- Origin of viruses in semen
- Viral persistence in the male genital tract
- Role of seminal fluid and infected cells on viral sexual transmission
- Interactions between viruses and the male germ line
Origin of viruses in semen
Semen is the main vector of HIV dissemination worldwide and an important vector for many other viruses such as Hepatitis B virus, papillomavirus, herpes viruses…. Furthermore, emerging viruses such as Zika virus and Ebola have also been found to be transmitted by semen. The origin of the infected cells and viral particles contaminating this body fluid remains unknown. We have previously established that several semen-producing organs are infected by HIV/SIV (Houzet et al, Journal of Infectious diseases 2014). We are currently deciphering their contribution to semen contamination, using phylogenetic analyses of HIV, as a model to understand where viruses contaminating semen arise from. We also focus on Zika virus infection of the male genital tract as part of a european project.
Contact: Nathalie Dejucq-Rainsford (DR2 Inserm)
Viral persistence in the male genital tract
In about 8% of men under effective antiretroviral therapy leading to undetectable viral load in the blood, HIV can still be detected in semen. Recently, prolonged excretion of Zika virus in semen has been reported in individuals despite several months of cleared viremia. Ebola virus was also shown to persist in semen from cured men for extended durations. Worryingly, the persistent shedding of Zika and Ebola virus in semen from cured men was reported to lead to the sexual transmission of these pathogens. Our aim is to identify the nature of the viral reservoirs in the male genital tract and decipher the mechanisms leading to persistence, focusing on HIV (Matusali et al, Journal of Virology 2015) and Zika virus.
Role of seminal fluid and infected cells on viral sexual transmission
Semen is a complex fluid with antimicrobial and immunomodulatory activities. We recently found that seminal plasma from HIV+ men modulates the infection of CD4+ T lymphocytes by HIV (Camus et al, AIDS 2016). We are currently exploring the role of infected seminal leukocytes in the sexual transmission of HIV, an essential aspect to improve strategies of prevention of sexual transmission.
Interactions between viruses and the male germ line
Endogenous retroviruses constitute 8% of our genome. The ancient infection of the germinal lineage by viruses of the same family as HIV (lentiviruses) has been recently evidenced in mammals. We and others have revealed the presence of HIV/SIV nucleic acids in the human and non-human primate testicular germ cells. To determine whether HIV may integrate into the germ line, we study HIV interactions with human testicular germ cells.