New cell type as the main target and reservoir of HIV

Nowadays, we can control HIV replication using the antiretroviral treatment, however latent viruses remain in some cells preventing HIV eradication. Recently, the Viral Immune Evasion and Vaccines (VIRIEVAC) group at IrsiCaixa led by Julia Garcia-Prado has collaborated in a study led by the Vall d'Hebron Research Institute (VHIR) in which they have identified that resident memory cells (TRMs) are the main target and reservoir in the tissue of people living with HIV. The project, published in Nature Communications, shows that TRMs are very abundant in peripheral tissue samples and propose to study it in parallel to blood samples, a type of sample that is easy to obtain but that only contains a 2% of the HIV target cells.

The study was led by the HIV Translational Research line of the VHIR Infectious Diseases group and the Germans Trias University Hospital, the Hospital del Mar and collaborated in the project.

Reservoirs consist of viruses that remain dormant within cells and have very low replication. When we stop the antiretroviral treatment that limits replication, the reservoir virus reactivate preventing the complete cure of the infection. This recent publication shows that TRMs have slow rate of proliferation and are one of the first cells to be infected by the HIV, a fact that makes them good candidates to act as a reservoir. The vast majority of these cells reside in the peripheral tissue, such as the female genital tract, and they have low presence in blood samples. Thus, the results of this project highlight the importance of considering peripheral tissue in our studies, because that is where most of the HIV target cells and viral reservoir are.

The new therapies aiming the complete elimination of the virus should take into account the TRMs, which are present in all tissues. The study proposes the CD69 molecule as a marker of the TRMs resident in the tissues, this marker could help identify the reservoirs of HIV in these samples.