Th17: a new participant in gut dysfunction in mice infected with Trichinella spiralis

Pumpkin seeds (Cucurbita pepo subsp. ovifera) decoction promotes Trichinella spiralis expulsion during intestinal phase via "Weep and Sweep" mechanism

Trichinosis is a zoonotic disease of communal health concern as it instigated human outbreaks in several countries. Besides, the development of resistance, traditional therapy has numerous antagonistic effects. Thereby, finding efficient natural alternatives is required. In comparison to albendazole, this study evaluated the impact of pumpkin decoction on Trichinella spiralis in experimentally infected mice. The anthelmintic action of pumpkin decoction (500 mg/kg) was determined using T. spiralis infected mice in enteric phase for 5 days. Pumpkin decoction anthelmintic activity fortified by mixing with honey (1:1). Pumpkin decoction and Pumpkin decoction-honey mixture were evaluated by comprising with reference drug, albendazole (50 mg/kg). The T. spiralis adult count was significantly lower in all treated groups, with the pumpkin decoction-honey mixture showing the largest reduction (83.2%) when compared to the infected group (P ≤ 0.001). The intestinal histological changes and the level of COX-2 expression in the intestinal tissue were both significantly reduced in the same group. The pumpkin decoction improved the immune response, as evidenced by a significant decrease in nitric oxide (NO) and tumor necrosis factor (TNF-α) and a significant increase in the expression of the transforming growth factor (TGF-1β) and interleukin-17 (IL-17). The pumpkin decoction's anthelmintic action was facilitated by the TGF-1β and IL-17-driven Weep and Sweep mechanism. Both administration of pumpkin decoction beside honey showed the best treatment group that resulted in high infection reduction besides amelioration of biochemical markers and restoration of histological to normal state. In conclusion, pumpkin decoction is highly effective against T. spiralis which could be a promising alternative herbal drug and the pumpkin decoction effect was higher in the case of combination with honey.

The impact of β-glucan on the therapeutic outcome of experimental Trichinella spiralis infection

Trichinellosis is a cosmopolitan zoonosis that is caused mainly by Trichinella spiralis infection. The human disease ranges from mild to severe and fatality may occur. The treatment of trichinellosis still presents a challenge for physicians. Anti-inflammatory drugs are usually added to antiparasitic agents to alleviate untoward immuno-inflammatory responses and possible tissue damage but they are not without adverse effects. Thus, there is a need for the discovery of safe and effective compounds with anti-inflammatory properties. This study aimed to evaluate the activity of β-glucan during enteral and muscular phases of experimental T. spiralis infection as well as its therapeutic potential as an adjuvant to albendazole in treating trichinellosis. For this aim, mice were infected with T. spiralis and divided into the following groups: early and late β-glucan treatment, albendazole treatment, and combined treatment groups. Infected mice were subjected to assessment of parasite burden, immunological markers, and histopathological changes in the small intestines and muscles. Immunohistochemical evaluation of NF-κB expression in small intestinal and muscle tissues was carried out in order to investigate the mechanism of action of β-glucan. Interestingly, β-glucan potentiated the efficacy of albendazole as noted by the significant reduction of counts of muscle larvae. The inflammatory responses in the small intestine and skeletal muscles were mitigated with some characteristic qualitative changes. β-glucan also increased the expression of NF-κB in tissues which may account for some of its effects. In conclusion, β-glucan showed a multifaceted beneficial impact on the therapeutic outcome of Trichinella infection and can be regarded as a promising adjuvant in the treatment of trichinellosis.

Modulation of the microbiota across different intestinal segments by Rifaximin in PI-IBS mice

BACKGROUND

Rifaximin has been increasingly applied in irritable bowel syndrome (IBS) treatment. Whether there were differences in the effects of rifaximin on microbiota from different intestinal segments, especially the small intestine where rifaximin predominantly acted, has not been confirmed.

METHODS

In this study, we used Trichinella spiralis infection to induce post infectious irritable bowel syndrome (PI-IBS) and measured visceral sensitivity of mice by means of abdominal withdrawal reflex (AWR) tests to colorectal distention (CRD). We compared the effects of rifaximin on the composition of ileal, colonic mucosal and fecal microbiota in PI-IBS mice.

RESULTS

Rifaximin significantly reduced AWR scores and increased pain threshold in PI-IBS mice, and this effect was associated with the change in the relative abundance of ileal mucosal microbiota. Rifaximin could obviously decrease ileum mucosal microbiota alpha diversity assessed by Shannon microbial diversity index. Meanwhile, the analysis of beta diversity and relative abundance of microbiota at phylum, family and genus levels showed that rifaximin could improve the microbiota structure of ileal mucosa. However, for colonic mucosal and fecal microbiota, this effect of rifaximin was not obvious. Rifaximin could reshape the correlation of genera between different intestinal segments.

CONCLUSION

Rifaximin improved visceral hypersensitivity in PI-IBS mice. Rifaximin mainly affected ileal mucosal microbiota, and its improvement effect on IBS might be closely related to the improvement of ileal microbiota structure.

