HPV in semen: evaluation of the link among infection, sperm parameters and viral genome integration

Human papillomaviruses (HPVs) are agents of the most common sexually transmitted diseases. Both in men and in women, HPVs cause a variety of clinical symptoms ranging from warts to cancer. It has been shown that infection with oncogenic HPV is the major cause of development of cervical cancer in women and less frequently of penile cancers in men. HPV infects epithelial cells and can bind other cell types. Its presence in semen is widely known, but the effects on fertility and reproductive function are still controversial. Partners of women with high-grade squamous intraepithelial lesions were enrolled. From each subject seminal parameters were evaluated. HPV was detected and genotyped both in total semen and in swim up-fraction. In order to verify the cause-effect relationship between HPV presence in semen and sperm quality, we developed a new approach (differential cell lysis, DNA extraction and nested PCR) to evaluate virus localization in the different semen components. Our data indicate a correlation between HPV infection of exfoliated cells and reduction of sperm cell motility. Moreover, we analyzed the physical state of HPV18 DNA in sperm cells by qPCR. Our results suggest a possible integration event during which a disruption of the HPV genome occurs, causing the deletion of E1 and E2 genes. The data support the proposed role of HPV in decreased male and couple fertility and prompt new possible consequences of the viral infection in semen.