Salmonella serovar-specific interaction with jejunal epithelial cells

Olive Mill Waste-Water Extract Enriched in Hydroxytyrosol and Tyrosol Modulates Host-Pathogen Interaction in IPEC-J2 Cells

The dietary supplementation of olive oil by-products, including olive mill waste-water (OMWW) in animal diets, is a novel application that allows for their re-utilization and recycling and could potentially decrease the use of antibiotics, antimicrobial resistance risk in livestock species, and the occurrence of intestinal diseases. Salmonella serovar typhimurium is one of the most widespread intestinal pathogens in the world, causing enterocolitis in pigs. The aim of this study was to investigate the effect of an OMWW extract enriched in polyphenols (hydroxytyrosol and tyrosol) in the immune response of an intestinal porcine epithelial cell line (IPEC-J2) following S. typhimurium infection. Cells were pre-treated with OMWW-extract polyphenols (OMWW-EP, 0.35 and 1.4 µg) for 24 h and then infected with S. typhimurium for 1 h. We evaluated bacterial invasiveness and assayed IPEC-J2 gene expression with RT-qPCR and cytokine release with an ELISA test. The obtained results showed that OMWW-EP (1.4 µg) significantly reduced S. typhimurium invasiveness; 0.35 µg decreased the IPEC-J2 gene expression of IL1B, MYD88, DEFB1 and DEFB4A, while 1.4 µg down-regulated IL1B and DEFB4A and increased TGFB1. The cytokine content was unchanged in infected cells. This is the first study demonstrating the in vitro immunomodulatory and antimicrobial activity of OMWW extracts enriched in polyphenols, suggesting a protective role of OMWW polyphenols on the pig intestine and their potential application as feed supplements in farm animals such as pigs.

Salmonella Derby adaptation to swine and simultaneous attenuation for humans go through decay of Salmonella Pathogenicity Island I

IMPORTANCE

This study integrated population data with in vitro assessment of virulence phenotypes to unveil that a considerable part of the global population of Salmonella Derby is evolving to enhance its host adaptation to the swine host and that this evolution is simultaneously increasing its attenuation for humans. The study shows that the fixation of deleterious mutations in SPI-1 has a role in this process. This evidence indicates that SPI-1 has a key role for S. Derby virulence in humans but not for its circulation in swine. The results show that genes generally considered essential for Salmonella pathogenesis do not play the same key role for all Salmonella serovars or lineages and/or all hosts. The study helps in understanding the molecular mechanisms underlying the ecology and host adaptation of Salmonella showing that the adaptation process can vary for different types of Salmonella and hosts.

Animal models of Soft Tissue Sarcoma for alternative anticancer therapy studies: characterization of the A-72 Canine Cell Line

Canine Soft Tissue Sarcoma (STS) cell line A-72 has been largely employed for antiviral and antiproliferative studies. However, there are few information on their characteristics. Our aim was to evaluate A-72 expression level of genes and proteins involved in the innate immune response and cell cycle, their ability to respond to infective stressors and their possible use as a cellular model for anti-cancer studies in human and animal medicine. For this purpose, we evaluated the basal expression of immune-related, cell cycle and DNA repair genes on this cell line and tumoral tissues. A-72 ability to respond to a wild-type strain of Salmonella typhimurium was assessed. S. typhimurium showed ability to penetrate A-72 causing pro-inflammatory response accompanied by a decrease of cell viability. IL10 and IL18 genes were not expressed in A-72 while CXCL8, NOS2, CXCR4 and PTEN were highly expressed in all samples and TP53 was slightly expressed, as shown in human STS. Our results outline the ability of A-72 to respond to a bacterial agent by modifying the expression of important genes involved in innate immune response and provide a useful model for in vitro evaluation of new therapeutic approaches that could be translated into the human oncology.

