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Feng N, Kim B, Fenaux M, Nguyen H, Vo P, Omary MB, Greenberg HB. Role of interferon in homologous and heterologous rotavirus infection in the intestines and extraintestinal organs of suckling mice. J Virol 2008; 82:7578-90. [PMID: 18495762 PMCID: PMC2493311 DOI: 10.1128/jvi.00391-08] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 05/12/2008] [Indexed: 02/05/2023] Open
Abstract
Recent studies demonstrated that viremia and extraintestinal rotavirus infection are common in acutely infected humans and animals, while systemic diseases appear to be rare. Intraperitoneal infection of newborn mice with rhesus rotavirus (RRV) results in biliary atresia (BA), and this condition is influenced by the host interferon response. We studied orally inoculated 5-day-old suckling mice that were deficient in interferon (IFN) signaling to evaluate the role of interferon on the outcome of local and systemic infection after enteric inoculation. We found that systemic replication of RRV, but not murine rotavirus strain EC, was greatly enhanced in IFN-alpha/beta and IFN-gamma receptor double-knockout (KO) or STAT1 KO mice but not in mice deficient in B- or T-cell immunity. The enhanced replication of RRV was associated with a lethal hepatitis, pancreatitis, and BA, while no systemic disease was observed in strain EC-infected interferon-deficient mice. In IFN-alpha/beta receptor KO mice the extraintestinal infection and systemic disease were only moderately increased, while RRV infection was not augmented and systemic disease was not present in IFN-gamma receptor KO mice. The increase of systemic infection in IFN-deficient mice was also observed during simian strain SA11 infection but not following bovine NCDV, porcine OSU, or murine strain EW infection. Our data indicate that the requirements for the interferon system to inhibit intestinal and extraintestinal viral replication in suckling mice vary among different heterologous and homologous rotavirus strains, and this variation is associated with lethal systemic disease.
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Hoard JL, Hoover DB, Mabe AM, Blakely RD, Feng N, Paolocci N. Cholinergic neurons of mouse intrinsic cardiac ganglia contain noradrenergic enzymes, norepinephrine transporters, and the neurotrophin receptors tropomyosin-related kinase A and p75. Neuroscience 2008; 156:129-42. [PMID: 18674600 DOI: 10.1016/j.neuroscience.2008.06.063] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Revised: 06/05/2008] [Accepted: 06/28/2008] [Indexed: 11/20/2022]
Abstract
Half of the cholinergic neurons of human and primate intrinsic cardiac ganglia (ICG) have a dual cholinergic/noradrenergic phenotype. Likewise, a large subpopulation of cholinergic neurons of the mouse heart expresses enzymes needed for synthesis of norepinephrine (NE), but they lack the vesicular monoamine transporter type 2 (VMAT2) required for catecholamine storage. In the present study, we determined the full scope of noradrenergic properties (i.e. synthetic enzymes and transporters) expressed by cholinergic neurons of mouse ICG, estimated the relative abundance of neurons expressing different elements of the noradrenergic phenotype, and evaluated the colocalization of cholinergic and noradrenergic markers in atrial nerve fibers. Stellate ganglia were used as a positive control for noradrenergic markers. Using fluorescence immunohistochemistry and confocal microscopy, we found that about 30% of cholinergic cell bodies contained tyrosine hydroxylase (TH), including the activated form that is phosphorylated at Ser-40 (pSer40 TH). Dopamine beta-hydroxylase (DBH) and norepinephrine transporter (NET) were present in all cholinergic somata, indicating a wider capability for dopamine metabolism and catecholamine uptake. Yet, cholinergic somata lacked VMAT2, precluding the potential for NE storage and vesicular release. In contrast to cholinergic somata, cardiac nerve fibers rarely showed colocalization of cholinergic and noradrenergic markers. Instead, these labels were closely apposed but clearly distinct from each other. Since cholinergic somata expressed several noradrenergic proteins, we questioned whether these neurons might also contain trophic factor receptors typical of noradrenergic neurons. Indeed, we found that all cholinergic cell bodies of mouse ICG, like noradrenergic cell bodies of the stellate ganglia, contained both tropomyosin-related kinase A (TrkA) and p75 neurotrophin receptors. Collectively, these findings demonstrate that mouse intrinsic cardiac neurons (ICNs), like those of humans, have a complex neurochemical phenotype that goes beyond the classical view of cardiac parasympathetic neurons. They also suggest that neurotrophins and local NE synthesis might have important effects on neurons of the mouse ICG.
