The frequency of Th17 and Th22 cells in patients with colorectal cancer at pre-operation and post-operation

Dynamics of Peripheral Blood Immune Cells during the Perioperative Period after Digestive System Resections: A Systematic Analysis of the Literature

An operation in itself is a kind of trauma and may lead to immunosuppression followed by a bounce back. Not many studies exist that describe dynamics of the distribution of peripheral blood (PB) immune cells during the perioperative period. Considering this scarcity, we aggregated the data on the dynamics of immune cells in patients with digestive system resections during the perioperative period and the relationship with short- and long-term prognoses. By the systematic retrieval of documents, we collected perioperative period data on white blood cells (WBC), lymphocytes, neutrophil-lymphocyte ratio (NLR), CD4⁺ T cells, CD8⁺ T cells, helper T cells (Th), B cells, natural killer cells (NK), dendritic cells (DCs), regulatory T cells (Tregs), regulatory B cells (Bregs), and Myeloid derived suppressor cells (MDSC). The frequency and distribution of these immune cells and the relationship with the patient's prognosis were summarized. A total of 1916 patients' data were included. Compared with before surgery, WBC, lymphocytes, CD4⁺ cells, CD8⁺ T cells, MDSC, and NK cells decreased after surgery, and then returned to preoperative levels. After operation DCs increased, then gradually recovered to the preoperative level. No significant changes were found in B cell levels during the perioperative period. Compared with the preoperative time-point, Tregs and Bregs both increased postoperatively. Only high levels of the preoperative and/or postoperative NLR were found to be related to the patient's prognosis. In summary, the surgery itself can cause changes in peripheral blood immune cells, which might change the immunogenicity. Therefore, the immunosuppression caused by the surgical trauma should be minimized. In oncological patients this might even influence long-term results.

Fusobacterium nucleatum promotes liver metastasis in colorectal cancer by regulating the hepatic immune niche and altering gut microbiota

Liver metastasis is the major cause of death in colorectal cancer (CRC) patients. Nevertheless, the underlying mechanisms remain unknown. Gut microbiota intricately affect the initiation and progression of CRC by instigating immune response through the secretion of pro-inflammatory cytokines. In this study, we investigated the contribution of Fusobacterium nucleatum (F.nucleatum) to the microbiota-liver axis of CRC in mice, focusing on the correlation between liver immunity and gut microbiota alterations. When F. nucleatum was orally administered to mice, CRC liver metastasis was evidently exaggerated and accompanied by noticeable deleterious effects on body weight, cecum weight, and overall survival time. Further evaluation of the immune response and cytokine profiles revealed a substantial increase in the levels of pro-inflammatory cytokines such as IL6, IL12, IL9, IL17A, CXCL1, MCP-1, TNF-α, and IFN-γ in the plasma of mice treated with F. nucleatum as compared to that in the untreated control mice. Besides, hepatic immune response was also modulated by recruitment of myeloid-derived suppressor cells, reduction in the infiltration of natural killer (NK) and T helper-17 (Th17) cells, as well as increase in regulatory T cell accumulation in the liver. Additionally, sustained F. nucleatum exposure abridged the murine gut microbiota diversity, inducing an imbalanced and restructured intestinal microflora. In particular, the abundance of CRC-promoting bacteria such as Enterococcus and Escherichia/Shigella was evidently elevated post F. nucleatum treatment. Thus, our findings suggest that F. nucleatum might be an important factor involved in promoting CRC liver metastasis by triggering of liver immunity through the regulation of gut microbiota structure and composition.

Features and roles of T helper 22 cells in immunological diseases and malignancies

T helper 22 (Th22) cell populations are a newly identified subset of CD4+  T cells that primarily mediate biological effects on the epithelial barrier through interleukin (IL)-22. Although, new studies showed that both Th22 and IL-22 are closely associated with the pathogenesis of inflammatory, autoimmune and allergic disease as well as malignancies. In this review, we aim to describe the development and characteristics of Th22 cells as well as their roles in the immunopathogenesis of immune-related disorders and cancer.