Toll-like Receptors and Cytokine Modulation by Goat Milk Extracellular Vesicles in a Model of Intestinal Inflammation

Extracellular vesicles (EVs) are nanometric spherical structures, enclosed in a lipid bilayer membrane and secreted by multiple cell types under specific physiologic and pathologic conditions. Their complex cargo modulates immune cells within an inflammatory microenvironment. Milk is one of the most promising sources of EVs in terms of massive recovery, and milk extracellular vesicles (mEVs) have immunomodulatory and anti-inflammatory effects. The aim of this study was to characterize goat mEVs' immunomodulating activities on Toll-like receptors (TLRs) and related immune genes, including cytokines, using a porcine intestinal epithelial cell line (IPEC-J2) after the establishment of a pro-inflammatory environment. IPEC-J2 was exposed for 2 h to pro-inflammatory stimuli as a model of inflammatory bowel disease (IBD), namely LPS for Crohn's disease (CD) and H₂O₂ for ulcerative colitis (UC); then, cells were treated with goat mEVs for 48 h. RT-qPCR and ELISA data showed that cell exposure to LPS or H₂O₂ caused a pro-inflammatory response, with increased gene expression of CXCL8, TNFA, NOS2 and the release of pro-inflammatory cytokines. In the LPS model, the treatment with mEVs after LPS determined the down-regulation of NOS2, MMP9, TLR5, TGFB1, IFNB, IL18 and IL12A gene expressions, as well as lower release of IL-18 in culture supernatants. At the same time, we observed the increased expression of TLR1, TLR2, TLR8 and EBI3. On the contrary, the treatment with mEVs after H₂O₂ exposure, the model of UC, determined the increased expression of MMP9 alongside the decrease in TGFB1, TLR8 and DEFB1, with a lower release of IL-1Ra in culture supernatants. Overall, our data showed that a 48 h treatment with mEVs after a pro-inflammatory stimulus significantly modulated the expression of several TLRs and cytokines in swine intestinal cells, in association with a decreased inflammation. These results further highlight the immunomodulatory potential of these nanosized structures and suggest their potential application in vivo.

Goat milk extracellular vesicles: immuno-modulation effects on porcine monocyte-derived macrophages in vitro

Introduction

Extracellular vesicles (EVs) are nanometric-membrane-bound sub-cellular structures, which can be recovered from milk. Milk EVs have drawn increasing interest due to their potential biomedical applications, therefore it is important to investigate their impact on key immune cells, such as macrophages.

Methods

In this work, the immunomodulatory effects of goat milk EVs on untreated (moMФ) and classically activated (moM1) porcine monocyte-derived macrophages were investigated using flow cytometry, ELISA, and gene expression assays.

Results

These particles were efficiently internalized by macrophages and high doses (60 mg protein weight) triggered the upregulation of MHC I and MHC II DR on moMФ, but not on moM1. In moMФ, exposure to low doses (0.6 mg) of mEVs enhanced the gene expression of IL10, EBI3, and IFNB, whereas high doses up-regulated several pro-inflammatory cytokines. These nanosized structures slightly modulated cytokine gene expression on moM1. Accordingly, the cytokine (protein) contents in culture supernatants of moMФ were mildly affected by exposure to low doses of mEVs, whereas high doses promoted the increased release of TNF, IL-8, IL-1a, IL-1b, IL-1Ra, IL-6, IL-10, and IL-12. The cytokines content in moM1 supernatants was not critically affected.

Discussion

Overall, our data support a clinical application of these molecules: they polarized macrophages toward an M1-like phenotype, but this activation seemed to be controlled, to prevent potentially pathological over-reaction to stressors.

