Dunne Margaret R, Ryan Ciara, Nolan Bláthnaid, Tosetto Miriam, Geraghty Robert, Winter Des C, O'Connell P Ronan, Hyland John M, Doherty Glen A, Sheahan Kieran, Ryan Elizabeth J, Fletcher Jean M
School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland; School of Medicine, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland.
Department of Pathology, St. Vincent's University Hospital , Dublin , Ireland.
Front Oncol. 2016 Mar 7;6:50. doi: 10.3389/fonc.2016.00050. eCollection 2016.
T cell infiltration into colorectal tumors has been shown to correlate with improved patient outcomes. However, more detailed information on the makeup and relationships between the infiltrating T cell subsets is lacking. We therefore correlated the extent of immune infiltration into colorectal tumors with the frequencies of various T cell subsets. We prospectively recruited 22 patients at the time of surgical resection for colorectal cancer. The Klintrup-Mäkinen (KM) score was used to estimate the extent of immune infiltration into colorectal tumors. The frequencies of CD4 and CD8 T cells that produced cytokines or expressed the inhibitory molecule programed cell death 1 (PD-1) were determined by flow cytometry in colorectal tumor and matched uninvolved colonic tissue. In addition, the frequency of CD4 regulatory T cell (Treg) subsets was determined. An increased frequency of CD4 T cells producing IL-17 (Th17 cells) was observed in colorectal tumor tissue compared with adjacent uninvolved tissue. These Th17 cells mostly coproduced TNF-α, but not IFN-γ. IL-17 expression correlated positively with TNF-α and IL-10. Increased expression of the immune checkpoint molecule PD-1 was found in colorectal tumors compared with adjacent uninvolved tissue. There was a negative correlation between expression of PD-1 and IFN-γ, but not IL-17, for both CD4(+) and CD8(+) T cells. CD4(+)CD25(+)CD127(lo) and CD4(+)CD25(+)CD127(lo)FoxP3(+)CD39(+) Treg cells were enriched in colorectal tumors. A positive correlation between KM score and percentage CD4(+)CD25(+)CD127(lo) Treg cells was observed in tumors, suggesting that increased immune infiltration is associated with an increased proportion of Treg cells. In addition, there was a negative correlation between the frequency of CD4(+)CD25(+)CD127(lo) Treg cells and the expression of IFN-γ and IL-2, but not IL-17, in tumors. Taken together, these data suggest that both PD-1 expressing T cells and Treg cells within the tumor may have a suppressive effect on T cells secreting IFN-γ, IL-2, or TNF-α, but not Th17 cells.
T细胞浸润到结直肠癌中已被证明与患者预后改善相关。然而，关于浸润性T细胞亚群的组成及其相互关系的更详细信息尚缺乏。因此，我们将结直肠癌肿瘤中的免疫浸润程度与各种T细胞亚群的频率进行了关联分析。我们前瞻性地招募了22例接受结直肠癌手术切除的患者。使用克林特鲁普-马基宁（KM）评分来评估免疫浸润到结直肠癌肿瘤中的程度。通过流式细胞术测定结直肠癌肿瘤组织及配对的未受累结肠组织中产生细胞因子或表达抑制性分子程序性细胞死亡1（PD-1）的CD4和CD8 T细胞的频率。此外，还测定了CD4调节性T细胞（Treg）亚群的频率。与相邻未受累组织相比，在结直肠癌肿瘤组织中观察到产生白细胞介素-17（IL-17）的CD4 T细胞（Th17细胞）频率增加。这些Th17细胞大多同时产生肿瘤坏死因子-α（TNF-α），但不产生干扰素-γ（IFN-γ）。IL-17表达与TNF-α和IL-10呈正相关。与相邻未受累组织相比，在结直肠癌肿瘤中发现免疫检查点分子PD-1的表达增加。对于CD4(+)和CD8(+) T细胞，PD-1表达与IFN-γ呈负相关，但与IL-17无负相关。CD4(+)CD25(+)CD127(lo)和CD4(+)CD25(+)CD127(lo)FoxP3(+)CD39(+) Treg细胞在结直肠癌肿瘤中富集。在肿瘤中观察到KM评分与CD4(+)CD25(+)CD127(lo) Treg细胞百分比呈正相关，表明免疫浸润增加与Treg细胞比例增加相关。此外，肿瘤中CD4(+)CD25(+)CD127(lo) Treg细胞频率与IFN-γ和IL-2的表达呈负相关，但与IL-17的表达无负相关。综上所述，这些数据表明肿瘤内表达PD-1的T细胞和Treg细胞可能对分泌IFN-γ, IL-2或TNF-α的T细胞具有抑制作用，但对Th17细胞无抑制作用。
