[GenomeLabTM GeXP analysis system to detect apoptosis-associated genes in A549 cells treated by recombinant human IL-24 combined with cisplatin]

Objective To investigate the changes of apoptosis-associated genes in human lung adenocarcinoma cell line A549 after treated by the recombinant human interleukin-24 (rhIL-24) combined with cisplatin (DDP). Methods The mRNA levels of Bax, Bcl-2, survivin, caspase-3, retinoblastoma (Rb) gene, p53 were analyzed by GenomeLab^TM GeXP genetic analysis system after A549 cells were treated with 160 ng/mL rhIL-24 or 3 μg/mL DDP or 160 ng/mL rhIL-24 combined with 3 μg/mL DDP. Results The rhIL-24 up-regulated the levels of Bax, Rb, caspase-3 mRNAs and down-regulated Bcl-2, survivin mRNAs, but the change of p53 mRNA was not regular. The combination of rhIL-24 and DDP strengthened the above changes. Conclusion The rhIL-24 protein can induce the apoptosis of A549 cells by up-regulating Bax, caspase-3, Rb mRNAs and down-regulating Bcl-2, survivin mRNAs.

Critical Role of IL-22/IL22-RA1 Signaling in Pneumococcal Pneumonia

IL-22-IL-22R signaling plays a crucial role in regulating host defenses against extracellular pathogens, particularly in the intestine, through the induction of antimicrobial peptides and chemotactic genes. However, the role of IL-22-IL-22R is understudied in Streptococcus pneumoniae lung infection, a prevalent pathogen of pneumonia. This paper presents the findings of IL-22 signaling during a murine model of pneumococcal pneumonia and improvement of bacterial burden upon IL-22 administration. IL-22 was rapidly induced in the lung during pneumococcal infection in wild-type mice, and Il22(-/-) mice had higher pneumococcal burdens compared with controls. Additionally, mice with hepatic-specific deletion of Il22ra1 also had higher bacterial burdens in lungs compared with littermate controls after intrapulmonary pneumococcal infection, suggesting that IL-22 signaling in the liver is important to control pneumococcal pneumonia. Thus, we hypothesized that enhancement of IL-22 signaling would control pneumococcal burden in lung tissues in an experimental pneumonia model. Administration of rIL-22 systemically to infected wild-type mice decreased bacterial burden in lung and liver at 24 h postinfection. Our in vitro studies also showed that mice treated with IL-22 had increased C3 expression in the liver compared with the isotype control group. Furthermore, serum from mice treated with IL-22 had improved opsonic capacity by increasing C3 binding on S. pneumoniae Taken together, endogenous IL-22 and hepatic IL-22R signaling play critical roles in controlling pneumococcal lung burden, and systemic IL-22 decreases bacterial burden in the lungs and peripheral organs by potentiating C3 opsonization on bacterial surfaces, through the increase of hepatic C3 expression.

Antibody-Based Targeted Delivery of Interleukin-22 Promotes Rapid Clinical Recovery in Mice With DSS-Induced Colitis

BACKGROUND

We have recently described the potential of the alternatively spliced extradomain A of fibronectin as a target for antibody-based pharmacodelivery applications in ulcerative colitis. Here, we report on the cloning and therapeutic properties of novel antibody-based fusion proteins, comprising the F8 antibody specific to extradomain A and murine interleukin (IL)-22, a globular cytokine belonging to the IL10 family. A protective function for IL22 in colitis has previously been described, as this cytokine induces antimicrobial, proliferative, and antiapoptotic pathways, preventing tissue damage and promoting epithelial repair.

METHODS

Two fusion proteins comprising IL22, fused at the N- or at the C-terminus of the F8 antibody in diabody format, were expressed in mammalian cells. The ability of radiolabeled preparations of the 2 fusion proteins to localize at sites of disease was assessed by autoradiography in a murine model of dextran sodium sulfate-induced colitis and by quantitative biodistribution analysis in a syngeneic mouse teratocarcinoma model. Therapeutic activity was assessed in mice with dextran sodium sulfate-induced colitis, which received intravenous injections of antibody-cytokine fusion proteins.

RESULTS

Both fusion proteins were able to selectively accumulate at the site of disease. The fusion protein with the cytokine moiety at the N-terminal extremity (IL22-F8) exhibited better results than the C-terminal fusion, both in terms of targeting selectivity and therapeutic efficacy. Mice treated with IL22-F8 showed a more rapid recovery from clinical symptoms compared with controls and improved macroscopic and microscopic morphology of the colon.

CONCLUSIONS

IL22-F8 is a promising biopharmaceutical drug candidate for the treatment of ulcerative colitis.