Differential gene expression of tumor-infiltrating CD4+ T cells in advanced versus early stage colorectal cancer and identification of a gene signature of poor prognosis

Tumor-infiltrating lymphocytes (TILs) play indispensable roles in the progression and response to treatment of solid tumors. However, the prognostic significance of CD4⁺ TILs is not fully disclosed in cancers generally and in CRC in particular, mainly due to the existence of different functional subsets of CD4⁺ T cells. We performed transcriptomic profiling of CD4⁺ TILs isolated from CRC patients in order to identify differentially expressed genes and their functional pathways in early versus advanced disease stages. We found that in advanced stages, genes related to immune and inflammatory responses, in particular Th1-mediated immune response and cytotoxicity-mediated genes, were downregulated; while epigenetic-mediated silencing genes were upregulated. Interestingly, we identified genes, which were steadily upregulated or downregulated in CD4⁺ TILs with CRC progression from stage I to IV. Additionally, of the top 200 deregulated genes, 43 upregulated and 64 downregulated genes showed similar deregulation trends in the cancer genome atlas CRC dataset. From these 97 deregulated genes, we identified a “poor prognosis CD4 gene signature (ppCD4sig)”. Patients with high ppCD4sig score showed shorter disease-specific survival (DSS) and progression-free interval (PFI). The ppCD4sig was an independent prognostic indicator for DSS (HR = 1.73, 95% CI 1.32–2.27, P = 0.0001) and PFI (HR = 1.75, 95% CI 1.3–2.35, P = 0.0016). Additionally, patients at advanced stages and at a younger age (<55 years) were more likely to have a high ppCD4sig score. Altogether, our data provide novel insights and a unique prognostic gene signature of CD4⁺ TILs in the CRC microenvironment.

TGF-β signaling in Th17 cells promotes IL-22 production and colitis-associated colon cancer

IL-22 has dual functions during tumorigenesis. Short term IL-22 production protects against genotoxic stress, whereas uncontrolled IL-22 activity promotes tumor growth; therefore, tight regulation of IL-22 is essential. TGF-β1 promotes the differentiation of Th17 cells, which are known to be a major source of IL-22, but the effect of TGF-β signaling on the production of IL-22 in CD4+ T cells is controversial. Here we show an increased presence of IL-17+IL-22+ cells and TGF-β1 in colorectal cancer compared to normal adjacent tissue, whereas the frequency of IL-22 single producing cells is not changed. Accordingly, TGF-β signaling in CD4+ T cells (specifically Th17 cells) promotes the emergence of IL-22-producing Th17 cells and thereby tumorigenesis in mice. IL-22 single producing T cells, however, are not dependent on TGF-β signaling. We show that TGF-β, via AhR induction, and PI3K signaling promotes IL-22 production in Th17 cells.

TH9, TH17, and TH22 Cell Subsets and Their Main Cytokine Products in the Pathogenesis of Colorectal Cancer

In recent years, several newly identified T helper (T_H) cell subsets, such as T_H9, T_H17, and T_H22 cells, and their respective cytokine products, IL-9, IL-17, and IL-22, have been reported to play critical roles in the development of chronic inflammation in the colorectum. Since chronic inflammation is a potent driving force for the development of human colorectal cancer (CRC), the contributions of T_H9/IL-9, T_H17/IL-17, and T_H22/IL-22 in the pathogenesis of CRC have recently become an increasingly popular area of scientific investigation. Extensive laboratory and clinical evidence suggests a positive relationship between these new T_H subsets and the growth and formation of CRC, whereas, administration of IL-9, IL-17, and IL-22 signaling inhibitors can significantly alter the formation of colorectal chronic inflammation or CRC lesions in animal models, suggesting that blocking these cytokine signals might represent promising immunotherapeutic strategies. This review summarizes recent findings and currently available data for understanding the vital role and therapeutic significance of T_H9/IL-9, T_H17/IL-17, and T_H22/IL-22 in the development of colorectal tumorigenesis.