The Role of Inflammatory Mediators in the Development of Gastrointestinal Motility Disorders

Feeding intolerance and the development of ileus is a common complication affecting critically ill, surgical, and trauma patients, resulting in prolonged intensive care unit and hospital stays, increased infectious complications, a higher rate of hospital readmission, and higher medical care costs. Medical treatment for ileus is ineffective and many of the available prokinetic drugs have serious side effects that limit their use. Despite the large number of patients affected and the consequences of ileus, little progress has been made in identifying new drug targets for the treatment of ileus. Inflammatory mediators play a critical role in the development of ileus, but surprisingly little is known about the direct effects of inflammatory mediators on cells of the gastrointestinal tract, and many of the studies are conflicting. Understanding the effects of inflammatory cytokines/chemokines on the development of ileus will facilitate the early identification of patients who will develop ileus and the identification of new drug targets to treat ileus. Thus, herein, we review the published literature concerning the effects of inflammatory mediators on gastrointestinal motility.

Oral vaccination with attenuated Salmonella encoding the Trichinella spiralis 43-kDa protein elicits protective immunity in BALB/c mice

A vaccine against Trichinella spiralis infection is urgently needed to interrupt its transmission from domestic animals to humans. However, no vaccine against T. spiralis is currently available. Our previous study demonstrated that the use of the 43-kDa glycoprotein present in excretory-secretory (ES) proteins of muscle larvae (ML) as an intramuscular DNA vaccine led to a 52.1% protection rate against T. spiralis infection. Attenuated Salmonella strains have the advantage of eliciting mucosal immunity, which is important for controlling T. spiralis infections at the intestinal stage and can be provided as vaccines via oral or intranasal routes. Therefore, in this study, complete 43-kDa glycoprotein (Ts43) sequences of T. spiralis were cloned into the vector pYA3681, and the recombinant plasmid pYA3681-Ts43 was transformed into the attenuated Salmonella typhimurium strain χ11802. The results showed that oral vaccination of mice with attenuated Salmonella carrying the recombinant plasmid pYA3681-Ts43 induced an evident elevation of the local intestinal mucosal sIgA and serum IgG antibody responses. The flow cytometry results showed that the percentages of CD4⁺ T cells and secreted IFN-γ, IL-4, and IL-17A in CD4⁺ T cells were significantly increased in the spleen and mesenteric lymph node (MLN) lymphocytes of the vaccinated groups. In addition, increased levels of the IFN-γ, IL-4, and IL-17A cytokines were also observed in the serum of the immunized groups. The above immune response results in the immunized groups demonstrated that protective immunity was elicited in this study. Finally, vaccinated mice demonstrated a significant 45.9% reduction in ML burden after infection with T. spiralis. This study demonstrated that oral vaccination with Ts43 delivered by attenuated Salmonella elicited local and systemic concurrent Th1/Th2/Th17 immune responses and provided partial protection against T. spiralis infection in BALB/c mice. This is a prospective strategy for the prevention and control of trichinellosis.

Higher mucosal type II immunity is associated with increased gut microbiota diversity in BALB/c mice after Trichinella spiralis infection

Understanding the interaction between the gut microbiota and Trichinella spiralis is of interest for the early diagnosis and development of therapeutics for trichinellosis and to reveal the potential role of microbiota in the mechanism of immunomodulation of this tissue-dwelling helminth. In this study, we utilized 16S rRNA gene sequencing to monitor the dynamics of the microbes in BALB/c mice challenged with T. spiralis. Flow cytometry and ELISA were used to analyze cytokines at the same time. Histopathological analysis of the duodenum was also conducted. We found that microbial perturbations occurred during infection. The abundance of the Lachnospiraceae NK4A136 group, Ruminococcus 1 and Lactococcus decreased. However, the abundance of proinflammatory Parabacteroides increased over time after infection. T. spiralis infection also tended to inhibit IFN-γ production, and promote IL-4 and IL-10 levels. In total, T. spiralis disrupts gut homeostasis and impairs the development of the intestinal ecosystem. Defining the bacterial populations affected by T. spiralis infection might help identify microbial markers for diagnosis of the disease, and the populations could also be further exploited as a novel option to treat T. spiralis infection.

Oral immunization with recombinant Lactobacillus plantarum expressing Nudix hydrolase and 43 kDa proteins confers protection against Trichinella spiralis in BALB/c mice

Trichinellosis is a significant food-borne zoonotic parasitic disease caused by parasite Trichinella. Given the side effects of anti-Trichinella drugs (e.g., Mebendazole) aroused in the course of treatments, an effective vaccine against the parasite is called for. The therapies available to date are in most instances targeting a single stage of Trichinella, resulting in an incomplete protective immunity against the parasite in terms of the complexity of its developmental stages. In this study, a recombinant dual-expression double anchor vector NC8-pLp-TsNd-S-pgsA'-gp43 was constructed carrying two antigen genes from Trichinella spiralis (T. spiralis), encoding the gp43 and T. spiralis Nudix hydrolase (TsNd) proteins which were mainly expressed in muscle larva (ML) and intestinal infective larva stages of the parasite respectively. These two proteins were to be expressed by Lactobacillus plantarum NC8 (L. plantarum NC8) which was designed to express the two anchored peptides, a truncated poly-γ-glutamic acid synthetase A (pgsA') and the surface layer protein of Lactobacillus acidophilus (SlpA), on its surface for attaching expressed foreign proteins. Oral immunization with the above recombinant vaccine induced higher levels of specific serum IgG and mucosal secretory IgA (SIgA) in BALB/c mice. In addition, cytokines, interferon-γ (IFN- γ), interleukin-4 (IL-4) and IL-17 released by lymphocytes, and CD4+ levels displayed on the surfaces of splenic and mesenteric lymph cells were significantly enhanced by the vaccination. Moreover, after larval challenges, a 75.67 % reduction of adult worms (AW) at 7 days post-infection (dpi) and 57.14 % reduction of ML at 42 dpi were observed in mice immunized with the recombinant vaccine. Furthermore, this oral vaccination reduced the counts of encysted larvae presented in tongue and masseter muscles after infected with T. spiralis in mice. The overall results demonstrated that the recombinant vaccine developed in this study could induce specific humoral, mucosal, and cellular immune responses, and provides protections against different stages (adult worms and muscle larva) of T. spiralis infections in BALB/c mice, which could make it a promising oral vaccine candidate against trichinellosis.

