Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

A potential role of protein extractions from Metagonimus yokogawai in amelionating inflammation in patients with ankylosing spondylitis

Helminth infections and their components has been recognized to have a positive impact on the immune system. This study aimed to investigate the potential of Metagonimus yokogawai-derived proteins (MYp) to provide protection against ankylosing spondylitis (AS) through modulation of immune responses. The cytotoxicity of MYp at various doses was first assessed using MTS and flow cytometry. Peripheral blood mononuclear cells (PBMCs) were collected from AS patients, and the production of inflammatory cytokines was analyzed through flow cytometry. In the experiments with SKG mice, MYp or vehicle was administered and inflammation was evaluated through immunohistochemistry and enzyme-linked immunosorbent assay. The results showed that MYp did not decrease cell viability of PBMCs even after 48 h. Additionally, the frequencies of IFN-γ and IL-17A producing cells were significantly reduced after MYp treatment in the PBMC cultures. Furthermore, MYp treatment significantly suppressed arthritis and enthesitis in the SKG mouse model. The results suggest the first evidence that MYp can effectively alleviate clinical symptoms and restore cytokine balance in patients with AS.

Intervention effects of Trichinella spiralis excretory-secretory antigens on allergic asthma in mice

Allergic asthma is a chronic, heterogeneous and inflammatory respiratory disease, and there are few medicines at present. An increasing number of studies indicate that Trichinella spiralis (T. spiralis) and its excretory-secretory (ES) antigens are inflammatory modulator. Therefore, this study focused on the effects of T. spiralis ES antigens on allergic asthma. Asthma model was established by sensitizing mice with ovalbumin antigen (OVA) and aluminum hydroxide (Al[OH]₃), the asthmatic mice were interfered using T. spiralis 43 kDa protein (Ts43), T. spiralis 49 kDa protein (Ts49), and T. spiralis 53 kDa protein (Ts53), the important components of ES antigens, to establish ES antigens intervention models. Then, asthma symptom changes, weight changes, and lung inflammation of mice were evaluated. The results showed that ES antigens could relieve symptoms, weight loss, and lung inflammation caused by asthma in the mice, and the effect of combined intervention of Ts43, Ts49, and Ts53 was better. Finally, the effects of ES antigens on type 1 helper T (Th1) and type 2 helper T (Th2) immune responses, and the differentiation direction of T lymphocytes in mice were discussed by detecting Th1 and Th2 cell-related factors and the ratio of CD₄⁺/CD₈⁺ T cells. The results suggested that the ratio of CD₄⁺/CD₈⁺ T cells decreased and the ratio of Th1/Th2 cells increased. In conclusion, this study indicated that T. spiralis ES antigens could mitigate allergic asthma in the mice by changing the differentiation direction of CD₄⁺ and CD₈⁺ T cells and regulating the imbalance of Th1/Th2 cells ratio.

Clonorchis sinensis-Derived Protein Attenuates Inflammation and New Bone Formation in Ankylosing Spondylitis

Helminth infections and their components have been shown to have the potential to modulate and attenuate immune responses. The objective of this study was to evaluate the potential protective effects of Clonorchis sinensis-derived protein (CSp) on ankylosing spondylitis (AS). Cytotoxicity of CSp at different doses was assessed by MTS and flow cytometry before performing experiments. Peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were obtained from AS patients. Inflammatory cytokine-producing cells were analyzed using flow cytometry. The levels of INF- γ , IL-17A, TNF-α, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). SKG mice were treated with CSp or vehicles. Inflammation and new bone formation were evaluated using immunohistochemistry, positron emission tomography (PET), and micro-computed tomography (CT). Treatment with CSp resulted in no reduced cell viability of PBMCs or SFMCs until 24 h. In experiments culturing PBMCs and SFMCs, the frequencies of IFN- γ and IL-17A producing cells were significantly reduced after CSp treatment. In the SKG mouse model, CSp treatment significantly suppressed arthritis, enthesitis, and enteritis. Micro-CT analysis of hind paw revealed reduced new bone formation in CSp-treated mice than in vehicle-treated mice. We provide the first evidence demonstrating that CSp can ameliorate clinical signs and cytokine derangements in AS. In addition, such CSp treatment could reduce the new bone formation of AS.

