Cellular and molecular characteristics of stromal Lkb1 deficiency-induced gastrointestinal polyposis based on single-cell RNA sequencing.

Liver kinase B1 (Lkb1), encoded by serine/threonine kinase (Stk11), is a serine/threonine kinase and tumor suppressor that is strongly implicated in Peutz-Jeghers syndrome (PJS). Numerous studies have shown that mesenchymal-specific Lkb1 is sufficient for the development of PJS-like polyps in mice. However, the cellular origin and components of these Lkb1-associated polyps and underlying mechanisms remain elusive. In this study, we generated tamoxifen-inducible Lkb1flox/flox;Myh11-Cre/ERT2 and Lkb1flox/flox;PDGFRα-Cre/ERT2 mice, performed single-cell RNA sequencing (scRNA-seq) and imaging-based lineage tracing, and aimed to investigate the cellular complexity of gastrointestinal polyps associated with PJS. We found that Lkb1flox/+;Myh11-Cre/ERT2 mice developed gastrointestinal polyps starting at 9 months after tamoxifen treatment. scRNA-seq revealed aberrant stem cell-like characteristics of epithelial cells from polyp tissues of Lkb1flox/+;Myh11-Cre/ERT2 mice. The Lkb1-associated polyps were further characterized by a branching smooth muscle core, abundant extracellular matrix deposition, and high immune cell infiltration. In addition, the Spp1-Cd44 or Spp1-Itga8/Itgb1 axes were identified as important interactions among epithelial, mesenchymal, and immune compartments in Lkb1-associated polyps. These characteristics of gastrointestinal polyps were also demonstrated in another mouse model, tamoxifen-inducible Lkb1flox/flox;PDGFRα-Cre/ERT2 mice, which developed obvious gastrointestinal polyps as early as 2-3 months after tamoxifen treatment. Our findings further confirm the critical role of mesenchymal Lkb1/Stk11 in gastrointestinal polyposis and provide novel insight into the cellular complexity of Lkb1-associated polyp biology. © 2024 The Pathological Society of Great Britain and Ireland.

Myeloid SENP3 deficiency protects mice from diet and age-induced obesity via regulation of YAP1 SUMOylation.

Obesity is characterized by chronic low-grade inflammation, which is driven by macrophage infiltration in adipose tissue and leads to elevated cytokines such as interleukin-1ß (IL-1ß) in the circulation and tissues. Previous studies demonstrate that SENP3, a redox-sensitive SUMO2/3-specific protease, is strongly implicated in the development and progression of cancer and cardiovascular diseases. However, the role of SENP3 in obesity-associated inflammation remains largely unknown. To better understand the effects of SENP3 on adipose tissue macrophage (ATM) activation and function within the context of obesity, we generated mice with myeloid-specific deletion of SENP3 (Senp3flox/flox;Lyz2-Cre mice). We found that the expression of SENP3 is dramatically increased in ATMs during high-fat diet (HFD)-induced obesity in mice. Senp3flox/flox;Lyz2-Cre mice show lower body weight gain and reduced adiposity and adipocyte size after challenged with HFD and during aging. Myeloid-specific SENP3 deletion attenuates macrophage infiltration in adipose tissue and reduces serum levels of inflammatory factors during diet and age-induced obesity. Furthermore, we found that SENP3 knockout markedly inhibits cytokine release from macrophage after lipopolysaccharide and palmitic acid treatment in vitro. Mechanistically, in cultured peritoneal macrophages, SENP3 protein level is enhanced by IL-1ß, in parallel with the upregulation of Yes-associated protein 1 (YAP1). Moreover, we demonstrated that SENP3 modulates de-SUMO modification of YAP1 and SENP3 deletion abolishes the upregulation of YAP1 induced by IL-1ß. Most importantly, SENP3 deficiency reduces YAP1 protein level in adipose tissue during obesity. Our results highlight the important role of SENP3 in ATM inflammation and diet and age-induced obesity.

