Immunomodulation of reproductive systems

Immunomodulation of reproductive systems is a means of increasing or decreasing reproductive efficiency. In veterinary medicine, it may be applied to ‘castrate’ animals without removing the gonads and to treat diseases caused by hormonal imbalance. Endogenous hormones are recognized as ‘self’ by an animal. To acquire a foreign antigen for immunization purposes, endogenous hormones are usually coupled to a molecule that is foreign to the animal. For immunoneutralization of endogenous hormones, a high titer of specific antibodies is required, a requirement that is often difficult to meet. Nevertheless, in the last decade it has been demonstrated that endocrine systems can be influenced using active and passive immunization against steroid hormones, such as androstenedione, protein hormones, such as inhibin, and peptide hormones, such as luteinizing hormone releasing hormone (LHRH). A new and promising development is the use of peptides as antigens in active immunization against hormones such as inhibin and human choriogonadotrophin.