MALDI-MSI for the analysis of a 3D tissue-engineered psoriatic skin model

MALDI-MS Imaging is a novel label-free technique that can be used to visualize the changes in multiple mass responses following treatment. Following treatment with proinflammatory cytokine interleukin-22 (IL-22), the epidermal differentiation of Labskin, a living skin equivalent (LSE), successfully modeled psoriasis in vitro. Masson's trichrome staining enabled visualization and quantification of epidermal differentiation between the untreated and IL-22 treated psoriatic LSEs. Matrix-assisted laser desorption ionization mass spectrometry imaging was used to observe the spatial location of the psoriatic therapy drug acetretin following 48 h treatments within both psoriatic and normal LSEs. After 24 h, the drug was primarily located in the epidermal regions of both the psoriatic and nonpsoriatic LSE models whereas after 48 h it was detectible in the dermis.

Interleukin-35 upregulates OPG and inhibits RANKL in mice with collagen-induced arthritis and fibroblast-like synoviocytes

IL-35 is a novel anti-inflammatory cytokine, but the exact role of IL-35 in the progression of RA remains unclear, especially associated with osteoporosis and bone erosion. The present research has not been reported. Our purpose is to study how IL-35 affects RA bone destruction.

INTRODUCTION

This study investigated the effect of interleukin-35 (IL-35) on OPG and RANKL expression in collagen-induced arthritis (CIA) in rats and in cultured fibroblast-like synoviocytes (FLS).

METHODS

Thirty DBA/1J mice were randomly assigned to three groups (n = 10 per group): the control group, the CIA group, and the CIA + IL-35 group. Collagen-induced arthritis was induced by immunization with collagen. IL-35 was intraperitoneally injected daily for 10 days, starting from the 24(th) day after immunization. FLS cells were isolated and cultured from CIA. The expression of IL-17, RANKL, and OPG was determined by RT-PCR and Western blot. Each experiment was repeated three times.

RESULTS

CIA mice exhibited arthritis symptoms on day 24, followed by a rapid progression of arthritis. The expression of IL-17 and RANKL was increased and the expression of OPG was decreased in CIA mice compared with control mice. IL-35 treatment inhibited the development of arthritis in CIA mice, accompanied by a decrease in the expression of IL-17 and RANKL and an increase in the expression of OPG. Furthermore, IL-35 dose-dependently inhibited the expression of RANKL and increased the expression of OPG in cultured FLS cells.

CONCLUSION

IL-35 inhibits RANKL expression and increases OPG expression in CIA mice. IL-35 may be used for treating rheumatoid arthritis.

Interleukin-22 contributes to liver regeneration in mice with concanavalin A-induced hepatitis after hepatectomy

AIM

To investigate the therapeutic effects and mechanisms of interleukin (IL)-22 in liver regeneration in mice with concanavalin A (ConA)-induced liver injury following 70% hepatectomy.

METHODS

Mice were injected intravenously with ConA at 10 μg/g body weight 4 d before 70% hepatectomy to create a hepatitis model, and recombinant IL-22 was injected at 0.125 μg/g body weight 30 min prior to 70% hepatectomy to create a therapy model. Control animals received an intravenous injection of an identical volume of normal saline.

RESULTS

IL-22 treatment prior to 70% hepatectomy performed under general anesthesia resulted in reductions in the biochemical and histological evidence of liver injury, earlier proliferating cell nuclear antigen expression and accelerated recovery of liver mass. IL-22 pretreatment also significantly induced signal transducer and activator of transcription factor 3 (STAT3) activation and increased the expression of a variety of mitogenic proteins, such as Cyclin D1. Furthermore, alpha fetal protein mRNA expression was significantly elevated after IL-22 treatment.

CONCLUSION

In this study, we demonstrated that IL-22 is a survival factor for hepatocytes and prevents and repairs liver injury by enhancing pro-growth pathways via STAT3 activation. Treatment with IL-22 protein may represent a novel therapeutic strategy for preventing liver injury in patients with liver disease who have undergone hepatectomy.

Intrinsic functional defects of type 2 innate lymphoid cells impair innate allergic inflammation in promyelocytic leukemia zinc finger (PLZF)-deficient mice

BACKGROUND

The transcription factor promyelocytic leukemia zinc finger (PLZF) is transiently expressed during development of type 2 innate lymphoid cells (ILC2s) but is not present at the mature stage. We hypothesized that PLZF-deficient ILC2s have functional defects in the innate allergic response and represent a tool for studying innate immunity in a mouse with a functional adaptive immune response.

OBJECTIVE

We determined the consequences of PLZF deficiency on ILC2 function in response to innate and adaptive immune stimuli by using PLZF(-/-) mice and mixed wild-type:PLZF(-/-) bone marrow chimeras.