An Unusual Anatomical Variation of Accessory Left Gastric Artery Arising from Left Hepatic Artery / Una Variación Anatómica Inusual de la Arteria Gástrica Izquierda Accesoria que se Origina de la Arteria Hepática Izquierda

SUMMARY: The stomach receives a rich blood supply from five sets of arteries, all of which originate from the celiac trunk. During the dissection of a female cadaver that had been fixed with formalin, an atypical branching pattern was observed. An accessory left gastric artery was found to originate from the left hepatic artery and send small branches to the esophagus, cardia, and fundus of the stomach. However, there was no anastomosis between the lower accessory left gastric artery and the left gastric artery. This is a rare variant of the gastric artery that has not been previously described in detail. It is important to recognize this variation for safe and effective interventional diagnosis and treatment techniques if dealing with the liver or gastric arteries.

El estómago recibe un rico suministro de sangre de cinco conjuntos de arterias, todas las cuales se originan en el tronco celíaco. Durante la disección de un cadáver femenino que había sido fijado con formalina, se observó un patrón de ramificación atípico. Se encontró una arteria gástrica izquierda accesoria que se originaba en la arteria hepática izquierda y enviaba pequeñas ramas al esófago, el cardias y el fondo del estómago. Sin embargo, no hubo anastomosis entre la arteria gástrica izquierda accesoria inferior y la arteria gástrica izquierda. Se trata de una variante rara de la arteria gástrica que no se ha descrito previamente en detalles. Es importante reconocer esta variación para la aplicación de técnicas de diagnóstico y tratamiento intervencionistas seguras y efectivas a nivel del hígado o las arterias gástricas.

An infectious clone of enterovirus 71(EV71) that is capable of infecting neonatal immune competent mice without adaptive mutations.

Enterovirus 71 (EV71) is a major pathogen that causes hand, foot and mouth disease (HFMD), which is a life threatening disease in certain children. The pathogenesis of EV71-caused HFMD is poorly defined due to the lack of simple and robust animal models with severe phenotypes that recapitulate symptoms observed in humans. Here, we generated the infectious clone of a clinical isolate from a severe HFMD patient. Virus rescued from the cDNA clone was infectious in cell lines. When administrated intraperitoneally to neonatal ICR, BALB/c and C57 immune competent mice at a dosage of1.4 × 104 pfu per mouse, the virus caused weight loss, paralysis and death in the infected mice after 4-5 days of infection. In the infected mice, detectable viral replication was detected in various tissues such as heart, liver, brain, lung, kidney, small intestine, leg skeletal muscle and medulla oblongata. The histology of the infected mice included massive myolysis, glomerular atrophy, villous blunting in small intestine, widened alveolar septum, diminished alveolar spaces and lymphocytes infiltration into the lung. By using the UV-inactivated virus as a control, we elucidated that the virus first amplified in the leg skeletal muscle tissue and the muscle tissue served as a primary viral replication site. In summary, we generated a stable EV71 infectious clone that is capable of infecting neonatal immune competent mice without adaptive mutations and provide a simple, valuable animal model for the studies of EV71pathogenesis and therapy.

Genome-wide linear B-cell epitopes of enterovirus 71 in a hand, foot and mouth disease (HFMD) population.

