Heterophilic binding of the adhesion molecules poliovirus receptor and immunoglobulin superfamily 4A in the interaction between mouse spermatogenic and sertoli cells
Heterophilic binding of the adhesion molecules poliovirus receptor and immunoglobulin superfamily 4A in the interaction between mouse spermatogenic and sertoli cells
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DOI：
10.1095/biolreprod.106.058974
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发表时间：
2007-06-01
影响因子：
3.6
通讯作者：
Iseki, Shoichi
中科院分区：
文献类型：
--
作者：
Wakayama, Tomohiko;Sai, Yoshimichi;Iseki, Shoichi
细胞粘附蛋白免疫球蛋白超家族4A （IGSF4A）在小鼠睾丸生精细胞表面表达。在精子发生过程中，IGSF4A被认为以嗜异性的方式与支持细胞表面结合。为了鉴定IGSF4A的未知伴侣，我们制备了针对原代培养的小鼠Sertoli细胞膜蛋白的大鼠单克隆抗体。利用这些单克隆抗体，我们分离出一个克隆，对Sertoli细胞进行免疫染色，并与小鼠睾丸匀浆的免疫沉淀产物与抗icsf4a抗体反应。随后，为了鉴定该单克隆抗体可识别的Sertoli细胞膜蛋白，我们对小鼠睾丸的cDNA文库进行了表达克隆。因此，我们确定了另一种igsf型细胞粘附分子脊髓灰质炎病毒受体（PVR）作为IGSF4A的结合伙伴。针对PVR和IGSF4A的抗体在小鼠睾丸匀浆中免疫沉淀。在精子发生的所有阶段，支持细胞中存在PVR的免疫反应性，但在生精细胞中不存在。在小鼠支持细胞系TM4中过表达PVR，使其粘附于表达IGSF4A的人类细胞系Tera-2的能力增加了三倍以上。这些发现表明，PVR与IGSF4A的异源性结合至少在一定程度上导致了小鼠精子发生过程中Sertoli与生精细胞之间的相互作用。
The cell adhesion protein immunoglobulin superfamily 4A (IGSF4A) is expressed on the surfaces of spermatogenic cells in the Mouse testis. During spermatogenesis, IGSF4A is considered to bind to the surface of Sertoli cells in a heterophilic manner. To identify this unknown partner of IGSF4A, we generated rat monoclonal antibodies against the membrane proteins of mouse Sertoli cells grown in primary culture. Using these monoclonal antibodies, we isolated a clone that immunostained Sertoli cells and reacted with the product of immunoprecipitation of the homogenate of mouse testis with anti-ICSF4A antibody. Subsequently, to identify the Sertoli cell membrane protein that is recognized by this monoclonal antibody, we performed expression cloning of a cDNA library from the mouse testis. As a result, we identified poliovirus receptor (PVR), which is another IGSF-type cell adhesion molecule, as the binding partner of IGSF4A. The antibodies raised against PVR and IGSF4A immunoprecipitated both antigens in the homogenate of mouse testis. Immunoreactivity for PVR was present in Sertoli cells but not in spermatogenic cells at all stages of spermatogenesis. Overexpression of PVR in TM4, a mouse Sertoli cell line, increased more than three-fold its capacity to adhere to Tera-2, which is a human cell line that expresses IGSF4A. These findings suggest that the heterophilic binding of PVR to IGSF4A is responsible, at least in part, for the interaction between Sertoli and spermatogenic cells during mouse spermatogenesis.