120. SPRASA A POTENTIAL CONTRACEPTIVE VACCINE TARGET?
L. W. Chamley A , A. Wagner A and A. N. Shelling AObstetrics and Gynaecology, University of Auckland, Auckland, New Zealand.
Reproduction, Fertility and Development 22(9) 38-38 https://doi.org/10.1071/SRB10Abs120
Published: 6 September 2010
Abstract
A number of attempts have been made to develop immunocontraceptive vaccines for use in humans or animals. We have reported the discovery of a sperm-specific protein, SPRASA, as the antigen for antisperm antibodies in some infertile men [1]. More recently we found that SPRASA is also expressed by oocytes. The expression of SPRASA by both sperm and oocytes makes it a potential target for an immunocontraceptive vaccine that might function in both males and females. We undertook this study to investigate whether immunising mice against SRPASA would affect fertility. Ethical approval was obtained from the Animal Ethics Committee. Two groups of five female CD1 mice were immunised, up to four times, with recombinant human SPRASA or with keyhole limpet haemocyanin (KLH, controls). After immunisation, the females were date-mated with males of proven fertility and monitored for coital plugs. Weights were monitored for 12 days post mating to confirm pregnancy or lack of pregnancy. Mice that were not pregnant were again dated-mated. Mice that were pregnant were euthanased and their litters examined. Ovaries from three SPRASA and three control immunised mice were sectioned to completion and examined for follicles of various stages. All of the control KLH immunised female mice became pregnant within two matings. In contrast, the SPRASA-immunised females were profoundly infertile and none of them became pregnant despite being mated no fewer than five times each. There were no significant differences in the numbers of primary, early antral, antral or pre-ovulatory follicles between the SPRASA and control mice but there were fewer primordial in the SPRASA immunised females (P = 0.0028). Antisperm (and antioocyte) antibodies have long been known to be associated with infertility. Our results show SPRASA appears to be crucial for fertility and which may be a useful target for a contraceptive vaccine.
(1) Chiu, W.W., et al., SPRASA, a novel sperm protein involved in immune-mediated infertility. Hum Reprod, 2004. 19(2): 243–9.
