Montel A H, Bochan M R, Goebel W S, Brahmi Z
Department of Microbiology/Immunology, Indiana University School of Medicine, Indianapolis 46202-5200, USA.
Cell Immunol. 1995 Oct 15;165(2):312-7. doi: 10.1006/cimm.1995.1219.
Cell-mediated cytotoxicity (CMC) has traditionally been thought to involve the release of granule components, including perforin and granzymes, from the effector cell (EC) onto the target cell (TC) membrane. Recently, a granule-independent cytolytic mechanism involving the interaction of Fas antigen (CD95) with Fas ligand has been described. We have generated antisense perforin (YT-xP1) and granzyme B (YT-xGrB) transfectants of the human NK-like cell line YT-INDY. These transfectants have greatly reduced cytolytic ability when compared to the vector-transfected control cell line (YT-neo). In this study, however, we demonstrate that the antisense transfectants retain the ability to lyse Fas+ TC. Fas-mediated lysis is Ca(2+)-independent and is inhibited by a monoclonal anti-Fas blocking Ab, M3. By RT-PCR, we detect message for FasL in unstimulated YT-xP1 and YT-xGrB transfectants, as well as in unstimulated YT-neo. By flow cytometry, we show that YT-neo, YT-xGrB, and YT-xP1 constitutively express surface FasL. These data indicate that in a human NK-like cell line, similar to the murine system, the granule and Fas pathways of cytotoxicity function independently of one another. At least with the TC tested, our data also indicate that the granule and Fas pathways together account for nearly 100% of the cytolytic ability of YT-INDY.
传统上认为细胞介导的细胞毒性（CMC）涉及效应细胞（EC）向靶细胞（TC）膜释放颗粒成分，包括穿孔素和颗粒酶。最近，已描述了一种不依赖颗粒的溶细胞机制，该机制涉及Fas抗原（CD95）与Fas配体的相互作用。我们构建了人NK样细胞系YT-INDY的反义穿孔素（YT-xP1）和颗粒酶B（YT-xGrB）转染子。与载体转染的对照细胞系（YT-neo）相比，这些转染子的溶细胞能力大大降低。然而，在本研究中，我们证明反义转染子保留了裂解Fas + TC的能力。Fas介导的裂解不依赖Ca(2+)，并被单克隆抗Fas阻断抗体M3抑制。通过RT-PCR，我们在未刺激的YT-xP1和YT-xGrB转染子以及未刺激的YT-neo中检测到FasL的信使RNA。通过流式细胞术，我们显示YT-neo、YT-xGrB和YT-xP1组成性表达表面FasL。这些数据表明，在人NK样细胞系中，类似于小鼠系统，细胞毒性的颗粒途径和Fas途径彼此独立发挥作用。至少对于所测试的TC，我们的数据还表明颗粒途径和Fas途径共同占YT-INDY溶细胞能力的近100%。
