Localization of IL-17+Foxp3+ T Cells in Esophageal Cancer

Unremitting pro-inflammatory T-cell phenotypes, and macrophage activity, following paediatric burn injury

Objectives

The aim of this study was to characterise the dynamic immune profile of paediatric burn patients for up to 18 months post-burn.

Methods

Flow cytometry was used to measure 25 cell markers, chemokines and cytokines which reflected both pro-inflammatory and anti-inflammatory immune profiles. Peripheral blood mononuclear cells from 6 paediatric burn patients who had returned for repeated burn and scar treatments for > 4 timepoints within 12 months post-burn were compared to four age-matched healthy controls.

Results

While overall proportions of T cells, NK cells and macrophages remained relatively constant, over time percentages of these immune cells differentiated into effector and proinflammatory cell phenotypes including Th17 and activated γδ T cells. Circulating proportions of γδ T cells increased their expression of pro-inflammatory mediators throughout the burn recovery, with a 3-6 fold increase of IL-17 at 1-3 weeks, and NFκβ 9-18 months post-burn. T-regulatory cell plasticity was also observed, and Treg phenotype proportions changed from systemically reduced skin-homing T-regs (CCR4+) and increased inflammatory (CCR6+) at 1-month post-burn, to double-positive cell types (CCR4+CCR6+) elevated in circulation for 18 months post-burn. Furthermore, Tregs were observed to proportionally express less IL-10 but increased TNF-α over 18 months.

Conclusion

Overall, these results indicate the circulating percentages of immune cells do not increase or decrease over time post-burn, instead they become highly specialised, inflammatory and skin-homing. In this patient population, these changes persisted for at least 18 months post-burn, this 'immune distraction' may limit the ability of immune cells to prioritise other threats post-burn, such as respiratory infections.

GFI1/HDAC1-axis differentially regulates immunosuppressive CD73 in human tumor-associated FOXP3+ Th17 and inflammation-linked Th17 cells

Plasticity between Th17 and Treg cells is regarded as a crucial determinant of tumor-associated immunosuppression. Classically Th17 cells mediate inflammatory responses through production of cytokine IL17. Recently, Th17 cells have also been shown to acquire suppressive phenotypes in tumor microenvironment. However, the mechanism by which they acquire such immunosuppressive properties is still elusive. Here, we report that in tumor microenvironment Th17 cell acquires immunosuppressive properties by expressing Treg lineage-specific transcription factor FOXP3 and ectonucleotidase CD73. We designate this cell as Th17reg cell and perceive that such immunosuppressive property is dependent on CD73. It was observed that in classical Th17 cell, GFI1 recruits HDAC1 to change the euchromatin into tightly-packed heterochromatin at the proximal-promoter region of CD73 to repress its expression. Whereas in Th17reg cells GFI1 cannot get access to CD73-promoter due to heterochromatin state at its binding site and, thus, cannot recruit HDAC1, failing to suppress the expression of CD73.

Esophageal Microenvironment: From Precursor Microenvironment to Premetastatic Niche

Esophageal cancer (EC) is the sixth most deadly cancer, and its incidence is still increasing year by year. Although the researches on the molecular mechanisms of EC have been widely carried out and incremental progress has been made, its overall survival rate is still low. There is cumulative evidence showing that the esophageal microenvironment plays a vital role in the development of EC. In precancerous lesions of the esophagus, high-risk environmental factors can promote the development of precancerous lesions by inducing the production of inflammatory factors and the recruitment of immune cells. In the tumor microenvironment, tumor-promoting cells can inhibit anti-tumor immunity and promote tumor progression through a variety of pathways, such as bone marrow-derived suppressor cells (MDSCs), tumor-associated fibroblasts (CAFs), and regulatory T cells (Tregs). The formation of extracellular hypoxia and acidic microenvironment and the change of extracellular matrix stiffness are also important factors affecting tumor progression and metastasis. Simultaneously, primary tumor-derived cytokines and bone marrow-derived immune cells can also promote the formation of pre-metastasis niche of EC lymph nodes, which are beneficial to EC lymph node metastasis. Further research on the specific mechanism of these processes in the occurrence, development, and metastasis of each EC subtype will support us to grasp the overall pre-cancerous prevention, targeted treatment, and metastatic assessment of EC.

