The primary determinant of influenza virus infectivity is the type of linkage between sialic acid and oligosaccharides on the host cells. Hemagglutinin of avian influenza viruses preferentially binds to sialic acids linked to galactose by an alpha-2,3 linkage whereas hemagglutinin of human influenza viruses binds to sialic acids with an alpha-2,6 linkage. The distribution patterns of influenza receptors in the avian respiratory tracts are of particular interest because these are important for initial viral attachment, replication, and transmission to other species. In this study, we examined the distribution patterns of influenza receptors in the respiratory tract of chickens, ducks, pheasants, and quails because these species have been known to act as intermediate hosts in interspecies transmission. Lectin histochemistry was performed to detect receptor-bearing cells. Cell-specific distribution of the receptors was determined and expression densities were compared. We observed species-, site-, and cell-specific variations in receptor expression. In general, receptor expression was the highest in quails and lowest in ducks. Pheasants and quails had abundant expression of both types of receptors throughout the respiratory tract. These results indicate that pheasants and quails may play important roles as intermediate hosts for the generation of influenza viruses with pandemic potential.
Animals ; Cell Membrane/metabolism/virology ; Hemagglutinin Glycoproteins, Influenza Virus/metabolism ; Host-Pathogen Interactions ; Influenza A virus/*metabolism ; Influenza in Birds/metabolism/transmission ; Lectins/metabolism ; Poultry/metabolism/*virology ; Poultry Diseases/metabolism ; Receptors, Cell Surface/analysis/chemistry/metabolism ; Receptors, Virus/*analysis/metabolism ; Respiratory System/*chemistry ; Sialic Acids/metabolism ; Species Specificity ; Specific Pathogen-Free Organisms

Reports of influenza A virus infections in dogs has received considerable attention from veterinarians, virologists, and epidemiologists. Interaction between influenza viral hemagglutinin and cell oligosaccharides containing sialic acid residues results in infection. Sialic acids have an alpha-2,3-linkage to the penultimate galactose in the avian influenza virus receptor and an alpha-2,6-linkage in the human receptor. To date, there are no detailed data on the tissue distribution or histological features of either type of sialic acid-linked influenza virus receptors in beagle dogs, which are common laboratory animals and pets. We conducted the current study to visualize the in situ tissue distribution of both sialic acid-linked influenza virus receptors in various organs of beagle dogs using Maackia amurensis lectin II and Sambucus nigra agglutinin. Both alpha-2,3- and alpha-2,6-sialic acid-linked receptors were detected in the endothelial cells of the respiratory tract and other organs. Endothelial cells of most gastrointestinal organs were negative for alpha-2,3-sialic acid-linked receptors in the dogs. Our results suggested that these canine organs may be affected by influenza virus infection. The findings from our study will also help evaluate the occurrence and development of influenza virus infections in dogs.
Animals ; Dog Diseases/metabolism ; Dogs/metabolism/*virology ; Female ; Influenza A Virus, H5N1 Subtype/*metabolism ; Maackia/chemistry ; Male ; N-Acetylneuraminic Acid/metabolism ; Organ Specificity ; Orthomyxoviridae Infections/metabolism/transmission/veterinary ; Plant Lectins/metabolism ; Receptors, Cell Surface/analysis/chemistry/metabolism ; Receptors, Virus/analysis/chemistry/*metabolism ; Sambucus nigra/chemistry

In order to study the roles of integrin beta6 in Foot-and-Mouth Disease Virus infection, pig integrin beta6 was firstly molecularly cloned from RNA of the tongue and lung of recovered pig infected experimentally with foot-and-mouth-disease virus (FMDV), and was compared with the beta6 gene of other animals available in GenBank at nucleotide and amino acid leves. GeneBank association number of the beta6 gene is EF432729. Pig integrin beta6 gene (2367bp) encodes a polypeptide of 788 amino acids consisting of 9 potential N-linked glycosylation sites, 3 Glycosaminoglycan attachment sites, a cGMP-dependent protein kinase phosphorylation site, 10 Protein kinase C phosphorylation sites, 2 EGF-like domains and 2 cysteine-rich regions. Pig integrin beta6 subunit has a 26-residue putative signal peptide, a 681-residue ectodomain, a 29-residue transmembrane domain, and a 52-residue cytoplasmic domain. 11 mutant nucleotides were found in beta6 gene coding region and 9 amino acids were changed. The nucleotide sequence similarity of integrin beta6 gene between rheses monkey, mouse, Norway rat, dog, guinea pig, human, bovine, sheep is 79.5%, 84.9%, 85.4%, 85.2%, 88.7%, 90.1%, 91.9% and 91.9%, and the amino acid sequence similarity is 93.5%, 88.2%, 88.5%, 88.3%, 91.0%, 92.8%, 93.3% and 93.4% respectively. This study will lay a foundation for understanding the interactions of FMDV with receptors.
Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; Foot-and-Mouth Disease Virus ; pathogenicity ; Integrin beta Chains ; genetics ; metabolism ; Molecular Sequence Data ; Mutation ; Receptors, Virus ; genetics ; metabolism ; Sequence Analysis ; Swine ; genetics

