Newly-Identified Immune Cells Are Key Drivers of HIV Infection

CD11c+ dendritic cells may be a potential therapeutic target for inhibiting the spread of HIV, according to new research published in Nature Communications.

These dendritic cells, which are only found in human genital tissues at the epithelial level, are the first immune cells to come into contact with HIV, transmitting the virus to other cells in the body, according to the study.

The authors suggested that CD11c+ dendritic cells, which are more susceptible to HIV infection, are key drivers of the infection.

In the study, the researchers were able to identify the CD11c+ dendritic cells by using donated genital tissues, which allowed them to observe the cells as they captured the virus and delivered it to the CD4 T cells.

According to the researchers, the CD11c+ dendritic cells’ role is to capture any incoming disease-causing virus or pathogen. Once the pathogen is captured, the cells communicate to the CD4 T cells in the lymph nodes. CD4 T cells are responsible for driving an immune response to the pathogen but are also the primary HIV target cells in which the virus replicates. In transmitting this information to the CD4 T cells, the immune system is prepped to either tolerate the bacteria or virus or attack it, according to the study.

“Our research team has shown that the newly discovered CD11c+ dendritic cells are more susceptible to HIV infection than any other known dendritic cells,” co-lead author Andrew Harman, PhD, associate professor at The Westmead Institute for Medical Research, said in a press release. “We have also shown that CD11c+ dendritic cells interact with CD4 T cells more efficiently than any other dendritic cells. Importantly CD11c+ dendritic cells transfer the virus to CD4 T cells, making them key drivers of HIV infection.”

Other potential avenues of research would be to determine how to block the transmission of HIV from the CD11c+ cells. According to the researchers, if there are low levels of CD4 T cells, this approach could stop the virus from spreading. The location of the dendritic cells in the epithelium provides the opportunity for early intervention to inhibit transmission, according to the study.

The researchers also noted that since dendritic cells are efficient at interacting with CD4 T cells, they are important vaccine candidates as well.

“Another avenue is to use this new information to develop a HIV vaccine,” co-lead author Tony Cunningham, AO, FAHMS, executive director of The Westmead Institute for Medical Research, concluded. “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.”

References

Newly discovered immune cells at the frontline of HIV infection [news release]. Westmead Institute. https://www.westmeadinstitute.org.au/news-and-events/2019/newly-discovered-immune-cells-at-the-frontline-of-. Accessed June 21, 2019.

Harman A, Cunningham T, Bertram KM, et al. Identification of HIV transmitting CD11c+ human epidermal dendritic cells. Nature Communications. 2019. https://www.nature.com/articles/s41467-019-10697-w#Sec9