Perioperative changes in lymphocyte subpopulations in patients undergoing surgery for colorectal cancer

Surgical procedure has immense impact on the immune balance. However, little is known about perioperative changes in T regulatory and Th17 lymphocyte subpopulations in patients undergoing colorectal resection. Patients with resectable colon cancer were enrolled in the study. Blood samples were obtained on two occasions, i.e. before the procedure and two days after the surgery. We also recruited a control group of young, healthy individuals. Lymphocyte subpopulations were analyzed with the use of flow cytometry. Investigated subpopulations consisted of total lymphocyte count, CD4+, CD8+, T regulatory Foxp3+ (Tregs), Th17 lymphocytes and white blood cell (WBC) count. There were significant differences in immune cell levels before and after the surgery. Reduction was recorded in the CD4+, CD8+, Tregs and total lymphocyte counts (p=0.002, p=0.01, p=0.008 and p=0.001, respectively). Increase was observed in total WBC and Th17 cells, however, Th17 lymphocytes did not reach statistical significance (p=0.01 and p=0.5, respectively). In conclusion, surgical intervention caused changes in all lymphocyte subpopulations investigated in patients undergoing surgery for colorectal cancer. However, it seemed to be an effect of perioperative trauma. Further studies are needed to investigate the impact of surgical intervention on lymphocyte subpopulations.

Recruitment and significance of Th22 cells and Th17 cells in malignant ascites

T helper (Th)22 and Th17 cells are implicated in the pathogenesis of a number of types of cancer. However, the function of Th22 and Th17 cells in malignant ascites (MA) remains unknown. The present study aimed at examining the distribution, phenotypes, recruitment, and prognostic value of Th22 and Th17 cells in MA from patients with hepatocellular carcinoma (HCC). A total of 26 patients with HCC with MA and 15 healthy controls were included in the present study. The proportion of Th22 cells, Th17 cells, C-C motif chemokine receptor (CCR)4, CCR6 and CCR10 were examined using flow cytometry. Interleukin (IL-)22, IL-17, C-C motif chemokine ligand (CCL)20, CCL22 and CCL27 were investigated using ELISA. In addition, the chemoattractant activity of chemokines for Th22 and Th17 cells in vitro were examined via a chemotaxis assay. The results of the present study demonstrated that Th22 cells, Th17 cells, IL-22 and IL-17 were significantly increased in MA compared with the corresponding blood and peripheral blood from healthy controls. Additionally, Th22 cells expressed increased concentrations of CCR6, CCR4 and CCR10, and Th17 cells expressed increased concentrations of CCR4 and CCR6 in MA compared with the corresponding blood. The chemotaxis assay revealed that CCL20/CCR6, CCL22/CCR4 and CCL27/CCR10 were responsible for the recruitment of Th22 cells into MA, whereas CCL22/CCR4 was responsible for the recruitment of Th17 cells. Furthermore, the patients with an increased number of Th17 cells exhibited an increased survival time compared with patients with a limited number of Th17 cells. Th22 and Th17 cells serve an important function in the development of MA, and the accumulation of Th22 and Th17 cells in MA may be due to a local increase in proinflammatory cytokines and chemokines. Increased Th17 cell numbers in MA may indicate the improvement of patient survival.

Analysis of Th22, Th17 and CD4+cells co-producing IL-17/IL-22 at different stages of human colon cancer

T-helper (Th) 22 cells are involved in the immunopathogenesis of inflammatory diseases, but their specific role in the immunopathogenesis of cancer is unknown. In this study, we examined the profile of circulating and intratumoral Th17, Th22 and CD4+ cells co-producing IL-17/IL-22 in colon cancer (CC) patients in relation to tumor staging. Thirty newly diagnosed colon cancer (CC) patients participated in this study. The percentage of Th1 (CD4+IFN-γ+IL-17-IL-22-), Th17 (CD4+IFN-γ-IL-17+IL-22-), Th22 (CD4+IFN-γ-IL-17-IL-22+) and CD4+ cells co-producing IL-17/IL-22 (CD4+IFN-γ-IL-17+IL-22+) in the peripheral blood, tumor and paratumor tissues was assessed by multicolor flow cytometry. The percentage of circulating Th17 and Th22 cells was significantly increased in CC patients compared to that in healthy controls (HCs). In addition, the percentage of infiltrating Th1, Th17, Th22 and CD4+ cells co-producing IL-17/IL-22 was significantly increased in the tumor tissues compared to that in the parartumor tissues. Furthermore, we also found that the percentage of circulating and intratumoral Th17, Th22 and CD4+ cells co-producing IL-17/IL-22 was higher in advanced stages than in early stages. Our findings revealed that Th17, Th22 and CD4+ cells co-producing IL-17/IL-22 were accumulated in colon cancer tissues and may be involved in the tumor development and progression. A better comprehension of the immunopathogenesis of Th17, Th22 and CD4+ cells co-producing IL-17/IL-22 in colon cancer patients would help in the development of novel therapies.