Heterogeneity of Phenotypic and Functional Changes to Porcine Monocyte-Derived Macrophages Triggered by Diverse Polarizing Factors In Vitro

Swine are attracting increasing attention as a biomedical model, due to many immunological similarities with humans. However, porcine macrophage polarization has not been extensively analyzed. Therefore, we investigated porcine monocyte-derived macrophages (moMΦ) triggered by either IFN-γ + LPS (classical activation) or by diverse "M2-related" polarizing factors: IL-4, IL-10, TGF-β, and dexamethasone. IFN-γ and LPS polarized moMΦ toward a proinflammatory phenotype, although a significant IL-1Ra response was observed. Exposure to IL-4, IL-10, TGF-β, and dexamethasone gave rise to four distinct phenotypes, all antithetic to IFN-γ and LPS. Some peculiarities were observed: IL-4 and IL-10 both enhanced expression of IL-18, and none of the "M2-related" stimuli induced IL-10 expression. Exposures to TGF-β and dexamethasone were characterized by enhanced levels of TGF-β2, whereas stimulation with dexamethasone, but not TGF-β2, triggered CD163 upregulation and induction of CCL23. Macrophages stimulated with IL-10, TGF-β, or dexamethasone presented decreased abilities to release proinflammatory cytokines in response to TLR2 or TLR3 ligands: IL-10 showed a powerful inhibitory activity for CXCL8 and TNF release, whereas TGF-β provided a strong inhibitory signal for IL-6 production. While our results emphasized porcine macrophage plasticity broadly comparable to human and murine macrophages, they also highlighted some peculiarities in this species.

Antimicrobial and Immunomodulatory Potential of Cow Colostrum Extracellular Vesicles (ColosEVs) in an Intestinal In Vitro Model

Extracellular Vesicles (EVs) are nano-sized double-lipid-membrane-bound structures, acting mainly as signalling mediators between distant cells and, in particular, modulating the immune response and inflammation of targeted cells. Milk and colostrum contain high amounts of EVs that could be exploited as alternative natural systems in antimicrobial fighting. The aim of this study is to evaluate cow colostrum-derived EVs (colosEVs) for their antimicrobial, anti-inflammatory and immunomodulating effects in vitro to assess their suitability as natural antimicrobial agents as a strategy to cope with the drug resistance problem. ColosEVs were evaluated on a model of neonatal calf diarrhoea caused by Escherichia coli infection, a livestock disease where antibiotic therapy often has poor results. Colostrum from Piedmontese cows was collected within 24 h of calving and colosEVs were immediately isolated. IPEC-J2 cell line was pre-treated with colosEVs for 48 h and then infected with EPEC/NTEC field strains for 2 h. Bacterial adherence and IPEC-J2 gene expression analysis (RT-qPCR) of CXCL8, DEFB1, DEFB4A, TLR4, TLR5, NFKB1, MYD88, CGAS, RIGI and STING were evaluated. The colosEVs pre-treatment significantly reduced the ability of EPEC/NTEC strains to adhere to cell surfaces (p = 0.006), suggesting a role of ColosEVs in modulating host−pathogen interactions. Moreover, our results showed a significant decrease in TLR5 (p < 0.05), CGAS (p < 0.05) and STING (p < 0.01) gene expression in cells that were pre-treated with ColosEVs and then infected, thus highlighting a potential antimicrobial activity of ColosEVs. This is the first preliminarily study investigating ColosEV immunomodulatory and anti-inflammatory effects on an in vitro model of neonatal calf diarrhoea, showing its potential as a therapeutic and prophylactic tool.

Assessment of the Impact of a Toll-like Receptor 2 Agonist Synthetic Lipopeptide on Macrophage Susceptibility and Responses to African Swine Fever Virus Infection