METHODS

PLZF(-/-) mice, wild-type littermates, or mixed bone marrow chimeras were treated with the protease allergen papain or the cytokines IL-25 and IL-33 or infected with the helminth Nippostrongylus brasiliensis to induce innate type 2 allergic responses. Mice were sensitized with intraperitoneal ovalbumin-alum, followed by intranasal challenge with ovalbumin alone, to induce adaptive TH2 responses. Lungs were analyzed for immune cell subsets, and alveolar lavage fluid was analyzed for ILC2-derived cytokines. In addition, ILC2s were stimulated ex vivo for their capacity to release type 2 cytokines.

RESULTS

PLZF-deficient lung ILC2s exhibit a cell-intrinsic defect in the secretion of IL-5 and IL-13 in response to innate stimuli, resulting in defective recruitment of eosinophils and goblet cell hyperplasia. In contrast, the adaptive allergic inflammatory response to ovalbumin and alum was unimpaired.

CONCLUSIONS

PLZF expression at the innate lymphoid cell precursor stage has a long-range effect on the functional properties of mature ILC2s and highlights the importance of these cells for innate allergic responses in otherwise immunocompetent mice.

Therapeutic Role of Interleukin 22 in Experimental Intra-abdominal Klebsiella pneumoniae Infection in Mice

Interleukin 22 (IL-22) is an IL-10-related cytokine produced by T helper 17 (Th17) cells and other immune cells that signals via IL-22 receptor alpha 1 (IL-22Ra1), which is expressed on epithelial tissues, as well as hepatocytes. IL-22 has been shown to have hepatoprotective effects that are mediated by signal transducer and activator of transcription 3 (STAT3) signaling. However, it is unclear whether IL-22 can directly regulate antimicrobial programs in the liver. To test this hypothesis, hepatocyte-specific IL-22Ra1 knockout (Il22Ra1(Hep-/-)) and Stat3 knockout (Stat3(Hep-/-)) mice were generated and subjected to intra-abdominal infection with Klebsiella pneumoniae, which results in liver injury and necrosis. We found that overexpression of IL-22 or therapeutic administration of recombinant IL-22 (rIL-22), given 2 h postinfection, significantly reduced the bacterial burden in both the liver and spleen. The antimicrobial activity of rIL-22 required hepatic Il22Ra1 and Stat3. Serum from rIL-22-treated mice showed potent bacteriostatic activity against K. pneumoniae, which was dependent on lipocalin 2 (LCN2). However, in vivo, rIL-22-induced antimicrobial activity was only partially reduced in LCN2-deficient mice. We found that rIL-22 also induced serum amyloid A2 (SAA2) and that SAA2 had anti-K. pneumoniae bactericidal activity in vitro. These results demonstrate that IL-22, through IL-22Ra1 and STAT3 singling, can induce intrinsic antimicrobial activity in the liver, which is due in part to LCN2 and SAA2. Therefore, IL-22 may be a useful adjunct in treating hepatic and intra-abdominal infections.

Th22 cell accumulation is associated with colorectal cancer development

AIM

To investigate the expression of Th22 cells and related cytokines in colorectal cancer (CRC) tissues, and the probably mechanism.

METHODS

CRC tumor and paratumor tissues were collected to detect the expression levels of Th22 cells and of related cytokines by immunohistochemistry, flow cytometry and real-time quantitative polymerase chain reaction (RT-qPCR). Interleukin (IL)-22 alone or with a STAT3 inhibitor was co-cultured with RKO cells in vitro to study the effects of IL-22 on colon cancer cells. IL-22 alone or with a STAT3 inhibitor was injected into a BALB/c nude mouse model with subcutaneously transplanted RKO cells to study the effects of IL-22 on colon cancer growth.

RESULTS

The percentage of Th22 cells in the CD4(+) T subset was significantly higher in tumor tissues compared with that in paratumor tissues (1.47% ± 0.083% vs 1.23% ± 0.077%, P < 0.05) as determined by flow cytometry. RT-qPCR analysis revealed that the mRNA expression levels of IL-22, aryl hydrocarbon receptor, CCL20 and CCL22 were significantly higher in tumor tissues compared with those in paratumor tissues. CCL27 mRNA also displayed a higher expression level in tumor tissues compared with that in paratumor tissues; however, these levels were not significantly different (2.58 ± 0.93 vs 2.30 ± 0.78, P > 0.05). IL-22 enhanced colon cancer cell proliferation in vitro and displayed anti-apoptotic effects; these effects were blocked by adding a STAT3 inhibitor. IL-22 promoted tumor growth in BALB/c nude mice; however, this effect was reversed by adding a STAT3 inhibitor.