Receptors play a crucial role in determining the pathogenesis and tissue tropism of virus. Foot-and-mouth disease virus (FMDV) has been showed to use four integrins, alphavbeta1, alphavbeta3, alphavbeta6 and alphavbeta8 as receptors to initiate infection. In this study, the porcine integrin alphav gene was cloned by RT-PCR from the lung tissue of healed pig infected experimently with FMDV, and compared its nucleotide and deduced amino acid sequence with the av gene of other animals. The 3141bp cDNA of bovine integrin alphav encodes a polypeptide of 1046 amino acids consisting of a 30-residue putative signal peptide, a 955-residue ectodomain, a 29-residue transmembrane domain, and a 32-residue cytoplasmic domain. The ectodomain contains 11 potential N-linked glycosylation sites (NXT/NXS), 2 calcium binding domains (DX[D/N] XDGXXD) and 18 cysteine residues. The nucleotide sequence similarities of integrin alphav between pig and cattle, human, rheses monkey, house mouse, chicken, dog are 93.3%, 91.5%, 91.4%, 85.6%, 73.2% and 89.9% respectively; and the amino acid sequence similarities are 96.3%, 94.6%, 94.1%, 90.8%, 81.6% and 93.8%, respectively. The alphav gene of cattle and pig exhibited the highest sequence homology. It is possible that host tropism of FMDV may related to divergence in receptors among different species.
Amino Acid Sequence ; Animals ; Base Sequence ; Cattle ; Cloning, Molecular ; DNA, Complementary ; genetics ; Foot-and-Mouth Disease Virus ; physiology ; Integrin alphaV ; genetics ; Macaca mulatta ; Molecular Sequence Data ; Receptors, Virus ; genetics ; metabolism ; Sequence Analysis ; Swine ; genetics

Recovery from hepatitis B virus (HBV) infection depends on the cellular immune responses. Chemokines and their receptors play significant roles in immune defense. This study was undertaken to investigate the association between HBV infection and single nucleotide polymorphisms (SNPs) of genes for the chemokines and their receptors. Between March 2002 and February 2004, a total of 957 single ethnic Korean patients were enrolled into two different groups; "HBV clearance group" (n=350), who have recovered from HBV infection, and "HBV persistence group" (n=607), who were repeatedly HBsAg-positive. The HBV persistence group was subdivided into "inactive carrier" and "HBV progression group (chronic hepatitis and cirrhosis)". We assessed polymorphisms in regulated and normal T-cell expressed and secreted (RANTES) at position -403, monocyte chemoattractant protein-1 (MCP-1) at position -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T and CXCR4 I138I using single primer extension assay. Genotype distributions of the "HBV clearance versus persistence group" and "inactive carrier versus HBV progression group" were compared. On the basis of unconditional logistic regression analysis with adjustment for age and sex, no statistically significant association with susceptibility to persistent HBV infection was observed with RANTES -403, MCP-1 -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T, and CXCR4 I138I polymorphisms. In addition, no association of analyzed SNPs with HBV disease progression was found.
Chemokine CCL2/*genetics ; Chemokine CCL5/*genetics ; Disease Progression ; Genotype ; Hepatitis B/ethnology/*genetics/*therapy ; Hepatitis B virus/metabolism ; Humans ; Korea ; *Polymorphism, Genetic ; Receptors, CCR2 ; Receptors, CCR5/*genetics ; Receptors, CXCR4/*genetics ; Receptors, Chemokine/*genetics ; Receptors, Interleukin-8A/*genetics ; Regression Analysis ; Treatment Outcome

OBJECTIVETo study the mechanism underlying the inhibitory effect of the anti-HIV peptide VIR576 on antigen-specific T cell activation.

