Premature Ovarian Failure Syndrome May Be Induced by Autoimmune Reactions to Zona Pellucida Proteins

Autoimmunity is thought to be involved in pathogenesis of the premature ovarian failure (POF) causing infertility. The zona pellucida (ZP), an extracellular matrix surrounding the oocyte, is considered to be pathogenic among autoantigens, because many contraceptive vaccine research has shown that anti-ZP antibodies impair ovarian function in animal experiments. In this article we describe the importance of ZP in oocyte growth and the possible effects of anti-ZP antibodies on ovarian failure. Clinical experiments were conducted to detect anti-ZP antibodies in POF patients by dot immunoassay and immunofluorescent staining method. Also, as an animal model experiment, we examined whether or not peptide ZP antigens of same-species amino acid sequences could produce autoantibodies reactive to ZP. The results showed that antibodies were produced by immunisation with the antigens and histological examination revealed that the number of growing follicles was considerably reduced. These results conclusively indicated that self-ZP protein is a possible pathogenic antigen for autoimmunity causing POF.