Mycobacterium-Induced Th1, Helminths-Induced Th2 Cells and the Potential Vaccine Candidates for Allergic Asthma: Imitation of Natural Infection

Bronchial asthma is one of the most chronic pulmonary diseases and major public health problems. In general, asthma prevails in developed countries than developing countries, and its prevalence is increasing in the latter. For instance, the hygiene hypothesis demonstrated that this phenomenon resulted from higher household hygienic standards that decreased the chances of infections, which would subsequently increase the occurrence of allergy. In this review, we attempted to integrate our knowledge with the hygiene hypothesis into beneficial preventive approaches for allergic asthma. Therefore, we highlighted the studies that investigated the correlation between allergic asthma and the two different types of infections that induce the two major antagonizing arms of T cells. This elucidation reflects the association between various types of natural infections and the immune system, which is predicted to support the main objective of the current research on investigating of the benefits of natural infections, regardless their immune pathways for the prevention of allergic asthma. We demonstrated that natural infection with Mycobacterium tuberculosis (Mtb) prevents the development of allergic asthma, thus Bacille Calmette-Guérin (BCG) vaccine is suggested at early age to mediate the same prevention particularly with increasing its efficiency through genetic engineering-based modifications. Likewise, natural helminth infections might inhabit the allergic asthma development. Therefore, helminth-derived proteins at early age are good candidates for designing vaccines for allergic asthma and it requires further investigation. Finally, we recommend imitation of natural infections as a general strategy for preventing allergic asthma that increased dramatically over the past decades.

In vivo and in vitro studies using Clonorchis sinensis adult-derived total protein (CsTP) on cellular function and inflammatory effect in mouse and cell model

Clonorchis sinensis (C. sinensis) can induce a food-borne parasitic disease (clonorchiasis). Numerous studies have analyzed functional proteins, immunologic factors, pro-inflammatory cytokines, and cell signaling transduction that promote the development of clonorchiasis. In a previous study, it was shown that C. sinensis adult-derived total protein (CsTP) might be involved in the pathogenesis and development of liver fibrosis via bringing about Th2 immune response. In the present study, further investigation of CsTP on cellular function and inflammatory effect in vitro and in vivo has been elicited. CsTP induced inflammation and autophagy as evidenced by upregulation of TNF-α, IFN-γ, and autophagic markers LC3B and P62. Exposed to CsTP upregulated the antiapoptotic gene Bcl-2 expression, diminished the apoptosis induced by H₂O₂, but promoted the proliferation and migration of LX-2 cells in proper concentration range. Additionally, the protein levels of p-AKT and p-mTOR were repressed in response to CsTP, suggesting a correlation of blocking the activation of mTOR/AKT signaling pathway. These results revealed that CsTP might exacerbate hepatic pathological changes by regulating cell proliferation, apoptosis, autophagy, and inflammation in the liver and LX-2 cells. Some effects might be partially involved in the mTOR and AKT pathways.

Chinese liver fluke Clonorchis sinensis infection changes the gut microbiome and increases probiotic Lactobacillus in mice

Chinese liver fluke Clonorchis sinensis changes the host's immune system. Recently, it has been reported that helminths including C. sinensis can ameliorate immune-related diseases such as allergy. In addition, recent studies showed that helminth infection can alleviate immune-mediated disorders by altering the gut microbiome. However, changes in the gut microbiome due to C. sinensis have not been reported yet. In this study, changes in the gut microbiome of C57BL/6 mice infected with C. sinensis metacercariae were evaluated over time. Stool was analyzed by 16S rRNA amplicon analysis using high-throughput sequencing technology. There was no apparent difference in species richness and diversity between the infected and control groups. However, the composition of the microbiome was different between the infected and control groups at 20 days and 30 days post-infection, and the difference disappeared at 50 days post-infection. In particular, this microbiome alteration was associated with a change in the relative abundance of genus Lactobacillus and the probiotic Lactobacillus species that are known to have an immune-modulation role in immune-mediated diseases.

Clonorchis sinensis adult-derived proteins elicit Th2 immune responses by regulating dendritic cells via mannose receptor

BACKGROUND

Clonorchis sinensis (C. sinensis) is the most widespread human liver fluke in East Asia including China and Korea. Clonorchiasis as a neglected tropical zoonosis, leads to serious economic and public health burden in China. There are considerable evidences for an etiological relation between chronic clonorchiasis and liver fibrosis in human beings. Liver fibrosis is a highly conserved and over-protected response to hepatic tissue injury. Immune cells including CD4+ T cell as well as dendritic cell (DC), and pro-fibrogenic cytokines like interleukin 4 (IL-4), IL-13 have been identified as vital manipulators in liver fibrogenesis. Our previous studies had a mere glimpse of T helper type 2 (Th2) dominant immune responses as key players in liver fibrosis induced by C. sinensis infection, but little is known about the involved mechanisms in this pathological process.

