A team of researchers from McMaster, a public research university in Hamilton, Ontario, has revealed that female sex hormone Estradiol can work to prevent women from sexually transmitted viral infections.
Estradiol is a female sex hormone that is present during the menstrual cycle and found in oral contraceptives.
Led by Charu Kaushic, the research demonstrates the underlying mechanism that helps estradiol improve anti-viral responses in mice infected with the herpes simplex virus, type 2 (HSV-2).
According to the World Health Organisation (WHO), HSV-2 is one of the most widespread sexually transmitted infections and has affected more than 530 million people worldwide. The rates of HSV-2 infection are found to be higher in women globally.
Michael G. DeGroote Institute for Infectious Disease Research and McMaster Immunology Research Centre member and the department of pathology and molecular medicine professor Charu Kaushic said: "To the best of our knowledge, this is the first study that has shown how estradiol could be enhancing the immune system to fight against viral infection.
"If this pathway can be verified in women, then we have laid the foundation to address a number of important public health issues, particularly whether some hormonal contraceptives may be better than others for women who are at higher risk of acquiring sexually transmitted infections, such as in Sub-Saharan Africa, where both HIV-1 and HSV-2 infection rates are high."
As part of the study, researchers had implanted estradiol-releasing pellets into female mice whose ovaries had been removed.
The mice were later administered two rounds of an HSV-2 vaccine, followed by a high dose of the virus.
The study revealed that the majority of the mice survived and demonstrated less severe symptoms of the disease, compared to a control group that was not immunised.
Further study of the molecular pathways has also revealed that estradiol primes dendritic cells in the vaginal tract that results in the initiation of anti-viral T cell immunity.
According to the team, the study will help them understand what type of immunity can protect women from sexually transmitted diseases, as well as develop better vaccines for them.
Image: Charu Kaushic led the research team from McMaster. Photo: courtesy of Daily News McMaster.
