Co-Expression of TIGIT and Helios Marks Immunosenescent CD8+ T Cells During Aging

Co-Expression of TIGIT and Helios Marks Immunosenescent CD8+ T Cells During Aging

Blog Article

Aging leads to alterations in the immune system that result in ineffective responsiveness against pathogens.Features of this process, collectively known as immunosenescence, accumulate in CD8+ T cells with age and have been ascribed to differentiation of these cells during the course of life.Here chiggate.com we aimed to identify novel markers in CD8+ T cells associated with immunosenescence.

Furthermore, we assessed how these markers relate to the aging-related accumulation of highly differentiated CD27-CD28- cells.We found that co-expression of the transcription factor Helios and the aging-related marker TIGIT identifies CD8+ T cells that fail to proliferate and show impaired induction of activation markers CD69 and CD25 in response to stimulation in vitro.Despite this, in blood of older adults we found TIGIT+Helios+ T cells to become highly activated during an influenza-A virus infection, but these higher frequencies of activated TIGIT+Helios+ T cells associate with longer duration of coughing.

Moreover, in healthy individuals, we found that TIGIT+Helios+ CD8+ T cells accumulate with age in the highly differentiated CD27-CD28- population.Interestingly, TIGIT+Helios+ CD8+ T cells also accumulate with age among the less differentiated CD27+CD28- T cells before their transit into jmannino.com the highly differentiated CD27-CD28- stage.This finding suggests that T cells with immunosenescent features become prominent at old age also within the earlier differentiation states of these cells.

Our findings show that co-expression of TIGIT and Helios refines the definition of immunosenescent CD8+ T cells and challenge the current dogma of late differentiation stage as proxy for T-cell immunosenescence.