Overview
Osel is the leading company in the emerging field of Bacterial Therapeutics and a pioneer in the development of genetically modified vaginal Lactobacillus. The company’s business approach is based on recent scientific discoveries demonstrating the vital role of naturally occurring beneficial bacteria in the maintenance of health and the prevention of disease. Osel’s mission is to harness the protective properties of these specialized non-pathogenic bacteria. This strategy has served as the basis for a series of innovative products initially targeted at prevention and treatment of diseases of the genitourinary and gastrointestinal tracts.
The mucous membranes of humans and animals are densely populated with commensal bacteria, which play an important role in host defense against pathogenic organisms. In the vaginal mucosa, for example, a deficiency of hydrogen peroxide-producing lactobacilli has been associated with an increased risk of bacterial vaginosis, urinary tract infections, and sexually transmitted infections, including Human Immunodeficiency Virus (HIV) and Herpes Simplex Virus-2 (HSV-2). A deficiency of vaginal lactobacilli has also been linked to adverse pregnancy outcomes. Similarly, disruption of the protective gastrointestinal microflora can lead to diarrhea, intestinal infections and colitis, as exemplified by antibiotic-associated diarrhea and Clostridium difficile disease.
Osel’s technologies are focused on harnessing the mucosal microflora in two complementary ways. First, we identify the most appropriate naturally occurring bacteria to treat and prevent diseases caused by disruptions in the protective microflora. Second, we develop technologies to genetically enhance the capabilities of these bacteria to combat disease-causing organisms, represented by the MucoCept line of second-generation products.
MucoCept Technology
Osel is pursuing an innovative strategy to prevent the transmission of viral diseases in humans. This strategy is effected by our platform technology, known as MucoCept. The MucoCept approach involves the use of proprietary technology designed to harness the natural microbial flora and its associated biofilm on mucosal surfaces – the site of entry of most viruses – to neutralize viral particles before infection of the host cell can occur. This approach may be used to prevent infection by a number of viruses in humans, including HIV and HSV-2. Dr. Peter P. Lee is the inventor of the MucoCept concept and a co-founder of Osel, Inc.
MucoCept HIV
The cervico-vaginal mucosa serves as the major portal of HIV entry in women worldwide. Women have been bearing much of the burden of HIV infection in recent years. In healthy women of childbearing age, the vaginal microflora is dominated by hydrogen peroxide producing lactobacilli, which normally colonize and protect the mucosal surface of the vagina. The principal Lactobacillus species isolated from the vaginal mucosa of healthy women are L. crispatus, L. jensenii, L. gasseri, and L. iners. Hydrogen peroxide producing lactobacilli can be genetically enhanced to express antiviral proteins. When re-introduced into the vaginal mucosa, these bacteria are expected to produce an HIV inhibitor in situ at a primary site of infection. This novel approach, termed MucoCept HIV, is designed to intercept and inactivate virus particles in the mucosa, preventing infection of underlying tissues. MucoCept HIV represents an additional and much needed strategy for preventing sexually transmitted HIV infection in women, that is complementary to other forms of protection, such as condoms.
Over the past several years, Osel has made substantial progress in the development of this novel topical microbicide, with a key proof-of-concept study published in the Proceedings of the National Academy of Sciences [PNAS, 2003, 100:11672-11677; see also AP and BBC news report]. Osel scientists have sequenced the genome of a human vaginal isolate L. jensenii 1153 in collaboration with Lawrence Berkeley National Laboratory and identified native regulatory elements and sites for chromosomal integration of heterologous genes. L. jensenii 1153 has been engineered to more efficiently express highly potent anti-HIV proteins, and a preferred MucoCept product is being optimized for manufacturing and formulation. 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 has received nearly $10 million in federal grants and private foundation support, most recently a $2.4 million NIH grant awarded in June of 2005.
