The glycoprotein 3 (GP3) of type II porcine reproductive and respiratory syndrome virus has the characteristic domains of a membrane protein. However, this protein has been reported to be retained in the endoplasmic reticulum (ER) rather than transported to the plasma membrane of the cell. In this study, we performed confocal laser scanning microscopy analysis of variants of GP3 and foundthat the signal sequence of the GP3 led to confinement of GP3 in the ER, while the functional ortransmembrane domain did not affect its localization. Based on these results, we concludedthat the signal sequence of GP3 contains the ER retention signal, which might play an important role in assembly of viral proteins.
Animals ; Cell Line ; Cell Membrane/*metabolism/virology ; Cricetinae ; Endoplasmic Reticulum/*metabolism/virology ; Microscopy, Confocal/veterinary ; Plasmids/genetics/metabolism ; Porcine respiratory and reproductive syndrome virus/*genetics/metabolism ; *Protein Sorting Signals ; Sequence Analysis, Protein/veterinary ; Viral Envelope Proteins/chemistry/*genetics/metabolism

Human T cell leukemia virus type 1 (HTLV-1), an etiological factor that causes adult T cell leukemia and lymphoma (ATL), infects over 20 million people worldwide. About 1 million of HTLV-1-infected patients develop ATL, a highly aggressive non-Hodgkin's lymphoma without an effective therapy. The pX region of the HTLV-1 viral genome encodes an oncogenic protein, Tax, which plays a central role in transforming CD4+ T lymphocytes by deregulating oncogenic signaling pathways and promoting cell cycle progression. Expression of Tax following viral entry is critical for promoting survival and proliferation of human T cells and is required for initiation of oncogenesis. Tax exhibits diverse functions in host cells, and this oncoprotein primarily targets IκB kinase complex in the cytoplasm, resulting in persistent activation of NF-κB and upregulation of its responsive gene expressions that are crucial for T cell survival and cell cycle progression. We here review recent advances for the pathological roles of Tax in modulating IκB kinase activity. We also discuss our recent observation that Tax connects the IκB kinase complex to autophagy pathways. Understanding Tax-mediated pathogenesis will provide insights into development of new therapeutics in controlling HTLV-1-associated diseases.
Autophagy ; CD4-Positive T-Lymphocytes ; metabolism ; virology ; Cell Cycle ; Cell Transformation, Neoplastic ; genetics ; Gene Expression Regulation, Neoplastic ; Gene Products, tax ; genetics ; metabolism ; Human T-lymphotropic virus 1 ; physiology ; Humans ; I-kappa B Kinase ; genetics ; metabolism ; Leukemia-Lymphoma, Adult T-Cell ; genetics ; metabolism ; virology ; Membrane Microdomains ; metabolism ; virology ; NF-kappa B ; genetics ; metabolism ; Protein Binding ; Signal Transduction ; genetics

OBJECTIVETo investigate the expression of matrix metalloproteinase 9 (MMP9) in mucosal natural killer/T cell and mature T cell lymphomas and its relation to Epstein-Barr virus (EBV) infection.

METHODSThe expression of MMP9 and EBV-encoded RNA (EBER) were detected by immunohistochemistry and in situ hybridization in 59 cases of mucosal natural killer/T cell and mature T cell lymphomas.

RESULTSThe positivity rates of MMP9 and EBERs were 83.05% and 72.88% respectively. The positivity rate of EBERs was correlated with histopathological subtype (P<0.05), but not with clinical stage, vascular invasion or the patients' survival time (P>0.05). The expression level of MMP9 was not correlated with the clinical stage, vascular invasion or survival time (P>0.05). No significant correlation was found between MMP9 expression and EBV infection.

CONCLUSIONEBV may play an important role in the development of mucosal natural killer/T cell and mature T cell lymphomas and promote disease progression by up-regulating MMP9 expression indirectly. Elimination of EBV infection may be helpful to prevent the development of lymphoma.

Female ; Gene Expression Regulation, Neoplastic ; Herpesvirus 4, Human ; physiology ; Humans ; Lymphoma, T-Cell ; genetics ; pathology ; virology ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Mucous Membrane ; pathology ; virology ; Natural Killer T-Cells ; pathology ; virology

