Since its discovery more than 30 years ago, there is still no cure or vaccine for HIV/AIDS. Transmission of HIV via unprotected anal intercourse is 10-100 times more efficient than vaginal intercourse, and is by far the most common mode of HIV acquisition in Australia. Whilst the percentage of both men and women who practice receptive anal intercourse has increased over the last 10 years, condom usage has decreased. Despite this, surprisingly little is known about how HIV crosses the anorectal mucosa and a better understanding of the mechanisms involved will enable the targeted development of strategies to block the transmission of HIV by this route. There is growing evidence that vaginal transmission of HIV is facilitated by trauma and inflammation.

We hypothesise that the high efficiency of HIV transmission across the anorectal tract is due to the trauma and inflammation resulting from receptive anal intercourse.

This exciting project will examine this hypothesis. We will acquire targeted anorectal biopsies from patients who give a detailed account of their recent anal sexual history. We will then histologically examine the biopsies for signs of trauma and inflammation. In samples where such inflammation is observed, we will then characterise the inflammatory cellular infiltrate for HIV target cells using fluorescence microscopy. In addition, we will acquire large anorectal tissue explants from colorectal surgery operations. We will topically apply agents commonly inserted into the anorectum prior to intercourse (e.g. lubricants and douching agents) to these explants, before extracting the cells from the tissue and look for signs of immune activation.

This is a highly translational project using human tissue to address the transmission of a disease that affects millions of people worldwide. You will form part of a hard working team of experts in sexual health, virology and immunology and will experience both clinical aspects as well as wet lab based medical research.


Supervisor: Associate Professor Andrew Harman