Production and characterization of anti-porcine CXCL10 monoclonal antibodies.

Research on C-X-C motif chemokine ligand 10 (CXCL10) has been widely reported for humans and select animal species, yet immune reagents are limited for pig chemokines. Our goal is to provide veterinary immunologists and the biomedical community with new commercial immune reagents and standardized assays. Recombinant porcine CXCL10 (rPoCXCL10) protein was produced by yeast expression and used to generate a panel of α CXCL10 monoclonal antibodies (mAbs). All mAbs were assessed for cross-inhibition and reactivity to orthologous yeast expressed CXCL10 proteins. Characterization of a panel of nine α PoCXCL10 mAbs identified six distinct antigenic determinants. A sensitive quantitative sandwich ELISA was developed with anti-PoCXCL10-1.6 and -1.9 mAb; reactivity was verified with both rPoCXCL10 and native PoCXCL10, detected in supernatants of peripheral blood mononuclear cells stimulated with rPoIFNγ or PMA/Ionomycin. Immunostaining of in vitro rPoIFNγ stimulated pig spleen and blood cells verified CXCL10 + cells as CD3-CD4-CD172+, with occasional CD3-CD4 + CD172 + subsets. Comparison studies determined that α PoCXCL10-1.4 mAb was the ideal mAb clone for intracellular staining, whereas with α PoCXCL10-1.1 and -1.2 mAbs were best for immunohistochemistry analyses. These techniques and tools will be useful for evaluating swine immune development, responses to infectious diseases and vaccines, as well as for improving utility of pigs as an important biomedical model.

Bioactive functions of chlorogenic acid and its research progress in pig industry.

Chlorogenic acid (CGA), also known as 3-caffeioylquinic acid or coffee tannin, is a water-soluble polyphenol phenylacrylate compound produced through the shikimate pathway by plants during aerobic respiration. CGA widely exists in higher dicotyledons, ferns and many Chinese medicinal materials, and enjoys the reputation of 'plant gold'. Here, we summarized the source, chemical structure, biological activity functions of CGA and its research progress in pigs, aiming to provide a more comprehensive understanding and theoretical basis for the prospect of CGA replacing antibiotics as a pig feed additive.

The Competitive Endogenous RNA (ceRNA) Regulation in Porcine Alveolar Macrophages (3D4/21) Infected by Swine Influenza Virus (H1N1 and H3N2).

H1N1 and H3N2 are the two most common subtypes of swine influenza virus (SIV). They not only endanger the pig industry, but are also a huge risk of zoonotic diseases. However, the molecular mechanism and regulatory network of pigs (hosts) against influenza virus infection are still unclear. In this study, porcine alveolar macrophage cell (3D4/21) models infected by swine influenza virus (H1N1 and H3N2) were constructed. The expression profiles of miRNAs, mRNAs, lncRNAs and circRNAs after H1N1 and H3N2 infected 3D4/21 cells were revealed in this study. Then, two ceRNAs (TCONS_00166432-miR10391-MAN2A1 and novel_circ_0004733-miR10391-MAN2A1) that regulated H1N1 and H3N2 infection in 3D4/21 cells were verified by the methods of bioinformatics analysis, gene overexpression, gene interference, real-time quantitative PCR (qPCR), dual luciferase activity assay and RNA immunoprecipitation (RIP). In addition, the important candidate molecules (miR-10391, TCONS_00166432, and novel_circ_0004733) were identified by qPCR and enzyme linked immunosorbent assay (ELISA). Finally, the regulatory effect and possible molecular mechanism of the target gene MAN2A1 were identified by the methods of gene interference, qPCR, Western blot and ELISA. The results of this study suggested that TCONS_00166432 and novel_circ_0004733 could competitively bind miR-10391 to target the MAN2A1 gene to regulate swine influenza virus infecting 3D4/21 cells. This study reported for the first time the ceRNA networks involved in the regulation of the swine influenza virus infecting 3D4/21 cells, which provided a new insight into the molecular mechanism of 3D4/21 cells against swine influenza virus infection.

New Insight into the Molecular Mechanism of the FUT2 Regulating Escherichia coli F18 Resistance in Weaned Piglets.

