Resistance to apoptosis and expansion of regulatory T cells in relation to the detection of circulating tumor cells in patients with metastatic epithelial cancer.
Regulatory T cells may be crucial in the development of T cell tolerance to malignancies and contribute to immune dysfunctions. We investigated the percentage, activity, and onset of apoptosis of T cell subpopulations by multicolor flow cytometry in metastatic epithelial cancer patients compared to normal controls. Furthermore, a possible relationship between the presence of circulating tumor cells detected by immunocytochemistry and immune cell abnormalities was evaluated. Our study demonstrated a significantly elevated proportion of regulatory T cells in cancer patients (p < 0.001). In contrast to all other T cell subpopulations, regulatory T cells showed comparable Annexin V-binding characteristics in patients and normal controls. No relationship between the detection of circulating tumor cells and immune dysfunction was observed. These results indicate that cancer patients have a higher number of regulatory T cells with resistance to apoptotic stimuli partly responsible for immune dysfunctions as often observed in cancer patients.
Stanzer
Stefanie
S
Division of Oncology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria. stefanie.stanzer@meduni-graz.at
Dandachi
Nadia
N
Balic
Marija
M
Resel
Margit
M
Samonigg
Hellmut
H
Bauernhofer
Thomas
T
D000368:Aged; D017304:Annexin A5 / Q000737:chemistry; D015703:Antigens, CD / Q000378:metabolism; D017209:Apoptosis / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D060908:CTLA-4 Antigen; D002277:Carcinoma / Q000097:blood* / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
D017304:Annexin A5; D015703:Antigens, CD; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D019014:fas Receptor