Toll-like receptor 2 (TLR2) ligands are attracting attention as prophylactic and immunopotentiator agents against pathogens, including viruses. We previously reported that a synthetic diacylated lipopeptide (Mag-Pam2Cys_P48) polarized porcine macrophages towards a proinflammatory antimicrobial phenotype. Here, we investigated its role in modulating monocyte-derived macrophage (moMΦ) responses against African swine fever virus (ASFV), the etiological agent of one of the greatest threats to the global pig industry. Two ASFV isolates were compared: the attenuated NH/P68 and the virulent 26544/OG10. No effect on virus infection nor the modulation of surface markers’ expression (MHC I, MHC II DR, CD14, CD16, and CD163) were observed when Mag-Pam2Cys_P48 treated moMΦ were infected using a multiplicity of infection (MOI) of 1. Mag-Pam2Cys_P48 treated moMΦ released higher levels of IL-1α, IL-1β, IL-1Ra, and IL-18 in response to infection with NH/P68 ASFV compared to 26544/OG10-infected and mock-infected controls. Surprisingly, when infected using a MOI of 0.01, the virulent ASFV 26544/OG10 isolate replicated even slightly more efficiently in Mag-Pam2Cys_P48 treated moMΦ. These effects also extended to the treatment of moMΦ with two other lipopeptides: Mag-Pam2Cys_P80 and Mag-Pam2Cys_Mag1000. Our data suggested limited applicability of TLR2 agonists as prophylactic or immunopotentiator agents against virulent ASFV but highlighted the ability of the virulent 26544/OG10 to impair macrophage defenses.

Molecular Characterization of CF33 Canine Cell Line and Evaluation of Its Ability to Respond against Infective Stressors in Sight of Anticancer Approaches

Simple Summary

Canine mammary cancer is very common and has many similarities with human breast cancer. Risk factors, physiological and pathological behaviors, and the clinical course in dogs are very similar to humans. Several molecular similarities have also been reported, such as overexpression of EGF, proliferation markers, metalloproteinase and cyclooxygenase, TP53 mutations, and CXCR4/SDF1 axis activation. These common characteristics make these breast tumors resistant to conventional therapies. It is therefore necessary to study therapeutic alternatives. Cell lines could be helpful to test in vitro immunomodulant anti-cancer therapies, allowing a reduction of laboratory animals’ involvement in the preliminary tests and achieving results in a shorter time. Although the canine mammary carcinoma cell line CF33 has been widely used in many studies on dog mammary cancer, characterization of its gene expression profile and of the influence of infective stressors of this cell line is poor. Our study shows the interaction of CF33 and Salmonella Typhimurium (ST) as an infective stressor, indicating that these cells may represent an in vitro model for assessing novel therapeutic approaches using bacteria.

Abstract

Spontaneous mammary tumors are the most frequent neoplasms in bitches and show similarities with human breast cancer in risk factors, clinical course, and histopathology. The poor prognosis of some cancer subtypes, both in human and dog, demands more effective therapeutic approaches. A possible strategy is the new anticancer therapy based on immune response modulation through bacteria or their derivatives on canine mammary carcinoma cell lines. The aim of the present study was to analyze the CF33 cell line in terms of basal expression of immune innate genes, CXCR4 expression, and interaction with infectious stressors. Our results highlight that CF33 maintains gene expression parameters typical of mammary cancer, and provides the basal gene expression of CF33, which is characterized by overexpression of CXCR4, CD44, RAD51, LY96, and a non-continuous expression of TP53 and PTEN. No mutations appeared in the CXCR4 gene until the 58th passage; this may represent important information for studying the CXCR4 pathway as a therapeutic target. Moreover, the CF33 cell line was shown to be able to interact with Salmonella Typhimurium (ST) (an infective stressor), indicating that these cells could be used as an in vitro model for developing innovative therapeutic approaches involving bacteria.