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Karmely M, Rubinstein DB, Pichinuk E, Ziv R, Benhar I, Feng N, Wreschner DH. Inhibiting MUC1 a/b chain interaction mediates cytotoxicity of cells expressing MUC1: The MUC1 dyad oncoprotein as a functional target. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.14000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Fenaux M, Cuadras MA, Feng N, Jaimes M, Greenberg HB. Extraintestinal spread and replication of a homologous EC rotavirus strain and a heterologous rhesus rotavirus in BALB/c mice. J Virol 2007; 80:5219-32. [PMID: 16699002 PMCID: PMC1472171 DOI: 10.1128/jvi.02664-05] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Although rotavirus infection has generally been felt to be restricted to the gastrointestinal tract, over the last two decades there have been sporadic reports of children with acute or fatal cases of rotavirus gastroenteritis testing positive for rotavirus antigen and/or nucleic acid in various extraintestinal locations such as serum, liver, kidney, bladder, testes, nasal secretions, cerebrospinal fluid, and the central nervous system. Recently, studies in animals and people have demonstrated that rotavirus antigenemia is a common event during natural infection. In this study, we extend these observations and compare the intestinal and extraintestinal spread of wild-type homologous murine rotavirus EC and a heterologous strain, rhesus rotavirus (RRV), in newborn mice. A strand-specific quantitative reverse transcription-PCR (ssQRT-PCR) assay was used to quantify the ability of different rotavirus strains to spread and replicate extraintestinally. Both strain EC and RRV were detected extraintestinally in the mesenteric lymph nodes (MLN), livers, lungs, blood, and kidneys. Extraintestinal replication, as measured by ssQRT-PCR, was most prominent in the MLN and occurred to a lesser degree in the livers, kidneys, and lungs. In the MLN, strain EC and RRV had similar (P < 0.05) RNA copy numbers, although EC was present at a 10,000-fold excess over RRV in the small intestine. Rotavirus nonstructural protein 4 (NSP4) and/or assembled triple-layered particles, indicated by immunostaining with the VP7 conformation-dependent monoclonal antibody 159, were detected in the MLN, lungs, and livers of EC- and RRV-inoculated mice, confirming the ssQRT-PCR findings. Infectious RRV was detected in the MLN in quantities exceeding the amount present in the small intestines or blood. The cells in the MLN that supported rotavirus replication included dendritic cells and potentially B cells and macrophages. These data indicate that extraintestinal spread and replication occurs commonly during homologous and some heterologous rotaviral infections; that the substantial host range restrictions for rhesus rotavirus, a heterologous strain present in the intestine, are not necessarily apparent at systemic sites; that the level and location of extraintestinal replication varies between strains; that replication can occur in several leukocytes subsets; and that extraintestinal replication is likely a part of the normal pathogenic sequence of homologous rotavirus infection.
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Forster GL, Feng N, Watt MJ, Korzan WJ, Mouw NJ, Summers CH, Renner KJ. Corticotropin-releasing factor in the dorsal raphe elicits temporally distinct serotonergic responses in the limbic system in relation to fear behavior. Neuroscience 2006; 141:1047-1055. [PMID: 16713119 DOI: 10.1016/j.neuroscience.2006.04.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Revised: 02/12/2006] [Accepted: 04/06/2006] [Indexed: 11/17/2022]
Abstract
The neurotransmitters serotonin and corticotrophin-releasing factor are thought to play an important role in fear and anxiety behaviors. This study aimed to determine the relationship between corticotrophin-releasing factor-evoked changes in serotonin levels within discrete regions of the limbic system and the expression of fear behavior in rats. The effects of corticotrophin-releasing factor administration to the serotonin cell body regions of the dorsal raphe nucleus on fear behavior, behavioral activity, and extracellular serotonin levels were assessed in freely moving rats with microdialysis probes implanted into the central nucleus of the amygdala and the medial prefrontal cortex. Infusion of corticotrophin-releasing factor (0.5 microg) into the dorsal raphe rapidly induced freezing behavior, which was positively correlated with an immediate increase in serotonin release in the central nucleus of the amygdala. In contrast, cessation of freezing behavior correlated with a delayed and prolonged increase in serotonin release within the medial prefrontal cortex. Our findings suggest that corticotrophin-releasing factor-induced freezing behavior is associated with regionally and temporally distinct serotonergic responses in the limbic system that may reflect differing roles for these regions in the expression of fear/anxiety behavior.
