Study of the relation between chlamydia trachomatis infection and beta-defensin 126 (DEFB126) gene deletion in infertile men refered to Royan Institute

Background: Chlamydia Trachomatis (CT), an obligate intracellular bacteria, requires living cells to replicate itself. Half of men infected with CT are asymptomatic. CT infection can remain up to four years in the couple and affect their fertility. The relationship between CT and infertility is very important because most patients are asymptomatic and untreated. Most common symptoms of infection in men include urethritis, epididymitis, urinary tract inflammations and reduced sperm quality. One of the most important components of the Sperm Glycocalyx surface coating in human is DEFB126 protein. This polypeptide covers surface of sperm cells during passing through epididymis and has important role in immune system. Human β-defensin 126 (12kDa) is a small cationic glycoprotein that is highly rich of cysteine. DEFB126 gene is located on the subtelomeric end of 20p13 in human. It is considered as an important component of the human sperm glycocalix and provides protection for sperms from infection-causing microbes and against the female immune system.Methods: According to the role of DEFB126 against infection, the aim of this study was to investigate the frequency of deletion of two nucleotides in gene DEFB126 and its relation with the prevalence of Chlamydia trachomatis (CT) in semen samples of Iranian infertile patients, referred to Royan Institute. In this study, among1080 patients with poor sperm parameters, were selected for primary screening and detecting, 155(14.3%) patients were diagnosed with ELISA test .The Sperm s DNA was extracted in order to confirm the presence of Chlamydia. Chlamydia genome amplification was performed using specific primers. Among these samples with CT, 50 patients of whom symptomatic and 50 patients were asymptomatic, were considered on cytosine dinucleotide deletion with Standard PCR ،Sequencing and 70 fertile men with normal sperm quality and without any past history of CT infection were selected as controls. Result: The results showed that among three types of genotypes seen in these cases, wt/wt, heterozygous wt/del and homozygous mutation del/del, males who had CT infection showed significantly higher frequency of homozygous mutations del/del in DEFB126. Conclusion: The results of this study demonstrated that, because of gene mutation in DEFB126 in Iranian infertile men with CT infection,the immunogenicity role of DEFB126 can be impaired. Accordingly, patients with this mutation are more susceptible and prone to develop infections such as Chlamydia Trachomatis.

کلیدواژه ها:

Glycocalyx ، β-defensin 126 ، Chlamydia trachomatis ، Male infertility