METHODOLOGY/PRINCIPAL FINDINGS

By flow cytometry (FACS), adult-derived total proteins of C. sinensis (CsTPs) down-regulated the expression of surface markers CD80, CD86 and major histocompatibility complex class II (MHC-II) on lipopolysaccharide (LPS) induced DC. ELISA results demonstrated that CsTPs inhibited IL-12p70 release from LPS-treated bone marrow-derived dendritic cells (BMDC). IL-10 level increased in a time-dependent manner in LPS-treated BMDCs after incubation with CsTPs. CD4+ T cells incubated with LPS-treated BMDCs plus CsTPs could significantly elevate IL-4 level by ELISA. Meanwhile, elevated expression of pro-fibrogenic mediators including IL-13 and IL-4 were detected in a co-culture system of LPS-activated BMDCs and naive T cells containing CsTPs. In vivo, CsTPs-immunized mice enhanced expression of type 2 cytokines IL-13, IL-10 and IL-4 in both splenocytes and hepatic tissue. Exposure of BMDCs to CsTPs activated expression of mannose receptor (MR) but not toll like receptor 2 (TLR2), TLR4, C-type lectin receptor DC-SIGN and Dectin-2 on the cell surface by RT-PCR and FACS. Blockade of MR almost completely reversed the capacity of CsTPs to suppress LPS-induced BMDCs surface markers CD80, CD86 and MHC-II expression, and further made these BMDCs fail to induce a Th2-skewed response as well as Th2 cell-associated cytokines IL-13 and IL-4 release in vitro.

CONCLUSIONS/SIGNIFICANCE

Collectively, we validated that CsTPs could suppress the maturation of BMDCs in the presence of LPS via binding MR, and showed that the CsTPs-pulsed BMDCs actively polarized naive T helper cells to Th2 cells though the production of IL-10 instead of IL-12. CsTPs endowed host with the capacity to facilitate Th2 cytokines production including IL-13 and IL-4 in vitro and vivo. The study might provide useful information for developing potential therapeutic targets against the disease.

Parasites and asthma

Nowadays, many studies have found low morbidity of asthma in epidemic areas of parasitic diseases, as shown by the hygiene hypothesis. It is obvious that some parasite infections can prevent asthma and studies have been carried out to clarify the mechanism of the preventive effect and search for the future asthmatic therapies. Previous findings have indicated that this mechanism may be related to the immune response switching from Th1 to Th2 and important cells induced by parasites, including the regulatory T cells, regulatory B cells, dendrite cells, and alternatively activated macrophages. Cytokine IL-10 also plays a nonredundant role in protection against allergic airway inflammation in asthma. This review focuses on the relationship between parasites and asthma, and the potential protection mechanism involved.

Regulatory B cells in infectious disease (Review)

Regulatory B cells (Bregs) are a subset of B cells, which reportedly exert significant immunomodulatory effects through the production of interleukin (IL)-10, IL-35 and transforming growth factor-β. Over the last decade, studies have indicated that Bregs function in autoimmune and allergic diseases through antigen-specific and non-specific immunoregulatory mechanisms. However, only a limited number of reviews have focused on the role of Bregs during infection, particularly their functions in intracellular infections. The present review discusses the role of Bregs in infectious diseases in animal models and human studies, and provides an overview of the immunoregulatory mechanisms used by Bregs.