The Fate of Th17 Cells is Shaped by Epigenetic Modifications and Remodeled by the Tumor Microenvironment

Th17 cells represent a subset of CD4+ T cells characterized by the master transcription factor RORγt and the production of IL-17. Epigenetic modifications such as post-translational histone modifications and DNA methylation play a key role in Th17 cell differentiation and high plasticity. Th17 cells are highly recruited in many types of cancer and can be associated with good or bad prognosis. Here, we will review the remodeling of the epigenome induced by the tumor microenvironment, which may explain Th17 cell predominance. We will also discuss the promising treatment perspectives of molecules targeting epigenetic enzymes to remodel a Th17-enriched tumor microenvironment.

Molecular networks of FOXP family: dual biologic functions, interplay with other molecules and clinical implications in cancer progression

Though Forkhead box P (FOXP) transcription factors comprising of FOXP1, FOXP2, FOXP3 and FOXP4 are involved in the embryonic development, immune disorders and cancer progression, the underlying function of FOXP3 targeting CD4 + CD25+ regulatory T (Treg) cells and the dual roles of FOXP proteins as an oncogene or a tumor suppressor are unclear and controversial in cancers to date. Thus, the present review highlighted research history, dual roles of FOXP proteins as a tumor suppressor or an oncogene, their molecular networks with other proteins and noncoding RNAs, cellular immunotherapy targeting FOXP3, and clinical implications in cancer progression.

Increased interleukin-17A levels promote rituximab resistance by suppressing p53 expression and predict an unfavorable prognosis in patients with diffuse large B cell lymphoma

Rituximab resistance has become increasingly common in patients with diffuse large B cell lymphoma (DLBCL). However, the mechanisms involved remain unclear. In this study, we aimed to examine the effect of rituximab on interleukin (IL)-17A and to investigate the role of IL-17A in rituximab resistance and its prognostic value in patients with DLBCL. Our retrospective analysis revealed that rituximab increased IL-6 expression levels in patients with DLBCL, and the increased IL-6 levels in turn induced the differentiation of Th17 and IL-17⁺Foxp3⁺ Treg cells, which secreted IL-17A both in vivo and in vitro. We then examined the effects of IL-17A on the apoptosis and proliferation of, and p53 expression in DLBCL cells, and found that IL-17A prevented rituximab-induced apoptosis and promoted the proliferation of DLBCL cells by suppressing p53 expression in vitro. The survival data of 73 patients with DLBCL suggested that high peripheral blood levels of IL-17A predicted an unfavorable survival. On the whole, our data indicate that rituximab promotes Th17 and IL-17⁺Foxp3⁺ Treg cells to secrete IL-17A, which in turn promotes rituximab resistance, partially by suppressing p53 expression and inhibiting rituximab-induced DLBCL cell apoptosis. IL-17A may thus prove to be a useful prognostic marker in patients with DLBCL.

The paradox of Th17 cell functions in tumor immunity

Immune system acts as a host defensive mechanism protecting against attacking pathogens and transformed cells, including cancer cells. Th17 cells are a specific subset of T helper lymphocytes determined by high secretion of IL-17 and other inflammatory cytokines. Th17 cells increase tumor progression by activating angiogenesis and immunosuppressive activities. They can also mediate antitumor immune responses through recruiting immune cells into tumors, stimulating effector CD8+ T cells, or surprisingly by altering toward Th1 phenotype and producing IFN-γ, so Th17 cells are supposed as a double-edged sword in cancer. A comprehensive approach to indicating the activity of Th17 cells in tumor progression could help in the planning of new therapeutic approaches specially targeting Th17 cells in cancer.