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Benatar T, Cao MY, Lee Y, Feng N, Gu X, Lee V, Jin H, Wang M, Der S, Wright JA, Young AH. Virulizin induces production of IL-17E to enhance antitumor activity by recruitment of eosinophils into tumors. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.2537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Gelernter-Yaniv L, Feng N, Sebring NG, Hochberg Z, Yanovski JA. Associations between a polymorphism in the 11 beta hydroxysteroid dehydrogenase type I gene and body composition. Int J Obes (Lond) 2003; 27:983-6. [PMID: 12861241 DOI: 10.1038/sj.ijo.0802327] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We investigated 11 beta hydroxysteriod dehydrogenase type 1 (11betaHSD-1) sequence variants in 103 healthy overweight (BMI >2 s.d.) and 160 nonoverweight (BMI -2 to +2 SD) children to examine the associations between body composition and 11betaHSD-1 polymorphisms. A total of 4.3% of children were homozygous and 30.0% heterozygous for an adenine insertion in intron 3 (ins4436A). By ANCOVA (adjusting for age, sex, race, and height), BMI-s.d. differed according to ins4436A genotype (P<0.005), with the greatest BMI-SD for ins4436A homozygotes (mean +/-s.d., 3.4+/-3.4, vs heterozygotes, 0.8+/-5.5, or wild-type, 1.8+/-7.5). Homozygotes also had greater waist circumference, waist-to-hip ratio, and insulin resistance indices than heterozygote or wild-type children (all P<0.05), but no significant differences in trunk fat by DXA, or in serum lipids. We conclude an intronic 11betaHSD-1 gene polymorphism is associated with greater body mass, altered body composition, and insulin resistance in children. 11betaHSD-1 may be one of the genes relevant for pediatric-onset obesity and its complications.
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Zhu W, Feng N, Wang Y, Ye G. [Gene polymorphism at apoB locus and the serum lipids profile in children]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 2001; 30:280-2. [PMID: 12561593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The relations of gene polymorphism at the apolipoprotein B locus and serum lipid profile in children was studied in 308 normal 7-11 year-old children, including 151 boys and 157 girls. Blood samples were collected for all subjects, and then the serum and blood clot were separated. Serum lipids, including TC, TG, LDL-C, HDL-C, apoB, apoA I and Lp(a) were detected. Genome DNA was extracted from blood clot, then apoB-Xba I gene polymorphism were tested by PCR-RFLP method. The results showed that the distribution of apoB-Xba I genotype in 308 children accorded with Hardy-Weiberg inheritance equilibrium law. The frequency of heterozygote(+/-) was 13.3%, allele(+) was 0.067. The frequency of allele(+) was closed to the internal and Japanese reports (0.033 and 0.04), but much less than the Caucasians (0.50). This showed a ethnic and population difference in the inheritance variation. The average LDL-C levels of the heterozygotes(+/-) were 2.17 mmol/L, no difference compared with homozygotes(-/-) (2.21 mmol/L, P > 0.05). There was also no difference for the genotype distribution between the hyperlipidemia group and control group, which may be the results of no enough sample size and the sample selection, and so on. On the other hand, in normal children, serum lipids controlled by many genes, the effect of a single gene might be small. More studies and analysis on the relationship between serum lipids and multiple genes in multisites should be the next step.
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Zhu W, Feng N, Wang Y. [Relationship between gene polymorphism at the apolipoprotein E locus and serum lipid profile in urban children of school age in Beijing]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2001; 35:297-300. [PMID: 11769625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To study the relationship between gene polymorphism at the apolipoprotein E (ApoE) locus and serum lipid levels in children of school age. METHODS Blood samples were collected from 307 normal children aged 7 to 11 years, including 150 boys and 157 girls, and their serum lipid profile, including total cholesterol (TC), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), apolipoprotein B(apoB), apoprotein A1 (ApoA I) and lipoptoein alpha[LP (alpha)], were detected and their ApoE-Hha I gene polymorphism were tested by the PCR-RFLP method. RESULTS The detection rates for the most frequent genotype ApoE3/3 was 54.7%, other genotypes E4/3, E4/4, E3/2, E4/2 and E2/2 were 23.8%, 9.1%, 8.1%, 3.9% and 0.3%, respectively, in 307 children, with no significant difference between girls and boys(P > 0.05). Frequency of the often seen allele E3 was 70.7%, and that of E4 and E2 was 23.0% and 6.4, respectively, with E4 significantly higher than and E2 similar to that in the other domestic reports. The levels of TC, LDL-C, ApoA I and ApoB were higher in boys with genotypes E4/3 and E3/3 than those with genotypes E3/2 and E4/2. Levels of TC and ApoA I in the boys with genotype E3/2 were higher, with TC of 4.28 mmol/L and ApoA I of 3.41 mmol/L. There were no significant difference in serum lipid levels of girls with different genotypes(P > 0.05). There also was no significant difference in the ApoE-Hha I genotype distribution between normal children and those with high TC. ApoE2 could decrease the level of TC by 0.377 mmol/L, and LDL-C by 0.329 mmol/L. CONCLUSIONS Serum level of TC associated with polymorphism of ApoE gene carrier in boys, with the lowest levels of TC, LDL-C and ApoE in three with allele E2.
