Harnessing Bacterial Species May Prevent HIV Transmission in Women

Engineering bacteria to deliver HIV-1 neutralizing antibodies at the site where the virus enters the body may offer a cost-effective barrier to HIV-1 transmission.

The engineered anaerobic bacteria Lactobacillus jensenii, which is found in the female lower genital tract, has the potential to be used as a novel protective agent against HIV transmission in women.

Typically, viruses enter into the body through muscosal surfaces. For women, HIV transmission occurs through the vagina and cervix entry sites during sexual intercourse.

“Lactobacilli already play a protective role in the vagina by reducing inflammation, which is a risk factor for HIV infection,” said senior study author Laurel Lagenaur, PhD. “Engineering these bacteria to deliver HIV-1 neutralizing antibodies mucosally at the site where the virus first enters the body may offer a cost-effective and long-lasting new barrier to HIV-1 transmission that is different but compatible with current antiviral therapies, barrier methods or future vaccines.”

A study published in AIDS Research and Human Retroviruses described how the engineering of Lactobacillus jensenii stably expressed broadly neutralizing antibody fragments against HIV.

Prior research has demonstrated that Lactobacilli could be engineered to secrete another anti-HIV protein. Additionally, the successful vaginal colonization by the engineered bacteria was able to reduce vaginal HIV transmission by over 63% in a primate animal model.

“Engineered vaginal Lactobacilli with anti-HIV properties, like the delivery of neutralizing antibodies or antiviral proteins, offer considerable potential as Live Biotherapeutic Products for an important global health need -- reducing the heterosexual transmission of HIV in women,” said Osel Chief Executive Officer, K.T. Moortgat, PhD. “If successfully developed, Osel's MucoCept technology could provide an accessible and durable approach that could be used inexpensively, discretely, and in a way that enhances the natural protective effects of the vaginal microbiota.”

Currently, the MucoCept technology is in pre-clinical development and is expected to reach clinical testing within the next 2 years.