RESEARCH: Stopping HIV from where it starts

Dr. Marianne Mureithi, from the University of Nairobi is part of a team of researchers carrying out study on mucosal immune responses to HIV in Kenya.

Funding and effort has gone into understanding the body’s immune response to HIV, with scientific investigations of the blood. Now a team of UoN researchers KAVI-Institute of Clinical Research (KAVI-ICR) at the University of Nairobi has been awarded two research grants from the National Institute of Health (NIH) and the Swedish Research Foundation to investigate the body’s defense but this time studying the mucosal tissues of sexual organs.

The human body comes into contact with the HIV virus first through the male and female reproductive tract after which a HIV infection occurs. The study is aimed at understanding how the HIV type 1 virus interacts with the cells in the reproductive tract in those first stages. This will move the country a step closer to finding HIV vaccine and other preventive measures.

The KAVI-Team and Prof. Tom Hope and his team from Northwestern University in the United States of America received the award from the National Institute of Health, United States of America’s primary body for biomedical and public health research. In addition, the KAVI-ICR team in collaboration with Prof. Kristina Broliden and her team from Karolinska Institute in Sweden also received an award to further these studies.

The researchers will also extend the curiosity into the reproductive system by studying a popular injectable hormonal contraception in Sub Saharan Africa depo medroxy-progesterone acetate known to many as Depo-Provera.

Dr. Marianne Mureithi explained to the reason for veering off studying the blood and focusing on the male and female sexual organs: “Human tissues are layered up with mucus as a protective barrier against germs. HIV transmission primarily occurs across the mucosal surfaces of the genital or anal tracts during sexual intercourse. To advance HIV prevention science, we need a better understanding of the male and female reproductive tract mucosal system”

During sexual intercourse between a man and a woman, the HIV positive partner will transmit the virus into the vaginal canal, into the cervix, into the uterus and subsequently into the blood stream. In men who have sex with men, the virus moves from the semen to the penis into anus then into the rectum.

Dr. Mureithi and her colleagues will study the mucosal layer of the reproductive tract mentioned above studying the actual sequence of events during transmission.

“We are studying the cells that are infected, at what rate they are infected, how deep the virus penetrates inside the cells and how the immune system interacts with the virus at this very initial stage of infection”, she said.

It is believed this is the first time a lab in sub-Saharan Africa has visualized this kind of virus-immune system interaction and this was through support and funding from the International AIDS Vaccine Initiative (IAVI) and USAID.

The scientists are cutting female reproductive tract tissues into small pieces—called explants (donated by patients undergoing hysterectomy surgery)—and vaginal-cervical mucus donated by people in Nairobi Kenya to observe the changes in the mucosal system that alters epithelial and mucus barrier function.

Using a new technology called explant model through which the scientists will watch how HIV infects and also what cells are involved in HIV transmission at this initial stage of HIV exposure in the reproductive tract.

The technology will also study at the cell level the effects of progestin on the female reproductive tract and the interactions between progestin and HIV.

In addition, there is epidemiological information suggesting that the use of progestin contraceptives such as Depo-Provera increases the risk of HIV infection in women following exposure. The above current technology will allow us to study at the cell level the effects of progestin on the female reproductive tract and the interactions between progestin and HIV.

The results obtained will be critical in policy formulation and use of progestin in family planning.