In vitro evaluation of immunomodulatory activities of goat milk Extracellular Vesicles (mEVs) in a model of gut inflammation

Gut represents a major immunological defense barrier with mucosal immune system and intestinal epithelial cells (IECs). In all intestinal diseases, in particular inflammatory bowel disease (IBD), both the absorption and the local immune system are compromised and alternative effective therapies are sought after. Extracellular Vesicles (EVs) have the capability to regulate immune cells within the inflammatory microenvironment, by dampening inflammation and restoring intestinal barrier integrity. Recently, the immune-modulatory role of EVs has also been confirmed for milk EVs (mEVs), notable for their easy production, high sample volumes, cost-effective scalable production and non-toxic and non-immunogenic behavior. In this context, the aim of this study was to evaluate goat mEV anti-inflammatory and immuno-modulating effects on an in vitro model (IPEC-J2) of intestinal inflammation through gene expression evaluation with RT-qPCR and cytokine release dosage with ELISA test. After the establishment of a pro-inflammatory environment due to LPS stimuli, IL6, CXCL8, IL12p35, IL12p40, IFNB, IL18, TLR7 and NOS2 resulted significantly up-regulated in stimulated IPEC-J2 cells compared to those of the basal culture. After 48 h of mEV treatment in inflamed IPEC-J2 a partial restoration of initial conditions was detected, with the IL18 and IL12p40 significant down-regulation, and IL12p35, EBI3, TLR7, BD1 and BD3 up-regulation. IL-18 reduced protein production was also detected in supernatants. Moreover, a decrease of MMP9 and NOS2 together with a strong up-regulation of MUC2 indicated a recovery of cellular homeostasis and, therefore, potential beneficial effects on the intestinal mucosa. Nevertheless, 48 h post-treatment, an increased gene expression and protein release of IL-8 was observed. This paper is one of the firsts to assess the effect of goat mEVs and the first one, in particular, of doing this on an in vitro model of gut inflammation. The obtained results show a potential capability of goat mEVs to modulate inflammation and to play beneficial effects on the intestinal mucosa.

Cadmium and wild boar: environmental exposure and immunological impact on macrophages

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Wild boar represents useful bioindicator for Cadmium environmental exposure.

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Cadmium can be absorbed by wild boar moMФ with subsequent cell viability decrease.

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Moderate cadmium concentration down-regulated IL-12p40, TNF-α expression in moMФ.

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Moderate cadmium concentration decreased antimicrobial molecules expression in moMФ.

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Moderate cadmium concentration down-regulated expression of several TLRs in moMФ.

Cadmium (Cd²⁺) is regarded as one of the most toxic heavy metals, which can enter the food chain through environmental contamination and be bioaccumulated. Its exposure in Ligurian wild boars was monitored between 2016–2020 and revealed high level of this heavy metal in different provinces. In one of these polluted area, 21 wild boars were additionally sampled and the relationship between hepatic and renal Cd²⁺ concentration suggested that majority of these animals presented chronic intoxication. Cd²⁺ exposure of wild boar might lead to an immunosuppression status, thus in vitro experiments on wild boar monocyte-derived macrophages (moMФ) were carried out. Effects of Cd²⁺ scalar doses were evaluated through viability and adsorption assays, ELISA, qPCR. Moderate doses of this environmental pollutant (20 μM) were absorbed by moMФ, with subsequent reduction of their viability. This heavy metal did not trigger release of either IFN- β, anti-inflammatory or pro-inflammatory cytokines by moMФ, instead 24 h treatment with 20 μM of Cd²⁺ resulted in down-regulated expression of TNF-α, IL-12p40, several TLRs, CD14, MD2, BD2, MyD88, p65, and NOS2. The results of our monitoring activity suggested that wild boar can be useful to monitor environmental exposure of this heavy metal and can help in understanding the type of contamination. In addition, in vitro experiments on wild boar moMФ revealed that Cd²⁺ exposure negatively affected the immune function of these cells, likely leading to increased susceptibility to infection.

In vitro study of chlorine dioxide on porcine intestinal epithelial cell gene markers

BACKGROUND

Chlorine dioxide (ClO₂ ) is an inorganic, potent biocide and is available in highly purified aqueous solution. It can be administered as an oral antiseptic in this form.

OBJECTIVES

Our aim is to determine the level of inflammatory markers and cytochrome genes expressed by enterocytes exposed to different concentrations of hyperpure chlorine dioxide solution.