Clonorchis sinensis, an oriental liver fluke, as a human biological agent of cholangiocarcinoma: a brief review

Parasitic diseases remain an unarguable public health problem worldwide. Liver fluke Clonorchis sinensis is a high risk pathogenic parasitic helminth which is endemic predominantly in Asian countries, including Korea, China, Taiwan, Vietnam, and the far eastern parts of Russia, and is still actively transmitted. According to the earlier 8^th National Survey on the Prevalence of Intestinal Parasitic Infections in 2012, C. sinensis was revealed as the parasite with highest prevalence of 1.86% in general population among all parasite species surveyed in Korea. This fluke is now classified under one of the definite Group 1 human biological agents (carcinogens) by International Agency of Research on Cancer (IARC) along with two other parasites, Opisthorchis viverrini and Schistosoma haematobium. C. sinensis infestation is mainly linked to liver and biliary disorders, especially cholangiocarcinoma (CCA). For the purposes of this mini-review, we will only focus on C. sinensis and review pathogenesis and carcinogenesis of clonorchiasis, disease condition by C. sinensis infestation, and association between C. sinensis infestation and CCA. In this presentation, we briefly consider the current scientific status for progression of CCA by heavy C. sinensis infestation from the food-borne trematode and development of CCA.

Oocyst-Derived Extract of Toxoplasma Gondii Serves as Potent Immunomodulator in a Mouse Model of Birch Pollen Allergy

Introduction

Previously, we have shown that oral infection with Toxoplasma gondii oocysts prevented type I allergy in mice. Here we investigated whether the application of a T. gondii oocyst lysate antigen (OLA) could also reduce allergy development. BALB/c mice were immunised twice with OLA followed by sensitisation with the major birch pollen (BP) allergen Bet v 1 and an aerosol challenge with BP extract.

Methods

First, we tested OLA in vitro. Stimulation of splenocytes and bone marrow-derived dendritic cells (BMDC) with OLA led to the production of pro-inflammatory and regulatory cytokines such as IL-6, IFN-γ and IL-10. Moreover, BMDC exposed to OLA upregulated the maturation markers CD40, CD80, CD86, and MHCII. Furthermore, OLA was recognised by TLR2-transfected human embryonic kidney cells.

Results

Immunisation of mice with OLA induced high levels of Toxoplasma-specific IgG antibodies in sera along with increased production of IFN-γ and IL-10 in Toxoplasma-antigen restimulated splenocytes. OLA reduced allergic airway inflammation as manifested by significant reduction of eosinophils in bronchoalveolar fluids, decreased cellular infiltrates and mucus production in the lungs. Accordingly, Bet v 1-specific IgE was decreased in OLA-pretreated mice. The reduced allergic immune responses were accompanied by increased numbers of CD4⁺CD25^highFoxp3⁺ regulatory T cells in spleens as well as by increased numbers of granulocytic myeloid-derived suppressor cells in lungs when compared to sensitised controls suggesting that these two cell populations might be involved in the suppression of the allergic immune responses.

Conclusion

Our data demonstrate that pretreatment with the oocyst extract can exert anti-allergic effects comparable to T. gondii infection. Thus, the immunomodulatory properties of the parasite extract indicate that this extract and in the future defined molecules thereof might serve as immunomodulatory adjuvants in allergy treatment and prophylaxis.

Exosome-transported microRNAs of helminth origin: new tools for allergic and autoimmune diseases therapy?

Chronic diseases associated with inflammation show fast annual increase in their incidence. This has been associated with excessive hygiene habits that limit contacts between the immune system and helminth parasites. Helminthic infections induce regulation and expansion of regulatory T cells (Treg) leading to atypical Th2 type immune responses, with downregulation of the inflammatory component usually associated with these type of responses. Many cells, including those of the immune system, produce extracellular vesicles called exosomes which mediate either immune stimulation (DCs) or immune modulation (T cells). The transfer of miRNAs contained in T-cell exosomes has been shown to contribute to downregulate the production of inflammatory mediators. It has been recently described the delivery to the host-parasite interface of exosomes containing miRNAs by helminths and its internalization by host cells. In this sense, helminth microRNAs transported in exosomes and internalized by immune host cells exert an important role in the expansion of Treg cells, resulting in the control of inflammation. We here provide relevant information obtained in the field of exosomes, cell-cell communication and miRNAs, showing the high potential of helminth miRNAs delivered in exosomes to host cells as new therapeutic tools against diseases associated with exacerbated inflammatory responses.

Toxoplasma gondii Infection Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice

PURPOSE

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects humans and animals via congenital or postnatal routes, and it is found worldwide. Modulation of the immune system by parasite infection is proposed to suppress allergic inflammation. Growing evidences have shown that interleukin (IL)-10-producing regulatory B cells (B(regs)) and CD4+CD25+FoxP3+ regulatory T cells (T(regs)) induced by parasite infection play a critical role in allergic or autoimmune diseases because these cells regulate negatively cellular immune responses and inflammation. Currently, the role of IL-10-producing regulatory B cells in host immune response during T. gondii infection is unknown. In this study, we investigate whether T. gondii infection can suppress the development of unrelated atopic dermatitis (AD)-like lesions.

