Kamada Masaharu, Maegawa Masahiko, Daitoh Toshihumi, Mori Kazumasa, Yamamoto Satoshi, Nakagawa Koji, Yamano Syuji, Irahara Minoru, Aono Toshihiro, Mori Takahide
Department of Obstetrics and Gynecology, Health Insurance Naruto Hospital, Naruto.
School of Medicine, The University of Tokushima, Tokushima and.
Reprod Med Biol. 2006 May 19;5(2):95-104. doi: 10.1007/BF03016145. eCollection 2006 Jun.
Immune reactions against gametes appear to be physiologically important for the maintenance of homeostasis in reproduction. In contrast, aberration of the immune homeostasis might give rise to 'immunological infertility'. Antisperm antibodies cause infertility by blocking fertilization. The mechanism can be explained as inhibiting the acrosome reaction of sperm by their blocking effect on capacitation through inhibiting an increase of fluidity of the sperm membrane. Autoantibodies against zona pellucida also cause infertility by blocking sperm-zona pellucida interaction, though the definitive mechanism has not been elucidated. Pretreatment of spermatozoa with D-mannnose completely inhibited sperm penetration through, but not binding to, the zona pellucida. Furthermore, very rapid kinetics between sperm extracts and D-mannnose by a BIAcore apparatus suggest that a D-mannose ligand of the sperm surface is easy to bind to and dissociate from a D-mannose residue in the sperm receptor site on the zona pellucida. Thus, D-mannnose on the human zona pellucida might be an essential molecule acting as a second sperm receptor, through which sperm penetrate into the zona pellucida. Because these antibodies appear to not cause any deleterious clinical symptoms, sperm and zona pellucida antigens are promising candidates in the development of an immunocontraceptive. (Reprod Med Biol 2006; : 95-104).
针对配子的免疫反应似乎对维持生殖内环境稳定具有重要的生理意义。相比之下，免疫内环境稳定的异常可能会导致“免疫性不孕”。抗精子抗体通过阻断受精导致不孕。其机制可解释为，通过抑制精子膜流动性增加对获能的阻断作用，从而抑制精子的顶体反应。针对透明带的自身抗体也通过阻断精子与透明带的相互作用导致不孕，尽管确切机制尚未阐明。用D-甘露糖预处理精子可完全抑制精子穿过透明带，但不影响其与透明带的结合。此外，通过BIAcore仪器检测发现精子提取物与D-甘露糖之间的动力学非常迅速，这表明精子表面的D-甘露糖配体很容易与透明带上精子受体位点的D-甘露糖残基结合并解离。因此，人透明带上的D-甘露糖可能是一种作为第二精子受体的关键分子，精子通过它穿透透明带。由于这些抗体似乎不会引起任何有害的临床症状，精子和透明带抗原有望成为免疫避孕研究的候选对象。（《生殖医学与生物学》2006年；：95 - 104）