METHODS

Porcine jejunal enterocyte cell (IPEC-J2) cultures were treated with the aqueous solution of hyper-pure chlorine dioxide of various concentrations. We determined the alterations in mRNA levels of inflammatory mediators, such as IL6, CXCL8/IL8, TNF, HSPA6 (Hsp70), CAT and PTGS2 (COX2); furthermore, the expression of three cytochrome genes (CYP1A1, CYP1A2, CYP3A29) were analysed by quantitative PCR method.

RESULTS

The highest applied ClO₂ concentration reduced the expression of all three investigated CYP genes. The gene expression of PTGS2 and CAT were not altered by most concentrations of ClO₂ . The expression of IL8 gene was reduced by all applied concentrations of ClO₂ . TNF mRNA level was also decreased by most ClO₂ concentrations used.

CONCLUSIONS

Different concentrations of chlorine dioxide exhibited immunomodulatory activity and caused altered transcription of CYP450 genes in porcine enterocytes. Further studies are needed to determine the appropriate ClO₂ concentration for oral use in animals.

Targeting Toll-Like Receptor 2: Polarization of Porcine Macrophages by a Mycoplasma-Derived Pam2cys Lipopeptide

Toll-like receptor 2 (TLR2) ligands are attracting increasing attention as prophylactic and immunotherapeutic agents against pathogens and tumors. We previously observed that a synthetic diacylated lipopeptide based on a surface protein of Mycoplasma agalactiae (Mag-Pam2Cys) strongly activated innate immune cells, including porcine monocyte-derived macrophages (moMΦ). In this study, we utilized confocal microscopy, flow cytometry, multiplex cytokine ELISA, and RT-qPCR to conduct a comprehensive analysis of the effects of scalar doses of Mag-Pam2Cys on porcine moMΦ. We observed enhanced expression of activation markers (MHC class I, MHC class II DR, CD25), increased phagocytotic activity, and release of IL-12 and proinflammatory cytokines. Mag-Pam2Cys also upregulated the gene expression of several IFN-α subtypes, p65, NOS2, and molecules with antimicrobial activities (CD14, beta defensin 1). Overall, our data showed that Mag-Pam2Cys polarized porcine macrophages towards a proinflammatory antimicrobial phenotype. However, Mag-Pam2Cys downregulated the expression of IFN-α3, six TLRs (TLR3, -4, -5, -7, -8, -9), and did not interfere with macrophage polarization induced by the immunosuppressive IL-10, suggesting that the inflammatory activity evoked by Mag-Pam2Cys could be regulated to avoid potentially harmful consequences. We hope that our in vitro results will lay the foundation for the further evaluation of this diacylated lipopeptide as an immunopotentiator in vivo.

Prevalence and Antimicrobial Resistances of Salmonella spp. Isolated from Wild Boars in Liguria Region, Italy

Salmonella spp. is an important zoonotic agent. Wild boars might host this pathogen in the intestinal tract and might represent a risk for Salmonella spp. transmission to humans. Wild boars are widely spread in Liguria, due to the environmental characteristics of the region. The aim of the study was the isolation, typing, and investigation of antimicrobial susceptibility of the isolated strains of Salmonella spp. During the 2013–2017 hunting seasons, 4335 livers of wild boars were collected and analyzed for the presence of Salmonella spp. A total of 260 strains of Salmonella spp. were isolated and characterized, with a prevalence of 6%. The isolated strains belonged to all six Salmonella enterica subspecies. Most of them were identified as Salmonella enterica subs. enterica of which 31 different serotypes were identified. The dominating serotype identified was S. Enteritidis. The antimicrobial resistance profiles of the isolated strains were analyzed against sixteen molecules. Of the isolated strains, 94.6% were resistant to at least one of the tested antimicrobials. This study showed the circulation of resistant Salmonella spp. strains in the wild boar population living in this area of Italy, underling the potential risk for these animals to disseminate this pathogen and its antimicrobial resistances.

