Yeung C H, Cooper T G, Nieschlag E
Institute of Reproductive Medicine of the University, Münster, Germany.
Mol Hum Reprod. 1997 Dec;3(12):1045-51. doi: 10.1093/molehr/3.12.1045.
CD52 is a glycosylphosphatidylinositol-anchored glycoprotein secreted by the epididymis where it is incorporated into sperm membranes. The antigen is common to spermatozoa and lymphocytes, and its role is not known. Quantitative analysis using immunostaining with the monoclonal antibody CAMPATH-1G and flow cytometry indicated positive signals from approximately 80% of viable, washed ejaculated spermatozoa. Staining intensity increased after capacitation overnight, and decreased after short incubation with high density lipoprotein. After incubation of Percoll-washed spermatozoa with CAMPATH-1G, motility was reduced from 83 to 74% after 5 min and from 73 to 52% after 3.5 h. Swimming velocities were reduced by approximately 30% and linearity by 15% in 5 min, but no further decreases were observed over 3.5 h. After 20 min incubation with the antibody, cell viability was decreased by 10 and 20% in freshly washed and capacitated spermatozoa respectively. Comparison of fertile and infertile patients revealed no difference in the percentages of immunostained spermatozoa or in staining intensity and there were no differences in sperm labelling between normozoospermia and teratozoospermia. Compared with normozoospermia, percentages of stained spermatozoa were lower by 20 and 27% in asthenozoospermia and oligozoospermia respectively, whereas staining intensity in asthenozoospermia was less than half that in oligozoospermia. The correlation of percentages of stained spermatozoa with percentages of motile cells suggests the involvement of epididymal CD52 in the maturation of sperm function.
CD52是一种糖基磷脂酰肌醇锚定糖蛋白，由附睾分泌并整合到精子膜中。该抗原在精子和淋巴细胞中都存在，其作用尚不清楚。使用单克隆抗体CAMPATH-1G进行免疫染色和流式细胞术的定量分析表明，约80%的存活、洗涤后的射出精子呈现阳性信号。过夜获能后染色强度增加，而与高密度脂蛋白短时间孵育后染色强度降低。用CAMPATH-1G孵育经Percoll洗涤的精子后，5分钟内活力从83%降至74%，3.5小时后从73%降至52%。5分钟内游泳速度降低约30%，直线性降低15%，但在3.5小时内未观察到进一步下降。与抗体孵育20分钟后，新鲜洗涤的精子和获能精子的细胞活力分别降低了10%和20%。对可育和不育患者的比较显示，免疫染色精子的百分比、染色强度均无差异，正常精子症和畸形精子症之间的精子标记也无差异。与正常精子症相比，弱精子症和少精子症中染色精子的百分比分别低20%和27%，而弱精子症中的染色强度不到少精子症的一半。染色精子百分比与活动细胞百分比之间的相关性表明附睾CD52参与了精子功能的成熟。
