Tumor Infiltrating T Lymphocytes and Apoptosis in Colorectal Cancer
Youssef, M.M.S.; Paish, E.C.; Murray, J.C.; Farag, N.M.; Saleh, K.; Ellis, I.O.
Egyptian Journal of Immunology 22(1): 19-28
2015
ISSN/ISBN: 1110-4902 PMID: 26415369 Document Number: 683826
Dysfunction of the immune system in colorectal cancer (CRC) can be due to a number of reasons including apoptosis of tumour infiltrating lymphocytes (TILs). The aims of this study was to investigate TILs in colorectal cancer and characterize apoptosis of TILs using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay for detecting DNA fragments. We used monoclonal antibodies (mAbs) to T lymphocytes to detect TILs and double immunohistochemistry to assess apoptosis. T lymphocytes were detected in the immune infiltrate in CRC. TUNEL staining disclosed a high level of cell death among TILs. Apoptosis of T lymphocytes showed significant correlation with Dukes' stage (P = 0.02), lymphatic metastasis (P = 0.03), vascular metastasis (P = 0.01), lymph node metastasis (P = 0.02) and age of patient (P = 0.01). In conclusion, CRC may elude immunological surveillance by inducing apoptosis of TILs.