The etiology of achalasia: An immune-dominant disease

There is accumulating evidence suggesting that an autoimmune component is involved in esophageal achalasia. An increase in immune cells, cytokines, chemokines, and autoimmune antibodies in serum and infiltration of immune cells in tissues support the view that immune-mediated inflammation is a crucial pathogenesis of inhibitory neuron degeneration in the lower esophageal sphincter. Infection of viruses such as the herpes virus family has been suspected of provoking the autoimmune reaction. Meanwhile, previous reports on immunogenetics have proposed that specific risk alleles on the human leukocyte antigen complex define the susceptible population to achalasia. In this study we reviewed current knowledge regarding the immune-related factors of achalasia, including immunology, viral infection and immunogenetic variations.

HcFAR, a functional inhibitor of goat TGF-β1 identified from excretory and secretory products of Haemonchus contortus

Haemonchus contortus has developed complexed and multifaceted mechanisms of immune evasion to enable the survival in the host. Generating excretion and secretion products (ESPs) to subvert or suppress the functions of host cytokines is a newly immune regulatory pattern found during recent years. Transforming growth factor-β (TGF-β) has critical immune regulatory functions in nematode infections. In this study, co-immunoprecipitation (co-IP) assay was used to identify the goat TGF-β1 binding proteins from HcESPs. The interaction between TGF-β1 and nematode fatty acid retinoid binding domain containing protein of H. contortus (HcFAR) was analyzed by glutathione S-transferase (GST)-pull down assay. The suppressive effect of rHcFAR on TGF-β1-induced immunoglobulin A (IgA) secretion was observed by co-incubation of rHcFAR and TGF-β1 with goat peripheral blood mononuclear cells (PBMCs). The IgA concentrations were determined using enzyme linked immunosorbent assay (ELISA) kit. Meanwhile, the suppressive effect of rHcFAR on TGF-β1-induced T helper (Th) 9 differentiation was investigated by co-incubation of rHcFAR, TGF-β1 and interleukin (IL)-4 with goats PBMCs. In parallel, IL-4 was replaced by IL-6 to determine the effects on the Th17 differentiation. The transcriptions of IL-9 and IL-17 in PBMCs were then evaluated by real-time PCR. Finally, we found that HcFAR from HcESPs could bind to goat TGF-β1 in vitro. The ELISA results of IgA showed that 40 μg/mL rHcFAR could suppress the IgA secretion of PBMCs induced by TGF-β1. Additionally, rHcFAR (at 10 μg/mL and 20 μg/mL) could inhibit the mRNA transcription of IL-9 induced by TGF-β1 and IL-4. Meanwhile, rHcFAR could also downregulate the transcription of IL-17 induced by TGF-β1 and IL-6 in a dose-dependent manner. These results indicated that HcFAR was a functional inhibitor of goat TGF-β1 and this information may help contribute to understanding of the relationship between the ESPs and host cytokines.

Primary characterization of the immune response in pigs infected with Trichinella spiralis

Trichinellosis, which is caused by Trichinella spiralis (T. spiralis), is a serious zoonosis. Pigs play an important role in the transmission of human trichinellosis. Characterizing the immune response to T. spiralis infection is key to elucidating host–parasite interactions. However, most studies on the immune response to T. spiralis infection have employed murine models. In this study, we investigated the immune response to T. spiralis infection in pigs. The results showed that the average numbers of larvae per gram (lpg) for the 100-muscle larvae (ML), 1000-ML, and 10 000-ML groups were 1.502, 35.947, and 398.811, respectively. The percentages of CD3+ T cells, B cells, CD4+ T cells, Treg cells, and Th17 cells were elevated in the infection groups compared to the control animals. In contrast, CD8+ T cell percentages were reduced after infection in the low-dose group. The number of neutrophils was increased at 3–17 days post-infection (dpi). Th1 cytokine IL-2 levels were significantly decreased at 7 dpi, and Th2 cytokine IL-4 levels were significantly elevated at 3 dpi. Treg cytokine IL-10 levels were significantly elevated between 7 dpi and 30 dpi. Th17 cytokine IL-17A levels were significantly increased beginning at 11 dpi. These results confirmed that pigs infected with T. spiralis predominantly induced Th2 and Treg immune responses, which suppress the Th1 immune responses. This study provides novel insights into the immune response of pigs infected with T. spiralis.