BACKGROUND: Enteroviruses cause hand, foot and mouth disease (HFMD). The host B-cells recognize the viral proteins and provoke humoral responses. Deciphering the B-cell responses to the viral epitopes helps diagnosis and vaccine development. OBJECTIVES: The objective of the present study was to investigate for the first time the landscape of genome-wide linear B-cell epitopes of enterovirus 71 in HFMD population. STUDY DESIGN: The peptides encompassing the entire coding region of EV71 were chemically synthesized and displayed on a microarray. The peptide microarray was used to screen serum samples from an HFMD population, including EV71-, CAV10-, CAV16- and CAV6-infected patients. We identified the dominant epitope-containing-peptides (DECPs) that react with the sera of more than 20% of the HFMD population and the common DECPs that cross-react with the sera from other enteroviruses-infected population. RESULTS: Ten DECPs reacting with IgM and 9 DECPs reacting with IgG antibodies were identified, of which, 6 IgM and 5 IgG common DECPs cross-reacted with the sera from other enteroviruses. Some DECPs preferentially reacted with IgG or IgM antibodies and some epitope-antibody interactions correlated with the severity of HFMD. CONCLUSIONS: We uncovered the DECPs and the common DECPs among a group of enteroviruses in HFMD population and found that some epitope-antibody reactions were associated with the outcome of HFMD. These data may guide developing vaccines against the enteroviruses and help the diagnosis and prognosis of HFMD.

AXL promotes Zika virus infection in astrocytes by antagonizing type I interferon signalling.

Zika virus (ZIKV) is associated with neonatal microcephaly and Guillain-Barré syndrome1,2. While progress has been made in understanding the causal link between ZIKV infection and microcephaly3-9, the life cycle and pathogenesis of ZIKV are less well understood. In particular, there are conflicting reports on the role of AXL, a TAM family kinase receptor that was initially described as the entry receptor for ZIKV10-22. Here, we show that while genetic ablation of AXL protected primary human astrocytes and astrocytoma cell lines from ZIKV infection, AXL knockout did not block the entry of ZIKV. We found, instead, that the presence of AXL attenuated the ZIKV-induced activation of type I interferon (IFN) signalling genes, including several type I IFNs and IFN-stimulating genes. Knocking out type I IFN receptor α chain (IFNAR1) restored the vulnerability of AXL knockout astrocytes to ZIKV infection. Further experiments suggested that AXL regulates the expression of SOCS1, a known type I IFN signalling suppressor, in a STAT1/STAT2-dependent manner. Collectively, our results demonstrate that AXL is unlikely to function as an entry receptor for ZIKV and may instead promote ZIKV infection in human astrocytes by antagonizing type I IFN signalling.

Enhanced human enterovirus 71 infection by endocytosis inhibitors reveals multiple entry pathways by enterovirus causing hand-foot-and-mouth diseases.

BACKGROUND: Human enterovirus 71 (EV71) was previously known to enter cells through clathrin or caveolar mediated endocytic pathways. However, we observed chlorpromazine (CPZ) or dynasore (DNS), which inhibit clathrin and dynamin mediated endocytosis, did not suppress EV71 cell entry in particular cell types. So the current knowledge of entry mechanisms by EV71 is not complete. METHODS: Viral infection was examined by flow cytometry or end-point dilution assays. Viral entry was monitored by immunofluorescence or pseudoviral infections. Various inhibitors were utilized for manipulating endocytic pathways. Cellular proteins were knockdown by siRNA. RESULTS: CPZ and DNS did not inhibit but rather enhance viral infection in A549 cells, while they inhibited infections in other cells tested. We further found CPZ did not affect EV71 binding to target cells and failed to affect viral translation and replication, but enhanced viral entry in A549 cells. Immunofluorescence microscopy further confirmed this increased entry. Using siRNA experiment, we found that the enhancement of EV71 infection by CPZ did not require the components of clathrin mediated endocytosis. Finally, CPZ also enhanced infection by Coxackivirus A16 in A549 cells. CONCLUSIONS: CPZ and DNS, previously reported as EV71 entry inhibitors, may rather lead to increased viral infection in particular cell types. CPZ and DNS increased viral entry and not other steps of viral life cycles. Therefore, our study indicated an unknown dynamin-independent entry pathway utilized by enteroviruses that cause Hand-Foot-and-Mouth Diseases.

Zika virus infects renal proximal tubular epithelial cells with prolonged persistency and cytopathic effects.