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Gilber JM, Feng N, Patton JT, Greenberg HB. Rotavirus assembly - interaction of surface protein VP7 with middle layer protein VP6. Arch Virol 2001; 146:1155-71. [PMID: 11504422 DOI: 10.1007/s007050170112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The interaction between the rotavirus proteins viral protein 6 (VP6) and VP7 was examined in several exogenous protein expression systems. These proteins associated in the absence of other rotaviral proteins as demonstrated by a coimmunoprecipitation assay. Deletion analysis of VP7 indicated that truncations of either the mature amino or carboxyl terminus disrupted the proper folding of the protein and were not able to coimmunoprecipitate VP6. Truncation analysis of VP6 indicated that trimerization of VP6 was necessary, but not sufficient, for VP7 binding. MAb mapping and coimmunoprecipitation interference assays indicate that the VP6 amino acid residues between 271 and 342 are required for VP7 interaction. The interaction of VP6 and VP7 was also examined by the assembly of soluble VP7 onto baculovirus-expressed virus-like particles containing VP2 and VP6. Abrogation of this binding by preincubation of the particles with VP6 MAbs mapped to this same domain of VP6, validated our coimmunoprecipitation results. VP6 IgA MAbs that have been shown to be protective in vivo, but not a nonprotective IgA MAb, can interfere with VP7 binding to VP6. This suggests that these IgA MAbs may protect against rotavirus infection by blocking rotavirus assembly.
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Ren YJ, Xu XH, Zhong CB, Feng N, Wang XL. Hypercholesterolemia alters vascular functions and gene expression of potassium channels in rat aortic smooth muscle cells. Acta Pharmacol Sin 2001; 22:274-8. [PMID: 11742577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
AIM To investigate the effects of hypercholesterolemia on functions of rat aorta and on gene expression of inward rectifier and ATP-sensitive potassium channels in aortic smooth muscle. METHODS Rats were treated with high-cholesterol emulsion ig for 2 weeks; the aortic rings with and without endothelium were prepared to examine the aortic contractile and relaxation responses; RT-PCR was used to observe the gene expression of inward rectifier and ATP-sensitive potassium channels. RESULTS Hypercholesterolemia damaged the endothelium-dependent vascular functions severely, but did not affect the endothelium-independent vascular functions; Kir6.2 mRNA expression was upregulated (P < 0.05) and Kir3.1 mRNA expression was downregulated markedly (P < 0.05) in hypercholesterolemic smooth muscle. CONCLUSION Hypercholesterolemia altered the vascular functions and regulated gene expression levels of specific inward rectifier and ATP-sensitive potassium channel subtypes.
