Contraceptive responses of female hamsters immunized with recombinant sperm protein P26h.
BACKGROUND
A number of antigens have been characterized and proposed as potential candidates for immunocontraception. P26h, a 26-kDa hamster sperm protein located on the acrosomal cap, is known to be involved in sperm-zona pellucida interactions. Furthermore, in vivo fertilization can be blocked by active immunization of male hamsters against P26h or maltose-binding protein recombinant P26h (MBP-P26h).


OBJECTIVE
The aim of this study was to investigate the immune response and reproductive function of female hamsters immunized against MBP-P26h.


RESULTS
Active immunization against MBP-P26h resulted in anti-P26h circulating antibodies, with enzyme-linked immunosorbent assay (ELISA) titers showing interindividual variability. The antibodies produced by the animals immunized against MBP-P26h reacted with the native P26h protein in ELISA, in Western blot analysis and in immunostaining performed on cauda epididymal spermatozoa. Mating of immunized female hamsters resulted in a significant decrease in the number of viable fetuses only in females with high titers of anti-P26h circulating antibodies.


CONCLUSIONS
This result is in agreement with the sperm-zona pellucida binding assay's results. Indeed, sera collected from immunized animals, and not from control animals, significantly blocked sperm-zona pellucida binding in vitro. Histological studies showed that active immunization did not cause any pathology in the reproductive tissues.


CONCLUSIONS
These findings suggest that P26h is a potential candidate for the development of a contraceptive vaccine in both males and females.
Dubé
Evemie
E
Centre de Recherche en Biologie de la Reproduction and Département d'Obstétrique-Gynécologie, Faculté de Médecine, Université Laval, Québec Canada.
Legaré
Christine
C
Gaudreault
Christian
C
Sullivan
Robert
R
D000429:Alcohol Oxidoreductases / Q000276:immunology*; D000818:Animals; D000906:Antibodies / Q000097:blood; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000276:immunology*; D003269:Contraception, Immunologic; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D004822:Epididymis / Q000276:immunology; D005260:Female; D007114:Immunization; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D011247:Pregnancy; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000276:immunology
D000906:Antibodies; D015815:Cell Adhesion Molecules; C118288:sperm antigen P26h; D000429:Alcohol Oxidoreductases