Zika virus (ZIKV) infection can cause fetal developmental abnormalities and Guillain-Barré syndrome in adults. Although progress has been made in understanding the link between ZIKV infection and microcephaly, the pathology of ZIKV, particularly the viral reservoirs in human, remains poorly understood. Several studies have shown that compared to serum samples, patients' urine samples often have a longer duration of ZIKV persistency and higher viral load. This finding suggests that an independent viral reservoir may exist in the human urinary system. Despite the clinical observations, the host cells of ZIKV in the human urinary system are poorly characterized. In this study, we demonstrate that ZIKV can infect renal proximal tubular epithelial cells (RPTEpiCs) in immunodeficient mice in vivo and in both immortalized and primary human renal proximal tubular epithelial cells (hRPTEpiCs) in vitro. Importantly, ZIKV infection in mouse kidneys caused caspase-3-mediated apoptosis of renal cells. Similarly, in vitro infection of immortalized and primary hRPTEpiCs resulted in notable cytopathic effects. Consistent with the clinical observations, we found that ZIKV infection can persist with prolonged duration in hRPTEpiCs. RNA-Seq analyses of infected hRPTEpiCs revealed a large number of transcriptional changes in response to ZIKV infection, including type I interferon signaling genes and anti-viral response genes. Our results suggest that hRPTEpiCs are a potential reservoir of ZIKV in the human urinary system, providing a possible explanation for the prolonged persistency of ZIKV in patients' urine.

Nuclear translocation of HIF-1α induced by influenza A (H1N1) infection is critical to the production of proinflammatory cytokines.

Infection with the influenza A (H1N1) virus is a major challenge for public health because it can cause severe morbidity and even mortality in humans. The over-secretion of inflammatory cytokines (cytokine storm) is considered to be a key contributor to the severe pneumonia caused by H1N1 infection. It has been reported that hypoxia-inducible factor 1-alpha (HIF-1α) is associated with the production of proinflammatory molecules, but whether HIF-1α participates in the acute inflammatory responses against H1N1 infection is still unclear. To investigate the role of HIF-1α in H1N1 infection, the expression and nuclear translocation of HIF-1α in A549 and THP-1 cell lines infected with H1N1 virus were observed. The results showed that without altering the intracellular mRNA or protein expression of HIF-1α, H1N1 infection only induced nuclear translocation of HIF-1α under normal oxygen concentrations. The use of 2-methoxyestradiol (2ME2), a HIF-1α inhibitor that blocks HIF-1α nuclear accumulation, in H1N1-infected cells decreased the mRNA and protein expression of tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-6 and increased the levels of IL-10. In contrast, H1N1-infected cells under hypoxic conditions had increased HIF-1α nuclear accumulation, increased expression of TNF-α and IL-6 and decreased levels of IL-10. In conclusion, our data implied that in vitro H1N1 infection induced nuclear translocation of HIF-1α without altering the expression of HIF-1α, which may promote the secretion of proinflammatory cytokines during H1N1 infection.

Acute viral hepatitis presenting as cytomegalovirus, hepatitis E and Epstein-Barr virus IgM antibody positive.

We report a case of acute cytomegalovirus (CMV) infection with positive HEV and Epstein-Barr virus (EBV) serology. No patients have been reported positive for immunoglobulin (Ig)M antibodies to all three viruses. This patient had progressively increasing titres of IgM antibody for CMV, HEV and EBV. Only CMV DNA was detectable before antiviral treatment. After antiviral treatment, the patient recovered completely. At day 180 the CMV IgG test had converted to positive with CMV IgM (+), EBV IgM (-) and HEV IgM (-). Our report indicates that dependence upon serology alone is unreliable in the diagnosis of acute CMV, EBV and HEV infections. The diagnosis of CMV, HEV and EBV should be based on a combination of clinical features, serology and confirmatory PCR testing.

Hepatitis B virus spliced variants are associated with an impaired response to interferon therapy.