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MESH Headings
- Animals
- Aorta, Thoracic/metabolism
- Aorta, Thoracic/pathology
- Gene Expression
- Hypercholesterolemia/metabolism
- Hypercholesterolemia/physiopathology
- Male
- Muscle Contraction/physiology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Potassium Channels/biosynthesis
- Potassium Channels/genetics
- Potassium Channels, Inwardly Rectifying/biosynthesis
- Potassium Channels, Inwardly Rectifying/genetics
- RNA, Messenger/genetics
- Rats
- Rats, Wistar
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Kuklin NA, Rott L, Feng N, Conner ME, Wagner N, Müller W, Greenberg HB. Protective intestinal anti-rotavirus B cell immunity is dependent on alpha 4 beta 7 integrin expression but does not require IgA antibody production. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 166:1894-902. [PMID: 11160237 DOI: 10.4049/jimmunol.166.3.1894] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Rotavirus (RV) is the main cause of severe gastroenteritis in young children; protection has been correlated with intestinal Ab responses. Using a mouse model of RV infection and beta(7)-deficient (beta(7)(-/-)) mice, which do not express alpha(4)beta(7) integrin, we demonstrated the importance of alpha(4)beta(7) integrin in B cell-mediated anti-RV immunity. beta(7)(-/-) mice acutely infected with murine RV resolved infection and developed normal serum IgG Abs but had diminished intestinal IgA responses. alpha(4)beta(7)(-/-) immune B cells did not resolve RV infection when adoptively transferred into RV-infected Rag-2-deficient mice. Fewer RV-specific B cells were found in the intestine of Rag-2-deficient mice transferred with beta(7)(-/-) B cells compared with wild type. The absence of alpha(4)beta(7) expression and/or a lower frequency of IgA-producing cells among transferred beta(7)(-/-) B cells could have accounted for the inability of these cells to resolve RV infection following passive transfer. To distinguish between these possibilities, we studied the importance of IgA production in RV infection using IgA-deficient (IgA(-/-)) mice. IgA(-/-) mice depleted of CD8(+) T cells were able to clear primary RV infection. Similarly, adoptive transfer of immune IgA(-/-) B cells into chronically infected Rag-2-deficient mice resolved RV infection. We further demonstrated in both wild-type and IgA(-/-) mice that, following oral RV infection, protective B cells reside in the alpha(4)beta(7)(high) population. Our findings suggest that alpha(4)beta(7) integrin expression is necessary for B cell-mediated immunity to RV independent of the presence of IgA.
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Qu S, Feng N, Liu Z, Zhou H, Deng Y, Feng Z. The binding ability analysis of the normal VLDL receptor and its mutant. Curr Med Sci 2001; 21:177-80, 194. [PMID: 12539569 DOI: 10.1007/bf02886422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2001] [Indexed: 10/19/2022]
Abstract
The ligand-binding domain of VLDL receptor contains eight imperfectly similar repeats. To discuss the contribution of each repeat to ligand binding, the RT-PCR technique was used to clone the VLDLR-cDNA from the heart muscle of Chinese people. Two recombinants were further constructed, which contained the full-length cDNA of VLDLR and the mutant lacking repeats 1-5. CHO cell line was transfected with two recombinants. The expression of VLDLR gene could be detected by RT-PCR from the CHO cells transfected with pCD-VR. The results of binding experiments showed that the ability of the CHO cells transfected with the full-length cDNA of VLDL-R binding DiI-labeled beta-VLDL was higher than that of the CHO cells transfected with the mutant. Our findings indicated that human VLDL-R gene could be expressed effectively on CHO cells, and the receptor was almost inactivated when repeats 1-5 were deleted.
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Kuklin NA, Rott L, Darling J, Campbell JJ, Franco M, Feng N, Müller W, Wagner N, Altman J, Butcher EC, Greenberg HB. alpha(4)beta(7) independent pathway for CD8(+) T cell-mediated intestinal immunity to rotavirus. J Clin Invest 2000; 106:1541-52. [PMID: 11120761 PMCID: PMC381473 DOI: 10.1172/jci10927] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2000] [Accepted: 11/06/2000] [Indexed: 11/17/2022] Open
Abstract
Rotavirus (RV), which replicates exclusively in cells of the small intestine, is the most important cause of severe diarrhea in young children worldwide. Using a mouse model, we show that expression of the intestinal homing integrin alpha(4)ss(7) is not essential for CD8(+) T cells to migrate to the intestine or provide immunity to RV. Mice deficient in ss7 expression (ss7(-/-)) and unable to express alpha(4)ss(7) integrin were found to clear RV as quickly as wild-type (wt) animals. Depletion of CD8(+) T cells in ss7(-/-) animals prolonged viral shedding, and transfer of immune ss7(-/-) CD8(+) T cells into chronically infected Rag-2-deficient mice resolved RV infection as efficiently as wt CD8(+) T cells. Paradoxically, alpha(4)ss(7)(hi) memory CD8(+) T cells purified from wt mice that had been orally immunized cleared RV more efficiently than alpha(4)ss(7)(low) CD8(+) T cells. We explained this apparent contradiction by demonstrating that expression of alpha(4)ss(7) on effector CD8(+) T cells depends upon the site of initial antigen exposure: oral immunization generates RV-specific CD8(+) T cells primarily of an alpha(4)ss(7)(hi) phenotype, but subcutaneous immunization yields both alpha(4)ss(7)(hi) and alpha(4)ss(7)(low) immune CD8(+) T cells with anti-RV effector capabilities. Thus, alpha(4)ss(7) facilitates normal intestinal immune trafficking to the gut, but it is not required for effective CD8(+) T cell immunity.