The role of regulatory B cells in digestive system diseases

INTRODUCTION

The past decade has provided striking insights into a newly identified subset of B cells known as regulatory B cells (Bregs). In addition to producing antibody, Bregs also regulate diseases via cytokine production and antigen presentation. This subset of B cells has protective and potentially therapeutic effects. However, the particularity of Bregs has caused some difficulties in conducting research on their roles. Notably, human B10 cells, which are Bregs that produce interleukin 10, share phenotypic characteristics with other previously defined B cell subsets, and currently, there is no known surface phenotype that is unique to B10 cells.

METHODS

An online search was performed in the PubMed and Web of Science databases for articles published providing evidences on the role of regulatory B cells in digestive system diseases.

RESULTS AND CONCLUSIONS

Abundant evidence has demonstrated that Bregs play a regulatory role in inflammatory, autoimmune, and tumor diseases, and regulatory B cells play different roles in different diseases, but future work needs to determine the mechanisms by which Bregs are activated and how these cells affect their target cells.

Emerging roles of T helper 17 and regulatory T cells in lung cancer progression and metastasis

Lung cancer is a leading cause of cancer-related deaths worldwide. Lung cancer risk factors, including smoking and exposure to environmental carcinogens, have been linked to chronic inflammation. An integral feature of inflammation is the activation, expansion and infiltration of diverse immune cell types, including CD4⁺ T cells. Within this T cell subset are immunosuppressive regulatory T (Treg) cells and pro-inflammatory T helper 17 (Th17) cells that act in a fine balance to regulate appropriate adaptive immune responses.In the context of lung cancer, evidence suggests that Tregs promote metastasis and metastatic tumor foci development. Additionally, Th17 cells have been shown to be an integral component of the inflammatory milieu in the tumor microenvironment, and potentially involved in promoting distinct lung tumor phenotypes. Studies have shown that the composition of Tregs and Th17 cells are altered in the tumor microenvironment, and that these two CD4⁺ T cell subsets play active roles in promoting lung cancer progression and metastasis.We review current knowledge on the influence of Treg and Th17 cells on lung cancer tumorigenesis, progression, metastasis and prognosis. Furthermore, we discuss the potential biological and clinical implications of the balance among Treg/Th17 cells in the context of the lung tumor microenvironment and highlight the potential prognostic function and relationship to metastasis in lung cancer.

Th17 Cell Plasticity and Functions in Cancer Immunity

Th17 cells represent a particular subset of T helper lymphocytes characterized by high production of IL-17 and other inflammatory cytokines. Th17 cells participate in antimicrobial immunity at mucosal and epithelial barriers and particularly fight against extracellular bacteria and fungi. While a role for Th17 cells in promoting inflammation and autoimmune disorders has been extensively and elegantly demonstrated, it is still controversial whether and how Th17 cells influence tumor immunity. Although Th17 cells specifically accumulate in many different types of tumors compared to healthy tissues, the outcome might however differ from a tumor type to another. Th17 cells were consequently associated with both good and bad prognoses. The high plasticity of those cells toward cells exhibiting either anti-inflammatory or in contrast pathogenic functions might contribute to Th17 versatile functions in the tumor context. On one hand, Th17 cells promote tumor growth by inducing angiogenesis (via IL-17) and by exerting themselves immunosuppressive functions. On the other hand, Th17 cells drive antitumor immune responses by recruiting immune cells into tumors, activating effector CD8(+) T cells, or even directly by converting toward Th1 phenotype and producing IFN-γ. In this review, we are discussing the impact of the tumor microenvironment on Th17 cell plasticity and function and its implications in cancer immunity.

Expression of Th17 cell population regulatory cytokines in laryngeal carcinoma - Preliminary study

Aim of the study

Aim of the study was to evaluate the potential role of regulatory and proinflammatory cytokines IL-23 and IL-17 as Th17 lymphocyte activity markers in relation to invasiveness in laryngeal cancer.