During hepatitis B virus (HBV) replication, spliced HBV genomes and splice-generated proteins have been widely described, however, their biological and clinical significance remains to be defined. Here, an elevation of the proportion of HBV spliced variants in the sera of patients with chronic hepatitis B (CHB) is shown to correlate with an impaired respond to interferon-α (IFN-α) therapy. Transfection of the constructs encoding the three most dominant species of spliced variants into cells or ectopic expression of the two major spliced protein including HBSP and N-terminal-truncated viral polymerase protein result in strong suppression of IFN-α signaling transduction, while mutation of the major splicing-related sites of HBV attenuates the viral anti-IFN activities in both cell and mouse models. These results have associated the productions of HBV spliced variants with the failure response to IFN therapy and illuminate a novel mechanism where spliced viral products are employed to resist IFN-mediated host defense.

Genotype distribution of norovirus around the emergence of Sydney_2012 and the antigenic drift of contemporary GII.4 epidemic strains.

BACKGROUND: The pattern of epochal evolution of NoV is ongoing, while novel GII.4 variants emerge and cause new pandemics. Since, the emergence in March 2012, Sydney_2012 had replaced GII.4-2009 as the primary NoV strain in most countries in the northern hemisphere by November 2012. OBJECTIVES: To determine the genotype distribution around the emergence of Sydney_2012 and to investigate the underlying evolution mechanisms of the contemporary GII.4 strains. STUDY DESIGN: From January 2012 to December 2013, molecular epidemiology of norovirus in 846 adults (≥16 years) in Shanghai were conducted. The VP1 proteins of the contemporary GII.4 strains (Den_Haag_2006b, New_Orleans_2009 and Sydney_2012) were expressed in vitro and purified. Receptor binding patterns of these three epidemic strains were determined through histo-blood group antigen (HBGA) binding assays. Convalescent serum from patients infected with GII.4 epidemic strains were employed to investigate the role of antigenic drift in the persistence of GII.4 epidemic strains through receptor-binding blockade assays. RESULTS: Epidemiological studies revealed that Sydeny_2012 has completely replaced Den_Haag_2006b and New_Orleans_2009 and has been the dominant circulating strain in Shanghai since its emergence in October 2012. Interestingly, Den_Haag_2006b and New_Orleans_2009 have been co-circulating in Shanghai before the emergence of Sydeny_2012. The contemporary GII.4 epidemic norovirus strains displayed commonly high tropism to the histo-blood group antigen receptors, whereas Sydeny_2012 was antigenically different from Den_Haag_2006b and New_Orleans_2009. CONCLUSIONS: Antigenic drift, rather than receptor switch, played a key role in the emergence and spreading of Sydney_2012. The contemporary GII.4 strains were evolving via epochal evolution without altered ligand binding profiles.

Polarization of Monocytic Myeloid-Derived Suppressor Cells by Hepatitis B Surface Antigen Is Mediated via ERK/IL-6/STAT3 Signaling Feedback and Restrains the Activation of T Cells in Chronic Hepatitis B Virus Infection.

Chronic hepatitis B virus (HBV) infection is characterized by T cell tolerance to virus. Although inhibition of T cell responses by myeloid-derived suppressor cells (MDSCs) has been observed in patients with chronic hepatitis B (CHB), the mechanism for expansion of MDSCs remains ambiguous. In this study, a significant increased frequency of monocytic MDSCs (mMDSCs) was shown positively correlated to level of HBsAg in the patients with CHB. We further found hepatitis B surface Ag (HBsAg) efficiently promoted differentiation of mMDSCs in vitro, and monocytes in PBMCs performed as the progenitors. This required the activation of ERK/IL-6/STAT3 signaling feedback. Importantly, the mMDSCs polarized by HBsAg in vitro acquired the ability to suppress T cell activation. Additionally, treatment of all-trans retinoic acid, an MDSC-targeted drug, restored the proliferation and IFN-γ production by HBV-specific CD4(+) and CD8(+) T cells in PBMCs from patients with CHB and prevented increase of viral load in mouse model. In summary, HBsAg maintains HBV persistence and suppresses T cell responses by promoting differentiation of monocytes into mMDSCs. A therapy aimed at the abrogation of MDSCs may help to disrupt immune suppression in patients with CHB.