CONCLUSION

Th22 cells that accumulate in CRC may be associated with the chemotactic effect of the tumor microenvironment. IL-22 is associated with CRC development, most likely via STAT3 activation.

rIL-22 as an adjuvant enhances the immunogenicity of rGroEL in mice and its protective efficacy against S. Typhi and S. Typhimurium

Salmonella infection, ranging from mild, self-limiting diarrhea to severe gastrointestinal, septicemic disease and enteric fever, is a global health problem both in humans and animals. Rapid development of microbial drug resistance has led to a need for efficacious and affordable vaccines against Salmonella. Microbial heat shock proteins (HSPs), including HSP60 and HSP70, are the dominant antigens that promote the host immune response. Co-administration of these antigens with cytokines, such as IL-22, which plays an important role in antimicrobial defense, can enhance the immune response and protection against pathogens. Therefore, the aim of the present study was to determine the immunogenicity of rGroEL (Hsp60) of S. Typhi, alone or administered in combination with murine rIL-22, and its protective efficacy against lethal infection with Salmonella, in mice. There was appreciable stimulation of the humoral and cell-mediated immune responses in mice immunized with rGroEL alone. However, co-administration of rGroEL with rIL-22 further boosted the antibody titers (IgG, IgG1 and IgG2a), T-cell proliferative responses and the secretion of both Th1 and Th2 cytokines. Additionally, rGroEL alone accorded 65%-70% protection against lethal challenge with S. Typhi and S. Typhimurium, which increased to 90% when co-administered with rIL-22.

Derivation of Phase 3 dosing for peginterferon lambda-1a in chronic hepatitis C, Part 2: Exposure-response analyses for efficacy and safety variables

This is the second of two manuscripts detailing the pharmacodynamic derivation of peginterferon lambda-1a (Lambda) dosing and treatment durations for Phase 3 studies in hepatitis C virus (HCV) infection, based on Phase 2 data. Herein, we describe the derivation of regression models for 12-week on-treatment virologic response and safety outcomes at 120, 180, and 240 μg Lambda with ribavirin. In patients with HCV genotypes 1 or 4, there was a significant (P = 0.024) relationship between undetectable HCV-RNA at Week 4 and Lambda exposure (AUC or Cmax ), with the largest difference between adjacent dose levels between the 180 and 120 μg exposure ranges. Risk of Grade 3-4 aminotransferase or bilirubin elevations relative to a peginterferon alfa-2a/ribavirin control were related to Lambda exposure for all patients, and the largest increase between adjacent dose levels was seen for 240 versus 180 μg. Anemia and neutropenia events were lower than control across all doses and exposures. Based on these data and those in our previous manuscript, Phase 3 studies will evaluate fixed 180 µg doses of Lambda in combination with ribavirin and a direct-acting antiviral for 24-48 weeks in HCV genotypes 1 or 4 or 12-24 weeks in genotypes 2 or 3.

Derivation of Phase 3 dosing for peginterferon lambda-1a in chronic hepatitis C, Part 1: Modeling optimal treatment duration and sustained virologic response rates

Peginterferon lambda-1a (Lambda) is under clinical development for the treatment of chronic hepatitis B and C virus (HBV, HCV, respectively) infection. This is the first of two manuscripts detailing the pharmacodynamic derivation of Lambda dosing and treatment durations for Phase 3 studies in HCV, based on Phase 2 data. We describe here the derivation of a population model of Lambda exposure; the adaptation of a previously published viral dynamic model for Lambda treatment and host genotype, and its use to simulate sustained virologic responses (SVR). Lambda population pharmacokinetics was described by a one-compartment model with first-order absorption, and 33.0 L per day clearance with 47% interindividual (36% intra-individual) variability. Weight explained a negligible proportion of the variability. Based on SVR predictions, optimum treatment durations were 48 weeks for HCV genotypes 1 or 4 (SVR estimates for 120, 180, and 240 μg Lambda: 58%, 54%, 47%, respectively) and 24 weeks for genotypes 2 or 3 (75%, 72%, 67%). SVR predictions for 240 μg were lower due to dropout predictions. The SVR model established the optimum treatment duration for Phase 3 studies but did not differentiate between 120 and 180 μg dosing. A companion manuscript describes dose selection based on exposure-response/safety modeling.

Dynamic and extensive metabolic state-dependent regulation of cytokine expression and circulating levels