Escherichia coli (E. coli) F18 is the main pathogen responsible for post-weaning diarrhea (PWD) in piglets. Resistance to E. coli F18 depends on the expression of the cognate receptors in the intestinal epithelial cells. However, the molecular mechanism of E. coli F18 resistance in weaned piglets remains unclear. Here, we performed a comparative transcriptome study of the duodenal tissue from Sutai E. coli F18 sensitive and resistant pigs by RNA-seq, and pig α(1,2) fucosyltransferase 2 (FUT2) was identified as a host differentially expressed gene controlling the E. coli F18 infection. Function analysis showed that the FUT2 expression was high in the duodenum and jejunum, with higher levels detected in sensitive individuals than in resistant individuals (p < 0.01). Expression levels of FUT2 were upregulated in IPEC-J2 cells after lipopolysaccharide (LPS)-induction or E. coli stimulation. FUT2 knockdown decreased the adhesion of E. coli F18 to IPEC-J2 cells (p < 0.05). FUT2 overexpression markedly increased the adhesion of E. coli F18 to IPEC-J2 cells (p < 0.05 or p < 0.01). Furthermore, the FUT2 mRNA levels correlated with methylation levels of the mC-22 site in the specificity protein 1 (Sp1) transcription factor (p < 0.05). Electrophoretic mobility shift assays (EMSA) showed that Sp1 interacts with the wild-type FUT2 promoter DNA, but not with methylated DNA. Our data suggested that FUT2 methylation at the mC-22 site inhibits Sp1 binding to the FUT2 promoter, thereby reducing FUT2 expression and enhancing E. coli F18 resistance in weaned piglets. These observations highlight FUT2 as a promising new target for combating E. coli F18 susceptibility in weaned piglets.

Berberine alleviates inflammation in polycystic ovary syndrome by inhibiting hyaluronan synthase 2 expression.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a heterogeneous metabolic and endocrine disorder that causes anovulatory infertility and abnormal folliculogenesis in women of reproductive age. Several studies have revealed inflammation in PCOS follicles, and recent evidence suggests that Berberine (BBR) effectively reduces inflammatory responses in PCOS, however, the underlying mechanisms remain unclear. PURPOSE: To determine the underlying mechanisms by which BBR alleviates inflammation in PCOS. STUDY DESIGN: Primary human GCs from healthy women and women with PCOS, and KGN cells were used for in vitro studies. ICR mice were used for in vivo studies. METHODS: Gene expression was measured using RT-qPCR. HAS2, inflammatory cytokines, and serum hormones were assayed by ELISA. Protein expression profiles were assayed by Western blot. Chronic low-grade inflammatory mouse models were developed by intraperitoneal injection with LPS, and PCOS mouse models were established by subcutaneous intraperitoneal injection of DHEA. BBR and 4-MU were administered by gavage. Ovarian morphologic changes were evaluated using H&E staining. HAS2 expression in the ovary was assayed using Western blot and immunohistochemistry. RESULTS: Our results confirmed that HAS2 expression and hyaluronan (HA) accumulation are closely associated with inflammatory responses in PCOS. Data obtained from in vitro studies showed that HAS2 and inflammatory genes (e.g., MCP-1, IL-1ß, and IL-6) are significantly upregulated in PCOS samples and LPS-induced KGN cells compared to their control groups. In addition, these effects were reversed by blocking HAS2 expression or HA synthesis using BBR or 4-MU, respectively. Furthermore, HAS2 overexpression induces the expression of inflammatory genes in PCOS. These results were further confirmed in LPS- and DHEA-induced mouse models, where inflammatory genes were reduced by BBR or 4-MU, and ovarian morphology was restored. CONCLUSIONS: Our results define previously unknown links between HAS2 and chronic low-grade inflammation in the follicles of women with PCOS. BBR exerts its anti-inflammatory effects by down-regulating HAS2. This study provides a novel therapeutic target for alleviating ovarian inflammation in women with PCOS.

Lipopolysaccharide accelerates tryptophan degradation in the ovary and the derivative kynurenine disturbs hormone biosynthesis and reproductive performance.

Lipopolysaccharide (LPS), also known as endotoxin, is a component of the outer membrane of gram-negative bacteria. LPS is released into the surrounding environment during bacterial death and lysis. Due to its chemical and thermal stability, LPS can be detected anywhere and easily exposed to humans and animals. Previous studies have shown that LPS causes hormonal imbalances, ovarian failure, and infertility in mammals. However, the potential mechanisms remain unclear. In this study, we investigated the effects and mechanisms of LPS on tryptophan degradation, both in vivo and in vitro. The effects of kynurenine, a tryptophan derivative, on granulosa cell function and reproductive performance were explored. Results showed that p38, NF-κB, and JNK signaling pathways were involved in LPS-induced Ido1 expressions and kynurenine accumulation. Furthermore, the kynurenine decreased estradiol production, but increased granulosa cell proliferation. In vivo, experiments showed that kynurenine decreased estradiol and FSH production and inhibited ovulation and corpus luteum formation. Additionally, pregnancy and offspring survival rates decreased considerably after kynurenine treatment. Our findings suggest that kynurenine accumulation disrupts hormone secretion, ovulation, corpus luteal formation, and reproductive performance in mammals.