Targeting IL-17A Improves the Dysmotility of the Small Intestine and Alleviates the Injury of the Interstitial Cells of Cajal during Sepsis

Intestinal dysmotility is a frequent complication during sepsis and plays an important role in the development of secondary infections and multiple organ failure. However, the central mechanisms underlying this process have not been well elucidated. Currently, effective therapies are still lacking for the treatment of sepsis-induced intestinal dysmotility. In this study, we found that the activation of IL-17 signaling within the muscularis propria might be associated with dysmotility of the small intestine during polymicrobial sepsis. Furthermore, we demonstrated that targeting IL-17A partially rescued the motility of the small intestine and alleviated interstitial cells of Cajal (ICC) injury during sepsis. The blockade of IL-17A suppressed the dominant sepsis-induced infiltration of M1-polarized macrophages into the muscularis. Additionally, impaired ICC survival may be associated with the oxidative stress injury induced by dominant infiltration of M1-polarized macrophages. Our findings reveal the important role of the IL-17 signaling pathway in the small intestine during sepsis and provide clues for developing a novel therapeutic strategy for treating gastrointestinal dysmotility during sepsis.

Trichinella spiralis and Tumors: Cause, Coincidence or Treatment?

Background:

Conventional therapeutic strategies for tumors have had limited success, and innovative and more effective approaches to treatment are urgently required. The ancient idea that various biological, bacterial, yeast, viral, and para-sitic agents can be used as cancer therapeutics has gradually attracted considerable interest. Certain parasites have been widely discussed in association with human and animal tumors. The purpose of this review was to examine previous literatures which investigates the relations between Trichinella spiralis (T. spiralis) and tumors.

Methods:

Using PubMed, articles published before 2018 in the whole world have been searched and comprehensively re-viewed.

Results:

Many researches have provided proofs that T. spiralis possesses antitumor activities. The antitumor effect of T. spi-ralis was first described in the 1970s. However, its research has been inconsistent, and little progress has been made in this field. Therefore, the mechanisms underlying these inhibitory effects are still unclear, and convincing evidence of the links be-tween T. spiralis and the prevention or treatment of tumors from clinical trials is absent. Meanwhile, some other researches al-so suggested that T. spiralis may cause or contribute to coinfection with a tumors.

Conclusion:

The review has highlighted the scientific literature focussing on evidence for T. spiralis to act as a pro- or anti-tumorigenic agent is summarized and discussed, in hope of contributing to a better understanding of the relations between T. spiralis and tumors

TGFβ-activation by dendritic cells drives Th17 induction and intestinal contractility and augments the expulsion of the parasite Trichinella spiralis in mice

Helminths are highly prevalent metazoan parasites that infect over a billion of the world's population. Hosts have evolved numerous mechanisms to drive the expulsion of these parasites via Th2-driven immunity, but these responses must be tightly controlled to prevent equally devastating immunopathology. However, mechanisms that regulate this balance are still unclear. Here we show that the vigorous Th2 immune response driven by the small intestinal helminth Trichinella spiralis, is associated with increased TGFβ signalling responses in CD4+ T-cells. Mechanistically, enhanced TGFβ signalling in CD4+ T-cells is dependent on dendritic cell-mediated TGFβ activation which requires expression of the integrin αvβ8. Importantly, mice lacking integrin αvβ8 on DCs had a delayed ability to expel a T. spiralis infection, indicating an important functional role for integrin αvβ8-mediated TGFβ activation in promoting parasite expulsion. In addition to maintaining regulatory T-cell responses, the CD4+ T-cell signalling of this pleiotropic cytokine induces a Th17 response which is crucial in promoting the intestinal muscle hypercontractility that drives worm expulsion. Collectively, these results provide novel insights into intestinal helminth expulsion beyond that of classical Th2 driven immunity, and highlight the importance of IL-17 in intestinal contraction which may aid therapeutics to numerous diseases of the intestine.

Recombinant Haemonchus contortus 24 kDa excretory/secretory protein (rHcES-24) modulate the immune functions of goat PBMCs in vitro

A 24 kDa protein is one of the important components in Haemonchus contortus (barber pole worm) excretory/secretory products (HcESPs), which was shown to have important antigenic function. However, little is known about the immunomodulatory effects of this proteinon host cell. In the present study gene encoding 24kDa excretory/secretory protein (HcES-24) was cloned. The recombinant protein of HcES-24 (rHcES-24) was expressed in a histidine-tagged fusion protein soluble form in Escherichia coli. Binding activity of rHcES-24 to goat PBMCs was confirmed by immunofluorescence assay (IFA) and its immunomudulatory effect on cytokine secretion, cell proliferation, cell migration and nitric oxide production were observed by co-incubation of rHcES-24. IFA results revealed that rHcES-24 could bind to the PBMCs. The interaction of rHcES-24 increased the production of IL4, IL10, IL17 and cell migration in dose dependent manner. However, rHcES-24 treatment significantly suppressed the production of IFNγ, proliferation of the PBMC and Nitric oxide (NO) production. Our findings showed that the rHcES-24 played important regulatory effects on the goat PBMCs.

Beneficial effects of Rifaximin in post-infectious irritable bowel syndrome mouse model beyond gut microbiota

BACKGROUND AND AIMS

Rifaximin is a minimally absorbed antibiotic, which has shown efficacy in irritable bowel syndrome (IBS) patients. However, the mechanism on how it effects in IBS is still incompletely defined. In this study, Trichinella spiralis-infected post-infectious (PI) IBS mouse model was used, to assess the action of rifaximin on visceral hypersensitivity, barrier function, gut inflammation, and microbiota.

