T lymphocytes and their age-related changes in healthy subjects and HNSCC patients

Introduction:

The number of aging cancer patients has increased continuously and will increase further in the future. As the immune system of elderly people experiences critical changes over the time, the influence of tumor cells on the immune system is believed to differ in young and elderly patients as well.

Methods:

The effect of aging on the immune system was measured in peripheral blood lymphocytes of healthy volunteers (n = 48) divided into three different age groups. Results were compared to peripheral blood lymphocytes and tumor infiltrating lymphocytes from elderly (n = 20; ≥70yrs.) and younger (n = 13; ≤69yrs.) head and neck squamous cell carcinoma (HNSCC) patients. Frequencies and phenotypes of CD4+ and CD8+ T cells and regulatory T cells were assessed by flow cytometry.

Results:

We observed a significant decrease in the frequency of CD8+ T cells during aging in healthy volunteers and tumor patients. The frequency of tumor infiltrating regulatory T cells decreased significantly in older tumor patients. Over time, the expression of immunosuppressive CD73 and CCR7 decreased and the expression of PD1 increased on T cells in PBL of healthy volunteers and tumor patients.

Conclusion:

Immunosenescence differs in healthy donors and cancer patients. The altered immune system is believed to influence cancer genesis in elderly patients. This observation may impact future treatment strategies for older cancer patients, so maybe treatment with checkpoint inhibitors could be more beneficial for elderly HNSCC patients.

Publication History

Publication Date:
23 April 2019 (online)