Interleukin-10 in viral diseases and cancer: exiting the labyrinth?

Crosstalk between gut microbiota and COVID-19 impacts pancreatic cancer progression

Pancreatic cancer (PC) is one of the most common causes of cancer-associated death worldwide, with a low rate of 5-year survival. Currently, the pathogenesis of PC is complicated, with no efficient therapy. Coronavirus disease 2019 (COVID-19) disease caused by severe acute respiratory syndrome coronavirus 2 further exacerbates the challenge of patients with PC. The alteration of gut microbiota caused by COVID-19 infection may impact PC progression in patients via immune regulation. The expression of inflammatory immune mediators such as interleukin (IL)-6, IL-8, and IL-10 has been found to increase in both PC and COVID-19 patients, which is associated with the disease severity and prognostic outcome. Gut microbiome serves as a critical connector between viral infection and PC. It can regulate host systemic immune response and impact the efficacy of immunotherapy. Here, we first demonstrated the features of inflammatory cytokines in both diseases and their impact on disease outcomes. Then, we demonstrated the importance of immunotherapeutic strategies. This includes the immune modulation that targets a single or dual receptors using a single agent or their combinations for the treatment of PC in patients who get infected with COVID-19. Additionally, we explored the possibility of managing the disease by regulating gut microbiome. Overall, modulation of the lung-gut-pancreases axis can boost anti-cancer immunotherapy and reduce adverse prognostic outcomes.

Effect of Programmed Death-Ligand 1 in Cancer-Associated Fibroblasts on Advanced Laryngeal Squamous Cell Carcinoma

This study aimed to explore the effect of programmed death-ligand 1 (PD-L1) in cancer-associated fibroblasts (CAFs) on advanced laryngeal squamous cell carcinoma (LSCC). The expression of PD-L1 in advanced LSCC tumor tissues was observed in 83 patients with LSCC by immunofluorescence microscopy and compared with that in normal laryngeal mucosa. The CAFs of LSCC and normal fibroblasts (NFs) were isolated, cultured, purified, and examined by fluorescence. The expression of PD-L1 in purified CAFs and NFs was measured by flow cytometry. The expression of PD-L1 in CAFs was downregulated through small interferring RNA (siRNA) transfection. The proliferation and migration capacities of CAFs were observed using proliferation and scratch tests, respectively. The proliferation of HEP-2 cells and T cells was measured after cocultured with CAFs. The secretion of interleukins IL-2 and IL-10 was detected using enzyme-linked immuno sorbent assay (ELISA). PD-L1 was expressed in 62 of 83 cases of the advanced LSCC tumor tissues. Also, CAFs expressed more PD-L1 compared with NFs. The proliferation and migration capacities of CAFs were significantly lower after transfection with PD-L1-siRNA. The proliferation rate of HEP-2 cells cocultured with CAFs decreased in PD-L1-siRNA-transfected cells. However, the proliferation rate of T cells increased in transfected cells. The ELISA results showed that the secretion of IL-2 increased and that of IL-10 decreased in PD-L1-siRNA-transfected cells. The expression of PD-L1 in CAFs of advanced LSCC was higher than that in NFs. The downregulation of PD-L1 reduced the proliferation and migration of CAFs and HEP-2 cells but enhanced the proliferation and pro-inflammatory function of T cells in the coculture experiment.

Herpes zoster and the subsequent risk of prostate cancer in an Asian population: A nationwide population-based cohort study

It has been suggested that herpes zoster may increase the risk of subsequent prostate cancer (PCa). We aimed to assess the risk of PCa following herpes zoster by the population-based follow-up study.This is a retrospective study and data are from the Taiwan National Health Insurance Research Database (NHIRD). The study cohort comprised all patients with a diagnosis of herpes zoster (International Classification of Diseases, 9th Revision, Clinical Modification code 053.0-053.9) and followed for PCa from 1997 to 2013 (n = 11,376). Subjects younger than 20 years of age were excluded. The match-control cohort was identified from the Registry of Beneficiaries of the NHIRD and randomly selected by matching with the study cohort at a 3:1 ratio based on age (every 5-year span), and year of herpes zoster diagnosis (n = 34,128). We used Cox proportional hazards regression models to estimate the hazard ratios (HRs) for subsequent PCa, after controlling for potential cormobidities.Men with and without herpes zoster had similar age and comorbidity distributions. Among the 45,504 sampled patients, 1011 (2.22%) developed PCa during the 10 years of follow-up, 276 (2.43%) from the study cohort and 735 (2.15%) from the match-control cohort and the incidence rate was 3.13 and 2.72 per 1000 person years respectively. Patients with herpes zoster were more likely to develop PCa than patients in the match-control cohort (HR = 1.15; 95% confidence interval (CI) = 1.00-1.32, P value = .045). After adjusting for age and comorbidities, herpes zoster was associated with a 1.15 increased risk of PCa (adjusted HR = 1.15, 95% CI = 0.99-1.32, P value = .054).Our study indicates that preceding herpes zoster infection is a suggestive risk marker for subsequent PCa after controlling for potential confounders. Further prospective studies are needed to determine the relationship between herpes zoster and PCa.

Targeting IL-10 Family Cytokines for the Treatment of Human Diseases

Members of the interleukin (IL)-10 family of cytokines play important roles in regulating immune responses during host defense but also in autoimmune disorders, inflammatory diseases, and cancer. Although IL-10 itself primarily acts on leukocytes and has potent immunosuppressive functions, other family members preferentially target nonimmune compartments, such as tissue epithelial cells, where they elicit innate defense mechanisms to control viral, bacterial, and fungal infections, protect tissue integrity, and promote tissue repair and regeneration. As cytokines are prime drug targets, IL-10 family cytokines provide great opportunities for the treatment of autoimmune diseases, tissue damage, and cancer. Yet no therapy in this space has been approved to date. Here, we summarize the diverse biology of the IL-10 family as it relates to human disease and review past and current strategies and challenges to target IL-10 family cytokines for clinical use.

Cancer vaccines: translation from mice to human clinical trials

Therapeutic cancer vaccines have been a long-sought approach to harness the exquisite specificity of the immune system to treat cancer, but until recently have not had much success as single agents in clinical trials. However, new understanding of the immunoregulatory mechanisms exploited by cancers has allowed the development of approaches to potentiate the effect of vaccines by removing the brakes while the vaccines step on the accelerator. Thus, vaccines that had induced a strong T cell response but no clinical therapeutic effect may now reach their full potential. Here, we review a number of promising approaches to cancer vaccines developed initially in mouse models and their translation into clinical trials, along with combinations of vaccines with other therapies that might allow cancer vaccines to finally achieve clinical efficacy against many types of cancer.

Prognostic value of PDL1 expression in pancreatic cancer

Pancreatic cancer is one of the most aggressive human cancers. PD1/PDL1-inhibitors recently showed promising results in different cancers with correlation between PDL1 tumor expression and responses. Expression of programmed cell death receptor ligand 1 (PDL1) has been scarcely studied in pancreatic cancer. In this retrospective study, we analyzed PDL1 mRNA expression in 453 clinical pancreatic cancer samples profiled using DNA microarrays and RNASeq. Compared to normal pancreatic samples, PDL1 expression was upregulated in 19% of cancer samples. Upregulation was not associated with clinicopathological features such as patients' age and sex, pathological type, tumor size, lymph node status, and grade, but was associated with shorter disease-free survival and overall survival in multivariate analyses. Analysis of correlations with biological parameters showed that PDL1 upregulation was associated with some degree of lymphocyte infiltration and signs of anti-tumor T-cell response, but to a lesser extent than what has been reported in breast cancer and GIST. PDL1-up pancreatic cancers displayed profiles of lymphocyte exhaustion, were more enriched in inhibitory molecules and pro-tumor populations (Tregs with upregulation of FOXP3 and IL10, myeloid-derived suppressor cells with upregulation of CD33 and S100A8/A9), and demonstrated a down-modulation of most MHC class I members (HLA-A/B/C, HLA-E/F/G) suggestive of a defect in antigen processing and presentation. In conclusion, our results suggest that PDL1 expression might refine the prediction of metastatic relapse in operated pancreatic cancer, and that PD1/PDL1 inhibitors might reactivate inhibited T-cells to increase the anti-tumor immune response in PDL1-upregulated tumors.