Development and characterization of a novel human CD137 agonistic antibody with anti-tumor activity and a good safety profile in non-human primates.

CD137 (4-1BB, TNFRSF9), an inducible T-cell costimulatory receptor, is expressed on activated T cells, activated NK cells, Treg cells, and several innate immune cells, including DCs, monocytes, neutrophils, mast cells, and eosinophils. In animal models and clinical trials, anti-CD137 agonistic monoclonal antibodies have shown anti-tumor potential, but balancing the efficacy and toxicity of anti-CD137 agonistic monoclonal antibodies is a considerable hindrance for clinical applications. Here, we describe a novel fully human CD137 agonistic antibody (PE0116) generated from immunized harbor H2L2 human transgenic mice. PE0116 is a ligand blocker, which is also the case for Utomilumab (one of the leading CD137 agonistic drugs); PE0116 partially overlaps with Urelumab's recognized epitope. In vitro, PE0116 activates NF-κB signaling, significantly promotes T-cell proliferation, and increases cytokine secretion in the presence of cross-linking. Importantly, PE0116 possesses robust anti-tumor activity in the MC38 tumor model. In vivo, PE0116 exhibits a good safety profile and has typical pharmacokinetic characteristics of an IgG antibody in preclinical studies of non-human primates. In summary, PE0116 is a promising anti-CD137 antibody with a good safety profile in preclinical studies.

Development of a fully human anti-GITR antibody with potent antitumor activity using H2L2 mice.

Glucocorticoid-induced TNF receptor-related (GITR) can act as a co-stimulatory receptor, representing a potential target for safely enhancing immunotherapy efficacy. GITR is triggered by a GITR ligand or an agonist antibody and activates CD8+ and CD4+ effector T cells, reducing tumor-infiltrating Treg numbers and resulting in activation of immune responses and tumor cell destruction by effector T cells. GITR is an attractive target for immunotherapy, especially in combination therapy with immune checkpoint inhibitors, as is being explored in clinical trials. Using H2L2 transgenic mice encoding the human immunoglobulin variable region and hybridoma technology, we generated a panel of fully human antibodies that showed excellent specific affinity and strong activation of human T cells. After conversion to fully human antibodies and engineering modification, we obtained an anti-GITR antibody hab019e2 with enhanced antitumor activity in a B-hGITR MC38 mouse model compared to Tab9H6V3, an anti-GITR antibody that activates T cells and inhibits Treg suppression from XenoMouse. As a fully human antibody with its posttranslational modification hot spot removed, the hab019e2 antibody exerted more potent therapeutic effects, and may have potential as a novel and developable antibody targeting GITR for follow-up drug studies.

Generation and characterization of a high-affinity chimeric anti-OX40 antibody with potent antitumor activity.

OX40 is a costimulatory molecule that belongs to the tumor necrosis factor receptor (TNFR) superfamily. OX40 agonist-based combinations are emerging as promising candidates for novel cancer immunotherapy. Clinical trials have shown that OX40 agonist antibodies could lead to better results in cancer patients. Using a hybridoma platform and three different types of immunization strategies, namely recombinant protein, DNA, and overexpressing cells, we identified a chimeric anti-OX40 antibody (mAb035-hIgG1 from DNA immunization) that shows excellent binding specificity, and slightly stronger activation of human memory CD4+ T cells and similar potent antitumor activity compared with BMS 986178, an anti-OX40 antibody currently being evaluated for the treatment of solid tumors. This paper further systematically investigates the antigen-specific immune response, the number of binders, epitope bins, and functional activities of antibodies among different immunization strategies. Interestingly, we found that different immunization strategies affect the biological activity of monoclonal antibodies.

Importance of the pig as a human biomedical model.

