Warnecke Gregor, Chapman Stephanie J, Bushell Andrew, Hernandez-Fuentes Maria, Wood Kathryn J
Transplantation Research Immunology Group, Nuffield Department of Surgery, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom.
Transplantation. 2007 Aug 15;84(3):392-9. doi: 10.1097/01.tp.0000269705.94545.3a.
The trans vivo delayed-type hypersensitivity (DTH) assay has been used for monitoring the immune status of clinical transplant recipients. Here we tested the hypothesis that the assay can reveal control of allograft rejection by CD25CD4 regulatory T cells (Treg).
CBA.Ca (H2) recipients of heterotopic C57BL/10 (H2, B10) heart transplants were untreated or pretreated with anti-CD4 antibody and donor-specific blood. This protocol has been shown previously to induce operational tolerance to alloantigens that is dependent on CD25CD4 Treg. Four weeks after transplantation leukocytes were harvested and used for the trans vivo DTH assay. Cells were stimulated with irradiated B10 leukocytes or subcellular antigen and injected into ear pinnae of immune deficient CB17.SCID.beige hosts.
Stimulation of leukocytes from recipients rejecting B10 cardiac allografts with recall alloantigen caused a "strong" swelling response, whereas similar stimulation of leukocytes from operationally tolerant mice resulted in significantly less swelling (n=17; P=0.003). When CD25 T cells were depleted from "tolerant" leukocytes, the swelling response triggered was similar to that obtained using cells from rejecting animals (P<0.001), while coinjection of purified CD25CD4 cells from tolerant recipients with rejecting cells suppressed the swelling response (P=0.007) to the level observed with cells from tolerant mice. Both the effector and the regulatory response were triggered by indirect allorecognition and blocking experiments showed that the regulation observed was dependent on cytoxic T lymphocyte antigen (CTLA) 4.
The trans vivo DTH assay can be used to reveal regulation mediated by CD25CD4 T cells and is CTLA4 dependent.
体内迟发型超敏反应（DTH）试验已用于监测临床移植受者的免疫状态。在此，我们检验了该试验能够揭示CD25⁺CD4⁺调节性T细胞（Treg）对同种异体移植排斥反应的控制作用这一假说。
将异位C57BL/10（H-2b，B10）心脏移植给CBA.Ca（H-2k）受体，受体未接受治疗或先用抗CD4抗体和供体特异性血液进行预处理。先前已证明该方案可诱导对同种异体抗原的操作性耐受，且这种耐受依赖于CD25⁺CD4⁺Treg。移植后4周，采集白细胞并用于体内DTH试验。用经辐照的B10白细胞或亚细胞抗原刺激细胞，然后将其注射到免疫缺陷的CB17.SCID.beige宿主的耳廓中。
用回忆性同种异体抗原刺激排斥B10心脏同种异体移植的受体的白细胞，会引起“强烈”的肿胀反应，而用类似方法刺激操作性耐受小鼠的白细胞，则肿胀明显减轻（n = 17；P = 0.003）。当从“耐受”白细胞中去除CD25⁺T细胞时，引发的肿胀反应与使用排斥动物的细胞所获得的反应相似（P < 0.001），而将来自耐受受体的纯化CD25⁺CD4⁺细胞与排斥细胞共同注射可将肿胀反应抑制（P = 0.007）至耐受小鼠细胞所观察到的水平。效应反应和调节反应均由间接同种异体识别引发，阻断实验表明所观察到的调节作用依赖于细胞毒性T淋巴细胞抗原（CTLA）4。
体内DTH试验可用于揭示由CD25⁺CD4⁺T细胞介导的调节作用，且该调节作用依赖于CTLA4。