Characterization of D-17 Canine Osteosarcoma Cell Line and Evaluation of Its Ability to Response to Infective Stressor Used as Alternative Anticancer Therapy

Simple Summary

Osteosarcoma (OSA) is the most common primary bone tumor both in dogs and in humans. Canine and human OSA share common characteristics making dogs a good model in comparative oncology. In the last years, in order to reduce animal testing, researchers shifted their attention to in vitro studies using cell lines. Aim of this work is to understand if cells obtained from canine metastatic pulmonary OSA can be a good model for cancer studies, both in humans and dogs. Results of this study were obtained by: the characterization of the expression of genes involved in the innate immune response, the sequencing of a single gene with a key role in immune response and the evaluation of the capacity of these cells to interact with microorganisms that can be used as alternative anticancer therapies. Obtained data were in agreement with those reported in literature regarding the expression of genes both in spontaneous tumors and in vitro cell lines. So, they confirmed the maintenance of cell line D-17 of the pulmonary metastatic OSA characteristics. The selected cells also demonstrated the ability to interact with the microorganism, this suggests that they may be a possible model for the preliminary evaluation of new therapeutic approaches based on the use of bacteria.

Abstract

Osteosarcoma (OSA) is a rare cancer both in human and dog although the incidence rate in dogs is 27 times higher than in human. Many studies employed D-17 as cell line for in vitro test to evaluate conventional anticancer therapies; however, little is known about D-17 cell line. The aim of our study was to evaluate the basal level of gene expression of pivotal molecules in the innate immune response and cell cycle regulation and to establish the ability of this cell line to react to Salmonella typhimurium (ST) infective stressor. IL15, IL10, iNOS, TLR5, CD14, PTEN and IL18 were expressed in an inconsistent manner among experiments. The other genes under study were expressed in all samples. ST showed ability to penetrate D-17 causing pro-inflammatory response. Our results outline the expression in D-17 of important genes involved in innate immune response. These results provide important data on D-17 basal gene expression profile useful for in vitro preliminary evaluation of new therapeutic approaches.

Yersinia enterocolitica-specific modulation of innate immune responses in jejunal epithelial cells

Gut is often subject to infection by different pathogens like Y. enterocolitica. To date, biotypes (BTs) 1A have been considered as non-pathogenic, because they do not express plasmid of virulence pYV; however, BTs 1A strains present other chromosomic virulence genes and recent studies suggest an implication of this microorganism in reactive arthritis. Although many studies highlighted the molecular basis of pathogenesis of Ye infection, scanty data are available about several environmental BTs 1A strains, often isolated in cases of foodborne disease but not included in pathogenicity studies. The aim of our work was to verify the ability of different Ye 1A strains to adhere and penetrate IPEC-J2 cells and to modulate intestinal innate immunity. Our results showed that all strains under study were able to adhere and penetrate enterocytes, causing inflammatory responses. Indeed, adhesion and invasion of enterocytes is an essential step in Ye pathogenesis (Fàbrega and Vila, 2012). Moreover, our data suggest the possible involvement of strains Ye2/O:9 in reactive arthritis, due to their ability (i) to penetrate enterocytes as pathogenic Ye1/O:8 strains do, and (ii) to increase IL-6, IL-8, IL-12 and IL-18 release. Lastly, our results confirm that IPEC-J2 cells are a very good model to evaluate host-pathogen interaction, and indicate IL-8, TNF-α, TLRs1 and 4 as possible markers of the ability of Ye strains to penetrate enterocytes. Moreover, we showed that Ye strains differently affect the host's innate immune responses.