Material and methods

The immunological analysis was conducted in 50 patients treated for squamous cell laryngeal carcinoma and 30 healthy volunteers as controls. The levels of IL-23 and IL-17 in supernatants of purified peripheral blood mononuclear cell cultures were determined by using the enzyme-linked immunosorbent assay (ELISA). The clinicomorphological criteria included pTNM, stage, G, and the total tumour front grading (TFG) score.

Results

Our data demonstrated higher concentrations of IL-23 in patients as compared to controls (p = 0.0001). No statistical difference for IL-17 in these groups was observed. Our study revealed significant dependences in IL-23 expression on pT (p = 0.04), histological differentiation (p = 0.04), and TFG total score (p = 0.02). Advanced tumours (pT3–pT4) with higher grade (G2–G3) and higher invasiveness (> 14 TFG points) were characterised by elevated IL-23 levels in PBMC supernatants. Our data did not indicate a relationship between cytokine levels and three- and five-year survival. However, a tendency towards lower content of IL-23 in PBMC cultures in patients who lived longer than five years after treatment was noted. The relationships between IL-17 level in PBMC cultures and clinicomorphological and prognostic parameters have not been disclosed.

Conclusions

The results of this study suggest the importance of regulatory cytokine IL-23 in determining the aggressive potential of laryngeal carcinomas.

IL-17+Foxp3+ T cells: an intermediate differentiation stage between Th17 cells and regulatory T cells

Foxp3(+) Tregs have been known as a major regulator of immune homeostasis through their immunosuppressive function. Th17 lineage is a CD4(+) T cell subset that exerts its function by secreting proinflammatory cytokines and protecting host against microbial infections. The altered ratio between Foxp3(+) Tregs and Th17 cells plays an important role in the pathogenesis of immune-related diseases. Recent mice and human studies have demonstrated that Tregs can be reprogrammed into a novel population, IL-17(+)Foxp3(+) T cells, phenotypically and functionally resembling Th17 cells under the complicated cytokine stimulation. The identification of IL-17(+)Foxp3(+) T cells may provide a new understanding of therapy targeting Tregs and Th17 cells in autoimmune diseases and cancer. Here, we highlight significant data regarding the phenotype profile, origination, differentiation, and the pleiotropic functions of IL-17(+)Foxp3(+) T cells and the reciprocal relationships of these cells to Tregs and Th17 cells. Furthermore, the role of IL-17(+)Foxp3(+) T cells in tumorigenesis and clinical implications in cancer therapy are discussed in this review.

Identity crisis of Th17 cells: many forms, many functions, many questions

Th17 cells are a subset of CD4(+) effector T cells characterized by expression of the IL-17-family cytokines, IL-17A and IL-17F. Since their discovery nearly a decade ago, Th17 cells have been implicated in the regulation of dozens of immune-mediated inflammatory diseases and cancer. However, attempts to clarify the development and function of Th17 cells in human health and disease have generated as many questions as answers. On one hand, cytokine expression in Th17 cells appears to be remarkably dynamic and is subject to extensive regulation (both positive and negative) in tissue microenvironments. On the other hand, accumulating evidence suggests that the human Th17 subset is a heterogeneous population composed of several distinct pro- and anti-inflammatory subsets. Clearly, Th17 cells as originally conceived no longer neatly fit the long-standing paradigm of stable and irrepressible effector T cell function. Here we review current concepts surrounding human Th17 cells, with an emphasis on their plasticity, heterogeneity, and their many, tissue-specific functions. In spite of the challenges ahead, a comprehensive understanding of Th17 cells and their relationship to human disease is key to ongoing efforts to develop safer and more selective anti-inflammatory medicines.