Cytokines play diverse and critical roles in innate and acquired immunity, and several function within the central nervous system and in peripheral tissues to modulate energy metabolism. The extent to which changes in energy balance impact the expression and circulating levels of cytokines (many of which have pleiotropic functions) has not been systematically examined. To investigate metabolism-related changes in cytokine profiles, we used a multiplex approach to assess changes in 71 circulating mouse cytokines in response to acute (fasting and refeeding) and chronic (high-fat feeding) alterations in whole body metabolism. Refeeding significantly decreased serum levels of IL-22, IL-1α, soluble (s)IL-2Rα, and soluble vascular endothelial growth factor receptor 3 (VEGFR3), but markedly increased granulocyte colony-stimulating factor (G-CSF), IL-1β, chemokine (C-C motif) ligand (CCL2), sIL-1RI, lipocalin-2, pentraxin-3, tissue inhibitor of metalloproteinase (TIMP-1), and serum amyloid protein (SAP) relative to the fasted state. Interestingly, only a few of these changes paralleled the alterations in expression of their corresponding mRNAs. Functional studies demonstrated that central delivery of G-CSF increased, whereas IL-22 decreased, food intake. Changes in food intake were not accompanied by acute alterations in orexigenic (Npy and Agrp) and anorexigenic (Pomc and Cart) neuropeptide gene expression in the hypothalamus. In the context of chronic high-fat feeding, circulating levels of chemokine (C-X-C) ligand (CXCL1), serum amyloid protein A3 (SAA3), TIMP-1, α1-acid glycoprotein (AGP), and A2M were increased, whereas IL-12p40, CCL4, sCD30, soluble receptor for advanced glycation end products (sRAGE), CCL12, CCL20, CX3CL1, IL-16, IL-22, and haptoglobin were decreased relative to mice fed a control low-fat diet. These results demonstrate that both short- and long-term changes in whole body metabolism extensively alter cytokine expression and circulating levels, thus providing a foundation and framework for further investigations to ascertain the metabolic roles for these molecules in physiological and pathological states.

Viral infection. Prevention and cure of rotavirus infection via TLR5/NLRC4-mediated production of IL-22 and IL-18

Activators of innate immunity may have the potential to combat a broad range of infectious agents. We report that treatment with bacterial flagellin prevented rotavirus (RV) infection in mice and cured chronically RV-infected mice. Protection was independent of adaptive immunity and interferon (IFN, type I and II) and required flagellin receptors Toll-like receptor 5 (TLR5) and NOD-like receptor C4 (NLRC4). Flagellin-induced activation of TLR5 on dendritic cells elicited production of the cytokine interleukin-22 (IL-22), which induced a protective gene expression program in intestinal epithelial cells. Flagellin also induced NLRC4-dependent production of IL-18 and immediate elimination of RV-infected cells. Administration of IL-22 and IL-18 to mice fully recapitulated the capacity of flagellin to prevent or eliminate RV infection and thus holds promise as a broad-spectrum antiviral agent.

In vitro anti-influenza A activity of interferon (IFN)-λ1 combined with IFN-β or oseltamivir carboxylate

Influenza viruses, which can cross species barriers and adapt to new hosts, pose a constant potential threat to human health. The influenza pandemic of 2009 highlighted the rapidity with which an influenza virus can spread worldwide. Currently available antivirals have a number of limitations against influenza, and novel antiviral strategies, including novel drugs and drug combinations, are urgently needed. Here, we evaluated the in vitro effects of interferon (IFN)-β, IFN-λ1, oseltamivir carboxylate (a neuraminidase (NA) inhibitor), and combinations of these agents against two seasonal (i.e., H1N1 and H3N2) influenza A viruses. We observed that A/California/04/09 (H1N1) and A/Panama/2007/99 (H3N2) isolates were equally sensitive to the antiviral activity of IFN-β and oseltamivir carboxylate in A549 and Calu-3 cells. In contrast, IFN-λ1 exhibited substantially lower protective potential against the H1N1 strain (64-1030-fold ↓, P<0.05), and was ineffective against H3N2 virus in both cell lines. Three dimensional analysis of drug-drug interactions revealed that IFN-λ1 interacted with IFN-β and oseltamivir carboxylate in an additive or synergistic manner, respectively, to inhibit influenza A virus replication in human airway epithelial cells. Overall, the present study demonstrated that anti-influenza agents with different mechanisms of action (e.g., a NA inhibitor combined with IFN-λ1) exerted a significantly greater (P<0.05) synergistic effect compared to co-treatment with drugs that target the same signaling pathway (i.e., IFN-β plus IFN-λ1) in vitro. Our findings provide support for the combined use of interferon plus oseltamivir as a potential means for treating influenza infections.

Suppression of hepatocellular carcinoma proliferation and hepatitis B surface antigen secretion with interferon-λ1 or PEG-interferon-λ1