METHODS

Post-infectious IBS model was established by T. spiralis infection in mice. Rifaximin were administered to PI-IBS mice for seven consecutive days. The abdominal withdrawal reflex and threshold of colorectal distention were employed to evaluate visceral sensitivity. Smooth muscle contractile response was recorded in the organ bath. Intestinal permeability was measured by Ussing chamber. Expression of tight junction protein and cytokines were measured by Western blotting. Ilumina miseq platform was used to analyze bacterial 16S ribosomal RNA.

RESULTS

Post-infectious IBS mice treated with rifaximin exhibited decreased abdominal withdrawal reflex score, increased threshold, reduced contractile response, and intestinal permeability. Rifaximin also suppressed the expression of interleukin-12 and interleukin-17 and promoted the expression of the major tight junction protein occludin. Furthermore, rifaximin did not change the composition and diversity, and the study reavealed that rifaximin had a tiny effect on the relative abundance of Lactobacillus and Bifidobacterium in this PI-IBS model.

CONCLUSIONS

Rifaximin alleviated visceral hypersensitivity, recovered intestinal barrier function, and inhibited low-grade inflammation in colon and ileum of PI-IBS mouse model. Moreover, rifaximin exerts anti-inflammatory effects with only a minimal effect on the overall composition and diversity of the gut microbiota in this model.

Haemonchus contortus excretory and secretory proteins (HcESPs) suppress functions of goat PBMCs in vitro

Excretory and secretory products (ESPs) of nematode contain various proteins which are capable of inducing the instigation or depression of the host immune response and are involved in the pathogenesis of the worms. In the present study, Haemonchus contortus excretory and secretory products (HcESPs) were collected from the adult worms. Binding of HcESPs to goat peripheral blood mononuclear cells (PBMCs) was confirmed by immune-fluorescence assay. Effects of the HcESPs on cytokine production, cell proliferation, cell migration and nitric oxide (NO) production of PBMCs were checked by co-incubation of HcESPs with goat PBMCs. The results indicated that the production of IL-4 and IFN-γ were significantly decreased by HcESPs in dose dependent manner. On the contrary, the production of IL-10 and IL-17 were increased. Cell migration was significantly enhanced by HcESPs, whereas, HcESPs treatment significantly suppressed the cell proliferation and NO production. These results indicated that the HcESPs played important suppressive regulatory roles on PBMCs and provided highlights to the understanding of the host-parasite interactions.

Recombinant protein of Haemonchus contortus small GTPase ADP-ribosylation factor 1 (HcARF1) modulate the cell mediated immune response in vitro

ADP-ribosylation factors (ARFs) are members of the Ras-related small GTPase family involved in the vesicular trafficking regulation. Immunomodulatory effects of these proteinson host cell arenot being addressed yet. H. contortus small GTPase ADP-ribosylation 1 gene (HcARF1) was cloned and recombinant protein of HcARF1 (rHcARF1) was successfully expressed in Escherichia coli. Binding activity of rHcARF1 to goat PBMCs was confirmed by immunofluorescence assay (IFA) and its immunomudulatory effects on cytokine secretion, cell proliferation, cell migration and nitric oxide production (NO) were observed by co-incubation of rHcARF1. IFA results revealed that rHcARF1 could bind to the PBMCs. The interaction of rHcARF1 modulated the cytokine production, the production of IL-4, IL-10 and IL-17 was increased in a dose dependent manner, however, the IFN-γ production was significantly decreased. Cell migration and NO production were significantly increased by rHcARF1, whereas, rHcARF1 treatment significantly suppressed the proliferation of the PBMC in a dose dependent manner. Our findings showed that the rHcARF1 play important roles on the goat PBMCs.

Melatonin suppresses eosinophils and Th17 cells in hamsters treated with a combination of human liver fluke infection and a chemical carcinogen

BACKGROUND

The combination of Opisthorchis viverrini (OV) infection and chemical carcinogen induces cholangiocarcinoma (CCA) in hamsters via inflammation-mediated mechanisms. Thus, suppression of inflammatory cells at the initial stages of CCA development would be of benefit. We aimed to investigate whether IL-17-producing CD4+ T cells (Th17) and CD4+ Foxp3+ T cells (Treg) are involved in the early stages of CCA genesis and can be targeted for suppression by melatonin.

METHODS

Inflammation, an initial stage of CCA development, was induced in hamsters by a combination of O. viverrini infection and N-nitrosodimethylamine (NDMA) administration. Melatonin (50mg/kg) was additionally administered to one group for the 30days of the experiment. Liver tissue-resident T cells were investigated using immunostaining, western blotting, and real-time PCR.

RESULTS

OV+NDMA-induced CCA tissues showed significantly higher numbers of inflammatory cells, especially eosinophils, bile duct proliferation and IL-17+ cell infiltration compared to normal livers. Expression of Foxp3 was localized in the bile duct epithelial cells, and especially in the bile duct hyperplasia. Accumulation of CD4+ and IL-17+ cells and intense staining of the Foxp3+ marker were consistent with their protein levels. Infiltration of IL-17+ inflammatory cells and Foxp3+ cells, as well as increases in their transcription expression levels, were significantly lower in the melatonin-treated group. In contrast, increased CD4+ cell infiltration and TNF-α expression were also observed through melatonin treatment.