Metabolic control of the Treg/Th17 axis

The interplay of the immune system with other aspects of physiology is continually being revealed and in some cases studied in considerable mechanistic detail. A prime example is the influence of metabolic cues on immune responses. It is well appreciated that upon activation, T cells take on a metabolic profile profoundly distinct from that of their quiescent and anergic counterparts; however, a number of recent breakthroughs have greatly expanded our knowledge of how aspects of cellular metabolism can shape a T-cell response. Particularly important are findings that certain environmental cues can tilt the delicate balance between inflammation and immune tolerance by skewing T-cell fate decisions toward either the T-helper 17 (Th17) or T-regulatory (Treg) cell lineage. Recognizing the unappreciated immune-modifying potential of metabolic factors and particularly those involved in the generation of these functionally opposing T-cell subsets will likely add new and potent therapies to our repertoire for treating immune mediated pathologies. In this review, we summarize and discuss recent findings linking certain metabolic pathways, enzymes, and by-products to shifts in the balance between Th17 and Treg cell populations. These advances highlight numerous opportunities for immune modulation.

The expressions of MIF and CXCR4 protein in tumor microenvironment are adverse prognostic factors in patients with esophageal squamous cell carcinoma

Background

Tumor-derived cytokines and their receptors usually take important roles in the disease progression and prognosis of cancer patients. In this survey, we aimed to detect the expression levels of MIF and CXCR4 in different cell populations of tumor microenvironments and their association with survivals of patients with esophageal squamous cell carcinoma (ESCC).

Methods

MIF and CXCR4 levels were measured by immunochemistry in tumor specimens from 136 resected ESCC. Correlation analyses and independent prognostic outcomes were determined using Pearson’s chi-square test and Cox regression analysis.

Results

The expression of CXCR4 in tumor cells was positively associated with tumor status (P = 0.045) and clinical stage (P = 0.044); whereas the expression of CXCR4 in tumor-infiltrating lymphocytes (TILs) and the expression of MIF in tumor cells and in TILs were not associated with clinical parameters of ESCC patients. High MIF expression in tumor cells or in TILs or high CXCR4 expression in tumor cells was significantly related to poor survival of ESCC patients (P < 0.05). Multivariate analysis showed that the expression of MIF or CXCR4 in tumor cells and the expression of MIF in TILs were adverse independent factors for disease-free survival (DFS) and overall survival (OS) in the whole cohort of patients (P < 0.05). Furthermore, the expression of MIF and CXCR4 in tumor cells were independent factors for reduced DFS and OS in metastatic/recurrent ESCC patients (P < 0.05). Interestingly, the expressions of MIF and CXCR4 in tumor cells and in TILs were significantly positively correlated (P < 0.05), and the combined MIF and CXCR4 expression in tumor cells was an independent adverse predictive factor for DFS and OS (P < 0.05).

Conclusion

The expressions of MIF and CXCR4 proteins in tumor cells and TILs have different clinically predictive values in ESCC.

Immune classification of colorectal cancer patients: impressive but how complete?

INTRODUCTION

There is now accumulating evidence to suggest that intratumoral adaptive immune responses predict patient prognosis. The presence of tumor-infiltrating lymphocytes has been correlated with patients' disease-free and overall survival. Recent exciting studies of human colorectal cancers (CRCs) have underlined the significance of including immunological biomarkers as prognostic markers.

AREAS COVERED

This review covers recent literature which suggests that the type, density and location of immune cells within the colorectal tumors represent a better predictor of patient survival than the histopathological methods currently used to stage CRC.

EXPERT OPINION

Remarkably, the quantity, quality and spatial distribution of immune cells within the tumor has a greater prognostic value than the standard tumor staging based on tumor burden, infiltration of draining and regional lymph nodes by tumor cells, and evidence of metastases. In addition, such an immune classification may also have a predictive value. Thus, by increasing the knowledge of the immune events inside the tumors and by better understanding the immune architecture of these tumors as well as the functional programs of their constituents, there will certainly be a more complete idea of how tumors evade from immunosurveillance. This knowledge will help to identify new targets for the development of therapeutic strategies.