Interleukin-23 facilitates Th1 and Th2 cell differentiation in vitro following respiratory syncytial virus infection.

Respiratory syncytial virus (RSV) infection induces activation and imbalance of the immune system; however, the role of T helper 17 cells (Th17) in the response to RSV infection remains unclear. Interleukin-23 (IL-23) is a key cytokine in Th17 cell differentiation. The aim of this study was to explore the function of IL-23 in determining the distribution of Th lymphocyte subsets (Th1, Th2, and Th17) after RSV infection in vitro. Human bronchial epithelial cell line BEAS-2B was infected with mock or RSV at various multiplicities of infection (MOI) and transcript expression of IL-6, IL-23p19, and transforming growth factor (TGF-ß) was detected by real-time polymerase chain reaction; IL-6, IL-23, and TGF-ß in the supernatant were measured by enzyme-linked immunosorbent assay. The Th subset distribution in lymphocytes was determined by flow cytometry after co-culture with supernatants from mock and 72-hr RSV infection cultures. The role of IL-23 in lymphocytes was assessed by specific receptor blockade (IL-23R) prior to co-culture with supernatants from RSV-infected BEAS-2B cells, followed by flow cytometry to analyze Th subset differentiation. Cytokine expression increased after RSV infection. IL-23R blockade suppressed the differentiation of Th1, Th2, and Th17 cells in the presence of supernatants from RSV-infected BEAS-2B cells. RSV infection may induce cytokine secretion, thus inducing Th1, Th2, and Th17 differentiation via an IL-23R-dependent process.

A novel norovirus GII.17 lineage contributed to adult gastroenteritis in Shanghai, China, during the winter of 2014­2015.

Norovirus (NoV) is now recognized as a leading cause of nonbacterial acute gastroenteritis; however, the NoV GII.17 genotype has rarely been reported as the predominant genotype in clinical diarrhea cases. During the winter of 2014­2015, the GII.17 genotype, together with the NoV GII.4 genotype, dominated in sporadic adult patients with gastroenteritis in Shanghai. Phylogenetic analysis based on full-length VP1 amino acid sequences showed that the GII.17 strains that emerged in Shanghai have close evolutionary relationships with strains recently collected in the Hong Kong area, Guangdong province of China, and Japan during the same period. This cluster in the phylogenetic tree may represent a novel NoV GII.17 lineage recently circulating in East Asia. Pairwise distances between clusters also revealed the evolution of the NoV GII.17 genotype in previous decades. Our study emphasizes the importance of combined surveillance of NoV-associated infections.

Comparison of circulating, hepatocyte specific messenger RNA and microRNA as biomarkers for chronic hepatitis B and C.