Hepatocellular carcinoma (HCC) is a common cancer associated with chronic hepatitis B virus (HBV) infection. Conventional interferon-α (IFN-α) and pegylated IFNs (PEG-IFNs) approved for chronic HBV infection treatment can reduce the risk of HCC but are not suitable for the majority of patients and cause significant side effects. IFN-λ1 is a type III IFN with antiviral, antiproliferative, and immunomodulatory functions similar to type I IFNs but with fewer side effects. However, the tolerability and antitumor activity of PEG-IFN-λ1 in HCC xenograft mice are unknown. In vitro IFN-λ1 treatment of Hep3B and Huh7 human hepatoma cell lines increased MHC class I expression, activated JAK-STAT signaling pathways, induced IFN-stimulated gene expression, and inhibited hepatitis B surface antigen (HBsAg) expression. IFN-λ1 treatment also caused 23.2 and 19.9% growth inhibition of Hep3B and Huh7 cells, respectively, and promoted cellular apoptosis. PEG-IFN-λ1, but not IFN-λ1 treatment, significantly suppressed tumor growth (P=0.002) and induced tumor cell apoptosis in a Hep3B cell xenograft mouse model without significant weight loss or toxicity. PEG-IFN-λ1 also significantly inhibited (P=0.000) serum HBsAg secretion from Hep3B xenograft tumors in vivo. Thus, PEG-IFN-λ1 can suppress Hep3B xenograft tumor growth and inhibit HBsAg production and may be a potential treatment for HBV-related HCC.

Interleukin-21 and T follicular helper cells in HIV infection: research focus and future perspectives

Interleukin (IL)-21 is a member of the γ chain-receptor cytokine family along with IL-2, IL-4, IL-7, IL-9, and IL-15. The effects of IL-21 are pleiotropic, owing to the broad cellular distribution of the IL-21 receptor. IL-21 is secreted by activated CD4 T cells and natural killer T cells. Within CD4 T cells, its secretion is restricted mainly to T follicular helper (Tfh) cells and Th17 cells to a lesser extent. Our research focus has been on the role of IL-21 and more recently of Tfh in immunopathogenesis of HIV infection. This review focuses on first the influence of IL-21 in regulation of T cell, B cell, and NK cell responses and its immunotherapeutic potential in viral infections and as a vaccine adjuvant. Second, we discuss the pivotal role of Tfh in generation of antibody responses in HIV-infected persons in studies using influenza vaccines as a probe. Lastly, we review data supporting ability of HIV to infect Tfh and the role of these cells as reservoirs for HIV and their contribution to viral persistence.

Adenovirus expressing IFN-λ1 (IL-29) attenuates allergic airway inflammation and airway hyperreactivity in experimental asthma

BACKGROUND

Asthma is thought to result from the generation of T helper type 2 (Th2) responses, leading to bronchial inflammation. IFN-λ1 (also known as IL-29) is a recently described member of the IFN-λ family and has been shown to decrease production of Th2 cytokines in vitro. However, the role and mechanism of IFN-λ1 in asthma remain unknown.

OBJECTIVES

The aim of this study was to clarify the importance of IFN-λ1 in allergen-induced airway hyperresponsiveness (AHR) and inflammation.

METHODS

We used a murine model for ovalbumin (OVA)-induced asthma to examine the effect of intranasal delivery of recombinant adenovirus expressing human IFN-λ1 (Ad-hIFN-λ1) on AHR and allergic airway inflammation.

RESULTS

Intranasal instillation of Ad-hIFN-λ1 before airway antigen challenge in OVA-immunized mice significantly decreased the severity of AHR and numbers of eosinophils and levels of IL-4, IL-5, and IL-13, but not IL-10 and IFN-γ; both in vivo, in the bronchoalveolar lavage fluid and in vitro, following stimulation of lymphocytes from spleens with OVA, compared with administration of a control virus (Ad-mock). Furthermore, Ad-hIFN-λ1 treatment inhibited serum IgE secretion and increased numbers of splenic CD4(+)CD25(+)FOXP3(+) Treg cells. Histological studies showed that Ad-hIFN-λ1 attenuated OVA-induced lung tissue eosinophilia.

CONCLUSIONS

These results demonstrate that delivery of the Ad-hIFN-λ1 can mitigate allergic airway inflammation in experimental asthma. The potent immunoregulatory action of IFN-λ1 may offer a novel therapeutic approach to treat allergic asthma.

Amelioration of Muc5b mucin hypersecretion is enhanced by IL-33 after 2-APB administration in a murine model of allergic rhinitis

We attempted to clarify whether hypersecretion of Muc5b mucin from mouse nasal submucosal glands that is enhanced by interleukin (IL)-33 under allergic conditions can be ameliorated by administration of 2-APB. Immunohistochemistry was used to examine both the distribution of T cells in the nasal mucosa of an allergic rhinitis mouse model and expressions of IL-33 receptor ST2 and Muc5b protein in mouse submucosal gland cells. The amounts of protein and mRNA of Orai1, Muc5b, IL-4, IL-5, IL-13 and IL-33 in mouse nasal lavage fluid (NLF) and nasal mucosa were determined using enzyme-linked immunosorbent assay and real-time reverse transcription-polymerase chain reaction. Expressions of Orai1, Muc5b, IL-4, IL-5, IL-13 and IL-33 were up-regulated in the allergic state and IL-33 increased the levels of Muc5b, IL-4, IL-5 and IL-13, but did not influence proliferation of T cells; however, ST2 was diminished in nasal submucosal gland cells. 2-APB reduced proliferation of T cells and the Orai1 level in the nasal mucosa. It also reduced the concentrations of IL-4, IL-5 and IL-13 in NLF and nasal mucosa, and hypersecretion of Muc5b from glandular cells that was enhanced by IL-33, but did not affect IL-33 production. 2-APB decreased Muc5b mucin hypersecretion from submucosal gland that was enhanced by IL-33 in allergic mice by limiting Ca(2+) release-activated Ca(2+) channel activity in which Orai1 plays a crucial role in the gland cells and/or by controlling channel activation in T cells and proliferation of these cells.