METHODS

AD is a chronically relapsing inflammatory skin disease accompanied by severe itching; for this, we used NC/Nga mice, a well-known experimental model of systemic AD. Repeated exposure to Dermatophagoides farinae crude extract (DfE), known as a major environmental allergen, evokes AD-like skin lesions in NC/Nga mice under specific pathogen-free conditions. NC/Nga mice were intraperitoneally infected with 10 cysts of T. gondii.

RESULTS

T. gondii infection significantly ameliorated AD-like skin lesions in NC/Nga mice. The subpopulation of B(regs) and T(regs) in the AD mice was expanded in the course of T. gondii infection. In addition, T. gondii infection inhibited Th2 and enhanced Th1 immune response in the DfE-treated AD mice.

CONCLUSIONS

We have experimentally demonstrated for the first time that T. gondii infection ameliorated AD-like skin lesions in a mouse model of AD. Our study could in part explain the mechanisms of how parasite infection prevents the development of allergic disorder. Therefore, these immunemechanisms induced by T. gondii infection may be beneficial for the host in terms of reduced risk of allergic immune reactions.

Worms as therapeutic agents for allergy and asthma: understanding why benefits in animal studies have not translated into clinical success

Helminth infections are associated with decreased rates of autoimmunity and allergy, and several clinical studies have demonstrated that intentional infection with helminths can reduce symptoms of autoimmune diseases. In contrast, though numerous animal studies have demonstrated that helminth infections ameliorate allergic diseases, clinical trials in humans have not shown benefit. In this article, we review in detail the 2 human studies that have prospectively tested whether helminth infections protect against allergy. We next review the research designs and results obtained from animal studies, and compare these to the human trials. We then postulate possible reasons for the lack of efficacy observed in clinical trials to date and discuss potential future areas of research in this field.

Microorganism-induced suppression of allergic airway disease: novel therapies on the horizon?

Allergic airway disease is a major global health burden, and novel treatment options are urgently needed. Numerous epidemiological and experimental studies suggest that certain helminths and bacteria protect against respiratory allergies. These microorganisms are strong regulators of the immune system, and various potential regulatory mechanisms by which they protect against allergic airway inflammation have been proposed. Whereas early studies addressed the beneficial effect of natural infections, the focus now shifts toward identifying the dominant protective molecules and exploring their efficacy in models of allergic airway disease. In this article, we will review the evidence for microbe-mediated protection from allergic airway disease, the potential modes of action involved and discuss advances as well as limitations in the translation of this knowledge into novel treatment strategies against allergic airway disease.

Identification of anti-allergic effect of Clonorchis sinensis-derived protein venom allergen-like proteins (CsVAL)

Previous studies demonstrated that Clonochis sinensis-derived crude antigens suppress development of allergic responses. We investigated the effects of C. sinensis venom allergen-like (CsVAL) proteins on immune-modulating activities in allergic inflammatory response. Using RBL-2H3 rat mast cells, we demonstrated that CsVAL inhibits antigen-induced β-hexosaminidase release from immunoglobulin E-sensitized RBL-2H3 cells, and this inhibitory activity occurs by suppressing Lyn phosphorylation and intracellular reactive oxygen species production. In addition, CsVAL peptide treatment inhibits activation of protein kinase C-α and extracellular signal-regulated kinase 1/2, which are involved in degranulation of immunoglobulin E-sensitized mast cells. Furthermore, immunization with CsVAL suppressed development of skin inflammation by assessing ear thickness and cutaneous infiltration by eosinophils and mast cells in oxazolone-induced contact hypersensitivity in vivo mouse model. These results suggest that CsVAL is a promising candidate as an effective mast cell inhibitor for allergic and inflammatory diseases.

Molecular characterization and immune modulation properties of Clonorchis sinensis-derived RNASET2

BACKGROUND

Clonorchis sinensis (C. sinensis, Cs) is a trematode parasite that often causes chronic cumulative infections in the hepatobiliary ducts of the host and can lead to pathological changes by continuously released excretory/secretory proteins (ESPs). A T2 ribonuclease in trematode ESPs, has been identified as a potent regulator of dendritic cell (DCs) modulation. We wondered whether there was a counterpart present in CsESPs with similar activity. To gain a better understanding of CsESPs associated immune responses, we identified and characterized RNASET2 of C. sinensis (CsRNASET2) in this paper.