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Tang FL, Xu WJ, Feng N. [Micro determination of acrylonitrile in ambient air by gas chromatography]. Se Pu 2000; 18:473-4. [PMID: 12541718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
Acrylonitrile in ambient air was collected by Tenax GC and then thermo-desorbed. It was separated on GDX-502 chromatographic column from other pollutants and determined by flame-ion ization detector. The minimum detectable concentration was 0.01 mg/m3 when 2 L ambient air was collected. The recoveries were 85.6%-105.4% and RSDs were 4.5%-6.2%.
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Lutz RA, Feng N, Moser R. Binding of interleukin-13 and interleukin-4 to the interleukin (IL)-4/IL-13 receptor of human synovial fibroblasts. J Recept Signal Transduct Res 1999; 19:181-90. [PMID: 10071757 DOI: 10.3109/10799899909036644] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Synovial fibroblasts expressed transcripts for IL-4R alpha, and IL-13R alpha 1 and IL-13R alpha 2. Using weighted nonlinear computer modeling of the data from equilibrium binding studies, a 2 bindings sites model fitted the data best. After occupation of the shared high affinity receptors by the non-signaling, double mutant IL-4(121)R-->D, 124Y-->D (RY-IL-4) the high affinity binding of IL-13 could be abolished. A 2 binding site model still could be fitted, however the improvement in fit over a onesite model was not statistically significant. Using affinity spectra, at least 2 binding sites are apparent. After treatment with RY-IL-4, some of the high affinity binding was abolished, however not completely. A correlation between the number of binding sites and the affinity is apparent, which seriously casts doubt on the classical evaluation of binding isotherms, where the parameters are assumed to be independent. In a previous study we suggested that the large number of IL-13R alpha 2 monomers are silent receptors, likely representing a decoy target for IL-13. The high affinity binding therefore most likely represents the binding to the heterodimer consisting of IL-4R alpha and IL-13R alpha 1 or IL-13R alpha 2. The low affinity binding may represent the IL-13R alpha 2.
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Feng N, Yan J, Qu F, Wei S. [Methods for assay of antibacterial activity of inorganic antibacterial agents]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1998; 32:315-6. [PMID: 10322781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
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Feng N, Lugli SM, Schnyder B, Gauchat JF, Graber P, Schlagenhauf E, Schnarr B, Wiederkehr-Adam M, Duschl A, Heim MH, Lutz RA, Moser R. The interleukin-4/interleukin-13 receptor of human synovial fibroblasts: overexpression of the nonsignaling interleukin-13 receptor alpha2. J Transl Med 1998; 78:591-602. [PMID: 9605184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Interleukin (IL)-4 and IL-13 are known to bind to shared heteromultimeric receptor complexes of variable composition. Given the many regulatory effects of IL-4 and IL-13 on synovial cells, we aimed to characterize their IL-4/IL-13 receptor (R). Cultivated synovial fibroblasts expressed transcripts for IL-4Ralpha and IL-13Ralpha1, the human homolog of the recently cloned mouse IL-13R, but not the common gamma-chain of the IL-2R. In particular, IL-13Ralpha2 mRNA, encoding a different IL-13R recently cloned from human renal carcinoma cells, was expressed at a strikingly high level. Correspondingly, a predominant protein migrating at 65 to 75 kd was cross-linked by iodinated IL-13 and was not cross-competed by an excess of unlabeled IL-4. However, by flow cytofluorometry, IL-13Ralpha1 (detected by the anti-lL-13Ralpha1 mAb 65) and IL-4Ralpha (detected by the mAb S697) were expressed at similar low density. Radioligand binding studies revealed for both cytokines approximately 300 receptors/cell with similar high affinity. An additional class of IL-13Rs was identified after occupation of the shared high-affinity receptors by the nonsignaling, double-mutant IL-4121R-->D, 124Y-->D (RY-IL-4). In these experiments, 1251-IL-13 bound to a single receptor population with a Kd of approximately 300 pM and approximately 5000 sites/cell, matching the published affinity of monomeric IL-13Ralpha2 when expressed in COS7 cells. RY-IL-4 blocked the IL-4- and IL-13-mediated vascular cell adhesion molecule (VCAM)-1 expression and Stat6 activation, suggesting that the large number of high-affinity IL-13Ralpha2 monomers are silent receptors, likely representing a decoy target for IL-13.
