The cervico-vaginal mucosa serves as the major portal of entry for sexually transmitted pathogens in women worldwide. Female-initiated preventative measures are urgently needed to help curtail the HIV/AIDS pandemic worldwide.
In healthy women of childbearing age worldwide, the Lactobacillus species most commonly isolated from the reproductive tract include L. crispatus, L. jensenii, L. gasseri, and L. iners. They are phylogenetically different from food and/or environmental Lactobacillus species.
Non-pathogenic commensal bacteria may be harnessed to help prevent transmission of mucosally transmitted viruses at these sites. In this approach (U.S. Patent #5,733,540), vulnerable mucosal surfaces will be colonized with commensal bacteria genetically modified to produce high levels of potent HIV-binding proteins as either secreted or surface-displayed molecules to sequester viruses, thus impeding the access of viruses to underlying epithelial cells and lymphocyte targets. These trapped viruses can sequentially be inactivated locally by antiviral compounds, such as lactic acid and hydrogen peroxide, secreted by the lactobacilli. The inactivation could abort the infection process and/or significantly reduce the number of infectious viral particles.
This novel approach will create a barrier to HIV transmission that is different from, yet compatible with, current antiviral therapies, future vaccines and other barrier methods. It will also be inexpensive to manufacture, store, and distribute. As a live, self-renewing microbicide, it does not have to be administered at the time of sexual activity, i.e. it is coital-independent. Administration is discreet and fully controlled by the female users. Since the Lactobacillus strain used is a commensal organism normally present in the human vagina and associated with vaginal health, its potential toxicity is expected to be low or nonexistent compared to chemical agents, which often harm both the normal protective bacterial flora and the underlying mucosal epithelial cells. This approach has potential utility against pathogens other than HIV.
Over the past several years, Osel has made substantial progress in the development of this novel topical microbicide (see more in Publication and Recent Presentation). The development of this MucoCept bacterium represents a major step towards the advancement of an inexpensive, yet durable, protein-based microbicide to address the urgent need for female-initiated approaches to block the heterosexual transmission of HIV.
The MucoCept program is supported in part by NIH/NIAID IPCP, Partnerships for Topical Microbicides, Microbicide Innovation Program, USAID funding through the International Partnership for Microbicides, CONRAD Global Microbicide Project, and the GATES GCE.