Senescence-induced changes in CD4 T cell differentiation can be alleviated by treatment with senolytics

Aging and senescence impact CD4 T helper cell (Th) subset differentiation during influenza infection. In the lungs of infected aged mice, there were significantly greater percentages of Th cells expressing the transcription factor FoxP3, indicative of regulatory CD4 T cells (Treg), when compared to young. TGF-beta levels, which drive FoxP3 expression, were also higher in the bronchoalveolar lavage of aged mice and blocking TGF-beta reduced the percentage of FoxP3(+) Th in aged lungs during influenza infection. Since TGF-beta can be the product of senescent cells, these were targeted by treatment with senolytic drugs. Treatment of aged mice with senolytics prior to influenza infection restored the differentiation of Th cells in those aged mice to a more youthful phenotype with fewer Th cells expressing FoxP3. In addition, treatment with senolytic drugs induced differentiation of aged Th toward a healing Type 2 phenotype, which promotes a return to homeostasis. These results suggest that senescent cells, via production of cytokines such as TGF-beta, have a significant impact on Th differentiation.

Automated summary

The differentiation of CD4 T helper cells during influenza infection is affected by aging, with an increase in regulatory T cells (Treg) and higher levels of TGF-beta in the lungs of aged mice. Treatment with senolytic drugs in aged mice prior to infection can restore Th cell differentiation and promote a return to homeostasis by reducing the percentage of Treg cells and inducing a healing Type 2 phenotype. Senescent cells play a significant role in impacting Th cell differentiation through production of cytokines like TGF-beta.