O'Connell P J, Pacheco-Silva A, Nickerson P W, Muggia R A, Bastos M, Kelley V R, Strom T B
Harvard Medical School, Department of Medicine, Beth Israel Hospital, Boston, MA 02215.
J Immunol. 1993 Feb 1;150(3):1093-104.
Polymerase chain reaction-assisted reverse transcription was used to study the temporal course of rejection in unmodified recipients of murine pancreatic islet cell allografts (DBA/2-->B6AF1) by using syngeneic tissues as controls. The histologic appearance of the grafts was analyzed in parallel. Preproinsulin and constant region of the TCR-beta chain transcripts were studied as markers of graft integrity and infiltrating T cell mass, respectively. The participation of certain cytokines and CTL were analyzed by the detection of IL-2, IFN-gamma, IL-4, and CTL-specific serine protease (granzyme B) transcripts. The time-related disappearance of intragraft preproinsulin transcripts correlated with graft destruction, whereas the intensity of intragraft TCR-beta chain transcript levels correlated with the magnitude of mononuclear leukocyte infiltration in allografts. In unmodified allografts, the magnitude of IL-2 and IFN-gamma intragraft mRNA levels correlated with the intense mononuclear leukocyte infiltrate found on histologic examination at day 8. Only after stable IL-2 gene transcription on day 8 does evidence of graft destruction become apparent, indicating that IL-2 gene activation is closely related to and probably required for expression of alloimmune cytopathic processes. In contrast, IL-4 transcripts were absent or detected in low copy number throughout this time course. Intragraft expression of granzyme B mRNA, a CTL-specific transcript, peaked from day 8 to day 12 in allografts compared with syngeneic grafts or normal tissue. In syngeneic grafts IL-2 and/or IL-4 mRNA was essentially not detected. Although IFN-gamma and granzyme B transcripts were detected in syngeneic grafts, after 4 days the levels of detected transcripts were far less than those noted in allografts. In vivo detection of intragraft IL-2 transcripts in the relative absence of detectable IL-4 transcripts strongly suggests IL-2-dependent immune effector mechanisms are associated with, and perhaps responsible, for allograft rejection. Apparently IL-4-dependent effector mechanisms are not necessary for allograft rejection.
采用聚合酶链反应辅助逆转录技术，以同基因组织作为对照，研究了未经修饰的小鼠胰岛细胞同种异体移植（DBA/2→B6AF1）受者排斥反应的时间进程。同时对移植组织的组织学表现进行了分析。分别研究了前胰岛素原和TCR-β链转录本的恒定区，作为移植完整性和浸润性T细胞数量的标志物。通过检测白细胞介素-2（IL-2）、干扰素-γ（IFN-γ）、白细胞介素-4（IL-4）和细胞毒性T淋巴细胞（CTL）特异性丝氨酸蛋白酶（颗粒酶B）转录本，分析了某些细胞因子和CTL的参与情况。移植内前胰岛素原转录本随时间的消失与移植组织破坏相关，而移植内TCR-β链转录本水平的强度与同种异体移植中单核白细胞浸润的程度相关。在未经修饰的同种异体移植中，移植内IL-2和IFN-γ mRNA水平与第8天组织学检查中发现的强烈单核白细胞浸润相关。只有在第8天IL-2基因转录稳定后，移植组织破坏的证据才变得明显，这表明IL-2基因激活与同种异体免疫细胞病变过程的表达密切相关，可能是其必需条件。相比之下，在整个时间进程中，IL-4转录本均未检测到或仅以低拷贝数被检测到。与同基因移植或正常组织相比，同种异体移植中CTL特异性转录本颗粒酶B mRNA的移植内表达在第8天至第12天达到峰值。在同基因移植中，基本上未检测到IL-2和/或IL-4 mRNA。虽然在同基因移植中检测到了IFN-γ和颗粒酶B转录本，但4天后检测到的转录本水平远低于同种异体移植中的水平。在相对未检测到IL-4转录本的情况下，对移植内IL-2转录本进行体内检测，强烈提示IL-2依赖性免疫效应机制与同种异体移植排斥相关，可能是其原因。显然，IL-4依赖性效应机制对于同种异体移植排斥并非必需。