Pigs have substantial potential as biomedical models for studying human developmental processes, congenital diseases, and pathogen response mechanisms in addition to utility as xenotransplant organ donors and tools for vaccine and drug design. The similarity of pigs to humans in anatomical size and structure, physiology, immunology, and genome enhances their potential as models for humans. Hence, it is imperative that research is relevant and reproducible in animal models that more closely resemble humans, such as the pig. This review summarizes the current status of pigs as an investigative model for humans and highlights their future applications.

Preclinical efficacy and toxicity studies of a highly specific chimeric anti-CD47 antibody.

Cluster of differentiation 47 (CD47) is a widely expressed self-protection transmembrane protein that functions as a critical negative regulator to induce macrophage-mediated phagocytosis. Overexpression of CD47 enables cancer cells to escape immune surveillance and destruction by phagocytes both in solid tumours and leukaemia. The usefulness of anti-CD47 antibody has been demonstrated in multiple immunotherapies associated with macrophages. However, antigen sinks and toxicity induced by inadvertent binding to normal cells restrict its clinical applications. Here, a novel anti-human CD47 antibody, 4D10, was generated, and its variable regions were grafted onto a human IgG4 scaffold. Compared with the anti-CD47 antibody Hu5F9, the resulting chimeric antibody (c4D10) has consistently demonstrated good tolerance in in vitro and in vivo toxicity studies. Additionally, c4D10 showed effective therapeutic potential through inducing the eradication of human cancer cells. Thus, c4D10 is a promising candidate therapeutic antibody with higher efficacy and reduced side effects compared to earlier antibodies, and its use may reduce the dose-limiting toxicity of CD47 antagonists for immunotherapy.

miR-215 Targeting Novel Genes EREG, NIPAL1 and PTPRU Regulates the Resistance to E.coli F18 in Piglets.

Previous research has revealed that miR-215 might be an important miRNA regulating weaned piglets' resistance to Escherichia coli (E. coli) F18. In this study, target genes of miR-215 were identified by RNA-seq, bioinformatics analysis and dual luciferase detection. The relationship between target genes and E. coli infection was explored by RNAi technology, combined with E. coli stimulation and enzyme linked immunosorbent assay (ELISA) detection. Molecular regulating mechanisms of target genes expression were analyzed by methylation detection of promoter regions and dual luciferase activity assay of single nucleotide polymorphisms (SNPs) in core promoter regions. The results showed that miR-215 could target EREG, NIPAL1 and PTPRU genes. Expression levels of three genes in porcine intestinal epithelial cells (IPEC-J2) in the RNAi group were significantly lower than those in the negative control pGMLV vector (pGMLV-NC) group after E. coli F18 stimulation, while cytokines levels of TNF-α and IL-1ß in the RNAi group were significantly higher than in the pGMLV-NC group. Variant sites in the promoter region of three genes could affect their promoter activities. These results suggested that miR-215 could regulate weaned piglets' resistance to E. coli F18 by targeting EREG, NIPAL1 and PTPRU genes. This study is the first to annotate new biological functions of EREG, NIPAL1 and PTPRU genes in pigs, and provides a new experimental basis and reference for the research of piglets disease-resistance breeding.

Regulation and Molecular Mechanism of TLR5 on Resistance to Escherichia coli F18 in Weaned Piglets.

Toll-like receptor 5 (TLR5) plays an important role in immune system. In this study, we performed transcriptome analysis of the duodenum in E. coli F18-resistant and -sensitive Sutai weaned piglets and analyzed the differential expression of TLR5. The cellular localization of TLR5 was investigated, and the effect of TLR5 expression on E. coli invasion was evaluated after pig small intestinal epithelial cell lines (IPEC-J2) were stimulated by E. coli. The results showed that TLR5 expression level in duodenum and jejunum were significantly higher in E. coli F18-sensitive than in E. coli F18-resistant piglets. TLR5 protein was mainly expressed in the cytoplasm and cell membrane. The expression of genes associated with the TLR5 signaling pathway were significantly higher in TLR5-overexpressed cells than in control cells. Bacterial adhesion was higher in TLR5-overexpressed cells than in blank cells and lower in TLR5 interference than in blank cells. The core promoter region of TLR5 included two CpG islands and 16 acting elements. The methylation of the mC-6 site in the second CpG island of the promoter region had a regulatory effect on TLR5 expression. Therefore, TLR5 plays an important regulatory role on E. coli invasion. Low expression of TLR5 inhibited the immune response and decreased cell damage, which was conducive to the resistance to E. coli stimulation. In conclusion, this study preliminarily revealed the molecular mechanism of TLR5 gene regulating the resistance of piglets to Escherichia coli, and provided a new candidate gene for screening Escherichia coli resistance markers in pigs.

