上。我们通过替换编码10个Lewis（LEW；RT1.A1）氨基酸（即Asp58、Arg62、Glu63、Gln65、Lys66、Gly69、Asn70、Asn73、Ser77和Asn80）的α1螺旋区域中的核苷酸，构建了嵌合大鼠RT1.Aa cDNA分子（[α(1h)1]-RT1.Aa）。在将嵌合的[α(1h)1]-RT1.Aa cDNA序列转染到布法罗（BUF；RT1b）肝癌细胞之前进行了验证。有趣的是，LEW大鼠（α(1h)1）和Wistar Furth（WF；RT1u）大鼠（α(1h)u）的螺旋区域共有四个氨基酸（Arg62、Glu63、Gln65和Gly69）。因此，皮下注射[α(1)1]-RT1.Aa转染细胞（20×10(6)；第-7天）使BUF大鼠免疫，从而快速排斥LEW心脏同种异体移植物（平均存活时间[MST]=4.2±0.4天，而对照组为5.6±0.5天；P<0.001）或WF心脏同种异体移植物（MST=4.4±0.6天，而对照组为6.0±0.0天；P<0.002）。用[α(1)1]-RT1.Aa转染细胞（带有10个LEW供体氨基酸）对ACI（RT1a）大鼠进行皮下免疫，加速了LEW心脏的排斥（MST=5.0±0.8天，而对照组为8.2±0.4天；P<0.001）。相比之下，将相同的[α(1)1]-RT1.Aa转染细胞（仅带有四个WF供体氨基酸）皮下注射到ACI大鼠中，使WF心脏的存活时间从对照组的5.4±0.5天适度延长至14.0±10.3天（P<0.001）。此外，通过门静脉单次注射可溶性[α(1)1]-RT1.Aa（但不是RT1.Aa、RT1.Au或[α(2)1]-RT1.Aa）抗原并结合环孢素的短期口服灌胃治疗，使ACI受体对WF心脏同种异体移植物产生耐受。因此，I类MHC抗原中选定的供体免疫原性氨基酸（Arg62、Glu63、Gln65和Gly69）在被宿主序列侧翼包围时会变成致耐受性的。