Cytokines and Prognostic Factors in Epithelial Ovarian Cancer

INTRODUCTION

Ovarian cancer has a high mortality and delayed diagnosis. Inflammation is a risk factor for ovarian cancer, and the inflammatory response is involved in almost all stages of tumor development. Immunohistochemical staining in stroma and epithelium of a panel of cytokines in benign and malignant ovarian neoplasm was evaluated. In addition, immunostaining was related to prognostic factors in malignant tumors.

METHOD

The study group comprised 28 ovarian benign neoplasias and 28 ovarian malignant neoplasms. A panel of cytokines was evaluated by immunohistochemistry (Th1: IL-2 and IL-8; Th2: IL-5, IL-6, and IL-10; and TNFR1). Chi-square test with Yates' correction was used, which was considered significant if less than 0.05.

RESULTS

TNFR1, IL-5, and IL-10 had more frequent immunostaining 2/3 in benign neoplasms compared with malignant tumors. Malignant tumors had more frequent immunostaining 2/3 for IL-2 in relation to benign tumors. The immunostaining 0/1 of IL 8 was more frequent in the stroma of benign neoplasms compared with malignant neoplasms. Evaluation of the ovarian cancer stroma showed that histological grade 3 was significantly correlated with staining 2/3 for IL-2 (P = 0.004). Women whose disease-free survival was less than 2.5 years had TNFR1 stromal staining 2/3 (P = 0.03) more frequently.

CONCLUSION

IL-2 and TNFR1 stromal immunostaining are related prognostic factors in ovarian cancer and can be the target of new therapeutic strategies.

Nasopharyngeal Cancer: Molecular Landscape

Nasopharyngeal carcinoma (NPC) is a unique epithelial malignancy arising from the superior aspect of the pharyngeal mucosal space, associated with latent Epstein-Barr virus infection in most cases. The capacity to characterize cancer genomes in unprecedented detail is now providing insights into the genesis and molecular underpinnings of this disease. Herein, we provide an overview of the molecular aberrations that likely drive nasopharyngeal tumor development and progression. The contributions of major Epstein-Barr virus–encoded factors, including proteins, small RNAs, and microRNAs, along with their interactions with pathways regulating cell proliferation and survival are highlighted. We review recent analyses that clearly define the role of genetic and epigenetic variations affecting the human genome in NPC. These findings point to the impact of DNA methylation and histone modifications on gene expression programs that promote this malignancy. The molecular interactions that allow NPC cells to evade immune recognition and elimination, which is crucial for the survival of cells expressing potentially immunogenic viral proteins, are also described. Finally, the potential utility of detecting host and viral factors for the diagnosis and prognosis of NPC is discussed. Altogether, the studies summarized herein have greatly expanded our knowledge of the molecular biology of NPC, yet much remains to be uncovered. Emerging techniques for using and analyzing well-annotated biospecimens from patients with NPC will ultimately lead to a greater level of understanding, and enable improvements in precision therapies and clinical outcomes.

Serum IL-10 Predicts Worse Outcome in Cancer Patients: A Meta-Analysis

Background

IL–10 is an important immunosuppressive cytokine which is frequently elevated in tumor microenvironment. Some studies have reported that overexpression of serous IL–10 is correlated with worse outcome in patients with malignant tumor. Here, we conducted a meta-analysis to assess the prognostic impact of serous IL–10 expression in cancer patients.

Methods

We searched PubMed and EBSCO for studies in evaluating the association of IL–10 expression—in serum and clinical outcome in cancer patients. Overall survival (OS) was the primary prognostic indicator and disease-free survival (DFS) was the secondary indicator. Extracted data were computed into odds ratios (ORs) and 95% confidence interval (CI) or a P value for survival at 1, 3 and 5 years. Pooled data were weighted using the Mantel–Haenszel Fixed-effect model. All statistical tests were two-sided.

Results

A total of 1788 patients with cancer from 21 published studies were incorporated into this meta-analysis. High level of serum IL–10 was significantly associated with worse OS at 1-year (OR = 3.70, 95% CI = 2.81 to 4.87, P < 0.00001), 3-year (OR = 3.33, 95% CI = 2.53 to 4.39, P < 0.0001) and 5-year (OR = 2.80, 95% CI = 1.90 to 4.10, P < 0.0001) of cancer. Subgroup analysis showed that the correlation between serous IL–10 expression and outcome of patients with solid tumors and hematological malignancies are consistent. The association of IL–10 with worse DFS at 1-year (OR = 3.34, 95% CI = 1.40 to 7.94, P = 0.006) and 2-year (OR = 3.91, 95% CI = 1.79 to 8.53, P = 0.0006) was also identified.

Conclusions

High expression of serous IL–10 leads to an adverse survival in most types of cancer. IL–10 is a valuable biomarker for prognostic prediction and targeting IL–10 treatment options for both solid tumors and hematological malignancies.

Chemical compounds from anthropogenic environment and immune evasion mechanisms: potential interactions

An increasing number of studies suggest an important role of host immunity as a barrier to tumor formation and progression. Complex mechanisms and multiple pathways are involved in evading innate and adaptive immune responses, with a broad spectrum of chemicals displaying the potential to adversely influence immunosurveillance. The evaluation of the cumulative effects of low-dose exposures from the occupational and natural environment, especially if multiple chemicals target the same gene(s) or pathway(s), is a challenge. We reviewed common environmental chemicals and discussed their potential effects on immunosurveillance. Our overarching objective was to review related signaling pathways influencing immune surveillance such as the pathways involving PI3K/Akt, chemokines, TGF-β, FAK, IGF-1, HIF-1α, IL-6, IL-1α, CTLA-4 and PD-1/PDL-1 could individually or collectively impact immunosurveillance. A number of chemicals that are common in the anthropogenic environment such as fungicides (maneb, fluoxastrobin and pyroclostrobin), herbicides (atrazine), insecticides (pyridaben and azamethiphos), the components of personal care products (triclosan and bisphenol A) and diethylhexylphthalate with pathways critical to tumor immunosurveillance. At this time, these chemicals are not recognized as human carcinogens; however, it is known that they these chemicalscan simultaneously persist in the environment and appear to have some potential interfere with the host immune response, therefore potentially contributing to promotion interacting with of immune evasion mechanisms, and promoting subsequent tumor growth and progression.

IL-10 enhances CTL-mediated tumor rejection by inhibiting highly suppressive CD4+ T cells and promoting CTL persistence in a murine model of plasmacytoma

Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine that regulates immune responses. IL-10 has also been shown to enhance antitumor CD8⁺ T-cell responses in tumor models although the underlying mechanisms are not fully understood. In this study, we used a series of genetic mouse models and the mouse plasmacytoma J558 model to investigate this issue. J558 tumors grew significantly faster in IL-10^-/- mice than in wild type (WT) mice, but similarly in IL-10 ^-/- Rag2 ^-/- and Rag2 ^-/- mice. Tumors from IL-10 ^-/- mice contained fewer IFN-γ-producing CD8⁺ and CD4⁺ T cells than tumors from WT mice. Strikingly, depletion of total CD4⁺ T cells, but not CD25⁺ cells, resulted in tumor eradication in IL-10 ^-/- mice. Adoptive transfer studies revealed that CD4⁺ T cells from IL-10 ^-/- mice exhibited more potent suppression of cytotoxic T lymphocyte (CTL)-mediated tumor rejection than their WT counterparts, and IL-10-deficient tumor-infiltrating CD4⁺ T cells expressed higher levels of PD-L1 and CTLA-4 inhibitory molecules. Although IL-10-deficient CD8⁺ T cells are not defective in activation and initial rejection of tumors, adoptive transfer studies using IL-10-deficient P1CTL transgenic T cells that recognize the tumor rejection antigen P1A reveal that IL-10 is required for long-term persistence of CTLs and control of tumor growth. Thus, we have found that IL-10 enhances antitumor CTL responses by inhibiting highly suppressive CD4⁺ T cells and promoting CTL persistence. These data have important implications for the design of immunotherapy for human cancer.