Insight into the molecular mechanism of miR-192 regulating Escherichia coli resistance in piglets.

MicroRNAs (miRNAs) have important roles in many cellular processes, including cell proliferation, growth and development, and disease control. Previous study demonstrated that the expression of two highly homologous miRNAs (miR-192 and miR-215) was up-regulated in weaned piglets with Escherichia coli F18 infection. However, the potential molecular mechanism of miR-192 in regulating E. coli infection remains unclear in pigs. In the present study, we analyzed the relationship between level of miR-192 and degree of E. coli resistance using transcription activator-like effector nuclease (TALEN), in vitro bacterial adhesion assays, and target genes research. A TALEN expression vector that specifically recognizes the pig miR-192 was constructed and then monoclonal epithelial cells defective in miR-192 were established. We found that miR-192 knockout led to enhance the adhesion ability of the E. coli strains F18ab, F18ac and K88ac, meanwhile increase the expression of target genes (DLG5 and ALCAM) by qPCR and Western blotting analysis. The results suggested that miR-192 and its key target genes (DLG5 and ALCAM) could have a key role in E. coli infection. Based on our findings, we propose that further investigation of miR-192 function is likely to lead to insights into the molecular mechanisms of E. coli infection.

Porcine CD14 gene silencing partially inhibited the bacterial immune response mediated by TLR4 signaling pathway.

Cluster of differentiation antigen 14 (CD14) is the membrane receptor protein in Toll-like Receptor 4 (TLR4) signaling pathway, which plays an important regulation role in not only innate immune response but also adaptive immune response. In this study, the pig kidney epithelial cell (PK15) line with CD14 gene silencing mediated by lentivirus was established and cells of CD14-RNAi and NC group were exposed to three kinds of Escherichia coli (E. coli F18ab, E. coli F18ac and E. coli K88ac) and LPS. Then qPCR and western blot were used to detect expression levels of TLR4 signaling pathway-related genes. Finally, ELISA was used to detect the level of proinflammatory cytokines in the cell culture supernatant. The results showed that the expression level of TLR4 signaling pathway-related genes in the entire signal pathway had obvious increases when cells were exposed to the stimulation induced by E. coli and LPS. In addition, the expression levels of CD14-RNAi group were overall significantly lower than NC group (P<0.05 or P<0.01), which was the same with the release levels of proinflammatory cytokines. This study revealed that pig CD14 gene silencing partially inhibited immune response to E. coli F18 invasion mediated by TLR4 signaling pathway.

Correlation between the methylation of the FUT1 promoter region and FUT1 expression in the duodenum of piglets from newborn to weaning.

Alpha-(1,2)-fucosyltransferase (FUT1) gene has some influence on economically important traits and disease resistance. DNA methylation plays an important role in human diseases but is relatively poorly studied in pigs by regulating the mRNA expression of genes. The aim of this study was to analyze the influence of promoter methylation on the expression of FUT1 gene. We used bisulfite sequencing PCR (BSP) and qPCR to analyze the methylation of the FUT1 5'-flanking region and FUT1 mRNA expression in the duodenum of Sutai piglets from newborn to weaning. FUT1 contains three CpG islands upstream of the start codon, of which two are located in the putative promoter region containing multiple promoter elements and transcription factor binding sites, such as CpG islands, a CAAT box, SP1, and EARLY-SEQ 1. The CpG island between nucleotides -1762 and -580 had a low degree of methylation, and its methylation level was significantly lower in 35-day-old piglets than 8- and 18-day-old piglets (P < 0.05). FUT1 mRNA expression was significantly higher in 35-day-old piglets than 8- and 18-day-old piglets (P < 0.05). Pearson's correlation analysis showed that the methylation of the CpG island between nucleotides -1762 and -580 of FUT1 was significantly, negatively correlated with FUT1 mRNA expression (P < 0.05). These results demonstrate that differential methylation of CpG islands negatively regulates the expression of FUT1 in the porcine duodenum, suggesting a probable influence on the resistance of piglets to infection with ETEC F18.

Effects of porcine MyD88 knockdown on the expression of TLR4 pathway-related genes and proinflammatory cytokines.

