Importance of CD2-LFA-3 interaction in differentiation and function of T and NK cells.

1.我们克隆和测序的小鼠CD 2的cDNA，并注意到一个高度保守的一级结构，其细胞质区域之间的人类和小鼠CD2.2。通过筛选大鼠抗小鼠CD 2单克隆抗体与转染小鼠CD 2 cDNA的大鼠成纤维细胞的反应性，建立了5株大鼠抗小鼠CD 2单克隆抗体.通过流式细胞仪和北方印迹分析，我们发现，大多数B细胞以及T和NK细胞表达的CD 2在小鼠中不同于在人类。小鼠B细胞在前B期出现CD 2.实验证明了小鼠CD 2细胞的粘附功能及单克隆抗体对CD 2细胞粘附的抑制作用.我们建立了额外的仓鼠单克隆抗体与不同的表位反应，从大鼠单克隆抗体识别的免疫亲和纯化的小鼠CD 2分子。大鼠和仓鼠单克隆抗体的某些组合诱导小鼠T细胞活化和增殖，表明小鼠CD 2与人CD2.6一样构成T细胞活化的替代途径。在通过cDNA转染引入CD 2后，CD 2 ^- T细胞杂交瘤可以对低40至10倍浓度的Ag产生应答。在引入缺失大部分胞质区域的突变体CD 2后没有观察到这种Ag应答的增强，表明CD 2介导的信号转导在调节T细胞Ag应答中的重要性。将CD 2引入CD 2 ^- NK细胞系诱导了针对某些靶细胞的结合和细胞毒性。相反，胞质缺失突变体的结合能力相当，但细胞毒性大大降低，表明CD 2在调节NK细胞结合和细胞毒性中具有重要作用. CD 2在小鼠胸腺发育早期即出现在胸腺细胞上。然而，到目前为止，当加入到胎儿胸腺器官培养物中时，尚未观察到抗CD 2 mAb对T细胞发育的影响。

1. We cloned and sequenced the murine CD2 cDNA and noted a highly conserved primary structure of its cytoplasmic region between human and mouse CD2.2. We established five rat anti-mouse CD2 mAbs by screening their reactivities to rat fibroblasts transfected with the mouse CD2 cDNA.3. By FACS and Northern blot analyses, we revealed that most B cells as well as T and NK cells express CD2 in mice unlike in humans. CD2 appeared on murine B cells at the pre-B stage.4. We demonstrated the adhesion function of mouse CD2 and inhibitory effects of our mAbs on it.5. We established additional hamster mabs reactive with distinct epitopes from those recognized by rat mabs by immunizing with affinity-purified mouse CD2 molecules. Certain combinations of the rat and hamster mabs induced mouse T cell activation and proliferation, indicating that mouse CD2 constitutes an alternative pathway of T cell activation like human CD2.6. A CD2^- T cell hybridoma could respond to 40 to 10-fold lower concentrations of the Ag after CD2 introduction by cDNA transfection. Such an augmentation of Ag response was not observed after introduction of a mutant CD2 lacking most of cytoplasmic region, indicating an importance of the CD2-mediated signal transduction in regulating T cell Ag response.7. Introduction of CD2 into a CD2^- NK cell line induced binding and cytotoxicity against certain target cells. In contrast, that of cytoplasmic deletion mutant led to a comparable binding but a greatly reduced cytotoxicity, demonstrating an important role of CD2 in regulating NK cell binding and cytotoxicity.8. CD2 appeared on murine thymocytes very early during fetal thymus ontogeny. However, so far no effect of anti-CD2 mAbs on T cell development has been observed when added into fetal thymus organ cultures.