Ex-Vivo Analysis of CD8+ T Cells Infiltrating Colorectal Tumors Identifies a Major Effector-Memory Subset with Low Perforin Content

SW Ye, Y Wang, D Valmori, M Ayyoub, Y Han… - Journal of clinical …, 2006 - Springer
SW Ye, Y Wang, D Valmori, M Ayyoub, Y Han, XL Xu, AL Zhao, L Qu, S Gnjatic, G Ritter…
Journal of clinical immunology, 2006Springer
Previous studies have indicated that the infiltration of CD8+ T cells in colorectal cancer is an
independent predictor of increased survival but clinical observations have suggested that
the cytotoxic function of CD8+ T cells infiltrating colorectal cancer may often be limited. In
this study, we have assessed the phenotype of colorectal cancer CD8+ tumor-infiltrating
lymphocytes (TILs) isolated ex vivo from tumor tissue, and assessed the perforin content of
TIL with respect to their location using immunohistochemistry. We found that CD8+ T cells …
Previous studies have indicated that the infiltration of CD8+ T cells in colorectal cancer is an independent predictor of increased survival but clinical observations have suggested that the cytotoxic function of CD8+ T cells infiltrating colorectal cancer may often be limited. In this study, we have assessed the phenotype of colorectal cancer CD8+ tumor-infiltrating lymphocytes (TILs) isolated ex vivo from tumor tissue, and assessed the perforin content of TIL with respect to their location using immunohistochemistry. We found that CD8+ T cells TILs isolated from colorectal cancer are mainly composed of antigen-experienced cells of effector memory type (TEM, CD45RA-CCR7−, and CD27+/CD28− or CD27−/CD28−), and contain only minor proportions of terminally differentiated CD8+ T cells (TEMRA, CD45RA+CCR7−). The perforin content of these TILs, however, is significantly lower than that of antigen-experienced T cells in PBMCs due to the much lower levels of perforin found in the CD27-CD28− subset in TILs compared with CD8+ T cells of similar phenotype in PBMCs.
Springer