Dialynas D P, Quan Z S, Wall K A, Pierres A, Quintáns J, Loken M R, Pierres M, Fitch F W
J Immunol. 1983 Nov;131(5):2445-51.
Monoclonal antibody GK1.5 recognizes a previously undescribed murine T cell surface molecule, designated L3T4, which migrates on SDS-PAGE under reducing conditions as a single band with an apparent m.w. of 52,000. L3T4 is expressed by approximately 80% of thymocytes and by approximately 20% of spleen cells. There appears to be poor correlation between expression of L3T4 by functional T cell clones and expression of Lyt-2, expression of the cytolytic phenotype, and class I MHC antigen reactivity. On the other hand, both a class II MHC antigen-reactive HTL clone and an Lyt-1- Mls-reactive HTL clone express L3T4. Analysis of the effect of mAb GK1.5 on PFC responses in adoptive transfer suggests that L3T4 is expressed by the helper/inducer subset of murine T cells. Expression of L3T4 by murine T cells, however, may correlate primarily with class II MHC antigen reactivity rather than with functional phenotype; mAb GK1.5 profoundly blocks antigen-specific cytolysis by the cloned class II MHC antigen-reactive CTL line A15-1.17. Antigen-specific cytolysis by A15-1.17 is blocked by mAb GK1.5 at a step before the lethal hit. Collectively, the flow cytometric, functional, and biochemical data indicate that L3T4 is similar to the human Leu-3/T4 molecule.
单克隆抗体GK1.5识别一种以前未描述过的小鼠T细胞表面分子，命名为L3T4，它在还原条件下的SDS-PAGE上迁移时呈现为一条单一的条带，表观分子量为52,000。约80%的胸腺细胞和约20%的脾细胞表达L3T4。功能性T细胞克隆中L3T4的表达与Lyt-2的表达、溶细胞表型的表达以及I类MHC抗原反应性之间似乎相关性较差。另一方面，一个II类MHC抗原反应性HTL克隆和一个Lyt-1-Mls反应性HTL克隆都表达L3T4。对单克隆抗体GK1.5在过继转移中对PFC反应的影响分析表明，L3T4由小鼠T细胞的辅助/诱导亚群表达。然而，小鼠T细胞中L3T4的表达可能主要与II类MHC抗原反应性相关，而不是与功能表型相关；单克隆抗体GK1.5可显著阻断克隆的II类MHC抗原反应性CTL系A15-1.17的抗原特异性细胞溶解作用。A15-1.17的抗原特异性细胞溶解作用在致死性打击之前的一个步骤被单克隆抗体GK1.5阻断。总体而言，流式细胞术、功能和生化数据表明，L3T4与人类Leu-3/T4分子相似。