Induction of innate lymphoid cell-derived interleukin-22 by the transcription factor STAT3 mediates protection against intestinal infection

Inhibitors of the transcription factor STAT3 target STAT3-dependent tumorigenesis but patients often develop diarrhea from unknown mechanisms. Here we showed that STAT3 deficiency increased morbidity and mortality after Citrobacter rodentium infection with decreased secretion of cytokines including IL-17 and IL-22 associated with the transcription factor RORγt. Administration of the cytokine IL-22 was sufficient to rescue STAT3-deficient mice from lethal infection. Although STAT3 was required for IL-22 production in both innate and adaptive arms, by using conditional gene-deficient mice, we observed that STAT3 expression in RORγt(+) innate lymphoid cells (ILC3s), but not T cells, was essential for the protection. However, STAT3 was required for RORγt expression in T helper cells, but not in ILC3s. Activated STAT3 could directly bind to the Il22 locus. Thus, cancer therapies that utilize STAT3 inhibitors increase the risk for pathogen-mediated diarrhea through direct suppression of IL-22 from gut ILCs.

Oral delivery of IL-27 recombinant bacteria attenuates immune colitis in mice

BACKGROUND & AIMS

Treatment of inflammatory bowel disease would benefit from specific targeting of therapeutics to the intestine. We developed a strategy for localized delivery of the immunosuppressive cytokine interleukin (IL)-27, which is synthesized actively in situ by the food-grade bacterium Lactococcus lactis (LL-IL-27), and tested its ability to reduce colitis in mice.

METHODS

The 2 genes encoding mouse IL-27 were synthesized with optimal codon use for L lactis and joined with a linker; a signal sequence was added to allow for product secretion. The construct was introduced into L lactis. Colitis was induced via transfer of CD4(+)CD45RB(hi) T cells into Rag(-/-) mice to induce colitis; 7.5 weeks later, LL-IL-27 was administered to mice via gavage. Intestinal tissues were collected and analyzed.

RESULTS

LL-IL-27 administration protected mice from T-cell transfer-induced enterocolitis and death. LL-IL-27 reduced disease activity scores, pathology features of large and small bowel, and levels of inflammatory cytokines in colonic tissue. LL-IL-27 also reduced the numbers of CD4(+) and IL-17(+) T cells in gut-associated lymphoid tissue. The effects of LL-IL-27 required production of IL-10 by the transferred T cells. LL-IL-27 was more effective than either LL-IL-10 or systemic administration of recombinant IL-27 in reducing colitis in mice. LL-IL-27 also reduced colitis in mice after administration of dextran sodium sulfate.

CONCLUSIONS

LL-IL-27 reduces colitis in mice by increasing the production of IL-10. Mucosal delivery of LL-IL-27 could be a more effective and safer therapy for inflammatory bowel disease.

IL-33 mediates the expressions of IL-5 and IL-13 in Angiostrongylus cantonensis-infected mice

Angiostrongylus cantonensis is the major cause of human eosinophilic meningoencephalitis. C57BL/6 mice were experimentally infected with 35 infectious larvae. Two groups of infected mice received intraperitoneal injections of mouse IL-33 (1μg) or anti-IL-33 monoclonal antibody (mAb) (10μg) 3days post infection (dpi) and subsequent booster shots of the same dose at 5day intervals. Blood samples from each group were collected weekly for assays. IgE levels were significantly increased in all infected mice. The eosinophil percentage and levels of IL-5 and IL-13 significantly increased in the IL-33-treated group relative to infected but non-treated animals. The level of IL-5 decreased in the mAb-treated group. The severity of eosinophilic meningitis was exacerbated in the IL-33 injected group. Taken together, these results suggest that IL-33 mediates the expressions of IL-5 and IL-13, and plays a crucial role in the pathogenesis of angiostrongylosis.

IL-33 promotes airway remodeling in pediatric patients with severe steroid-resistant asthma

BACKGROUND

TH2 cytokines are not responsible for the ongoing symptoms and pathology in children with severe therapy-resistant asthma (STRA). IL-33 induces airway hyperresponsiveness, but its role in airway remodeling and steroid resistance is unknown.

