What's so special about semen?

            Not too long ago AIDS was known as GRID, the gay-related immunodeficiency disease.  Several theories explained the correlation between men who slept with men and the prevalence of this disease.  Back in the day people believed that poppers, a stimulating drug that young gay men took at parties, created the perfect chemical atmosphere in the body for certain infections to take hold and create disease.  Others reverted to the old belief that sin, vice, and immorality were to blame.  Modern theories include the idea that anal tissues have more cellular receptors for the virus.  Nadia Roan, a researcher at UCSF, believes that there may be something special about semen. 

            There are several reasons why Roan has been looking at semen and it’s role in HIV infection.  Several clinical trials looking at microbicides’ ability to inhibit HIV have failed, and one possible reason for these failures is semen.  Simply put in the presence of semen, microbicides are not effective.  In fact including semen with a microbicide makes the substances 20 times less effective and actually makes it 10 times easier for the virus to infect the subject.  “We think this may be one of the factors explaining why so many drugs that efficiently blocked HIV infection in laboratory experiments did not work in a real world setting,” said Roan. But does semen render the microbicides ineffective or does semen enhance the capabilities of the virus to infect an individual even in the presence of a microbicide?  Research shows that the amyloid fibrils, a major component of semen coagulum, provide the virus with a surface to attach to, and these amyloid fibril HIV complexes can easily invade the cell while also repelling microbicides.  But why are microbicides so important?

            For a long time, women in Sub-Saharan Africa have had little options to protect themselves from STIs.  Due to gender power imbalances and gender inequality in many African countries, women don’t have the power to suggest condom use.  Furthermore many areas with these types of gender relations also have higher incidences of rape.  Initially microbicides were established as an option for women who needed a quick fix to protect against HIV and other STIs.  Fortunately, a drug called maraviroc has performed better than other microbicides in the presence of semen. Despite this potential drug, due to the sexual properties of HIV looking further into the relationship of semen and HIV infection must be a priority.      

- Nalani Wakinekona

References

http://www.nbcnews.com/health/sexual-health/semen-boosts-aids-virus-study-finds-n247186

http://stm.sciencemag.org/content/6/262/262ra157.abstract?sid=6959a886-5cee-402b-ab8b-73e32e081523

https://urology.ucsf.edu/people/nadia-r-roan