Research progress on NLRP3 inflammasomes in male reproductive immunity

Abstract

The male reproductive immune system plays a pivotal role in safeguarding sperm from immune attacks and preventing the incursion of foreign pathogens. Nucleotide-binding and oligomerization domain-like receptors (NOD-like receptors, NLRs) family protein domain containing 3 (NLRP3) is a cytoplasmic sensor binding to the inflammasome and critically involved in inducing innate immunity in the testes. It also has a substantial impact on male reproductive immunity, which is closely associated with male infertility stemming from disorders related to the male reproductive immune system. This review introduces the distinct characteristics of the NLR family, elucidates the activation pathways and factors of NLRP3 inflammasomes, and discusses how they participate in male reproductive immune diseases such as bacterial orchitis, autoimmune orchitis, varicocele, and epididymitis. In bacterial orchitis, elevated levels of NLRP3 inflammasomes exacerbate the testicular inflammatory injury and lead to decreased testosterone, thus contributing to male infertility. In autoimmune orchitis, the NLRP3 inflammasomes inhibit testosterone synthesis by decreasing the expression of cytochrome P450, thereby impacting male reproductive function. Therefore, targeting NLRP3 could offer novel immunological strategies for the clinical treatment of male infertility.