Vaccines and passive immunological approaches for the control of fertility and hormone‐dependent cancers

Abstract

Reviewed here is the development of a vaccine against the human chorionic gonadotropin that prevents pregnancy in sexually active women without impairment of ovulation or derangement of menstrual regularity. Also reviewed are the vaccines inducing antibodies against the luteinizing hormone-releasing hormone, which have immunotherapeutic potential in prostatic hypertrophy and other sex hormone-dependent male and female cancers. The adoption of passive immunization using humanized recombinant antihormone antibodies is advocated for assured efficacy and safe, prompt therapeutic action.

The development of contraceptive vaccines

“…The other members of the family are luteinising hormone (LH), follicle-stimulating hormone (FSH) and thyroid-stimulating hormone (TSH). Even though each carries a hormone-unique β-chain, there is extensive sequence homology between the β-chains of hCG and LH leading to the production of LH-cross-reactive antibodies following vaccination with the intact hCG β-chain [24]. However, the carboxy-terminal region of the hCG β-chain, referred to as the Cterminal peptide (CTP), is a unique feature of hCG.…”

“…The HSD vaccine was therefore extremely successful in preventing pregnancy, but only in the moderate to high antibody responders. Although this has been the only phase II clinical trial of a contraceptive vaccine so far, the HSD trial was of extreme importance because it established the efficacy of a vaccine approach for protecting against undesired pregnancy [24].…”

“…This strategy endowed upon the β-chain a structure more akin to the native heterodimer than is the case for the isolated β-chain alone. Furthermore, the HSD is more immunogenic than the isolated β-chain and more faithfully mimics the native hormone in functional assays [24]. The HSD was conjugated to either tetanus toxoid (TT) or to diphtheria toxoid (DT) used as alternating carriers for the vaccine.…”

“…The phase II trials were carried out in India, with informed written consent obtained from healthy females aged [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. Three primary injections were given at 6 week intervals, and boosters administered when necessary to maintain antibody titres above 50ng/ml of hCG bioneutralising specific antibody.…”

Active immunisation of mice with GnRH lipopeptide vaccine candidates: Importance of T helper or multi-dimer GnRH epitope

“…An active area of research is the development of synthetic GnRH-based vaccines against reproductive hormone-dependent male and female cancers. 1 Studies have shown that immunisation against GnRH can reduce prostate levels of testosterone similar to surgical castration in numerous mammalian models, including mice and humans. 2,3 Immunisation of both males and females against GnRH can have a profound effect on fertility through the reduction in sex steroids and cessation of gametogenesis.…”