IMMUNOCHEMICAL CHARACTERIZATION AND ANTIFERTILITY EFFECT OF AN ANDROGEN-INDEPENDENT ANTIGEN OF SPERMATOZOA IDENTIFIED BY A MONOCLONAL-ANTIBODY (D(7)G(3))
Je. Fernandes et Uc. Hegde, IMMUNOCHEMICAL CHARACTERIZATION AND ANTIFERTILITY EFFECT OF AN ANDROGEN-INDEPENDENT ANTIGEN OF SPERMATOZOA IDENTIFIED BY A MONOCLONAL-ANTIBODY (D(7)G(3)), Indian Journal of Biochemistry & Biophysics, 34(3), 1997, pp. 274-287
Monoclonal antibody, (mAb) D(7)G(3), directed to human spermatozoa and
cross-reactive with mouse and rat spermatozoa was found to be a sperm
agglutinating antibody. It reacted with antigen present on the post a
crosomal region of human spermatozoa and acrosomal region of mouse spe
rmatozoa. The antigen reacting with mAb D(7)G(3) was localized in mous
e testicular germ cells and Sertoli cells. It was also localized in th
e epithelium and spermatozoa of the caput, corpus and cauda epididymid
es. In addition, the antigen was detected in the epithelial cells and
secretions of the prostate and seminal vesicle. The mAb D(7)G(3) react
ed with a band of molecular mass 16 kDa in testicular and epididymal s
perm and protein preparations of ventral prostate. In the seminal vesi
cle, an additional band of molecular mass 36 kDa was also identified.
The effect of castration on the expression of proteins was studied in
the rat. Immunohistochemical localization and Western blotting experim
ents showed that the antigens identified by the mAb D(7)G(3) was detec
table in the epididymis, ventral prostate and seminal vesicle after tw
o weeks of castration. In the seminal vesicle, three additional bands
were identified by mAb D(7)G(3) following castration. The expression o
f this antigen throughout spermatogenesis and sperm maturation indicat
ed that it may have an important biological function. A polyclonal ant
iserum directed to the 16 kDa mouse epididymal sperm protein was raise
d in rabbits. Passive immunization of female mice with this antibody c
aused a significant reduction in fertility only if administered 24 hou
rs prior to mating, indicating that the antibody inhibited a pre-ferti
lization event by inhibiting sperm function.