Testicular Isoform of Angiotensin I-Converting Enzyme (ACE, CD143) on the Surface of Human Spermatozoa: Revelation and Quantification Using Monoclonal Antibodies
Article first published online: 6 DEC 2005
American Journal of Reproductive Immunology
Volume 55, Issue 1, pages 54–68, January 2006
How to Cite
Nikolaeva, M. A., Balyasnikova, I. V., Alexinskaya, M. A., Metzger, R., Franke, F. E., Albrecht, R. F., Kulakov, V. I., Sukhikh, G. T. and Danilov, S. M. (2006), Testicular Isoform of Angiotensin I-Converting Enzyme (ACE, CD143) on the Surface of Human Spermatozoa: Revelation and Quantification Using Monoclonal Antibodies. American Journal of Reproductive Immunology, 55: 54–68. doi: 10.1111/j.1600-0897.2005.00326.x
- Issue published online: 6 DEC 2005
- Article first published online: 6 DEC 2005
- Submitted April 28, 2005; revised July 21, 2005; accepted September 21, 2005.
- Flow cytometry;
- monoclonal antibodies;
- testicular ACE
Problem The elucidation of the role of angiotensin-converting enzyme (ACE, CD143) in the male fertility has been hampered by the absence of highly specific antibodies to the native testicular isoform (tACE). The quantification of tACE expression on human-ejaculated spermatozoa was performed using a novel panel of monoclonal antibodies (mAbs).
Method of study The expression of tACE on the surface of live and fixed human spermatozoa was analyzed by flow cytometry and immunocytochemistry using new mAbs to human tACE.
Results Monoclonal antibodies 1E10 and 4E3 similarly revealed tACE on the surface of live and fixed spermatozoa. The high percentage of tACE-positive spermatozoa (median 81%) was revealed in the swim-up fraction of sperm. Antibody-induced tACE shedding occurs preferentially from live sperm with defective function and/or morphology. Testicular ACE is located on the plasma membrane of the post-acrosomal region, the neck and midpiece of normal spermatozoa, but showed a variable distribution on the defective cells.
Conclusions The new mAbs recognizing the C-terminal domain of human ACE are useful tools for quantification of tACE expression on human live and fixed spermatozoa and further adequate analysis of the tACE role in reproduction.