Researchers at the Westmead Institute for Medical Research have discovered a new subset of immune cells that are more susceptible to getting overpowered by HIV. Researchers are now exploring two new avenues to pursue more effective HIV treatment.
The newly discovered CD11+c dendritic cells are found only in the epithelial level of human genital tissue. By nature of its location, this thin level of skin on the surface of the vagina, inner foreskin, and anus is often the first immune cells to interact with HIV. The role of these cells is to capture any dangerous virus of bacteria and transfer them to the CD4 T cells.
“CD4 T cells are responsible for driving an immune response to the pathogen,” said Associate Professor Andrew Harman, one of the project’s lead researchers. “Interestingly, they are also the primary HIV target cells in which the virus replicates.”
Dendretic cells capture a pathogen, then essentially communicate their findings to CDT 4 cells in the lymph nodes, which in turn decides whether to tolerate the virus or to attack it. Harman likens that process to providing the immune system with constant status updates.
The findings show the CD11+c interacts more efficiently with CDT 4 cells than any other dendritic cell, but are also more susceptible to being corrupted by HIV. They are, in effect, key drivers of HIV transmission and as such are also important as vaccine candidates.
According to Professor Tony Cunningham, the Westmead Institute’s Executive Director, their research has opened two new avenues of treatment research.
“This finding opens up a potential for the development of strategies to block the transmission of HIV,” said Cunningham. “If we can block HIV’s ability to bind to the CD11+c dendritic cells, which are often the first immune cells to encounter the HIV virus, then we can stop their ability to transmit the virus to the CD4T cells. In a situation where there are low levels of CD4 T cells, this could stop the virus from spreading. Another avenue is to use this new information to develop a HIV vaccine. If HIV fragments or inactivated HIV were targeted at these CD11+c dendritic cells, this would have the potential to prime an immune response against HIV as soon as it enters the body.”
The study used donated human genital tissue, some only 30 minutes after being surgically removed. The research also developed groundbreaking RNAscope technology which allowed the team to observe living CD11+c cells as they captured then transferred the HIV virus to the CD4 T cells.
The study was funded in part by the National Health and Medical Research Council and published in the journal Nature Communications.