Dr. Okeoma Unlocks Hidden Clues for Potential HIV Treatment
Tiny Particles in Semen May Block HIV’s Ability to Multiply—Pointing to New Pathways for More Effective Therapies
While semen is a common transmission route for HIV through sexual contact, it may hold the key to new treatments. Semen contains tiny particles called extracellular vesicles, which act like messengers that carry signals between cells and influence how those cells behave. These vesicles may contain HIV-suppressing molecules, which can block the virus by interfering with the virus’s ability to make copies of itself within the body, according to a new study in Science Signaling by Chioma M. Okeoma, Ph.D., professor and vice chair of research of pathology, microbiology and immunology.
HIV used to be death sentence more than 40 years ago. Although there is no cure, the lifespan for individuals with the disease has increased with treatment with antiretroviral therapy (ART), medicines that stop HIV from multiplying. A major challenge in eradicating the virus is that HIV can hide in the body and create “reservoirs,” causing the continuation of inflammation and allow the virus to persist, despite the use of ART. Current ART treatment is unable to prevent every way in which HIV can make copies of itself, therefore researchers are exploring ways to target the virus, including investigating a protein made by HIV called Tat.
“These findings may lead to opportunities for the development of more effective and durable repressors of HIV by targeting a part of the HIV lifecycle that has not been targeted before,” said Dr. Okeoma.
For HIV to spread, the virus needs a transactivation protein made by the virus, called Tat, and proteins from the body, NF-κB. In the study, "Identification of proteins in semen-derived extracellular vesicles that bind to HIV Tat and host NF-κB and may impair viral replication," researchers, using HIV-infected cells, found that the way that the two key proteins, Tat and NF-κB, worked were disrupted when extracellular vesicles, which are naturally present in human semen, were added. This suggests that extracellular vesicles may have a component that can help stop the virus from spreading.
Dr. Okeoma and her team also studied the extracellular vesicles from HIV-positive and HIV-negative semen and found that there were proteins inside the vesicles that can attach themself to Tat and NF-κB and other proteins that control cell signaling and gene activity. Some of these proteins worked together to slow down the virus’s ability to make copies of itself. This suggests that semen-derived extracellular vesicles may fight HIV through multiple channels, providing important clues for the development of new HIV treatments.
“When HIV first became a public health emergency, it was like the world was coming to an end,” said Dr. Okeoma. “But through the unrelenting work of researchers, antiretroviral drugs were developed. Now, our focus is to develop drugs that could cure and/or eradicate HIV. So, we should be hopeful.”
Dr. Okeoma and her team will further explore the data and the underlying mechanisms to gain a deeper insight that may inform the development of more effective or more durable therapeutics against HIV.