Circulating microRNAs have been widely recognized as a novel category of biomarker in a variety of physiological and pathological conditions. Other reports revealed that fragments of organ specific messenger RNAs are also detectable in serum/plasma and can be utilized as sensitive indicators of liver pathology and cancer. In order to assess the sensitivity and reliability of these two class of RNAs as marker of hepatitis B or C induced chronic liver disease, we collected plasma samples from 156 chronic hepatitis B or C patients (HBV active n = 112, HBV carrier n = 19, hepatitis C n = 25) and 22 healthy donors and quantified their circulating mRNA for albumin, HP (haptoglobin), CYP2E1 (cytochrome P450, family 2, subfamily E) and ApoA2 (Apolipoprotein A2) in conjunction with microRNA-122, a well established marker for acute and chronic liver injury. We found that plasma microRNA-122 level is significantly elevated in patients with active HBV but not in HBV carriers. Furthermore, microRNA-122 is not elevated in HCV patients even though their median serum alanine aminotransferase (sALT) was three fold of the healthy donors. Nevertheless, circulating mRNAs, especially albumin mRNA, showed much more sensitivity in distinguishing active hepatitis B, hepatitis B carrier or HCV patients from healthy control. Correlation and multiple linear regression analysis suggested that circulating mRNAs and miRNAs are much more related to HBsAg titre than to sALT. Immunoprecipitation of HBsAg in HBV patients' plasma resulted in enrichment of albumin and HP mRNA suggesting that fragments of liver specific transcripts can be encapsidated into HBsAg particles. Taken together, our results suggest that hepatocyte specific transcripts in plasma like albumin mRNA showed greater sensitivity and specificity in differentiating HBV or HCV induced chronic liver disease than microRNA-122. Circulating mRNA fragments merit more attention in the quest of next generation biomarkers for various maladies.

TLR4-dependant immune response, but not hepatitis B virus reactivation, is important in radiation-induced liver disease of liver cancer radiotherapy.

Toll-like receptor 4 (TLR4) is an important trigger of the immune response against hepatitis B virus (HBV) infection and liver injuries. The roles of HBV reactivation versus TLR4-dependant immune response may be critical factors in preventing radiation-induced liver diseases (RILDs) after liver cancer radiotherapy. This study consists of three phases. In the primary phase, livers of mutant TLR4 (TLR4(-)) mice were irradiated with 30 Gy in either the absence or presence of HBV infection. The latter was done by introduction of plasmid pAAV/HBV 1.2. In the advanced phase, RILDs were compared in normal TLR4 (TLR4(+)) versus TLR4(-) mice. In the validation phase, 28 liver cancer patients who had undergone radiotherapy before hepatectomy were enrolled. Liver biopsies near tumors, irradiated with 35-48 Gy, were used to construct tissue microarrays. HBV reactivation, TLR4 expression, and severity of RILDs were studied in both mouse and human. More HBV reactivation, without significant RILD, was observed in irradiated versus unirradiated TLR4(-) mice. RILD scores of TLR4(+) mice were higher than TLR4(-) mice. In humans, serious RILDs tended to develop in patients with high TLR4 expression, but not in patients with low TLR4 or high HBV surface antigen expression. High TLR4 expression was seen in only 2 of 12 HBV-reactive patients, but in HBV-nonreactive patients, it was seen in 6 of 9 (P < 0.03). In summary, RILDs correlated with high TLR4 expression, but not with HBV reactivation, which is inhibited in liver with high TLR4 expression after liver cancer radiotherapy.

Hepatitis B virus surface antigen selectively inhibits TLR2 ligand-induced IL-12 production in monocytes/macrophages by interfering with JNK activation.

It is widely accepted that chronic hepatitis B virus (HBV) infection is the result of an ineffective antiviral immune response against HBV infection. Our previous study found that the hepatitis B surface Ag (HBsAg) was related to decreased cytokine production induced by the TLR2 ligand (Pam3csk4) in PBMCs from chronic hepatitis B patients. In this study, we further explored the mechanism involved in the inhibitory effect of HBsAg on the TLR2 signaling pathway. The results showed that both Pam3csk4-triggered IL-12p40 mRNA expression and IL-12 production in PMA-differentiated THP-1 macrophage were inhibited by HBsAg in a dose-dependent manner, but the production of IL-1ß, IL-6, IL-8, IL-10, and TNF-α was not influenced. The Pam3csk4-induced activation of NF-κB and MAPK signaling were further examined. The phosphorylation of JNK-1/2 and c-Jun was impaired in the presence of HBsAg, whereas the degradation of IκB-α, the nuclear translocation of p65, and the phosphorylation of p38 and ERK-1/2 were not affected. Moreover, the inhibition of JNK phosphorylation and IL-12 production in response to Pam3csk was observed in HBsAg-treated monocytes/macrophages (M/MΦs) from the healthy donors and the PBMCs and CD14-positive M/MΦs from chronic hepatitis B patients. Taken together, these results demonstrate that HBsAg selectively inhibits Pam3csk4- stimulated IL-12 production in M/MΦs by blocking the JNK-MAPK pathway and provide a mechanism by which HBV evades immunity and maintains its persistence.

