CD8糖蛋白对T细胞发育和活化具有重要作用。啮齿类CD8是异二聚体,由α和β链组成。在人类,由于过去只发现存在α链,因而长期认为CD8是同型二聚体。最近,Johnson等克隆了人CD8β基因组的部分片段,并在人胸腺细胞和人T细胞瘤中发现有CD8β转录产物,而且其转录水平与CD8α相当。为了证明人CD8β基因转录产物包含编码具有正常 CD8 glycoproteins play an important role in the development and activation of T cells. Rodent CD8 is a heterodimer composed of alpha and beta chains. In humans, CD8 is thought to be a homodimeric for a long time because only alpha chains were found in the past. Recently, Johnson et al cloned partial fragments of the human CD8β genome and found CD8β transcripts in human thymocytes and human T-cell tumors, with transcription levels comparable to those of CD8α. In order to demonstrate that human CD8β gene transcription products contain coding sequences with normal