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

To study the effect of simian vacuolating virus 40 (SV40) on development and differentiation of dendritic cells (DC) from rhesus macaque, the peripheral blood-derived dendritic cells from rhesus monkey were pulsed with inactivated SV40 and infective SV40, respectively at the 5th day post DC cultivation. Expressions of CD1a, HLA-DR, CD86 and CD83 on the cell surface at the 7th, 9th day post DC cultivation were analyzed by flow cytometry (FCM). The results showed that expressions of CD1a, HLA-DR, CD86 and CD83 on the cell surface in the inactivated SV40-pulsed experimental group were higher than those in the infective SV40-pulsed experimental group (P < 0.05). These cell surface molecules represented characteristic development and differentiation phase of DC. Down-regulation of expressions of these cell surface molecules indicated that infective SV40 might hamper differentiation and maturation of dendritic cells from rhesus monkey.
Animals ; Antigens, CD ; metabolism ; Antigens, CD1 ; metabolism ; B7-2 Antigen ; metabolism ; Cell Differentiation ; Cells, Cultured ; Dendritic Cells ; cytology ; immunology ; virology ; Flow Cytometry ; HLA-DR Antigens ; metabolism ; Immunoglobulins ; metabolism ; Macaca mulatta ; Membrane Glycoproteins ; metabolism ; Polyomavirus Infections ; physiopathology ; Simian virus 40 ; physiology

The incidence of posttransplantation lymphoproliferative disorders (PTLDs) has increased in recent years. Although rare, various types of T-cell lymphoma have been reported and their association with Epstein-Barr virus (EBV) has been compared with B-cell PTLDs. We report a case of splenic peripheral T-cell lymphoma occurring in a 47-yr-old male patient 7 yr after renal allograft transplantation. The spleen showed sinusoidal proliferation of focal CD30 positive, large, atypical lymphoid cells. Positivity for CD3 and cytolytic granule-associated proteins was also demonstrated in the tumor cells, while anaplastic large cell lymphoma kinase (ALK) and CD8 were not expressed. Strong nuclear signals for EBV mRNA were noted by EBER1 in situ hybridization. A molecular genetic study demonstrated a rearrangement of the gamma T-cell receptor gene. To our knowledge, this case is unique in terms of a posttransplant T-cell lymphoma that shows focal CD30, cytolytic granule-associated proteins, and EBV positivity.
Antigens, CD30/genetics ; Antigens, CD30/metabolism ; Herpesvirus 4, Human/genetics ; Herpesvirus 4, Human/metabolism* ; Human ; Kidney Transplantation* ; Lymphoma, T-Cell, Peripheral/pathology ; Lymphoma, T-Cell, Peripheral/virology* ; Male ; Membrane Proteins/metabolism ; Middle Aged ; RNA, Viral ; RNA-Binding Proteins/metabolism ; Serine Endopeptidases/metabolism ; Splenic Neoplasms/pathology ; Splenic Neoplasms/virology*

To study the impact of the enterovirus 71(EV71) on the nuclear transport mechanism,The pGFP-NLS vector with nuclear location signal(NLS) was constructed, RD cells transfected by the pGFP-NLS vector were inoculated with the EV71 or cotransfected by EV71-2A vector. The results showed that GFP protein with NLS was expressed in the cytoplasm due to the inhibition of nuclear transport. In order to further study the mechanism of the EV71 to prevent nuclear transport,Nup62 was detected by Western blotting after RD cells were infected with EV71 or transfected by EV71-2A vector. The results showed that decreased expression of Nup62 could be detected after infection with EV71 and transfection by EV71-2A vector. This study demonstrates that the cleavage of Nup62 by EV71 2A protease may be the mechanism of nuclear transport inhibition.
Active Transport, Cell Nucleus ; Cell Line, Tumor ; Cell Nucleus ; metabolism ; Enterovirus A, Human ; enzymology ; genetics ; metabolism ; Enterovirus Infections ; virology ; Gene Expression Regulation, Viral ; Genetic Vectors ; Green Fluorescent Proteins ; metabolism ; Humans ; Membrane Glycoproteins ; metabolism ; Nuclear Localization Signals ; metabolism ; Nuclear Pore Complex Proteins ; metabolism ; Peptide Hydrolases ; metabolism ; Recombinant Fusion Proteins ; metabolism ; Transfection

OBJECTIVETo construct hu-PBL/SCID chimeras and to investigate the development of lymphoma and oncogenicity of the Epstein-Barr virus (EBV).

METHODSHuman peripheral blood lymphocytes (PBLs) were isolated from healthy adult donors and transplanted intraperitoneally into severe combined immunodeficient (SCID) mice. Mice with hu-PBL engraftment from healthy EBV seronegative donors were injected intraperitoneally with EBV-containing supernatant from suspension culture of B95-8 cell line (active infection), whereas mice receiving lymphocytes from healthy EBV seropositive donors were not re-infected with B95-8 derived EBV (latent infection). Pathological examination and molecular analysis were performed on experimental animals and induced neoplasms.

