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Immune cell infiltration in colorectal cancer effectively predicts clinical outcome. IL22, produced by immune cells, plays an important role in inflammatory bowel disease, but its relevance in colorectal cancer remains unclear. Here, we addressed the prognostic significance of IL22 + cell infiltration in colorectal cancer and its effects on the composition of tumor microenvironment. Tissue microarrays (TMA) were stained with an IL22-specific mAb, and positive immune cells were counted by expert pathologists. Results were correlated with clinicopathologic data and overall survival (OS). Phenotypes of IL22-producing cells were assessed by flow cytometry on cell suspensions from digested specimens. Chemokine production was evaluated in vitro upon colorectal cancer cell exposure to IL22, and culture supernatants were used to assess neutrophil migration in vitro Evaluation of a testing ( n = 425) and a validation TMA ( n = 89) revealed that high numbers of IL22 tumor-infiltrating immune cells were associated with improved OS in colorectal cancer. Ex vivo analysis indicated that IL22 was produced by CD4 + and CD8 + polyfunctional T cells, which also produced IL17 and IFNγ. Exposure of colorectal cancer cells to IL22 promoted the release of the neutrophil-recruiting chemokines CXCL1, CXCL2, and CXCL3 and enhanced neutrophil migration in vitro Combined survival analysis revealed that the favorable prognostic significance of IL22 in colorectal cancer relied on the presence of neutrophils and was enhanced by T-cell infiltration. Altogether, colorectal cancer-infiltrating IL22-producing T cells promoted a favorable clinical outcome by recruiting beneficial neutrophils capable of enhancing T-cell responses., (©2020 American Association for Cancer Research.)

Purpose: Tumor infiltration by different T lymphocyte subsets is known to be associated with favorable prognosis in colorectal cancer. Still debated is the role of innate immune system. We investigated clinical relevance, phenotypes, and functional features of colorectal cancer-infiltrating CD66b + neutrophils and their crosstalk with CD8 + T cells. Experimental Design: CD66b + and CD8 + cell infiltration was analyzed by IHC on a tissue microarray including >650 evaluable colorectal cancer samples. Phenotypic profiles of tissue-infiltrating and peripheral blood CD66b + cells were evaluated by flow cytometry. CD66b + /CD8 + cells crosstalk was investigated by in vitro experiments. Results: CD66b + cell infiltration in colorectal cancer is significantly associated with increased survival. Interestingly, neutrophils frequently colocalize with CD8 + T cells in colorectal cancer. Functional studies indicate that although neutrophils are devoid of direct antitumor potential, coculture with peripheral blood or tumor-associated neutrophils (TAN) enhances CD8 + T-cell activation, proliferation, and cytokine release induced by suboptimal concentrations of anti-CD3 mAb. Moreover, under optimal activation conditions, CD8 + cell stimulation in the presence of CD66b + cells results in increasing numbers of cells expressing CD45RO/CD62L "central memory" phenotype. Importantly, combined tumor infiltration by CD66b + and CD8 + T lymphocytes is associated with significantly better prognosis, as compared with CD8 + T-cell infiltration alone. Conclusions: Neutrophils enhance the responsiveness of CD8 + T cells to T-cell receptor triggering. Accordingly, infiltration by neutrophils enhances the prognostic significance of colorectal cancer infiltration by CD8 + T cells, suggesting that they might effectively promote antitumor immunity. Clin Cancer Res; 23(14); 3847-58. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Purpose: Colorectal cancer infiltration by CD16(+) myeloid cells correlates with improved prognosis. We addressed mechanistic clues and gene and protein expression of cytokines potentially associated with macrophage polarization., Experimental Design: GM-CSF or M-CSF-stimulated peripheral blood CD14(+) cells from healthy donors were cocultured with colorectal cancer cells. Tumor cell proliferation was assessed by (3)H-thymidine incorporation. Expression of cytokine genes in colorectal cancer and autologous healthy mucosa was tested by quantitative, real-time PCR. A tumor microarray (TMA) including >1,200 colorectal cancer specimens was stained with GM-CSF- and M-CSF-specific antibodies. Clinicopathological features and overall survival were analyzed., Results: GM-CSF induced CD16 expression in 66% ± 8% of monocytes, as compared with 28% ± 1% in cells stimulated by M-CSF (P = 0.011). GM-CSF but not M-CSF-stimulated macrophages significantly (P < 0.02) inhibited colorectal cancer cell proliferation. GM-CSF gene was expressed to significantly (n = 45, P < 0.0001) higher extents in colorectal cancer than in healthy mucosa, whereas M-CSF gene expression was similar in healthy mucosa and colorectal cancer. Accordingly, IL1β and IL23 genes, typically expressed by M1 macrophages, were expressed to significantly (P < 0.001) higher extents in colorectal cancer than in healthy mucosa. TMA staining revealed that GM-CSF production by tumor cells is associated with lower T stage (P = 0.02), "pushing" growth pattern (P = 0.004) and significantly (P = 0.0002) longer survival in mismatch-repair proficient colorectal cancer. Favorable prognostic effect of GM-CSF production by colorectal cancer cells was confirmed by multivariate analysis and was independent from CD16(+) and CD8(+) cell colorectal cancer infiltration. M-CSF expression had no significant prognostic relevance., Conclusions: GM-CSF production by tumor cells is an independent favorable prognostic factor in colorectal cancer., (©2014 American Association for Cancer Research.)