Intracellular CTLA4 and regulatory T cells in patients with laryngeal squamous cell carcinoma

To explore if the increased percentages of Regulatory T (Treg) cells, as well as, overexpression of Cytotoxic T-Lymphocyte Antigen-4 (CTLA-4) are involved in laryngeal-squamous cell carcinoma (SCC), 45 patients with laryngeal-SCC and 27 healthy controls were enrolled. Flow cytometry was performed to investigate, in the peripheral blood, the prevalence of CD4+CD25+FoxP3+ Treg cells, as well as, surface and intracellular expression of CTLA-4 by the main lymphocyte subsets (CD4+, CD8+ and CD19+). The results indicated intracellular (In)CTLA4 with considerable higher expression in the CD8+ lymphocytes among patients with laryngeal-SCC compared with the control group (8.2 ± 8.7 versus 2.3 ± 3.5, P = 0.001). The mean percentage of InCTLA4+CD4+ and InCTLA4+CD19+ lymphocytes was also significantly higher in patients (8.7 ± 7.8 versus 4.4 ± 4.2, P = 0.018 and 0.6 ± 0.8 versus 0.2 ± 0.2, P = 0.024, respectively). With respect to surface (Sur)CTLA4, the difference between patients and controls was, however, significant only in the case of CD8+ lymphocytes (0.7 ± 0.6 versus 0.3 ± 0.3, P = 0.003, respectively). The percentage of Treg cells was observed to be significantly higher in patients (7.5 ± 6.3 and 3.2 ± 1.9, P < 0.0001). Furthermore, association analysis revealed the association of Treg cell increase with the higher tumor-size and lymphnode stage (P < 0.005). These data collectively suggest that patients with laryngeal-SCC may benefit from immunotherapy targeting CTLA4 and Treg cells.

FOXP3-marked IL-17a-producing regulatory T cells are increased in patients with allergic rhinitis

CONCLUSION

The deficient regulatory T cells may play a role in the development of allergic rhinitis.

OBJECTIVE

A subpopulation of regulatory T cell that produce IL-17a were proved to show an apparent duality of regulatory T cell and effector T helper-17 cells. We studied this subpopulation in patients with allergic rhinitis.

METHODS

Fresh whole blood from 20 patients with allergic rhinitis and 19 healthy donors was used to investigate the frequencies of CD4(+)IFN-γ(+) T cells (effector T helper-1), CD4(+)IL-4(+) T cells (effector T helper-2) and CD4(+)IL-17a(+) T cells (effector T helper-17) by flow cytometry after stimulation for 4-6 h. Simultaneously, CD4(+) T lymphocytes were isolated from peripheral blood mononuclear cells and then the frequencies of regulatory T cells and IL-17a-producing regulatory T cells in the allergic rhinitis group were compared with healthy controls after T-cell antigen receptor stimulation for 48 h. The suppressive capacity of CD4(+)CD25(high)CD127(low) regulatory T cells that were stimulated by Dermatophagoides pteronyssinus in both groups was isolated and assessed.

RESULTS

The frequencies of effector T helper-17 and effector T helper-2 cells were higher in the allergic group compared with healthy controls. Regulatory T cells were similar in both groups, but IL-17a-producing regulatory T cells were increased in the allergic group. In addition, the capacity of regulatory T cells to suppress effector T helper-17 cytokine production was significantly decreased in the allergic group.

The role and regulation of human Th17 cells in tumor immunity

T helper 17 (Th17) cells play critical roles in the pathogenesis of inflammatory and autoimmune diseases, as well as in host protection against pathogens. The contribution of Th17 cells to human tumor immunity, however, remains largely unknown. Since their identification in 2005, Th17 cells have been extensively studied in mouse tumor models and human cancer patients. Although accumulating data suggest the importance of Th17 cells to tumor immunity, conclusions regarding the functional role of Th17 cells remain controversial. In this review, we summarize current knowledge regarding the regulation and functional role of Th17 cells in human cancers. In particular, we emphasize several recently identified characteristics of Th17 cells, including plasticity, their relationship with regulatory T cells, and Th17 cell heterogeneity in the tumor microenvironment. Improved understanding of these issues is critical to elucidating the role of Th17 cells in antitumor immunity and for the design of novel therapeutic approaches specifically targeting Th17 cells.