[Relationship between CD4 + CD25 + Foxp3 + regulatory T cells and Th17 responses in Chlamydia muridarum pulmonary infection].

OBJECTIVE: To study the relationship between CD4 + CD25 + Foxp3 + regulatory T cells and Th17 responses during pulmonary infection of Chlamydia muridarum (Cm) in BALB/c mice. [Methods] BALB/c mice aged 6-8 weeks were inoculated intranasally with 5 x 103 IFU of Cm to set up the murine model of Chlamydial pneumonia. The boet weight changes, the growth of Cm and the pathology in the lung were monitored at different time post-infection. In determine the CD4 + CD25 + Foxp3 + regulatory T cells responses in BALB/c mice, intracellular cytokine staining was used to assay the percentage of CD4 + CD25 + Foxp3 + T cells in the spleen and mediastinum lymph node (MLN). The production of cytokines/chemokines in the lung were monitored, including IL-6,TGF-beta,IL-17 ,IL-2 (by ELISA), K(C and MIP-2 (by RT-PCR). RESULTS: Intranasally infected with 5 x 10(3) IFU of Cm in mice resulted in chlamydial pneumonitis featured by body weight lost, chlamydia growth and pathological damage in the lung compared with their uninfected counterparts. On day 3 post-infection, the percentage of CD4 + CD25 + Foxp3 + T cells in the spleen and MLN were significantly decreased than the control mice; then began to increase and recover to the original level on day 7 post-infection. The production of Th17 associated cytokines/chemokines such as IL-6, IL-17, KCand MIP-2 increased, which peaked on day 7 post-infection, then gradually reduced. The production of TGF-beta and IL-2 was consistent with the trend of CD4 + CD25 + Foxp3 + T cells. CONCLUSION: During pulmonary infection of Cm in BALB/c mice, CD4 + CD25 + Foxp3 + regulatory T cells may promote type 17 T cell immunity through providing TGF-beta in the presence of IL-6.

[The emergence of novel GII.4 norovirus variant, Sydney_2012, in Shanghai, China].

To describe the epidemiological characteristics of norovirus (NOV) associated acute gastroenteritis in Shanghai and characterize the evolution pattern of circulating strains. From March 2012 to February 2013, 502 stool specimens were collected from adult (> or = 16 years) outpatients who visited either of the two sentinel hospitals in Shanghai for acute gastroenteritis. Molecular detection and genotyping of NoV were performed and the phylogenetic relationship of the circulating strains has also been comprehensively analyzed. The epidemics level of GI NoV was low throughout the surveillance period, with the positive rate of 3.78% (19 cases), and no seasonality of GI NoV infection could be distinguished. For GII genogroup, higher epidemics in adults in Shanghai, with the detection rate of 17.13% (86 cases), were observed. And relatively high epidemics of GII NoV infection were spotted between October and December in 2012. The frequency of NoV associated acute gastroenteritis in older people is significantly higher than that in young individuals (P < 0.05). Sequencing and genotyping analysis revealed that the high epidemics of GII NoV infection between October and December in 2012 is associated with the emergence of a novel GII.4 norovirus strain, termed Sydney_2012. Sequence analysis also demonstrated that this was a recombinant virus between a GII.e polymerase and GII.4 capsid, which has also been the dominant circulating strain in Shanghai. In 2012, a new GII.4 variant, termed Sydney_2012, emerged in Shanghai and caused high epidemics of acute gastroenteritis during late autumn and winter.