CONCLUSION

Melatonin exerts an immunomodulatory effect, suppressing eosinophils and Th17 cells and expression of Foxp3, but enhancing CD4+ cells and TNF-α. This suggests that melatonin may be used for CCA chemoprevention.

Recombinant protein of Haemonchus contortus 14-3-3 isoform 2 (rHcftt-2) decreased the production of IL-4 and suppressed the proliferation of goat PBMCs in vitro

14-3-3 proteins have been found to be an excreted/secreted antigen and assumed to be released into the host-parasite interface and described in several unicellular and multicellular parasites. However, little is known about the immunomodulatory effects of H. controtus 14-3-3 protein on host cell. In present study, 14-3-3 isoform 2 gene, designated as Hcftt-2, was amplified by reverse transcription-polymerase chain reaction (RT-PCR) from the adult H. contortus cDNA and cloned into expression plasmid pET32a (+) and expression of the recombinant protein (rHcftt-2) was induced by IPTG. Binding activity of rHcftt-2 to goat peripheral blood mononuclear cells (PBMCs) was confirmed by immunofluorescence assay (IFA) and modulatory effects on cytokine production, cell proliferation, cell migration and nitric oxide (NO) production were observed by co-incubation of rHcftt-2 with goat PBMCs. Sequence analysis showed that it had significant homology with the known 14-3-3 protein isoform 2. Results of IFA revealed that, the rHcftt-2 was bound to the cell surface. We found that, the productions of IL10, IL-17, IFN-γ and cell migration of PBMCs were increased after the cells were incubated with rHCftt-2. However, the productions of IL-4, NO and cell proliferation of the PBMCs were significantly decreased in dose depended manner. Our results showed that the Hcftt-2 played important suppressive regulatory effects on the goat PBMCs.

Induction of protection in murine experimental models againstTrichinella spiralis: an up-to-date review

The parasitic nematodeTrichinella spiralis, an aetiological agent of the disease known as trichinellosis, infects wild and domestic animals through contaminated pig meat, which is the major source forTrichinellatransmission. Prevention of this disease by interrupting parasite transmission includes vaccine development for livestock; however, major challenges to this strategy are the complexity of theT. spiralislife cycle, diversity of stage-specific antigens, immune-evasion strategies and the modulatory effect of host responses. Different approaches have been taken to induce protective immune responses byT. spiralisimmunogens. These include the use of whole extracts or excretory–secretory antigens, as well as recombinant proteins or synthesized epitopes, using murine experimental models for trichinellosis. Here these schemes are reviewed and discussed, and new proposals envisioned to block the zoonotic transmission of this parasite.

The Differentiation of CD4(+) T-Helper Cell Subsets in the Context of Helminth Parasite Infection

Helminths are credited with being the major selective force driving the evolution of the so-called “type 2” immune responses in vertebrate animals, with their size and infection strategies presenting unique challenges to the immune system. Originally, type 2 immune responses were defined by the presence and activities of the CD4⁺ T-helper 2 subset producing the canonical cytokines IL-4, IL-5, and IL-13. This picture is now being challenged by the discovery of a more complex pattern of CD4⁺ T-helper cell subsets that appear during infection, including Tregs, Th17, Tfh, and more recently, Th22, Th9, and ThGM. In addition, a clearer view of the mechanisms by which helminths and their products selectively prime the CD4⁺ T-cell subsets is emerging. In this review, we have focused on recent data concerning the selective priming, differentiation, and functional role of CD4⁺ T-helper cell subsets in the context of helminth infection. We argue for a re-evaluation of the original Th2 paradigm and discuss how the observed plasticity of the T-helper subsets may enable the parasitized host to achieve an appropriate compromise between elimination, tissue repair, containment, and pathology.

Are there any different effects of Bifidobacterium, Lactobacillus and Streptococcus on intestinal sensation, barrier function and intestinal immunity in PI-IBS mouse model?

Background and Aims

Research has increasingly suggested that gut flora plays an important role in the development of post-infectious irritable bowel syndrome (PI-IBS). Studies of the curative effect of probiotics for IBS have usually been positive but not always. However, the differences of treatment effects and mechanisms among probiotic stains, or mixture of them, are not clear. In this study, we compared the effects of different probiotics (Befidobacterium, Lactobacillus, Streptococcus or mixture of the three) on intestinal sensation, barrier function and intestinal immunity in PI-IBS mouse model.

Methods

PI-IBS model was induced by Trichinella spiralis infection in mice. Different probiotics were administered to mice after 8 weeks infection. Visceral sensitivity was measured by scores of abdominal withdrawal reflex (AWR) and the threshold intensity of colorectal distention. Colonic smooth muscle contractile response was assessed by contraction of the longitudinal muscle strips. Plasma diamine oxidase (DAO) and d-lactate were determined by an enzymatic spectrophotometry. Expression of tight junction proteins and cytokines in ileum were measured by Western blotting.