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Ludert JE, Mason BB, Angel J, Tang B, Hoshino Y, Feng N, Vo PT, Mackow EM, Ruggeri FM, Greenberg HB. Identification of mutations in the rotavirus protein VP4 that alter sialic-acid-dependent infection. J Gen Virol 1998; 79 ( Pt 4):725-9. [PMID: 9568967 DOI: 10.1099/0022-1317-79-4-725] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To explore further the role of VP4 as the rotavirus cell attachment protein, VP7 monoreassortants derived from the sialic-acid-dependent simian strain RRV and from the sialic-acid-independent human strains D, DS-1 and ST-3 were tested for susceptibility of infectivity of neuraminidase-treated MA-104 cells. Infectivity of RRV x D VP7 and RRV x ST-3 VP7 monoreassortants decreased when sialic acid was removed from the cell surface. However, of three separate RRV x DS-1 VP7 monoreassortants tested, only one was sialic-acid-dependent. Sequence analysis showed that both sialic-acid-independent strains contained a single amino acid change, Lys to Arg, at position 187. In addition, sialic-acid-independent infectivity was seen in one of 14 RRV VP4 neutralization escape mutants tested, and this strain was found to have a Gly to Glu change at amino acid position 150. These results indicate that positions 150 and 187 of VP4 play an important role in early rotavirus-cell interactions.
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Feng N, Ma J, Shao L. [Association between levels of plasma lipid profile with apolipoprotein B gene polymorphism in 93 children]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1998; 32:106-8. [PMID: 10322811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
OBJECTIVE To study the relationship between levels of plasma lipid profile and variation of apolipoprotein (Apo) B gene. METHODS The relationship between frequency of polymorphism genotype of Apo B gene Xba I locus and levels of plasma lipid profile was studied in 93 children aged eight to eleven years. RESULTS The frequency of dominant X- allele (common allele) in Xba I locus was 0.967 in the children and that of uncommon X+ allele 0.033. Average levels of plasma total cholesterol (TC) and low density lipoprotein cholesterol (LDL-ch) in children with X- X+ genotype (4.59 and 2.98 mmol/L, respectively) were significantly higher than those with X-X- genotype (3.84 and 2.32 mmol/L, respectively). Levels of TC and/or LDL-ch in 4 of 6, cases of X-X+ genotype exceeded their the 90th percentile, indicating association between X+ allele and high plasma cholesterol level. CONCLUSION To certain extent, there is association between polymorphism of Xba I locus of Apo B gene and levels of plasma lipid profile in children, which may be a genetic marker for abnormal level of plasma lipid profile during childhood.
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Angel J, Tang B, Feng N, Greenberg HB, Bass D. Studies of the role for NSP4 in the pathogenesis of homologous murine rotavirus diarrhea. J Infect Dis 1998; 177:455-8. [PMID: 9466536 DOI: 10.1086/517374] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A rotavirus (RV) nonstructural protein, NSP4, has recently been proposed to function as an enterotoxin in the pathogenesis of RV diarrhea. The role of NSP4 in the pathogenesis of RV diarrhea was examined by infecting cystic fibrosis transmembrane conductance regulator (CFTR) knockout mice with virulent murine RV and by comparing deduced amino acid sequences of RV gene 10 encoding NSP4 from three distinct sets of virulent and tissue culture-adapted avirulent variant RVs. Homozygous CFTR (CFTR-/-) mice, which do not respond to any known intestinal secretagogues, experienced diarrhea comparable to that in normal CFTR+/+ littermates after RV challenge. Comparison of amino acid sequences of NSP4 from virulent and attenuated pairs of RVs failed to show consistent or significant changes. Together, these data suggest that enterotoxigenic properties of RV NSP4 are not critical in the pathogenesis of murine RV diarrhea and that attenuation of murine RVs is not usually mediated by mutations in the gene encoding NSP4.
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Feng N, Zhang Z, An D, Huang W, Wang G, Han X, Bao X. Investigation of the metabolism of 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine chloride in the rat. Eur J Drug Metab Pharmacokinet 1998; 23:41-4. [PMID: 9625271 DOI: 10.1007/bf03189825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The metabolism of 7-(4-chlorbenzyl)-7,8,13,13a-tetrahydroberberine chloride (CTHB), a compound with promising pharmacological effects against arrhythmia, was investigated in rat bile. A metabolite and unchanged CTHB were found in the bile. Characterization and structural elucidation of the metabolite was achieved by LC/MS and LC/NMR. The following metabolic pathway is proposed: CTHB is metabolized by demethylation at position 10 to produce a new entity.
