Breast cancer patients have immune system functional deviations, that affect immune cells that infiltrate the tumor, but also cells from the blood compartment, even in the absence of a metastatic disease. Blood monocytes of these patients, for example, have impaired ability to differentiate into dendritic cells. Little is known, however, about systemic alterations in T cells from these patients. To address this issue, we evaluated T cell populations in peripheral blood of cancer patients, comparing it to those of healthy donors. For this, peripheral blood mononuclear cells (PBMCs) were isolated by Ficoll-Paque centrifugation, stained with antibodies to different T cell markers, and evaluated by flow cytometry. Patients had lower CD4:CD8 ratio then healthy donors (Healthy: 2.91±0.31; Cancer: 2.06±0.32; n=10; p=0.04). There was a positive correlation between the histological grade of the tumor and the CD4:CD8 ratio, where those with the lower grade had the lower CD4:CD8 ratio (r2=0.5679; p=0.03). Regarding CD4+ T cells, cancer patients had the same percentage of effector (CD45RA+CCR7-) and central memory (CD45RA-CCR7+) CD4+ T cells, but significantly lower naïve (CD45RA+CCR7+) CD4+ T cells (Healthy: 30.82±5.94, n=8; Cancer: 14.21±3.46, n=10; p=0.02) and a tendency to have higher effector memory (CD45RA-CCR7-) CD4+ T cells (Healthy: 35.13±5.54, n=8; Cancer: 48.64±4.52, n=10; p=0.08). When comparing CD8+ T cells, patients also had significantly lower naïve CD8+ T cells (Healthy: 42.74±6.97, n=8; Cancer: 19.16±3.42, n=10; p=0.005) and higher effector memory CD8+ T cells (Healthy: 29.69±5.35, n=8; Cancer: 45.37±5.15, n=10; p=0.05). Interestingly, cancer patients seemed to have higher percentage of effector CD8+ T cells than healthy patients (Healthy: 19.54±5.30, n=8; Cancer: 30.30±5.49, n=10; p=0.18). No difference in the expression of the IL-2 high affinity receptor (CD25) was observed between individuals with or without breast cancer. In conclusion, breast cancer patients had significant alterations in the percentage of the different peripheral blood T cell populations, suggesting that these may affect their ability to respond to the tumor, but also to other antigens.
Financial Support: FAPESP (2014/25988-1).
Citation Format: Mariana Pereira Pinho, José Alexandre Marzagão Barbuto. Systemic alterations in T cell subpopulations of breast cancer patients. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B069.
- ©2016 American Association for Cancer Research.