Results

Compared to control mice, PI-IBS mice treated either alone with Befidobacterium or Lactobacillus (but not Streptococcus), or the mixture of the three exhibited not only decreased AWR score and contractile response, but also reduced plasma DAO and D-lactate. These probiotic treatments also suppressed the expression of proinflammatory cytokine IL-6 and IL-17 and promoted the expression of major tight junction proteins claudin-1 and occludin. The mixture of the three probiotic strains performed better than the individual in up-regulating these tight junction proteins and suppressing IL-17 expression.

Conclusions

Bifidobacterium and Lactobacillus, but not Streptococcus, alleviated visceral hypersensitivity and recovered intestinal barrier function as well as inflammation in PI-IBS mouse model, which correlated with an increase of major tight junction proteins. In addition, Mixture of three species was indicated to be superior to a single one.

The role of T helper (TH)17 cells as a double-edged sword in the interplay of infection and autoimmunity with a focus on xenobiotic-induced immunomodulation

Extensive research in recent years suggests that exposure to xenobiotic stimuli plays a critical role in autoimmunity induction and severity and that the resulting response would be exacerbated in individuals with an infection-aroused immune system. In this context, heavy metals constitute a prominent category of xenobiotic substances, known to alter divergent immune cell responses in accidentally and occupationally exposed individuals, thereby increasing the susceptibility to autoimmunity and cancer, especially when accompanied by inflammation-triggered persistent sensitization. This perception is learned from experimental models of infection and epidemiologic studies and clearly underscores the interplay of exposure to such immunomodulatory elements with pre- or postexposure infectious events. Further, the T_H17 cell subset, known to be associated with a growing list of autoimmune manifestations, may be the “superstar” at the interface of xenobiotic exposure and autoimmunity. In this review, the most recently established links to this nomination are short-listed to create a framework to better understand new insights into T_H17's contributions to autoimmunity.

Mechanisms of smooth muscle responses to inflammation

BACKGROUND

Inflammation-induced changes in smooth muscle may be the consequence of changes in the properties of smooth muscle itself, in the control by nerves and hormones, in the microenvironment, or in the balance of constitutive or induced mediators. A general concept is that the specific characteristics and effects of inflammation can be linked to the nature of the infiltrate and the associated mediators, which are dictated predominantly by the immune environment. Inflammatory mediators may regulate smooth muscle function by directly acting on smooth muscle cells or, indirectly, through stimulation of the release of mediators from other cells. In addition, smooth muscle is not a passive bystander during inflammation and our knowledge of molecular signaling pathways that control smooth muscle function, and the contribution of the immune mechanisms to smooth muscle homeostasis, has expanded greatly in the last decade. Recent studies also demonstrated the relevance of extracellular proteases, of endogenous or exogenous origin, redox imbalance, or epigenetic mechanisms, to gastrointestinal dismotility and inflammation in the context of functional and organic disorders.

PURPOSE

In this review we discuss the various types of inflammation and the established and emerging mechansims of inflammation-induced changes in smooth muscle morphology and function.

Alteration of helper T-cell related cytokine production in splenocytes during Trichinella spiralis infection

Infection by Trichinella spiralis takes place in two distinct phases: one is the intestinal phase and the other is the muscle phase. To evaluate alterations in cytokine production during a T. spiralis infection, we periodically assessed the cytokine production of splenocytes in mice after infection (AI). The levels of Th2-related cytokines immediately increased after the initiation of T. spiralis larval intestinal invasion (1 week AI). These early elevations in the Th2 response might be associated with the innate immune responses of intestine epithelial cells against T. spiralis larval invasion. IL-4 and IL-13 levels reached a peak prior to the initiation of nurse cell formation (2 weeks AI). Additionally, all Th17-related cytokines, except for IL-17, increased slightly until 2 weeks AI. However, expression levels for all of the Th2 and Th17-related cytokines began to decrease after the initiation of nurse cell formation and reached basal levels at 4 weeks AI, except for IL-5. At the same time, the CD4(+)CD25(+)Foxp3(+) T (regulatory T, T(reg)) cell population increased significantly in the spleen. Additionally, the number of cells in the peripheral lymph nodes increased. In conclusion, T. spiralis larva intestinal invasion induced the production of Th2 and Th17 cell-related cytokines, and the cytokines decreased with T(reg) cell-related cytokine.

Evaluation of the immune response induced by DNA vaccines expressing MIF and MCD-1 genes ofTrichinella spiralisin BALB/c mice

Plasmids expressing macrophage migration inhibitory factor (MIF) ofTrichinella spiralis(TsMIF), multi-cystatin-like domain protein (MCD-1) ofT. spiralis(TsMCD-1), or co-expressingTsMIF andTsMCD-1 were constructed with a pVAX1 vector. Their ability to generate a protective immune response againstT. spiralisinfection was evaluated in BALB/c mice. Groups of mice were immunized twice at 2-week intervals with 100 μg of recombinant plasmids pVAX1-Tsmif, pVAX1-Tsmcd-1or pVAX1-Tsmif-Tsmcd-1. Control animals were immunized with phosphate-buffered saline (PBS) or blank vector plasmid. Specific antibody levels (IgG, IgG1, IgG2a, IgG2b, IgM, IgA, IgE) against the recombinant proteinTsMIF-TsMCD-1, serum cytokines (interferon (IFN)-γ, interleukin (IL)-4, IL-5, transforming growth factor (TGF)-β1 and IL-17) and CD4+/CD8+T cells were monitored. Challenge infection was performed 2 weeks following the second immunization and worm burden was assayed at 35 days post-challenge. Vaccination with pVAX1-Tsmifinduced moderate serum IFN-γ and increases of CD4+and CD8+T cells, but no specific immunoglobulin antibody response. Vaccination with pVAX1-Tsmcd-1induced a predominant Th1 antibody (IgG2a and IgG2b) response and strong levels of serum IFN-γ, and increases of CD4+T cells. Importantly, co-expression ofTsMIF andTsMCD-1 in DNA immunization produced more serum IFN-γ and markedly enhanced CD4+and CD8+T cells than the single DNA vaccine of the two genes. Challenge infection demonstrated that immunization with pVAX1-Tsmif-Tsmcd-1reduced worm burdens (by 23.17%;P < 0.05).

