Regulatory T cells are a self-check subpopulation of T cells and are one of the most progressing T cell lines in task of research programs. Their main task is to prevent the immune system of excessive reactions. Besides their importance in the field of autoimmunity correlating with age and cancer causing disabilities, this cell type plays also an important role in the research of the so called subclinical uncontrolled processes referred to as ``inflammaging``.
Although CD8+ regulatory T cells have first been described to show immunosuppressive properties, it took quite a time to characterize a distinct phenotype whereas CD4+ regulatory T cells were intensively studied meanwhile.
Recently, CD8+ HLA-DR+ T cells were reported to have immunoregulatory porperties and as such, could play an important role in modulating the immune balance. We were able to prove this cell line as Regulatory T cells through my master thesis and checked their suppressive activity also in the old age where they show lower suppressive impact correlating with increased number of expression of this cell line. We also checked for the expression of the classical checkpoint inhibitory markers CTLA-4, PD-1, TIM-3 and LAG-3 where they showed decreased numbers in old age. At least we found out, that persons without CMV-infection show increased numbers of these mentionend molecules.
With my upcoming PhD I aim for a more detailed characterization of this cell line and what cell functions and what cell types correlating with age can get influenced by the activity of CD8+ HLA-DR+ Regulatory T cells. Therefore I hope to contribute to a better understanding of the immune system leading to a healthier aging.
