Publications by year
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PhD (University of Otago)
Development of vaccines to prevent chlamydial infections
Traditional vaccine approaches have been unsuccessful in preventing chlamydial infections. We have used novel DNA vaccination and bioinformatics approaches to identify protective chlamydial antigens that are conserved across several chlamydial species. Using combinations of these antigens we can reduce both the duration and magnitude of infection and reduce infection-associated inflammation that is the cause of infertility in animal models of chlamydial infection. We are now working with collaborators in the US and a major vaccine company to develop a human Chlamydia vaccine. We have also used these antigens to develop the world’s first Chlamydia vaccine for the koala. This vaccine has been shown to protect young koalas in a wild population with a high incidence of chlamydial infection and disease and has increased reproductive success in this population. The vaccine is currently undergoing registration.
Chlamydia infections and male fertility.
Despite overwhelming evidence that chlamydial infection adversely affects fertility in females there have been few studies on the effects of Chlamydia on male fertility. Our world-first studies in mice have shown that Chlamydia is transported from the penile urethra to the testes in immune cells called macrophages, which serve as a “Trojan Horse”. In the testes, infection fails to resolve, becoming chronic. Chronic testicular infections adversely affect sperm development, reducing sperm numbers, motility and egg-binding capacity and significantly increasing DNA damage in sperm. These factors result in greatly reduced fertility in infected males. Studies in human males with reduced sperm counts attending fertility clinics showed that more than 40% of these men had evidence of undetected chronic testicular Chlamydia infection, almost 8 times the incidence in the general population. Together our animal and human studies strongly suggest that undetected chlamydial infection in the testes could be a major contributor to unexplained male infertility. Recent studies have shown that damage to sperm in Chlamydia-infected mice can be partially prevented by vaccination. Testicular Chlamydia infections have also been found in wild koalas and correlated with reduced sperm quality. We are now testing our Chlamydia vaccine in male as well as female koalas.
Other Research Interests.
Neisseria gonorrhea is another human STI and is a disease of increasing concern due to antibiotic resistance. We have established a new mouse model of Neisseria infection in male mice and have shown that infection adversely affects sperm production similar to what we find with Chlamydia infection. We are currently using this model to further investigate the effects of Neisseria infection on male fertility and for development of vaccines to prevent infections.
Memberships:
Prof. Beagley is a past-president of the International Society for Mucosal Immunology and is a member of the Australian and New Zealand Society for Immunology, the American Association of Immunologists, the Society for Reproductive Biology, the American Society for Reproductive Immunology, the International Society for Vaccines and the International Society for Immunology of Reproduction.