OBJECTIVE

We sought to investigate the relationship between IL-33 and airway remodeling in pediatric patients with STRA.

METHODS

IL-33 levels were quantified in neonatal mice given inhaled house dust mite (HDM), and the effect of blocking IL-13 on remodeling and IL-33 levels was assessed. HDM-induced allergic airways disease (AAD) in neonatal ST2(-/-) mice lacking the IL-33 receptor was assessed, together with collagen production after IL-33 administration. The effect of steroid therapy on IL-33 levels in patients with neonatal AAD was explored. IL-33 expression was quantified in endobronchial biopsy (EB) specimens from children with STRA and related to remodeling, and collagen production by airway fibroblasts from pediatric patients stimulated with IL-33 and budesonide was quantified.

RESULTS

Blocking IL-13 after AAD was established in neonatal mice and did not reduce remodeling or IL-33 levels; airway hyperresponsiveness was only partially reduced. IL-33 promoted collagen synthesis both from asthmatic fibroblasts from pediatric patients and after intranasal administration in mice. Increased cellular expression of IL-33, but not IL-13, was associated with increased reticular basement membrane thickness in EB specimens from children with STRA, whereas remodeling was absent in HDM-exposed ST2(-/-) mice. IL-33 levels were maintained, whereas IL-13 levels were abrogated by steroid treatment in neonatal HDM-exposed mice and in EB specimens from children with STRA.

CONCLUSION

IL-33 is a relatively steroid-resistant mediator that promotes airway remodeling in patients with STRA and is an important therapeutic target.

Application of interleukin-22 mediates protection in experimental acetaminophen-induced acute liver injury

Acetaminophen (APAP, paracetamol)-induced hepatotoxicity, although treatable by timely application of N-acetylcysteine, can be fatal. Because it is among the common causes of acute liver failure in intensive care units and in light of its gradually increasing incidence, the need for novel therapeutic strategies aimed at severe intoxication is apparent. Recently, it has been shown that IL-22, a STAT3-activating cytokine, has the capability to mediate liver protection. Herein, the protective potential of IL-22 in murine APAP-induced hepatotoxicity was assessed. Intravenous administration of prophylactic IL-22 significantly reduced serum alanine aminotransferase levels and histopathologic damage in APAP-induced liver injury, a process that coincided with increased hepatocyte proliferation in vivo. Concomitant gene expression analysis revealed hepatic induction of genes prototypically up-regulated by the IL-22/STAT3 axis, among others suppressor of cytokine signaling-3, lipocalin-2, and α1-antichymotrypsin. Notably, in a translational setting of therapeutic treatment 2 hours after APAP, IL-22 supported protection in the context of suboptimal N-acetylcysteine dosing. IL-22 likewise connected to augmented hepatocyte proliferation in this experimental setting. As detected by analysis of inflammatory cytokine production, systemically applied IL-22 did not display acute immunomodulation/stimulation in otherwise untreated or endotoxemic mice. Those latter observations clearly confirm acute tolerability of systemically applied IL-22. Observations presented altogether suggest that therapeutic IL-22 administration is a conceivable tissue-protective regimen aimed at hard-to-treat patients with severe APAP-induced hepatotoxicity.

Macrophages as IL-25/IL-33-responsive cells play an important role in the induction of type 2 immunity

Type 2 immunity is essential for host protection against nematode infection but is detrimental in allergic inflammation or asthma. There is a major research focus on the effector molecules and specific cell types involved in the initiation of type 2 immunity. Recent work has implicated an important role of epithelial-derived cytokines, IL-25 and IL-33, acting on innate immune cells that are believed to be the initial sources of type 2 cytokines IL-4/IL-5/IL-13. The identities of the cell types that mediate the effects of IL-25/IL-33, however, remain to be fully elucidated. In the present study, we demonstrate that macrophages as IL-25/IL-33-responsive cells play an important role in inducing type 2 immunity using both in vitro and in vivo approaches. Macrophages produced type 2 cytokines IL-5 and IL-13 in response to the stimulation of IL-25/IL-33 in vitro, or were the IL-13-producing cells in mice administrated with exogenous IL-33 or infected with Heligmosomoides bakeri. In addition, IL-33 induced alternative activation of macrophages primarily through autocrine IL-13 activating the IL-4Rα-STAT6 pathway. Moreover, depletion of macrophages attenuated the IL-25/IL-33-induced type 2 immunity in mice, while adoptive transfer of IL-33-activated macrophages into mice with a chronic Heligmosomoides bakeri infection induced worm expulsion accompanied by a potent type 2 protective immune response. Thus, macrophages represent a unique population of the innate immune cells pivotal to type 2 immunity and a potential therapeutic target in controlling type 2 immunity-mediated inflammatory pathologies.