METHODS

We expressed CsRNASET2 in Pichia pastoris and identified its molecular characteristics using bioinformatic analysis and experimental approaches. The immune modulation activities of CsRNASET2 were confirmed by evaluating cytokine production and surface markers of recombinant CsRNASET2 (rCsRNASET2) co-cultured DCs, and monitoring levels of IgG isotypes from rCsRNASET2 administered BALB/c mice.

RESULTS

CsRNASET2 appeared to be a glycoprotein of T2 ribonuclease family harboring conserved CAS motifs and rich in B-cell epitopes. Furthermore, CsRNASET2 was present in CsESPs and was able to modulate cytokine production of DCs. In addition, rCsRNASET2 could significantly suppress the expression of lipopolysaccharide-induced DCs maturation markers. In addition, when subcutaneously administered with rCsRNASET2 there was a marked effect on IgG isotypes in mouse sera.

CONCLUSION

Collectively, we revealed that CsRNASET2, a T2 ribonuclease present in CsESPs, could modulate DCs maturation and might play an important role in C. sinensis associated immune regulation in the host.

Induction of IL-10-producing CD1dhighCD5+ regulatory B cells following Babesia microti-infection

Background

Understanding the induction of immune regulatory cells upon helminth infection is important for understanding the control of autoimmunity and allergic inflammation in helminth infection. Babesia microti, an intraerythrocytic protozoan of the genus Babesia, is a major cause of the emerging human disease babesiosis, an asymptomatic malaria-like disease. We examined the influence of acute B. microti infection on the development of regulatory B cells together with regulatory T cells.

Principal Findings

Our data demonstrate that B cells stimulated in vitro with B. microti produce interleukin (IL)-10. This cytokine is also secreted by B cells isolated from B. microti-infected mice in response to lipopolysaccharide stimulation. In addition, high levels of IL-10 were detected in the serum of mice after infection with B. microti. The frequency of IL-10-producing CD1d^highCD5⁺ regulatory B cells (Bregs) and CD4⁺CD25⁺FoxP3⁺ T cells increased during the course of B. microti infection. Furthermore, adoptive transfer of IL-10-producing B cells induced by B. microti infection led to increased susceptibility of recipient mice to infection with B. microti. In contrast, experiments with B cell-deficient (µMT) mice demonstrated that lack of B cells enhances susceptibility to B. microti infection.

Conclusions

This study is the first demonstration of the expansion of Bregs following infection by an intraerythrocytic protozoan parasite. These data suggest that B. microti infection in mice provides an excellent model for studying Breg-mediated immune responses and begins to elucidate the mechanism by which helminth infection regulates autoimmunity and allergic inflammation.

Parasitic helminth cystatin inhibits DSS-induced intestinal inflammation via IL-10(+)F4/80(+) macrophage recruitment

Many immune down-regulatory molecules have been isolated from parasites, including cystatin (cystain protease inhibitor). In a previous study, we isolated and characterized Type I cystatin (CsStefin-1) of the liver fluke, Clonorchis sinensis. To investigate whether the CsStefin-1 might be a new host immune modulator, we induced intestinal inflammation in mice by dextran sodium sulfate (DSS) and treated them with recombinant CsStefin-1 (rCsStefin-1). The disease activity index (DAI) increased in DSS only-treated mice. In contrast, the DAI value was significantly reduced in rCsStefin-1-treated mice than DSS only-treated mice. In addition, the colon length of DSS only-treated mice was shorter than that of rCsStefin-1 treated mice. The secretion levels of IFN-γ and TNF-α in the spleen and mesenteric lymph nodes (MLNs) were significantly increased by DSS treatment, but the level of TNF-α in MLNs was significantly decreased by rCsStefin-1 treatment. IL-10 production in both spleen and MLNs was significantly increased, and IL-10⁺F4/80⁺ macrophage cells were significantly increased in the spleen and MLNs of rCsStefin-1 treated mice after DSS treatment. In conclusion, rCsStefin-1 could reduce the intestinal inflammation occurring after DSS treatment, these effects might be related with recruitment of IL-10 secreting macrophages.