IPEC-1 variable immune response to different serovars of Salmonella enterica subsp. enterica

Salmonella is a genus of Gram-negative bacteria in the Enterobacteriaceae family causing various illnesses. The ability of the different serovars of Salmonella enterica subsp. enterica to infect a host and to induce pathology relies in part on their cellular and molecular interactions with the intestinal epithelium. In the current study, an in vitro approach using non-polarized or polarized IPEC-1 porcine intestinal epithelial cells were used in order to assess the relation between adhesion, invasion, and induction of the immune response as a function of the serotype of Salmonella. Five serovars, Choleraesuis (host-adapted), Typhimurium (ubiquitous), Typhisuis (host-restricted), which are relevant for pig infection, and Dublin and Gallinarum, which are host-restricted or host-adapted, were studied. A strong variation was observed in the percentages of adhesion and invasion amongst the S. enterica serovars used to interact with the non-polarized and polarized cells. Subsequently, differences were identified between serovars in terms of immune response induced. Serovars Typhimurium and Typhisuis induced a strong innate immune response four and half hours after the beginning of cell stimulation while Choleraesuis, Gallinarum, and Dublin did not. A strong inflammatory response could limit the spread of the porcine serovars to the gut while, with a weak response, bacteria may not be constrained by the immune response enabling severe systemic diseases. Different repertoires of adhesion factors and of secreted protein effectors between Salmonella serovars interacting with IPEC-1 cells probably explains the differences in their early pathogenic behaviours.

Campylobacteriosis, Salmonellosis, Yersiniosis, and Listeriosis as Zoonotic Foodborne Diseases: A Review

Zoonoses are diseases transmitted from animals to humans, posing a great threat to the health and life of people all over the world. According to WHO estimations, 600 million cases of diseases caused by contaminated food were noted in 2010, including almost 350 million caused by pathogenic bacteria. Campylobacter, Salmonella, as well as Yersinia enterocolitica and Listeria monocytogenes may dwell in livestock (poultry, cattle, and swine) but are also found in wild animals, pets, fish, and rodents. Animals, often being asymptomatic carriers of pathogens, excrete them with faeces, thus delivering them to the environment. Therefore, pathogens may invade new individuals, as well as reside on vegetables and fruits. Pathogenic bacteria also penetrate food production areas and may remain there in the form of a biofilm covering the surfaces of machines and equipment. A common occurrence of microbes in food products, as well as their improper or careless processing, leads to common poisonings. Symptoms of foodborne infections may be mild, sometimes flu-like, but they also may be accompanied by severe complications, some even fatal. The aim of the paper is to summarize and provide information on campylobacteriosis, salmonellosis, yersiniosis, and listeriosis and the aetiological factors of those diseases, along with the general characteristics of pathogens, virulence factors, and reservoirs.

Impact of cadmium exposure on swine enterocytes

We tested cadmium (Cd2+) effects on porcine IPEC-J2 cells, which represent an in vitro model of the interaction between intestinal cells and both infectious and non-infectious stressors. Accordingly, we investigated the effects of low (2 μM) to moderate (20 μM) concentrations of Cd2+, in terms of pro-inflammatory gene expression and protein release, as well as of infectivity in a Salmonella typhimurium penetration model. Our data showed a significant (P < .001) increase of intracellular Cd2+ after 3, 6 and 24 h of exposure with respect to levels at 1 h. These data showed the ability of IPEC-J2 to absorb Cd2+ as a function of both time and concentration. Also, the absorption of this heavy metal was related to a significant modulation of important pro-inflammatory messengers. In particular, down-regulation of IL-8 was associated with a significant decrease of Salmonella typhimurium ability to penetrate into IPEC-J2 cells, in agreement with a previous study in which an anti-IL 8 antibody could significantly inhibit Salmonella penetration into the same cells (Razzuoli et al., 2017). This finding demonstrates the ability of Cd2+ to affect the outcome of an important host-pathogen relationship. In conclusion, our study highlighted the ability of an environmental pollutant like Cd2+ to modulate innate immune responses in terms of chemokine release and gene expression, and susceptibility to microbial infections.