The role of the mediators of inflammation in cancer development

Epigenetic disorders such as point mutations in cellular tumor suppressor genes, DNA methylation and post-translational modifications are needed to transformation of normal cells into cancer cells. These events result in alterations in critical pathways responsible for maintaining the normal cellular homeostasis, triggering to an inflammatory response which can lead the development of cancer. The inflammatory response is a universal defense mechanism activated in response to an injury tissue, of any nature, that involves both innate and adaptive immune responses, through the collective action of a variety of soluble mediators. Many inflammatory signaling pathways are activated in several types of cancer, linking chronic inflammation to tumorigenesis process. Thus, Inflammatory responses play decisive roles at different stages of tumor development, including initiation, promotion, growth, invasion, and metastasis, affecting also the immune surveillance. Immune cells that infiltrate tumors engage in an extensive and dynamic crosstalk with cancer cells, and some of the molecular events that mediate this dialog have been revealed. A range of inflammation mediators, including cytokines, chemokines, free radicals, prostaglandins, growth and transcription factors, microRNAs, and enzymes as, cyclooxygenase and matrix metalloproteinase, collectively acts to create a favorable microenvironment for the development of tumors. In this review are presented the main mediators of the inflammatory response and discussed the likely mechanisms through which, they interact with each other to create a condition favorable to development of cancer.

Evaluation of Interleukin-10 Levels in Patients Diagnosed with Chronic Hepatitis

OBJECTIVE

One of the most important factors playing a role in chronic hepatitis B pathogenesis is cytokine release and one of the cytokines with anti-inflammatory characteristic is interleukin-10 (IL-10). The aim of the present study is to examine IL-10 levels in patients with chronic hepatitis B.

SUBJECTS AND METHODS

Sixty-three patients with chronic hepatitis B disease who had not received any antiviral treatment were included in the study. Serum IL-10 level was investigated by enzyme-linked immunosorbent assay (ELISA) method. In the control group, 25 healthy individuals with mean age similar to the patient population were included. Control and patient groups were compared and data were statistically analysed.

RESULTS

Interleukin-10 levels of 25 patients with hepatitis B virus (HBV) DNA levels between 2000 and 20 000 IU/mL were compared with those of 25 subjects in the control group, and the level in the chronic hepatitis B group was statistically significantly higher (p < 0.05). Interleukin-10 levels of 38 patients with HBV DNA > 20 000 IU/mL were statistically significantly higher than those in the control group. When chronic hepatitis B patients were compared among themselves, IL-10 levels increased as HBV DNA levels increased. Also, when IL-10 levels of hepatitis B 'e' antigen (HBeAg) positive patients were compared with those of HBeAg negative patients, the difference was not statistically significant.

CONCLUSION

It is believed that decreasing IL-10 levels by various methods would have significant contributions in disease progression and treatment. Moreover, IL-10 level may be an important marker in HBeAg seroconversion and evaluation of treatment response.

Link between chronic inflammation and human papillomavirus-induced carcinogenesis (Review)

Inflammation is a defense strategy against invading agents and harmful molecules that is activated immediately following a stimulus, and involves the release of cytokines and chemokines, which activate the innate immune response. These mediators act together to increase blood flow and vascular permeability, facilitating recruitment of effector cells to the site of injury. Following resolution of the injury and removal of the stimulus, inflammation is disabled, but if the stimulus persists, inflammation becomes chronic and is strongly associated with cancer. This is likely to be due to the fact that the inflammation leads to a wound that does not heal, requiring a constant renewal of cells, which increases the risk of neoplastic transformation. Debris from phagocytosis, including the reactive species of oxygen and nitrogen that cause damage to DNA already damaged by the leukotrienes and prostaglandins, has an impact on inflammation and various carcinogenic routes. There is an association between chronic inflammation, persistent infection and cancer, where oncogenic action is mediated by autocrine and paracrine signals, causing changes in somatic cells under the influence of the microbial genome or of epigenetic factors. Among the infectious agents associated with cancer, certain genotypes of human papillomavirus (HPV) stand out. HPV is responsible for virtually all cases of cervical cancer and a lower proportion of cancers of the vagina, vulva, anus, penis and a number of extragenital cancers. In the present review, recent advances in the mechanisms involved in the inflammatory response are presented with their participation in the process of carcinogenesis, emphasizing the role of chronic inflammation in the development of HPV-induced cervical cancer.

Immunosuppressive mediators of oral squamous cell carcinoma in tumour samples and saliva

The goal of this study was to compare the salivary concentrations of IL-10, TGF-β1 and soluble HLA-G (sHLA-G) in patients with oral squamous cell carcinoma (OSCC) to those in healthy individuals (control group), and to correlate the expression of these mediators in saliva with that in the tumour microenvironment. Neoplastic tissue and saliva samples from patients with OSCC (n=22) were analysed by immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) respectively. We detected high expression of IL-10 and HLA-G in the tumour microenvironment when compared to healthy oral mucosa samples. Determination of IL-10 salivary concentration enabled us to distinguish patients with OSCC from healthy individuals (P=0.038), which showed correlation with tissue expression of this cytokine. HLA-G salivary release was similar in both groups (P=0.17) and no correlation with tumour expression was observed. TGF-β1 expression was low or absent in tumours, and salivary concentration was similar between groups. Our results suggest that of the three markers analysed, IL-10 is a potential salivary biomarker. Furthermore, the elevated expression of HLA-G and IL-10 in tumour sites could favour the escape of tumour cells from immune defense mechanisms.

Therapeutic implications of Epstein-Barr virus infection for the treatment of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is highly endemic in certain regions including the People’s Republic of China and Southeast Asia. Its etiology is unique and multifactorial, involving genetic background, epigenetic, and environment factors, including Epstein–Barr virus (EBV) infection. The presence of EBV in all tumor cells, aberrant pattern of antibodies against EBV antigens in patient sera, and elevated viral DNA in patient circulation as well as nasopharyngeal site underline the role of EBV during NPC development. In NPC tumors, EBV expresses latency type II, where three EBV-encoded proteins, Epstein–Barr nuclear antigen 1, latent membrane protein 1 and 2 (LMP1, 2), are expressed along with BamH1-A rightward reading frame 1, Epstein–Barr virus-encoded small nuclear RNAs, and BamH1-A rightward transcripts. Among all encoded proteins, LMP1 plays a central role in the propagation of NPC. Standard treatment of NPC consists of radiotherapy with or without chemotherapy for early stage, concurrent chemoradiotherapy in locally advanced tumors, and palliative systemic chemotherapy in metastatic disease. However, this standard care has limitations, allowing recurrences and disease progression in a certain proportion of cases. Although the pathophysiological link and molecular process of EBV-induced oncogenesis are not fully understood, therapeutic approaches targeting the virus may increase the cure rate and add clinical benefit. The promising results of early phase clinical trials on EBV-specific immunotherapy, epigenetic therapy, and treatment with viral lytic induction offer new options for treating NPC.

USP18 is crucial for IFN-γ-mediated inhibition of B16 melanoma tumorigenesis and antitumor immunity

Background

Interferon (IFN)-γ-mediated immune response plays an important role in tumor immunosurveillance. However, the regulation of IFN-γ-mediated tumorigenesis and immune response remains elusive. USP18, an interferon stimulating response element, regulates IFN-α-mediated signaling in anti-viral immune response, but its role in IFN-γ-mediated tumorigenesis and anti-tumor immune response is unknown.