As a critical adapter protein in Toll-like receptor (TLR)/Interleukin (IL)-1R signalling pathway, myeloid differentiation protein 88 (MyD88) plays an important role in immune responses and host defence against pathogens. The present study was designed to provide a foundation and an important reagent for the mechanistic study of MyD88 and its role TLR/IL-1R signalling pathways in porcine immunity. Lentivirus-mediated RNAi was used to generate a porcine PK15 cell line with a silenced MyD88 gene and quantitative real-time PCR (qPCR) and Western blotting were used to detect changes in the expression of critical genes in the Toll-like receptor 4 (TLR4) signalling pathway. ELISA was used to measure the levels of seven proinflammatory cytokines-interleukin-1ß (IL-1ß), tumour necrosis factor-α (TNF-α), IL-6, IL-8, IL-12, macrophage inflammatory protein (MIP)-1α and MIP-1ß-in cell culture supernatants after MyD88 silencing. We successfully obtained a PK15 cell line with 61% MyD88 mRNA transcript down-regulated. In PK15 cells with MyD88 silencing, the transcript levels of TLR4 and IL-1ß were significantly reduced, whereas there were no significant changes in the expression levels of cluster of differentiation antigen 14 (CD14), interferon-α (IFN-α) or TNF-α The ELISA results showed that the levels of most cytokines were not significantly changed apart from IL-8 without stimulation, which was significantly up-regulated. When cells were induced by lipopolysaccharide (LPS) (0.1 µg/ml) for 6 h, the global level of seven proinflammatory cytokines up-regulated and the level of IL-1ß, TNF-α, IL-6, IL-8 and IL-12 of Blank and negative control (NC) group up-regulated more significantly than RNAi group (P<0.05), which revealed that the MyD88 silencing could reduce the TLR4 signal transduction which inhibited the release of proinflammatory cytokines and finally leaded to immunosuppression.

Effects of the -791(C→T) mutation in the promoter for tumor necrosis factor alpha on gene expression and resistance of Large White pigs to enterotoxigenic Escherichia coli F18.

Tumor necrosis factor alpha (TNF-α) plays an important role in the immune system. In this study, TNF-α expression was analyzed in 11 tissues of 8 piglets resistant to enterotoxigenic Escherichia coli (ETEC) F18 and 8 ETEC F18-susceptible piglets from the Large White breed. The expression levels of TNF-α were high in immune organs (spleen, lung, thymus, and lymph nodes). The levels were higher in ETEC F18-resistant piglets than in ETEC F18-susceptible piglets, with significant differences in spleen, kidney, thymus, lymph node, and duodenum (P < 0.05). The mutation TNF-α -791(C→T) and 3 genotypes (CC, CT, and TT) were identified. The TNF-α expression levels in the spleen, kidney, lymph nodes, and duodenum were significantly higher in the TT pigs than in the CC pigs (P < 0.05). Thus, TNF-α -791(C→T) has significant effects on mRNA expression and may regulate ETEC F18 resistance of weaning piglets. Therefore, the -791(C→T) mutation of the TNF-α gene could be considered an important potential genetic marker of ETEC F18 resistance.

Le facteur alpha nécrosant des tumeurs (TNF-α) joue un rôle important dans le système immunitaire. Dans la présente étude, l'expression de TNF-α a été analysée dans 11 tissus provenant de huit porcelets résistants à une souche d'Escherichia coli entérotoxinogène (ETEC) F18 et huit porcelets sensibles à une souche ETEC F18 de race Large White. Les degrés d'expression de TNF-α étaient élevés dans les organes immunitaires (rate, poumon, thymus, et noeuds lymphatiques). Les niveaux étaient plus élevés chez les porcelets résistants à la souche ETEC F18 que chez les porcelets sensibles à la souche ETEC F18, avec des différences significatives dans la rate, rein, thymus, noeud lymphatique, et duodénum (P < 0,05). La mutation TNF-α ­791(C→T) et 3 génotypes (CC, CT, et TT) ont été identifiés. Les niveaux d'expression de TNF-α dans la rate, rein, noeuds lymphatiques, et duodénum étaient significativement plus élevés dans les porcs TT que dans les porcs CC (P < 0,05). Ainsi, TNF-α −791(C→T) avait des effets significatifs sur l'expression d'ARNm et pourrait réguler la résistance envers ETEC F18 chez des porcelets au sevrage. Ainsi, la mutation −791(C→T) du gène du TNF-α pourrait être considérée comme un important marqueur génétique potentiel de la résistance envers les ETEC F18.(Traduit par Docteur Serge Messier).