Cytokine-induced alterations of gastrointestinal motility in gastrointestinal disorders

Inflammation and immune activation in the gut are usually accompanied by alteration of gastrointestinal (GI) motility. In infection, changes in motor function have been linked to host defense by enhancing the expulsion of the infectious agents. In this review, we describe the evidence for inflammation and immune activation in GI infection, inflammatory bowel disease, ileus, achalasia, eosinophilic esophagitis, microscopic colitis, celiac disease, pseudo-obstruction and functional GI disorders. We also describe the possible mechanisms by which inflammation and immune activation in the gut affect GI motility. GI motility disorder is a broad spectrum disturbance of GI physiology. Although several systems including central nerves, enteric nerves, interstitial cells of Cajal and smooth muscles contribute to a coordinated regulation of GI motility, smooth muscle probably plays the most important role. Thus, we focus on the relationship between activation of cytokines induced by adaptive immune response and alteration of GI smooth muscle contractility. Accumulated evidence has shown that Th1 and Th2 cytokines cause hypocontractility and hypercontractility of inflamed intestinal smooth muscle. Th1 cytokines downregulate CPI-17 and L-type Ca²⁺ channels and upregulate regulators of G protein signaling 4, which contributes to hypocontractility of inflamed intestinal smooth muscle. Conversely, Th2 cytokines cause hypercontractilty via signal transducer and activator of transcription 6 or mitogen-activated protein kinase signaling pathways. Th1 and Th2 cytokines have opposing effects on intestinal smooth muscle contraction via 5-hydroxytryptamine signaling. Understanding the immunological basis of altered GI motor function could lead to new therapeutic strategies for GI functional and inflammatory disorders.

Low-grade inflammation plays a pivotal role in gastrointestinal dysfunction in irritable bowel syndrome

The pathogenesis of irritable bowel syndrome (IBS) is considered to be multifactorial and includes psychosocial factors, visceral hypersensitivity, infection, microbiota and immune activation. It is becoming increasingly clear that low-grade inflammation is present in IBS patients and a number of biomarkers have emerged. This review describes the evidence for low-grade inflammation in IBS and explores its mechanism with particular focus on gastrointestinal motor dysfunction. Understanding of the immunological basis of the altered gastrointestinal motor function in IBS may lead to new therapeutic strategies for IBS.

Trichinella inflammatory myopathy: host or parasite strategy?

The parasitic nematode Trichinella has a special relation with muscle, because of its unique intracellular localization in the skeletal muscle cell, completely devoted in morphology and biochemistry to become the parasite protective niche, otherwise called the nurse cell. The long-lasting muscle infection of Trichinella exhibits a strong interplay with the host immune response, mainly characterized by a Th2 phenotype.

The aim of this review is to illustrate the role of the Th2 host immune response at the muscle level during trichinellosis in different experimental models, such as knock-out or immuno-modulated mice. In particular, in knock-out mice a crucial role of IL-10 is evident for the regulation of inflammation intensity.

The muscular host immune response to Trichinella is partially regulated by the intestinal phase of the parasite which emphasizes the intensity of the following muscle inflammation compared with animals infected by synchronized injections of newborn larvae. In eosinophil-ablated mice such as PHIL and GATA-- animals it was observed that there was an increased NOS2 expression in macrophages, driven by higher IFN-γ release, thus responsible for muscle larva damage.

Besides modulation of the intestinal stage of the infection, using recombinant IL-12, increases the muscular parasite burden delaying adult worm expulsion from the intestine. Furthermore, a Th1 adjuvant of bacterial origin called Helicobacter pylori neutrophil activating protein (HP-NAP), administered during the intestinal phase of trichinellosis, alters the Th2 dependent response at muscle level.

All these data from the literature delineate then a mutual adaptation between parasite and host immune response in order to achieve a strategic compromise between two evolutionary forces pointed towards the survival of both species.

Low-grade inflammation plays a pivotal role in gastrointestinal dysfunction in irritable bowel syndrome

The pathogenesis of irritable bowel syndrome (IBS) is considered to be multifactorial and includes psychosocial factors, visceral hypersensitivity, infection, microbiota and immune activation. It is becoming increasingly clear that low-grade inflammation is present in IBS patients and a number of biomarkers have emerged. This review describes the evidence for low-grade inflammation in IBS and explores its mechanism with particular focus on gastrointestinal motor dysfunction. Understanding of the immunological basis of the altered gastrointestinal motor function in IBS may lead to new therapeutic strategies for IBS.