Method

In this study, USP18 in tumorigenesis and anti-tumor immune response was comprehensively appraised in vivo by overexpression or downregulation its expression in murine B16 melanoma tumor model in immunocompetent and immunodeficient mice.

Results

Ectopic expression or downregulation of USP18 in B16 melanoma tumor cells inhibited or promoted tumorigenesis, respectively, in immunocompetent mice. USP18 expression in B16 melanoma tumor cells regulated IFN-γ-mediated immunoediting, including upregulating MHC class-I expression, reducing tumor cell-mediated inhibition of T cell proliferation and activation, and suppressing PD-1 expression in CD4⁺ and CD8⁺ T cells in tumor-bearing mice. USP18 expression in B16 melanoma tumor cells also enhanced CTL activity during adoptive immunotherapy by prolonging the persistence and enhancing the activity of adoptively transferred CTLs and by reducing CTL exhaustion in the tumor microenvironment. Mechanistic studies demonstrated that USP18 suppressed tumor cell-mediated immune inhibition by activating T cells, inhibiting T-cell exhaustion, and reducing dendritic cell tolerance, thus sensitizing tumor cells to immunosurveillance and immunotherapy.

Conclusion

These findings suggest that stimulating USP18 is a feasible approach to induce B16 melanoma specific immune response.

Pancreatic ductal adenocarcinoma: a review of immunologic aspects

With the continued failures of both early diagnosis and treatment options for pancreatic cancer, it is now time to comprehensively evaluate the role of the immune system on the development and progression of pancreatic cancer. It is important to develop strategies that harness the molecules and cells of the immune system to treat this disease. This review will focus primarily on the role of immune cells in the development and progression of pancreatic ductal adenocarcinoma and to evaluate what is known about the interaction of immune cells with the tumor microenvironment and their role in tumor growth and metastasis. We will conclude with a brief discussion of therapy for pancreatic cancer and the potential role for immunotherapy. We hypothesize that the role of the immune system in tumor development and progression is tissue specific. Our hope is that better understanding of this process will lead to better treatments for this devastating disease.

Maternal immune activation leads to age-related behavioral and immunological changes in male rat offspring - the effect of antipsychotic drugs

BACKGROUND

Prenatal immune system disturbances have been postulated to play an important role in pathogenesis of schizophrenia and related disorders. In the present study, we sought to answer the question whether behavioral changes in the neurodevelopmental model of schizophrenia in rats are accompanied by alterations in proliferative activity of splenocytes and pro- and anti-inflammatory cytokine levels. Furthermore, the effects of two antipsychotic drugs on these parameters were determined.

METHODS

Lipopolysaccharide (LPS) was administered subcutaneously to pregnant dams at a dose of 1 mg/kg every second day from the 7(th) day of pregnancy till delivery. Age-dependent behavioral and immunological changes were studied when control and prenatally LPS-pretreated offspring male rats were 30 and 90 days old. Chlorpromazine (10 mg/kg ip) or clozapine (10 mg/kg ip) was administered chronically (21 days) after behavioral verification to 3 months old offspring males. Changes in sensorimotor gating (prepulse inhibition, PPI), mitogen-induced proliferative activity of splenocytes ([(3)H]-thymidine incorporation) and cytokine levels (ELISA) were measured.

RESULTS

Prenatally LPS-pretreated rats showed PPI deficit only at 90 but not at 30 days of age, whereas an enhancement of mitogen-stimulated proliferative activity of splenocytes was observed in both time points. Additionally, the level of proinflammatory cytokines (IL-1β, IL-2, IL-6, TNF-α) in prenatally LPS-pretreated rats was enhanced when they were 30 days old and remained elevated in 90 days old offspring. No changes in IL-10 level were observed. Chronic administration of chlorpromazine or clozapine reduced the deficit in PPI deficit in prenatally LPS-treated rats. In the used model, chlorpromazine normalized both T and B lymphocyte proliferation, whereas clozapine B lymphocyte activity only. Moreover, both antipsychotics modulated the enhanced levels of IL-1β, IL-2 and TNF-α in the offspring of LPS-treated mothers.

CONCLUSIONS

This study indicates that in LPS-evoked model of schizophrenia, peripheral immunological changes are long-lasting and precede behavioral deficit. The disturbances in T cell-mediated immunity as well as cytokine production were attenuated by antipsychotic drug administration.

An emerging role for the anti-inflammatory cytokine interleukin-10 in dengue virus infection

Infection with dengue virus (DENV) causes both mild dengue fever and severe dengue diseases, such as dengue hemorrhagic fever and dengue shock syndrome. The pathogenic mechanisms for DENV are complicated, involving viral cytotoxicity, immunopathogenesis, autoimmunity, and underlying host diseases. Viral load correlates with disease severity, while the antibody-dependent enhancement of infection largely determines the secondary effects of DENV infection. Epidemiological and experimental studies have revealed an association between the plasma levels of interleukin (IL)-10, which is the master anti-inflammatory cytokine, and disease severity in patients with DENV infection. Based on current knowledge of IL-10-mediated immune regulation during infection, researchers speculate an emerging role for IL-10 in clinical disease prognosis and dengue pathogenesis. However, the regulation of dengue pathogenesis has not been fully elucidated. This review article discusses the regulation and implications of IL-10 in DENV infection. For future strategies against DENV infection, manipulating IL-10 may be an effective antiviral treatment in addition to the development of a safe dengue vaccine.

Expanding roles for CD4 T cells and their subpopulations in tumor immunity and therapy

The importance of CD4 T cells in orchestrating the immune system and their role in inducing effective T cell-mediated therapies for the treatment of patients with select established malignancies are undisputable. Through a complex and balanced array of direct and indirect mechanisms of cellular activation and regulation, this functionally diverse family of lymphocytes can potentially promote tumor eradication, long-term tumor immunity, and aid in establishing and/or rebalancing immune cell homeostasis through interaction with other immune cell populations within the highly dynamic tumor environment. However, recent studies have uncovered additional functions and roles for CD4 T cells, some of which are independent of other lymphocytes, that can not only influence and contribute to tumor immunity but paradoxically promote tumor growth and progression. Here, we review the recent advances in our understanding of the various CD4 T cell lineages and their signature cytokines in disease progression and/or regression. We discuss their direct and indirect mechanistic interplay among themselves and with other responding cells of the antitumor response, their potential roles and abilities for "plasticity" and memory cell generation within the hostile tumor environment, and their potentials in cancer treatment and immunotherapy.

The risk of a subsequent cancer diagnosis after herpes zoster infection: primary care database study

Background:

Herpes zoster and cancer are associated with immunosuppression. Zoster occurs more often in patients with an established cancer diagnosis. Current evidence suggests some risk of cancer after zoster but is inconclusive. We aimed to assess the risk of cancer following zoster and the impact of prior zoster on cancer survival.

Methods:

A primary care database retrospective cohort study was undertaken. Subjects with zoster were matched to patients without zoster. Risk of cancer following zoster was assessed by generating hazard ratios using Cox regression. Time to cancer was generated from the index date of zoster diagnosis.

Results:

In total, 2054 cancers were identified in 74 029 patients (13 428 zoster, 60 601 matches). The hazard ratio for cancer diagnosis after zoster was 2.42 (95% confidence interval 2.21, 2.66) and the median time to cancer diagnosis was 815 days. Hazard ratios varied between cancers, and were highest in younger patients. There were more cancers in patients with zoster than those without for all age groups and both genders. Prior immunosuppression was not associated with change in risk, and diagnosis of zoster before cancer did not affect survival.

Conclusion:

This study establishes an association between zoster and future diagnosis of cancer having implications for cancer case finding after zoster diagnosis.

