Systemic inflammation naturally occurs as part of the aging process and is common in the normal geriatric population. Chronic inflammation also occurs in patients infected with HIV that are undergoing treatment with retroviral drugs, even when they are responding well to treatment.
The cause of this inflammation and the cells involved is not understood; however, researchers at the Boston University School of Medicine believe that, for the first time, the unique immune cells involved in the process have been identified.
To investigate which cells are causing the inflammation in old age and HIV patients, the researchers measured markers on the surface of immune cells in the blood in individuals with and without HIV. Those groups were further split into two age groups: Under 35s and over 50s. The markers were then compared with the levels of inflammatory proteins in the plasma in each group.
The researchers identified a specific marker on gamma delta T cells – names TIGIT – which corresponded with inflammatory proteins in the plasma of the HIV positive individuals and the uninfected 50+ age group.
The immune cells involved in the inflammatory process could potentially be targeted to prevent chronic inflammation in the general geriatric population and could prevent age-associated morbidities in HIV positive patients undergoing anti-retroviral therapy.
Over half of HIV positive patients in the United Sates are over 50 years old and the number is expected to double by 2050. Over the same time frame the geriatric population is predicted to increase fourfold. Therefore, developing drugs that can target age-related chronic inflammation is a major global health priority.
“Our study indicates that there’s a previously uninvestigated cell subset new player in the immune landscape that could be driving widespread illnesses and with targeted gamma delta therapeutics maybe there may be a chance of reducing onset, symptoms, and/or severity of inflammation-related diseases,” said, Jennifer Snyder-Cappione, Ph.D., assistant professor of microbiology and director of the Flow Cytometry Core Facility at Boston University School of Medicine.
The research team, headed by Anna C. Belkina, hopes the research will help pharma firms identify drugs that can target gamma delta T cells to control inflammation before it leads to the development of many chronic diseases.
The research is detailed in the paper – Multivariate Computational Analysis of Gamma Delta T Cell Inhibitory Receptor Signatures Reveals the Divergence of Healthy and ART-Suppressed HIV+ Aging – which was recently published in the journal Frontiers in Immunology. DOI: 10.3389/fimmu.2018.02783