The Different Functional Distribution of "Not Effector" T Cells (Treg/Tnull) in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer worldwide, ranking as high as the second leading cause of cancer-related deaths in industrialized countries. Consistent with immunosurveillance theory, the immune system is crucial to protect the host from developing tumors, and the major players in tumoral immunity are effector T cells. Anyway, cancer cells develop strategies of immunoevasion influencing the cancer-specific lymphocyte priming, activation, and effector function. Therefore, the T cell subsets that mature during the stages of tumor growth, differently contribute to disease progression and/or regression. In our study, we analyzed the intra-tumoral and peripheral T cell subsets’ distribution in 30 patients with CRC, in order to clarify their functional role toward cancer. We found that percentage of infiltrating effector T cells decreased in cancer tissue than in healthy mucosa and that the tumor microenvironment negatively influences the cytolytic activity of T lymphocytes reactive to cancer cells. Moreover, we found that the tumor tissue was infiltrated by a large amount of “not effector” T (neT) cells with a regulatory or an anergic profile, which are unable to kill cancer cells, may be contributing to the CRC promotion. The presence of neT cells was investigated also in the peripheral blood of CRC patients, demonstrating that the peripheral T regulatory cells can inhibit the proliferation of effector T cells, confirming their immunosuppressive properties. Finally, monitoring the changes in circulating neT cells’ frequencies after the tumor removal, we confirmed the role of cancer in the modulation of immune system, in particular, in supporting a Tregs-mediated immunosuppression.

Preoperative Tim‑3 expression on peripheral NK cells is correlated with pathologic TNM staging in colorectal cancer

Previous research has indicated that T cell immunoglobulin and mucin domain 3 (Tim-3) serves an important regulatory role in lymphocytes and in several cancers. However, the association between Tim‑3 expression on various lymphocyte subsets and human colorectal cancer (CRC) has not been elucidated. The present study aimed to characterize Tim‑3 expression on peripheral lymphocytes, including cluster of differentiation CD3+CD56‑ T cells, CD3‑CD56+ natural killer (NK) cells and CD3+CD56+ natural killer T (NKT) cells, in patients with CRC. The frequency of T cells, NK cells and NKT cells expressing Tim‑3 was assessed by multicolor flow cytometry of peripheral blood collected from 36 preoperative CRC patients and 38 healthy donors. The expression of Tim‑3 on lymphocyte subsets from 53 postoperative blood samples of CRC patients was also analyzed. There were fewer circulating NK cells in patients with CRC compared with healthy controls (P=0.0027); NK cell expression of Tim‑3 was also significantly decreased (P=0.0239). The frequency of circulating NK cells and Tim‑3+ NK cells was negatively correlated with clinical cancer stage, compared with healthy controls, but not with other clinicopathological parameters or serum concentrations of CRC biomarkers. Furthermore, the expression of Tim‑3 in NK cells was higher in CRC patients without metastasis. Notably, NK cell Tim‑3 expression in CRC patients was significantly restored following surgical resection of the primary tumor. In conclusion, the present study indicates the presence of an altered frequency and expression of Tim‑3 in peripheral NK cells in CRC patients. Preoperative Tim‑3 expression on peripheral NK cells is correlated with differential staging in colorectal cancer, and may be useful as a serum biomarker.