Inflammatory events during murine squamous cell carcinoma development

Background

Squamous cell carcinoma (SCC) is one of the most common human cancers worldwide. In SCC, tumour development is accompanied by an immune response that leads to massive tumour infiltration by inflammatory cells, and consequently, local and systemic production of cytokines, chemokines and other mediators. Studies in both humans and animal models indicate that imbalances in these inflammatory mediators are associated with cancer development.

Methods

We used a multistage model of SCC to examine the involvement of elastase (ELA), myeloperoxidase (MPO), nitric oxide (NO), cytokines (IL-6, IL-10, IL-13, IL-17, TGF-β and TNF-α), and neutrophils and macrophages in tumour development. ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment.

Results

ELA and MPO activity and NO, IL-10, IL −17, TNF-α and TGF-β levels were increased in the precancerous microenvironment. Significantly higher levels of IL-6 and lower levels of IL-10 were detected at 4 weeks following 7,12-Dimethylbenz(a)anthracene (DMBA) treatment. Similar levels of IL-13 were detected in the precancerous microenvironment compared with control tissue. We identified significant increases in the number of GR-1⁺ neutrophils and F4/80⁺/GR-1^- infiltrating cells in tissues at 4 and 8 weeks following treatment and a higher percentage of tumour-associated macrophages (TAM) expressing both GR-1 and F4/80, an activated phenotype, at 16 weeks. We found a significant correlation between levels of IL-10, IL-17, ELA, and activated TAMs and the lesions. Additionally, neutrophil infiltrate was positively correlated with MPO and NO levels in the lesions.

Conclusion

Our results indicate an imbalance of inflammatory mediators in precancerous SCC caused by neutrophils and macrophages and culminating in pro-tumour local tissue alterations.

Differential impact of IL-10 expression on survival and relapse between HPV16-positive and -negative oral squamous cell carcinomas

Human papillomavirus (HPV) is a risk factor in a subset of oropharyngeal cancer; however, the contribution of HPV in the malignancy of oral squamous cell carcinomas (OSCC) is not fully understood in Taiwanese. Herein, 61 patients with no risk factors and 117 patients with one or more risk factors were enrolled in this study. HPV16/18 infection rate in non-smokers, non-drinkers and non-betel quid chewers was higher than their counterparts. The development of HPV-infected cancer has been shown to be associated with interleukin-10 (IL-10) expression. To this end, IL-10 mRNA expression in OSCC tumors was evaluated by real-time RT-PCR. Data showed that HPV-positive patients had higher IL-10 mRNA levels than in HPV-negative patients. Kaplan-Meier and Cox-regression analysis indicated that the prognostic significance of IL-10 mRNA on overall survival and relapse free survival was only observed in HPV-positive OSCC, but not in HPV-negative OSCC. Mechanistically, the elevation of IL-10 by E6 was responsible for increased colony formation and migration capability in OSCC cells. Therefore, we suggest that IL-10 induced by E6 promotes cell growth and migration capability and consequent poor survival and relapse in HPV-positive OSCC.

Update: Cytokine Dysregulation in Chronic Nonbacterial Osteomyelitis (CNO)

Chronic nonbacterial osteomyelitis (CNO) with its most severe form chronic recurrent multifocal osteomyelitis (CRMO) is a non-bacterial osteitis of yet unknown origin. Secondary to the absence of both high-titer autoantibodies and autoreactive T lymphocytes, and the association with other autoimmune diseases, it was recently reclassified as an autoinflammatory disorder of the musculoskeletal system. Since its etiology is largely unknown, the diagnosis is based on clinical criteria, and treatment is empiric and not always successful. In this paper, we summarize recent advances in the understanding of possible etiopathogenetic mechanisms in CNO.

Regulatory T cells in arterivirus and coronavirus infections: do they protect against disease or enhance it?

Regulatory T cells (T_regs) are a subset of T cells that are responsible for maintaining peripheral immune tolerance and homeostasis. The hallmark of T_regs is the expression of the forkhead box P3 (FoxP3) transcription factor. Natural regulatory T cells (nT_regs) are a distinct population of T cells that express CD4 and FoxP3. nTregs develop in the thymus and function in maintaining peripheral immune tolerance. Other CD4⁺, CD4^-CD8^-, and CD8⁺CD28^- T cells can be induced to acquire regulatory function by antigenic stimulation, depending on the cytokine milieu. Inducible (or adaptive) T_regs frequently express high levels of the interleukin 2 receptor (CD25). Atypical T_regs express FoxP3 and CD4 but have no surface expression of CD25. Type 1 regulatory T cells (Tr1 cells) produce IL-10, while T helper 3 cells (Th3) produce TGF-β. The function of inducible T_regs is presumably to maintain immune homeostasis, especially in the context of chronic inflammation or infection. Induction of T_regs in coronaviral infections protects against the more severe forms of the disease attributable to the host response. However, arteriviruses have exploited these T cell subsets as a means to dampen the immune response allowing for viral persistence. T_reg induction or activation in the pathogenesis of disease has been described in both porcine reproductive and respiratory syndrome virus, lactate dehydrogenase elevating virus, and mouse hepatitis virus. This review discusses the development and biology of regulatory T cells in the context of arteriviral and coronaviral infection.

The influence of human leukocyte antigen and IL-10 gene polymorphisms on hepatitis B virus outcome

CONTEXT

The clinical outcome of hepatitis B virus (HBV) infection is variable, ranging from spontaneous recovery to an inactive carrier state, chronic hepatitis, occult HBV infection, liver cirrhosis, or hepatocellular carcinoma.

EVIDENCE ACQUISITION

This variable pattern and clinical outcomes of the infection were mainly determined by virological and host genetic factors. Since the most of host genetic factors associated with HBV infection have currently focused on human leukocyte antigen (HLA) associations and interleukin (IL)-10 gene polymorphisms, this review focuses on the recent progresses in these issues to provide prognostic markers for the outcome of HBV infection.

RESULTS

A study on serum levels of IL-10 in occult HBV infected patients reported that the higher level of IL-10 production may suppress function of the immune system against HBV in patients with occult HBV infection. IL-10 promoter polymorphism at position -592 is associated with susceptibility to occult HBV infection.

CONCLUSIONS

Findings of this study suggest that the host HLA polymorphism is an important factor in determining outcome of HBV infection but regarding IL-10 gene promoter polymorphisms, we are still have a long way to achieve a definite conclusion.

Pancreatic ductal adenocarcinoma: a review of immunologic aspects

With the continued failures of both early diagnosis and treatment options for pancreatic cancer, it is now time to comprehensively evaluate the role of the immune system on the development and progression of pancreatic cancer. It is important to develop strategies that harness the molecules and cells of the immune system to treat this disease. This review will focus primarily on the role of immune cells in the development and progression of pancreatic ductal adenocarcinoma and to evaluate what is known about the interaction of immune cells with the tumor microenvironment and their role in tumor growth and metastasis. We will conclude with a brief discussion of therapy for pancreatic cancer and the potential role for immunotherapy. We hypothesize that the role of the immune system in tumor development and progression is tissue specific. Our hope is that better understanding of this process will lead to better treatments for this devastating disease.

Stress significantly increases mortality following a secondary bacterial respiratory infection

A variety of mechanisms contribute to the viral-bacterial synergy which results in fatal secondary bacterial respiratory infections. Epidemiological investigations have implicated physical and psychological stressors as factors contributing to the incidence and severity of respiratory infections and psychological stress alters host responses to experimental viral respiratory infections. The effect of stress on secondary bacterial respiratory infections has not, however, been investigated. A natural model of secondary bacterial respiratory infection in naive calves was used to determine if weaning and maternal separation (WMS) significantly altered mortality when compared to calves pre-adapted (PA) to this psychological stressor. Following weaning, calves were challenged with Mannheimia haemolytica four days after a primary bovine herpesvirus-1 (BHV-1) respiratory infection. Mortality doubled in WMS calves when compared to calves pre-adapted to weaning for two weeks prior to the viral respiratory infection. Similar results were observed in two independent experiments and fatal viral-bacterial synergy did not extend beyond the time of viral shedding. Virus shedding did not differ significantly between treatment groups but innate immune responses during viral infection, including IFN-γ secretion, the acute-phase inflammatory response, CD14 expression, and LPS-induced TNFα production, were significantly greater in WMS versus PA calves. These observations demonstrate that weaning and maternal separation at the time of a primary BHV-1 respiratory infection increased innate immune responses that correlated significantly with mortality following a secondary bacterial respiratory infection.

