早在80年代,科学家已经认识HIV(buman im-munodeficiency virus)的感染与其外膜蛋白gp120与细胞表面的CD_4分子的相互作用密切相关,CD_4分子被认为是HIV的受体,但科学家在1986年就发现单CD_4分子并不足以使HIV进入细胞体内。1996年,哥伦比亚大学Maddon用基因工程手段得到表达人CD_4分子的小鼠细胞系,发现其不被HIV感染,说明在艾滋病毒感染的过程中存在其它的因素。 As early as the 1980s, scientists have recognized that the infection of HIV (buman im-munodeficiency virus) is closely related to the interaction between its outer membrane protein gp120 and the cell surface CD_4 molecule, which is considered as HIV receptor. However, scientists in 1986 Found that a single CD_4 molecule is not enough to make HIV into the cell body. In 1996, Maddon obtained a mouse cell line expressing human CD_4 gene by genetic engineering and found that it was not infected with HIV, indicating that there are other factors in the process of HIV infection.