METHODSCCK-8 assay was used to investigate the effect of VIR576 on the proliferation of splenocytes of OVA-specific DO11.10 Tg mice in response to chicken OVA. Hemolysis test, hemolysis inhibition assay and fluorescence binding assay were used to investigate the interaction of VIR576 with the transmembrane domain (TMD) of the T cell receptor (TCR).

RESULTSVIR576 inhibited HIV glycoprotein gp41 fusion peptide-mediated antigen specific T cell activation, and VIR576 itself also inhibited splenocyte proliferation in responses to OVA (P<0.05). Hemolysis test, hemolysis inhibition assay and fluorescence binding assay demonstrated that VIR576 suppressed TCR-TMD-mediated hemolysis and competitively inhibited Rho-VIR576 binding to TCR-TMD peptide.

CONCLUSIONVIR576 is effective in suppressing the antigen-specific T cell activation via TCR and can interact with TCR-TMD. VIR576 may serve as a potent microbicide candidate to block sexual transmission of HIV due to of its inhibitory effect on both HIV entry and antigen-specific T cell activation.

Animals ; Anti-HIV Agents ; pharmacology ; Cell Membrane ; metabolism ; HIV Infections ; prevention & control ; Humans ; Lymphocyte Activation ; drug effects ; Mice ; Receptors, Antigen, T-Cell ; immunology ; Sincalide ; analysis ; Spleen ; cytology ; immunology ; T-Lymphocytes ; immunology ; Virus Internalization ; drug effects

Betacoronavirus ; isolation & purification ; pathogenicity ; Bile Acids and Salts ; metabolism ; Bile Ducts, Intrahepatic ; pathology ; virology ; Cell Culture Techniques ; Coronavirus Infections ; complications ; pathology ; Cytokine Release Syndrome ; etiology ; physiopathology ; Cytopathogenic Effect, Viral ; Epithelial Cells ; enzymology ; pathology ; virology ; Humans ; Hyperbilirubinemia ; etiology ; Liver ; pathology ; Organoids ; pathology ; virology ; Pandemics ; Peptidyl-Dipeptidase A ; analysis ; Pneumonia, Viral ; complications ; pathology ; Receptors, Virus ; analysis ; Serine Endopeptidases ; analysis ; Viral Load

OBJECTIVETo study the expression of Galectin-9 and Tim-3 in lungs of mice with asthma and the effect of rosiglitazone (PPAR-γ agonist) on their expression.

METHODSFortyfive BALB/c SPF female mice were randomized into control group and asthma groups with and without rosiglitazone intervention. After ovalbumin stimulation and rosiglitazone intervention the pathological changes of the lung tissues were observed. Galectin-9 and Tim-3 mRNA levels in lung tissues were determined using RT-PCR. The levels of IL-4 and IFN-γ in peripheral blood were measured using ELISA.

RESULTSThe expression of Galectin-9 and Tim-3 mRNA of lung tissues in the untreated asthma group increased significantly compared with the control and the rosiglitazone treated groups (P<0.05). A significantly increased blood expression of IL-4 and a significantly decreased blood expression of IFN-γ were found in the untreated asthma group compared with the control and the rosiglitazone-treated groups (P<0.05). The expression of Galectin-9 and Tim-3 mRNA was positively correlated with blood IL-4 level (r=0.792, r=0.794 respectively; P<0.05), but negatively correlated with blood IFN-γ level (r=-0.692, r=-0.757 respectively; P<0.05).

CONCLUSIONSGalectin-9 and Tim-3 mRNA levels in lungs increase in mice with asthma and significantly correlate with the levels of blood Th1/Th2 cytokines. This suggests that Galectin-9 and Tim-3 are closely related to inflammatory process in asthma. Rosiglitazone treatment may decrease the expression of Galectin-9 and Tim-3.

Animals ; Asthma ; drug therapy ; immunology ; pathology ; Female ; Galectins ; genetics ; Hepatitis A Virus Cellular Receptor 2 ; Interferon-gamma ; blood ; Interleukin-4 ; blood ; Lung ; metabolism ; pathology ; Mice ; Mice, Inbred BALB C ; PPAR gamma ; physiology ; RNA, Messenger ; analysis ; Receptors, Virus ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Th1 Cells ; immunology ; Th2 Cells ; immunology ; Thiazolidinediones ; therapeutic use