Endogenous interleukin-10 constrains Th17 cells in patients with inflammatory bowel disease

Background

Th17 cells play a role in inflammation. Interleukin (IL)-10 is a potent anti-inflammatory cytokine. However, it is poorly understood whether and how endogenous IL-10 impacts the development of Th17 cells in human pathologies.

Materials and methods

We examined the relationship between IL-10 and Th17 cells in patients with Crohn's disease and in IL-10-deficient (IL-10^-/-) mice. Th17 cells and dendritic cells (DCs) were defined by flow cytometry and evaluated by functional studies.

Results

We detected elevated levels of IL-17 and Th17 cells in the intestinal mucosa of patients with Crohn's disease. Intestinal DCs from Crohn's patients produced more IL-1β than controls and were superior to blood DCs in Th17 induction through an IL-1-dependent mechanism. Furthermore, IL-17 levels were negatively associated with those of IL-10 and were positively associated those of IL-1β in intestinal mucosa. These data point toward an in vivo cellular and molecular link among endogenous IL-10, IL-1, and Th17 cells in patients with Crohn's disease. We further investigated this relationship in IL-10^-/- mice. We observed a systemic increase in Th17 cells in IL-10^-/- mice when compared to wild-type mice. Similar to the intestinal DCs in patients with Crohn's disease, murine IL-10^-/- DCs produced more IL-1β than their wild-type counterparts and promoted Th17 cell development in an IL-1-dependent manner. Finally, in vivo blockade of IL-1 receptor signaling reduced Th17 cell accumulation and inflammation in a mouse model of chemically-induced colitis.

Conclusions

Endogenous IL-10 constrains Th17 cell development through the control of IL-1 production by DCs, and reaffirms the crucial anti-inflammatory role of IL-10 in patients with chronic inflammation.

Interleukin-10 ablation promotes tumor development, growth, and metastasis

Interleukin-10 (IL-10) is a broadly acting immune inhibitory cytokine that is generally thought to support tumor growth. Here we challenge this view with evidence that genetic ablation of IL-10 in the mouse significantly heightens sensitivity to chemical carcinogenesis, growth of transplanted tumors, and formation of metastases. Tumor growth in IL-10-deficient (IL-10(-/-)) mice was associated with an increased level of myeloid-derived suppressor cells (MDSC) and CD4(+)Foxp3(+) regulatory T (Treg) cells in both the tumor microenvironment and the tumor-draining lymph nodes. IL-10(-/-) MDSCs express high levels of MHC and IL-1, and they efficiently induced formation of Treg cells. IL-1 signaling blockade reduced tumor growth mediated by IL-10 deficiency, associated with a partial rescue of tumor infiltration and function of effector T cells and a decrease in tumor angiogenesis and tumor infiltration by Treg cells. Taken together, our findings establish that endogenous IL-10 inhibits inflammatory cytokine production and hampers the development of Treg cells and MDSCs, two key components of the immunosuppressive tumor microenvironment, thereby inhibiting tumor development, growth, and metastasis.

Improving cancer immunotherapy by targeting tumor-induced immune suppression

The status of a host's immune response influences both the development and progression of a malignancy such that immune responses can have both pro- and anti-tumorigenic effects. Cancer immunotherapy is a form of treatment that aims to improve the ability of a cancer-bearing individual to reject the tumor immunologically. However, antitumor immunity elicited by the host or by immunotherapeutic strategies, can be actively attenuated by mechanisms that limit the strength and/or duration of immune responses, including the presence of immunoregulatory cell types or the production of immunosuppressive factors. As our knowledge of tumor-induced immune suppression increases, it has become obvious that these mechanisms are probably a major barrier to effective therapy. The identification of multiple mechanisms of tumor-induced immune suppression also provides a range of novel targets for new cancer therapies. Given the vital role that a host's immune response is known to play in cancer progression, therapies that target immune suppressive mechanisms have the potential to enhance anticancer immune responses thus leading to better immune surveillance and the limitation of tumor escape. In this review, mechanisms of tumor-associated immune suppression have been divided into four forms that we have designated as (1) regulatory cells; (2) cytokines/chemokines; (3) T cell tolerance/exhaustion and (4) metabolic. We discuss select mechanisms representing each of these forms of immunosuppression that have been shown to aid tumors in evading host immune surveillance and overview therapeutic strategies that have been recently devised to "suppress these suppressors."

Chronic non-bacterial osteomyelitis is associated with impaired Sp1 signaling, reduced IL10 promoter phosphorylation, and reduced myeloid IL-10 expression

Chronic non-bacterial osteomyelitis (CNO) is an auto-inflammatory disorder that affects the skeletal system. Interleukin (IL-)10 is an immune-modulatory cytokine that controls inflammation, and limits inflammatory cytokine responses. Dysregulation of IL-10 expression has been shown to result in autoimmune and infectious diseases. We investigated IL-10 expression by monocytic cells from CNO patients and controls. In response to stimulation with LPS, IL-10 expression from CNO monocytes was reduced (p<0.001). This was independent of IL10 promoter polymorphisms. Thus, we investigated Sp1 recruitment to the IL10 promoter and saw markedly reduced binding in CNO monocytes. This was accompanied with reduced phosphorylation of histone H3 serine 10 (H3S10), an activating epigenetic mark. Impaired recruitment of Sp1 to the IL10 promoter, and reduced H3S10 phosphorylation, may be a reflection of deficient MAPK signaling in CNO monocytes in response to LPS stimulation. Thus, we have discovered a mechanism that may be central in the pathophysiology of CNO.

Novel highly sensitive IL-10-beta-lactamase reporter mouse reveals cells of the innate immune system as a substantial source of IL-10 in vivo

In this study, we report on a novel, highly sensitive IL-10 reporter mouse based on the reporter enzyme β-lactamase and the fluorescence resonance energy transfer substrate coumarin-cephalosporin-fluorescein (4). In contrast to an IL-10 reporter mouse model that we generated by using enhanced GFP as reporter and allowed tracking IL-10 expression only in T cells, the IL-10-β-lactamase reporter (ITIB) mouse enables us to easily analyze and quantify IL-10 production at the single-cell level in all myeloid and lymphoid cell types. Furthermore, the ITIB mouse allows studying of the kinetics of IL-10 expression on a single-cell basis and provides a valuable tool for in vivo screening of cell type-specific IL-10-modulating drugs. Remarkably, the ITIB mouse revealed that, although a significant portion of each myeloid and lymphoid cell type produces IL-10, macrophages represent the major IL-10 producer population in several organs of naive mice. Moreover, using the examples of bacterial infection and transplantable skin melanoma models, we demonstrate the exceptional applicability of the ITIB mouse for the identification of IL-10-producing cells during immune responses in vivo. In this study, we identified tumor-infiltrating F4/80(+) macrophages as the major source for IL-10 in B16-F10 melanoma in vivo. During systemic infection with Yersinia enterocolitica, although the proportion of IL-10(+) cells increased in each myeloid and lymphoid cell type population, infiltrating CD11b(+)Ly6G(+) neutrophils represent a majority among IL-10-producing cells at the site of infection. We conclude that cells of the innate immune system that are involved in immune homeostasis or immune responses are substantial sources of IL-10.