The Effect of Surgical Stress on Postoperative Tαβ and Tγδ Cell Distribution

BACKGROUND

It was previously shown that appropriate distribution of immune cells between different tissues and organs of the body is required for proper function of the immune system. Our previous experiments demonstrated that surgical trauma in mice induces Tγδ lymphocyte migration from peripheral blood to peritoneal lymphoid organs. Tγδ cells have regulatory activity as they suppress the cell-mediated immune response in vitro via TGF-β. In the current study, we aim to evaluate the influence of surgery on both Taβ and Tγδ lymphocyte distribution in patients that underwent operation.

MATERIALS AND METHODS

We investigated the percentage of Tαβ and Tγδ cells in peripheral blood of patients undergoing standard surgical procedures (gastric resection, colorectal resection, cholecystectomy, and strumectomy) before and 3 days after operation. The percentage of Tαβ and Tγδ cells was evaluated by FACS Canto II cytofluorimeter.

RESULTS

We showed that only major surgery located in the peritoneal cavity (gastric and colorectal surgery) decreases the percentage of Tγδ cells in peripheral blood as opposed to less traumatic surgery (strumectomy and cholecystectomy) which does not have such effect. However, significant reduction of Tγδ cells after operation was only observed in a group of patients that underwent gastrectomy. Additionally, we found that gastrectomy results in significant reduction of cumulative Tγδ CD4 and Tγδ CD25 lymphocyte counts.

CONCLUSION

Surgery results in decreased percentage of Tγδ lymphocytes in peripheral human blood, and this correlates with the severity and location of the surgical trauma. This observation may help to predict postoperative recovery after gastroabdominal surgery.

Functional impairment of infiltrating T cells in human colorectal cancer

T cells play a crucial role in preventing the growth and spread of colorectal cancer (CRC). However, immunotherapies against CRC have only shown limited success, which may be due to lack of understanding about the effect of the local tumor microenvironment (TME) on T cell function. The goal of this study was to determine whether T cells in tumor tissue were functionally impaired compared to T cells in non-tumor bowel (NTB) tissue from the same patients. We showed that T cell populations are affected differently by the TME. In the tumor, T cells produced more IL-17 and less IL-2 per cell than their counterparts from NTB tissue. T cells from tumor tissue also had impaired proliferative ability compared to T cells in NTB tissue. This impairment was not related to the frequency of IL-2 producing T cells or regulatory T cells, but T cells from the TME had a higher co-expression of inhibitory receptors than T cells from NTB. Overall, our data indicate that T cells in tumor tissue are functionally altered by the CRC TME, which is likely due to cell intrinsic factors. The TME is therefore an important consideration in predicting the effect of immune modulatory therapies.

Stem and immune cells in colorectal primary tumour: Number and function of subsets may diagnose metastasis

An important percentage of colorectal cancer (CRC) patients will develop metastasis, mainly in the liver, even after a successful curative resection. This leads to a very high mortality rate if metastasis is not detected early on. Disseminated cancer cells develop from metastatic stem cells (MetSCs). Recent knowledge has accumulated about these cells particularly in CRC, so they may now be tracked from the removed primary tumour. This approach could be especially important in prognosis of metastasis because it is becoming clear that metastasis does not particularly rely on testable driver mutations. Among the many traits supporting an epigenetic amplification of cell survival and self-renewal mechanisms of MetSCs, the role of many immune cell populations present in tumour tissues is becoming clear. The amount of tumour-infiltrating lymphocytes (T, B and natural killer cells), dendritic cells and some regulatory populations have already shown prognostic value or to be correlated with disease-free survival time, mainly in immunohistochemistry studies of unique cell populations. Parallel analyses of these immune cell populations together with MetSCs in the primary tumour of patients, with later follow-up data of the patients, will define the usefulness of specific combinations of both immune and MetSCs cell populations. It is expected that these combinations, together to different biomarkers in the form of an immune score, may predict future tumour recurrences, metastases and/or mortality in CRC. It will also support the future design of improved immunotherapeutic approaches against metastasis.