Symington F W, Santos E B
Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104.
J Invest Dermatol. 1990 Aug;95(2):224-8. doi: 10.1111/1523-1747.ep12478064.
This study analyzed whether human keratinocytes (KC) express conventional HLA class-I molecules as detected by class-I-specific cytotoxic T lymphocytes (CTL), and whether exposure of KC to interferon-gamma (IFN-g) is required for CTL recognition. Basal KC grown in serum-free medium and exposed to recombinant IFN-g for 24-96 h were used as targets in 51Cr-release assays. Target-cell susceptibilities to lysis were compared by analyzing the lytic unit (LU) activity of a given CTL population against IFN-g-treated and untreated KC. CTL effectors were cloned from alloantigen-primed cultures by limiting dilution in the presence of antigenic B lymphoblastoid cells (BCLL) and IL-2. These T-cell clones lysed appropriate BCLL and PHA blasts but not third-party BCLL or K562. Lysis of antigenic BCLL was specifically blocked by antibodies against CD3 or class-I antigens. Specificity of the clones for conventional class-I antigen was demonstrated by cytotoxicity tests employing a panel of HLA-typed BCLL. The clones specifically lysed KC syngeneic with the original effector immunogen, and lysis was also blocked by anti-class-I antibodies. The effect of IFN-g treatment was to increase KC susceptibility to lysis by these clones. From 3-25 times more LU were measured against IFN-g-treated KC than against nontreated KC, and the degree of enhancement was similar for KC treated with concentrations of IFN-g ranging from 2.5-200 U/ml. This effect of IFN-g treatment on KC lysis by CTL, which was detected after only 24 h at all doses tested, emphasizes the potential role of IFN-g in enhancing CTL-mediated antiviral epidermal immunity and in exacerbating epidermal disease mediated by specific lytic T cells. In addition, the finding that normal human KC can be recognized by MHC class-I-specific CTL demonstrates that KC do express conventional class-I-antigens and that KC lysis by CTL can occur independently of exogenous cytokines.
本研究分析了人角质形成细胞（KC）是否如通过I类特异性细胞毒性T淋巴细胞（CTL）检测到的那样表达传统的HLA I类分子，以及KC暴露于干扰素-γ（IFN-γ）是否是CTL识别所必需的。在无血清培养基中生长并暴露于重组IFN-γ 24 - 96小时的基底KC被用作51Cr释放试验的靶细胞。通过分析给定CTL群体对IFN-γ处理和未处理的KC的裂解单位（LU）活性，比较靶细胞对裂解的敏感性。CTL效应细胞通过在抗原性B淋巴母细胞（BCLL）和IL-2存在下进行有限稀释，从同种异体抗原致敏培养物中克隆得到。这些T细胞克隆可裂解合适的BCLL和PHA刺激的细胞，但不能裂解第三方BCLL或K562。抗CD3或I类抗原的抗体可特异性阻断抗原性BCLL的裂解。通过使用一组HLA分型的BCLL进行细胞毒性试验，证明了这些克隆对传统I类抗原的特异性。这些克隆特异性地裂解与原始效应免疫原同基因的KC，并且裂解也被抗I类抗体阻断。IFN-γ处理的作用是增加KC对这些克隆裂解的敏感性。与未处理的KC相比，针对IFN-γ处理的KC测得的LU多3 - 25倍，并且对于用2.5 - 200 U/ml浓度的IFN-γ处理的KC，增强程度相似。IFN-γ处理对CTL裂解KC的这种作用，在所有测试剂量下仅24小时后就被检测到，强调了IFN-γ在增强CTL介导的抗病毒表皮免疫以及加剧由特异性裂解性T细胞介导的表皮疾病中的潜在作用。此外，正常人KC可被MHC I类特异性CTL识别这一发现表明，KC确实表达传统的I类抗原，并且CTL对KC的裂解可以独立于外源性细胞因子发生。
