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. Accordingly, the percentage of both men and women who practice receptive anal intercourse has increased over the last 10 years and associated condom usage is decreasing. 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 spread of this virus at the time of acquisition.
We hypothesise that the high efficiency of HIV transmission across the anorectal tract is due to the fact that the anorectal tissue contains a unique repertoire of HIV target cells. In order to address this issue we have formed collaborations with surgeons at Westmead Hospital such that we have regular access to anal and rectal tissue and we have begun to determine the subsets of HIV target cells (dendritic cells, macrophages and CD4 T cells) within these tissues. We are using multicolour flow cytometry to define these cell subsets after extracted them form the tissue by enzymatic digestion and fluorescence microscopy to visualise the cells within the tissue (in situ). We are also infecting the tissue with HIV to see which cell subsets take up the virus and play the critical role in transmission of this virus.
This is an exciting 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 virology and immunology and you will have access to close one to one supervision.
Supervisor: Associate Professor Andrew Harman - andrew.harman@sydney.edu.au