Identification of the peripheral blood levels of interleukin-12, interleukin-10, and transforming growth factor-β in patients with laryngeal squamous cell carcinoma

BACKGROUND

The aim of this study was to investigate the biology of laryngeal squamous cell carcinoma (SCC) to develop effective novel treatment modalities.

METHODS

Serum concentrations of interleukin (IL)-10, IL-12, and transforming growth factor-β (TGF-β) were evaluated in 50 patients with laryngeal SCC and 15 controls. Results were compared according to tumor-node-metastasis (TNM) classification criteria.

RESULTS

IL-12 and TGF-β levels were not different between the early- and late-stage patients and controls. Tumor classification or nodal involvement was not associated with IL-12 and TGF-β levels. Patients with laryngeal SCC had significantly more detectable serum IL-10 levels than those of controls, given that IL-10 could be detected in only 1 early-stage and 9 late-stage patients, but not in the control group (p = .003). IL-10 was increasingly detectable with advanced T classification (p = .009) and nodal involvement (p = .008).

CONCLUSIONS

Serum IL-12 or TGF-β levels were not affected with disease activity and classification; however, serum IL-10 levels were correlated with both parameters.

Wilms' tumor protein Wt1 regulates the Interleukin-10 (IL-10) gene

We identified the Wilms' tumor protein, Wt1, as a novel transcriptional activator of the immunosuppressant cytokine interleukin-10 (IL-10). Silencing of Wt1 by RNA interference reduced IL-10 mRNA levels by approximately 90%. IL-10 transcripts were increased more than 15-fold upon forced expression of Wt1. Electrophoretic mobility shift assay and chromatin immunoprecipitation revealed a cis-element that was responsible for activation of the IL-10 promoter by Wt1 in murine macrophages. Mutation of the Wt1 binding motif abrogated stimulation of the IL-10 promoter by tumor necrosis factor-α (TNFα). These results suggest a novel immune regulatory function of Wt1 in controlling IL-10 gene expression.

Blood dendritic cells suppress NK cell function and increase the risk of leukemia relapse after hematopoietic cell transplantation

NK cells play an important role in hematopoietic stem cell transplantation (HCT) and in cross talk with dendritic cells (DCs) to induce primary T cell response against infection. Therefore, we hypothesized that blood DCs should augment NK cell function and reduce the risk of leukemia relapse after HCT. To test this hypothesis, we conducted laboratory and clinical studies in parallel. We found that although, phenotypically, NK cells could induce DC maturation and DCs could in turn increase activating marker expression on NK cells, paradoxically, both BDCA1(+) myeloid DCs and BDCA4(+) plasmacytoid DCs suppressed the function of NK cells. Patients who received an HLA-haploidentical graft containing a larger number of BDCA1(+) DCs or BDCA4(+) DCs had a higher risk of leukemia relapse and poorer survival. Further experiments indicated that the potent inhibition on NK cell cytokine production and cytotoxicity was mediated in part through the secretion of IL-10 by BDCA1(+) DCs and IL-6 by BDCA4(+) DCs. These results have significant implications for future HCT strategies.

Immune evasive mechanisms contributing to persistent Leishmania donovani infection

The protozoan parasite Leishmania donovani, a causative agent of visceral leishmaniasis, has evolved several strategies to interfere with the immune system and establish persistent infections that are potentially lethal. In this article, we discuss two mechanisms of immune evasion adopted by the parasite: the induction of immune suppressive IL-10 responses and the generation of poor and functionally impaired CD8(+) T-cell responses.

Cell type-specific regulation of IL-10 expression in inflammation and disease

IL-10 plays an essential part in controlling inflammation and instructing adaptive immune responses. Consequently, dysregulation of IL-10 is linked with susceptibility to numerous infectious and autoimmune diseases in mouse models and in humans. It has become increasingly clear that appropriate temporal/spatial expression of IL-10 may be the key to how IL-10 contributes to the delicate balance between inflammation and immunoregulation. The mechanisms that govern the cell type- and receptor-specific induction of IL-10, however, remain unclear. This is due largely to the wide distribution of cellular sources that express IL-10 under diverse stimulation conditions and in a variety of tissue compartments. Further complicating the issue is the fact that human IL-10 expression patterns appear to be under genetic influence resulting in differential expression and disease susceptibility. In this review, we discuss the cellular sources of IL-10, their link to disease phenotypes and the molecular mechanisms implicated in IL-10 regulation.

Inhibiting the inhibitors: evaluating agents targeting cancer immunosuppression

IMPORTANCE OF THE FIELD

Immunotherapy of cancer has not improved disease-free or overall patient survival. The lack of concordance between immunological and clinical responses in cancer immunotherapy trials is thought to result from the pervasive presence of tumor-driven immune suppression that allows tumor to escape and that has not been adequately targeted by current therapies.

AREAS COVERED IN THIS REVIEW

Because multiple mechanisms of tumor induced suppression have been identified and shown to contribute to tumor escape, the opportunity arises to interfere with these mechanisms. A range of known tumor-derived inhibitors can now be blocked or neutralized by biologic or metabolic agents. Used alone or in combination with each other or with conventional cancer therapies, these agents offer novel therapeutic strategies for the control of tumor escape.

WHAT THE READER WILL GAIN

This review deals with currently available inhibitors for counteracting tumor immune escape. The restoration of effective anti-tumor immunity in patients with cancer will require new approaches aiming at: i) protection of immune cells from adverse effects of myeloid-derived suppressor cells, regulatory T cells or inhibitory factors thus enhancing effector functions; and ii) prolonging survival of central memory T cells, thus ensuring long-term protection.

TAKE HOME MESSAGE

Inhibitors of mechanisms responsible for tumor escape could restore anti-tumor immune responses in patients with cancer.

Hepatitis B immunology for clinicians

Hepatitis B virus (HBV) is a hepatotrophic DNA virus that causes acute and chronic hepatitis. Despite an effective vaccine, more than 350 million people are chronically infected with HBV worldwide and are at risk for progressive liver disease. There are marked geographic variations in HBV prevalence (ranging from 0.1% to 2% in low prevalence areas and 10% to 20% in high prevalence areas) related to the timing and mode of HBV exposure. In many developed countries, HBV exposure typically occurs in adults via sexual transmission with a low chronicity rate (5%). In regions with high HBV prevalence (eg, Asia, sub-Saharan Africa), HBV exposure tends to occur in the perinatal period (eg, vertical transmission from mother to infant) with a high rate of persistence in the absence of timely vaccination. The course of viral infection is defined by the interplay between the virus and host immune defense. This article introduces the innate and adaptive immune defense mechanisms in general and as related to HBV. In particular, the current concepts regarding the innate and adaptive immune components contributing to the clinical, virologic and therapeutic outcome in acute and chronic hepatitis B are examined.

Analysis of peripheral immune activation in schizophrenia using quantitative reverse-transcription polymerase chain reaction (RT-PCR)

Immune system abnormalities in schizophrenia include a shift from a Type 1 (cellular) to a Type 2 (humoral) immune response. To characterize the activation status of the immune system in schizophrenia, we examined the pattern of gene expression in peripheral blood cells for three Th1 cytokines (interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2)), and one Th2 cytokine (interleukin-10 (IL-10)). In a cross-sectional study, we used quantitative reverse-transcription polymerase chain reaction (RT-PCR) to compare the mRNA levels of IFN-gamma, TNF-alpha, IL-2, and IL-10 in peripheral blood mononuclear cells (PBMCs) between 15 schizophrenia patients and 15 matched healthy controls. Expression of IFN-gamma and TNF-alpha was significantly reduced in patients with schizophrenia compared with normal controls. No differences in IL-2 and IL-10 gene expression were observed. These results are consistent with impaired Type 1 cellular immunity in schizophrenia. While the data illustrate the potential utility of mRNA-based approaches for the identification and analysis of immune biomarkers for neuropsychiatric disorders, correlation of gene expression with direct measures of cytokine concentrations is required.

