Breitmeyer J B, Oppenheim S O, Daley J F, Levine H B, Schlossman S F
J Immunol. 1987 Feb 1;138(3):726-31.
Monoclonal antibodies that bind to the T cell MHC-antigen recognition complex (anti-T3 or anti-Ti) are known to either mimic ligand binding and activate T cells or block ligand binding, leading to an inhibition of T cell activation. In the present experiments, we demonstrate a direct inhibitory effect on the growth of human T cells by anti-T3 or anti-Ti antibodies. The proliferation of human peripheral blood T cells preactivated by exposure to PHA was inhibited in a specific manner by anti-T3. Colony formation in soft agar by REX cells, a leukemic cell line of early T cell phenotype, was completely inhibited by anti-T3 or anti-Ti antibodies, whereas isotype-matched antibodies to a variety of other T cell markers had no effect. Growth of REX cells in suspension culture was not affected by anti-T3 or anti-Ti. A cell line, T3.N1, was established from an agar colony of anti-T3-resistant REX cells. T3.N1 was phenotypically identical to REX except for failure to express any detectable T3 or Ti surface antigen. T3.N1 colony formation in soft agar was not inhibited by anti-T3 or anti-Ti. There was no rise in [Ca2+]i of T3.N1 cells after anti-T3 or anti-Ti exposure. These results indicate that in addition to the well-known positive regulatory effects of ligand binding to the T3/Ti complex, T3/Ti binding can also result in a down-regulatory signal for human T cell growth.
已知与T细胞MHC-抗原识别复合物结合的单克隆抗体（抗T3或抗Ti）要么模拟配体结合并激活T细胞，要么阻断配体结合，从而导致T细胞激活受到抑制。在本实验中，我们证明了抗T3或抗Ti抗体对人T细胞生长具有直接抑制作用。经PHA预激活的人外周血T细胞的增殖被抗T3以特异性方式抑制。REX细胞（一种早期T细胞表型的白血病细胞系）在软琼脂中的集落形成被抗T3或抗Ti抗体完全抑制，而针对多种其他T细胞标志物的同型匹配抗体则没有作用。抗T3或抗Ti不影响REX细胞在悬浮培养中的生长。从抗T3抗性REX细胞的琼脂集落中建立了一个细胞系T3.N1。T3.N1在表型上与REX相同，只是未能表达任何可检测到的T3或Ti表面抗原。抗T3或抗Ti不抑制T3.N1在软琼脂中的集落形成。抗T3或抗Ti作用于T3.N1细胞后，其细胞内钙离子浓度[Ca2+]i没有升高。这些结果表明，除了配体与T3/Ti复合物结合的众所周知的正调节作用外，T3/Ti结合还可导致人T细胞生长的下调信号。