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Ishida SI, Feng N, Gilbert JM, Tang B, Greenberg HB. Immune responses to individual rotavirus proteins following heterologous and homologous rotavirus infection in mice. J Infect Dis 1997; 175:1317-23. [PMID: 9180169 DOI: 10.1086/516462] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Serum and intestinal humoral immune responses to rotavirus proteins VP2, VP4, VP6, VP7, NSP2, and NSP4 were quantitatively compared in mice infected with a homologous murine rotavirus (EHPw) or a heterologous simian rotavirus (RRV). Viral protein-specific antibody responses were measured by an immunohistochemistry assay that uses recombinant baculovirus-expressed rotavirus proteins as antigens. In serum, IgG responses to VP6 were dominant and comparable in both RRV- and EHPw-infected groups, but responses to VP2, VP4, VP7, and NSP2 were higher in RRV infection. In feces, IgA responses to VP2, VP4, and VP6 were higher in EHPw-infected mice, but responses to VP7 and NSP2 were detected only in the RRV-infected group. These findings indicate that immune responses to homologous and heterologous rotavirus infection vary both quantitatively and qualitatively. Differences in humoral responses may play a role in the differences in protection induced following homologous or heterologous rotavirus infection.
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Lugli SM, Feng N, Heim MH, Adam M, Schnyder B, Etter H, Yamage M, Eugster HP, Lutz RA, Zurawski G, Moser R. Tumor necrosis factor alpha enhances the expression of the interleukin (IL)-4 receptor alpha-chain on endothelial cells increasing IL-4 or IL-13-induced Stat6 activation. J Biol Chem 1997; 272:5487-94. [PMID: 9038152 DOI: 10.1074/jbc.272.9.5487] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Functional receptors for interleukin (IL)-4 and IL-13 on endothelial cells consist of the 130-kDa IL-4 receptor alpha-chain (IL-4Ralpha) and a 65-75-kDa IL-13 binding subunit that are expressed in a ratio of about 1:3, respectively. The restricted number of IL-4Ralpha limits subunit heterodimerization and in turn receptor-mediated signaling. We report here, the effects of tumor necrosis factor alpha (TNF-alpha) on the expression of the receptor subunits for IL-4 and IL-13. By flow cytofluorometry and receptor-binding analysis of iodinated IL-4 and IL-13, stimulation with TNF-alpha-induced a 2-3-fold increase of the IL-4Ralpha expression. The up-regulation was also confirmed at the transcriptional level by reverse transcription-polymerase chain reaction. Radioligand cross-linking experiments revealed no change in the subunit composition of the TNF-alpha-induced receptor complex. Nevertheless, TNF-alpha stimulation led to increased activation of the IL-4-specific signal transducers and activators of transcription protein (Stat6) by IL-4 and IL-13. Thus, TNF-alpha corrects the subunit imbalance of the endothelial IL-4.IL-13 receptor complex thereby increasing receptor heterodimerization and in turn the signaling capability by IL-4 and IL-13.
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Feng N, Vo PT, Chung D, Vo TV, Hoshino Y, Greenberg HB. Heterotypic protection following oral immunization with live heterologous rotaviruses in a mouse model. J Infect Dis 1997; 175:330-41. [PMID: 9203654 DOI: 10.1093/infdis/175.2.330] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A Jennerian approach using live animal viruses to immunize humans is the current lead strategy for developing rotavirus vaccines. This strategy has been modified by incorporating human rotavirus VP7 genes into vaccine strains to induce serotype-specific neutralizing antibodies to human strains. However, the role of homotypic versus heterotypic immunity in protection is unclear. To investigate the importance of serotype-specific immunity in a mouse model, mice were immunized with rhesus rotavirus (RRV: G3, P5[3]), RRV-based modified Jennerian vaccine strains DxRRV (G1, P5[3]), DS1xRRV (G2, P5[3]), or ST3xRRV (G4, P5[3]), or bovine rotavirus NCDV (G6, P6[1]) and challenged with murine rotavirus ECw (G3, P[16]). Mice immunized with modified Jennerian vaccines exhibited complete to near-complete protection from challenge. NCDV-immunized mice also showed partial protection. The protection was correlated with fecal IgA levels to VP6, not serum IgG responses. Modified Jennerian vaccines induce both heterotypic and homotypic immunity in mice.
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