Boosting high-intensity focused ultrasound-induced anti-tumor immunity using a sparse-scan strategy that can more effectively promote dendritic cell maturation

Background

The conventional treatment protocol in high-intensity focused ultrasound (HIFU) therapy utilizes a dense-scan strategy to produce closely packed thermal lesions aiming at eradicating as much tumor mass as possible. However, this strategy is not most effective in terms of inducing a systemic anti-tumor immunity so that it cannot provide efficient micro-metastatic control and long-term tumor resistance. We have previously provided evidence that HIFU may enhance systemic anti-tumor immunity by in situ activation of dendritic cells (DCs) inside HIFU-treated tumor tissue. The present study was conducted to test the feasibility of a sparse-scan strategy to boost HIFU-induced anti-tumor immune response by more effectively promoting DC maturation.

Methods

An experimental HIFU system was set up to perform tumor ablation experiments in subcutaneous implanted MC-38 and B16 tumor with dense- or sparse-scan strategy to produce closely-packed or separated thermal lesions. DCs infiltration into HIFU-treated tumor tissues was detected by immunohistochemistry and flow cytometry. DCs maturation was evaluated by IL-12/IL-10 production and CD80/CD86 expression after co-culture with tumor cells treated with different HIFU. HIFU-induced anti-tumor immune response was evaluated by detecting growth-retarding effects on distant re-challenged tumor and tumor-specific IFN-γ-secreting cells in HIFU-treated mice.

Results

HIFU exposure raised temperature up to 80 degrees centigrade at beam focus within 4 s in experimental tumors and led to formation of a well-defined thermal lesion. The infiltrated DCs were recruited to the periphery of lesion, where the peak temperature was only 55 degrees centigrade during HIFU exposure. Tumor cells heated to 55 degrees centigrade in 4-s HIFU exposure were more effective to stimulate co-cultured DCs to mature. Sparse-scan HIFU, which can reserve 55 degrees-heated tumor cells surrounding the separated lesions, elicited an enhanced anti-tumor immune response than dense-scan HIFU, while their suppressive effects on the treated primary tumor were maintained at the same level. Flow cytometry analysis showed that sparse-scan HIFU was more effective than dense-scan HIFU in enhancing DC infiltration into tumor tissues and promoting their maturation in situ.

Conclusion

Optimizing scan strategy is a feasible way to boost HIFU-induced anti-tumor immunity by more effectively promoting DC maturation.

European genotype of porcine reproductive and respiratory syndrome (PRRSV) infects monocyte-derived dendritic cells but does not induce Treg cells

The aim of this study was to characterize the immune responses of DCs after infection with four different EU strains of PRRSV and whether they show any ability to immunomodulate T cells activation. Our results show that all EU strains can efficiently infect and replicate in DCs. Nevertheless, SLA-II levels remained unaltered in DC infected by all EU PRRSV strains, whereas SLA-I expression was only reduced when strain 2992 was used. IL-10 production was induced by three EU PRRSV strains, being strain 2992 the highest inducer. However, no induction of Treg cells, measured by CD25 and Foxp3 expression on lymphocytes co-cultured with infected DCs, was found. TGF-beta induction was not detected in DC infected with any EU strain tested. In conclusion, DCs infected with EU PRRSV strains exhibited an unbalanced ability to stimulate T cell response and was strain dependent. However, Treg cells were not induced, at least in vitro.

A human IL10 BAC transgene reveals tissue-specific control of IL-10 expression and alters disease outcome

Interleukin (IL)-10 is an immunoregulatory cytokine that is produced by diverse cell populations. Studies in mice suggest that the cellular source of IL-10 is a key determinant in various disease pathologies, yet little is known regarding the control of tissue-specific human IL-10 expression. To assess cell type-specific human IL-10 regulation, we created a human IL-10 transgenic mouse with a bacterial artificial chromosome (hIL10BAC) in which the IL10 gene is positioned centrally. Since human IL-10 is biologically active in the mouse, we could examine the in vivo capacity of tissue-specific human IL-10 expression to recapitulate IL-10-dependent phenotypes by reconstituting Il10(-/-) mice (Il10(-/-)/hIL10BAC). In response to LPS, Il10(-/-)/hIL10BAC mice proficiently regulate IL-10-target genes and normalize sensitivity to LPS toxicity via faithful human IL-10 expression from macrophages and dendritic cells. However, in the Leishmania donovani model of pathogen persistence, Il10(-/-)/hIL10BAC mice did not develop the characteristic IL-10(+)IFN-gamma(+)CD4 T cell subset thought to mediate persistence and, like Il10(-/-) mice, cleared the parasites. Furthermore, the IL-10-promoting cytokine IL-27 failed to regulate transgenic human IL-10 production in CD4(+) T cells in vitro which together suggests that the hIL10BAC encodes for weak T cell-specific IL-10 expression. Thus, the hIL10BAC mouse is a model of human gene structure and function revealing tissue-specific regulatory requirements for IL-10 expression which impacts disease outcomes.

IL-10-dependent S100A8 gene induction in monocytes/macrophages by double-stranded RNA

The S100 calcium-binding proteins S100A8 and S100A9 are elevated systemically in patients with viral infections. The S100A8-S100A9 complex facilitated viral replication in human CD4(+) T lymphocytes latently infected with HIV-1- and S100A8-induced HIV-1 transcriptional activity. Mechanisms inducing the S100 genes and the potential source of these proteins following viral activation are unknown. In this study, we show that S100A8 was induced in murine macrophages, and S100A8 and S100A9 in human monocytes and macrophages, by polyinosinic:polycytidylic acid, a dsRNA mimetic. Induction was at the transcriptional level and was IL-10 dependent. Similar to LPS-induced S100A8, induction by dsRNA was dependent on p38 and ERK MAPK. Protein kinase R (PKR) mediates antiviral defense and participates in MyD88-dependent/independent signaling triggered by TLR4 or TLR3. Like IL-10, S100 induction by polyinosinic:polycytidylic acid and by LPS was inhibited by the specific PKR inhibitor 2-aminopurine, indicating a novel IL-10, PKR-dependent pathway. Other mediators such as IFN-beta, which synergized with dsRNA, may also be involved. C/EBPbeta bound the defined promoter region in response to dsRNA. S100A8 was expressed in lungs of mice infected with influenza virus and was maximal at day 8 with strong immunoreactivity in epithelial cells lining the airways and in mononuclear cells and declined early in the recovery phase, implying down-regulation by mediator(s) up-regulated during resolution of the infection. IL-10 is implicated in viral persistence. Since S100A8/S100A9 levels are likely to be maintained in conditions where IL-10 is raised, these proteins may contribute to viral persistence in patients infected by some RNA viruses.

Balancing between antitumor efficacy and autoimmune pathology in T-cell-mediated targeting of carcinoembryonic antigen

Carcinoembryonic antigen (CEA) is intensively studied as a potential target for immunotherapy of colorectal cancers. Although overexpressed by tumors, CEA is also expressed in normal tissues, raising questions about the feasibility and safety of CEA-targeted immunotherapy. We investigated these issues in transgenic mice in which the expression of human CEA in normal tissues closely resembles that in man. Our data show that the T-cell response against CEA in these mice is blunted by both thymic and peripheral tolerance. Consequently, effective tumor targeting is only achieved by adoptive transfer of T cells from nontolerant donors in combination with interventions that eliminate peripheral immune regulatory mechanisms. However, such treatments can result in severe intestinal autoimmune pathology associated with weight loss and mortality. Interestingly, preconditioning of recipient mice by depletion of T-regulatory cells results in immune-mediated tumor control in the absence of toxicity. In this setting, CEA-specific T-cell responses are lower than those induced by toxic regimens and accompanied by additional T-cell responses against non-self antigen. These findings illustrate the importance of testing adoptive immunotherapies targeting self antigens such as CEA in preclinical in vivo models and show that the choice of immune intervention regimen critically determines the balance between therapeutic efficacy and toxicity.