Chapters authored
Sertoli Cell Phagocytosis: An Essential Event for Spermatogenesis
During spermatogenesis, most male germ cells undergo apoptosis, and the cytoplasmic portions of the elongating spermatids are shed as residual bodies (RB). Both apoptotic germ cells (AGC) and RB must be phagocytosed by Sertoli cells, which are essential to maintain testicular homeostasis for normal spermatogenesis. The phagocytosis of AGC and RB by Sertoli cells confers various meanings, including elimination of apoptotic components, removal of autoantigens, and the recycle of degenerated substrates as an energy source. Sertoli cell phagocytosis can be regulated by various mechanisms. The impairment of Sertoli cell phagocytosis may disrupt tissue homeostasis in the testis, thereby impairing to testicular function and spermatogenesis. This chapter discusses the mechanisms underlying phagocytic removal of AGC and RB by Sertoli cells and the consequences of this biological event for spermatogenesis and male fertility.
Part of the book: Male Reproductive Health
Innate Immune Defense in the Male Reproductive System and Male Fertility
To protect the male germ cells from adverse immune reaction, the male reproductive system adopts special immune environment such as immunoprivileged status. The male genital organs can be infected by various microorganisms via hematogenous dissemination and ascending genitourinary tracts. To overcome the immunoprivileged status, the male genital organs also adopt their own innate defense against microbial infection. The tissue-specific cells in the male reproductive system are well equipped with innate immune machineries, including pattern recognition receptors (PRRs) and their negatively regulatory system. PRR-initiated immune responses must be tightly regulated by the negative regulatory system for the maintenance of immune homeostasis. The immune homeostasis can be disrupted by unrestrictive innate immune response, which may lead to inflammatory conditions in the male genital tracts, an important etiological factor contributing to male infertility. This chapter describes the current understanding of the innate immune responses in the male reproductive system and their effects on male fertility.
Part of the book: Innate Immunity in Health and Disease