RESULTSIn the early stage of this experiment, 12 mice died of acute graft-versus-host disease, mortality was 34.3% (12/35 mice) with an average life span of 17.5 days. In 19 survival hu-PBL/SCID chimeric recipients from 12 healthy donors, tumor incidence was 84.2% (16/19 mice). The average survival time of tumor-bearing mice was 65.5 days. EBV-related neoplasms in SCID mice were nodular tumors with aggressive and fatal features. Histological morphology of tumors exhibited diffuse large cell lymphomas. Immunohistochemistry revealed that LCA (CD45) and L26 (CD20) were positive, but both PS1 (CD3) and UCHL-1 (CD45RO) were negative, and EBV products ZEBRA, LMP1, and EBNA2 were expressed in a small number of tumor cells. EB virus particles were seen in the nuclei of some tumor cells by electron microscopy, and EBV DNA could be amplified in the tumor tissues by PCR. In situ hybridization indicated that the nuclei of tumor cells contained human-specific Alu sequence.

CONCLUSIONSEBV-induced tumors were human B-cell malignant lymphomas. We obtained direct causative evidence dealing with EBV-associated tumor deriving from normal human cells.

Adult ; Animals ; Antigens, CD20 ; metabolism ; Chimera ; Epstein-Barr Virus Infections ; immunology ; virology ; Graft vs Host Disease ; prevention & control ; virology ; Herpesvirus 4, Human ; physiology ; Humans ; Leukocyte Common Antigens ; metabolism ; Leukocyte Transfusion ; methods ; Lymphoma, B-Cell ; immunology ; virology ; Lysosomal-Associated Membrane Protein 1 ; metabolism ; Mice ; Mice, SCID

In order to research into the cytology mechanism of anti-virus action of total flavone of Scutellaria barbata (TFSB), the effects of TFSB on host cells membrane potential, Na(+)-K(+)-ATPase activity and membrane fluidity after parainfluenza virus type1 (PIV-1) infection were studied. The changes of membrane potential which was fluorescent labeled with DiBAC4(3) and its changes were measured by flow cytometer. Phosphorus determination method and spectrophotometry were used to measure the Na(+)-K(+)-ATPase activity of Hep-2 cells membrane after PIV-1 infection. Hep-2 cells membrane phospholipids were fluorescent labeled with NBD-C6-HPC and membrane fluidity was measured by confocal scanning laser microscope. The result demonstrated that post PIV-1 infection membrane potential decreased significantly and the membrane was in a state of hyperpolarization, Na(+)-K(+)-ATPase activity increased significantly and membrane fluidity decreased significantly. There was no apparent interfere effect of TFSB on the changes of membrane potential and Na(+)-K(+)-ATPase activity after PIV-1 infection, while membrane fluidity improved significantly. It was indicated that the cytology mechanism of PIV-1 infection might be related to membrane hyperpolarization, Na(+)-K(+)-ATPase activity increase and membrane fluidity decrease. TFSB can improve membrane fluidity and prevent the infection by protecting the cell membrane. But it is possible that the anti-PIV-1 mechanisms of TFSB had nothing to do with membrane potential and Na(+)-K(+)-ATPase activity.
Antiviral Agents ; isolation & purification ; pharmacology ; Cell Line, Tumor ; Cell Membrane ; drug effects ; Flavones ; isolation & purification ; pharmacology ; Humans ; Laryngeal Neoplasms ; pathology ; virology ; Membrane Fluidity ; drug effects ; Membrane Potentials ; drug effects ; Parainfluenza Virus 1, Human ; drug effects ; Phospholipids ; metabolism ; Plants, Medicinal ; chemistry ; Respirovirus Infections ; drug therapy ; Scutellaria ; chemistry ; Sodium-Potassium-Exchanging ATPase ; metabolism

Lactobacillus casei 393 was selected as a bacterial carrier for the expression of Porcine Parvovirus (PPV) protective antigen VP2 protein. The gene encoding PPV VP2 protein was cloned into the Lactobacillus casei surface expression vector pPG, and then the constructed recombinant vector pPG-VP2 was electrotransformed into Lactobacillus casei 393 generating the recombinant system pPG-VP2/L. casei393 expressing PPV VP2 protein. The recombinant strain was induced by 2% Lactose in MRS and about 74kD protein was detected with SDS-PAGE. The result of Western-blot indicated that the expressed protein possessed the antigenic specificity which could be recognized by mouse anti-PPV serum. The indirect immunofluorescent test showed that the expressed protein was secreted on the cell surface Lactobacillus casei.
Animals ; Antigens, Viral ; genetics ; metabolism ; Blotting, Western ; Capsid Proteins ; genetics ; metabolism ; Cell Membrane ; metabolism ; Electrophoresis, Polyacrylamide Gel ; Fluorescent Antibody Technique ; Lactobacillus casei ; genetics ; metabolism ; Parvovirus, Porcine ; genetics ; metabolism ; Plasmids ; genetics ; Recombinant Proteins ; metabolism ; Swine ; virology ; Transformation, Genetic ; Viral Proteins ; genetics ; metabolism