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At least 199 records · Page 11Linked to original sources
PubMed1975

Corneal endothelium in viral induced anterior uveitis. Ultrastructural changes following canine adenovirus type 1 infection.

Dogs inoculated intravenously with attenuated canine adenovirus type 1 developed anterior segment inflammation and corneal edema. During the stage of mild anterior uveitis, virus was isolated from the aquious fluid, and by electron microscopy, viral replication was found to occur in corneal endothelial cells. Later, at the stage of severe anterior uveitis with corneal edema, virus was not isolated from the aqueous fluid and cells containing intranuclear (replicating) virus were not found. At this stage, many inflammatory cells had infiltrated the anterior chamber and contained numerous membrane-bound viral aggregates (viral-antibody complexes). Phagocytized viral-antibody complexes were present in the areas of most prominent endothelial cell destruction. Peripheral to the principal lesion sites, inflammatory cells had dissected the endothelium from Descemet membrane. After recovery from the disease, an intact endothelial cell layer was present.

Animals↗
PubMed1982

[The behavior of circulating immune complexes in acute viral hepatitis].

The authors analyse the behaviour of the circulating immune complexes in acute virus hepatitides with and without HBs antigenaemia in correlation with the bilirubin level and the transaminases. No essential differences were found depending on the severity of the lesion of the liver parenchyma and on the proof of the HBs-antigen. Constantly increased immune complexes were found during the whole period of observation. It seems that 4 weeks after the beginning of the disease a normalisation of the immunogenic reactivity and an end of the elimination of the causative organism did not yet appear.

Adolescent↗
PubMed2006

Proteomics analysis of the tombusvirus replicase: Hsp70 molecular chaperone is associated with the replicase and enhances viral RNA replication.

Plus-strand RNA virus replication occurs via the assembly of viral replicase complexes involving multiple viral and host proteins. To identify host proteins present in the cucumber necrosis tombusvirus (CNV) replicase, we affinity purified functional viral replicase complexes from yeast. Mass spectrometry analysis of proteins resolved by two-dimensional gel electrophoresis revealed the presence of CNV p33 and p92 replicase proteins as well as four major host proteins in the CNV replicase. The host proteins included the Ssa1/2p molecular chaperones (yeast homologues of Hsp70 proteins), Tdh2/3p (glyceraldehyde-3-phosphate dehydrogenase, an RNA-binding protein), Pdc1p (pyruvate decarboxylase), and an unknown approximately 35-kDa acidic protein. Copurification experiments demonstrated that Ssa1p bound to p33 replication protein in vivo, and surface plasmon resonance measurements with purified recombinant proteins confirmed this interaction in vitro. The double mutant strain (ssa1 ssa2) showed 75% reduction in viral RNA accumulation, whereas overexpression of either Ssa1p or Ssa2p stimulated viral RNA replication by approximately threefold. The activity of the purified CNV replicase correlated with viral RNA replication in the above-mentioned ssa1 ssa2 mutant and in the Ssa overexpression strains, suggesting that Ssa1/2p likely plays an important role in the assembly of the CNV replicase.

Adenosine Triphosphatases↗
PubMed1993

Structure of a human rhinovirus-bivalently bound antibody complex: implications for viral neutralization and antibody flexibility.

The structure of a neutralizing immunoglobulin (monoclonal antibody mAb17-IA), bound to human rhinovirus 14 (HRV14), has been determined by cryo-electron microscopy and image reconstruction. The antibody bound bivalently across icosahedral twofold axes of the virus, and there were no detectable conformational changes in the capsid. Thus, bivalently bound IgGs do not appear to cause gross deformations in the capsid. Differences between the electron density of the constant domains of the bound Fab fragment and IgG structures suggested that conformational changes occur about elbow axes upon bivalent attachment as was previously predicted. No significant density was observed for the Fc fragment, which adds further evidence for a high degree of mobility about the hinge region.

Antibodies, Viral↗
PubMed1978

Virus-induced immune complex disease: identification of specific viral antigens and antibodies deposited in complexes during chronic lymphocytic choriomeningitis virus infection.

Structural proteins of LCMV were identified and their role in the immune complex glomerulonephritis of LCMV carrier mice was examined. Purified LCMV contained three major polypeptides, a single nonglycosylated nucleoprotein with an estimated m.w. of 63,000, and two surface glycoproteins of 54,000 and 35,000. Deposition of nucleoprotein antigen in the glomeruli of LCMV carrier mice of several strains was demonstrated by immunofluorescent staining with a monospecific antibody. In addition, Ig eluted from kidneys of three strains of LCMV carrier mice was shown by immune precipitation to react against all of major viral polypeptides of LCMV. Antibody from normal mice, and from mice with immune complex disease unrelated to LCMV did not show deposition of LCMV antigen in glomeruli, and Ig eluted from the kidneys of these mice did not react against LCMV antigens. Hence, mice infected at birth with LCMV and persistently infected throughout their life make antibodies to all the known structural polypeptides of the virus.

Animals↗
PubMed1977

Studies on viral DNA protein complexes isolated at different times after infection of monkey kidney cells with simian virus 40.

The major protein components of the DNA complex, isolated from SV40-infected monkey cells, are the major viral structural polypeptide VP1 and cellular histones. At early times (24 h) after infection, VP1 is present in large amounts relative to histones, whereas at late times (48 h), the complex contains mostly histones. The amount of VP1 in the complex can be correlated to the amount of "free" VP1 present in the cells, i.e. VP1 not yet incorporated into virus particles. At early times about 40% of VP1 is "free" VP1; at late times, most of the VP1 is incorporated into virus particles. In contrast, viral DNA is produced in huge excess and only about 13% is incorporated into virions. In agreement with the above result, we find that only about 16% of the DNA in the DNA complex can be chased into virions. There is, apparently, no turnover of newly synthesized VP1 that is associated with the DNA complex at late times after infection.

Animals↗
PubMed2005

Toll-like receptor-7 modulates immune complex glomerulonephritis.

Viral infections may trigger immune complex glomerulonephritis via Toll-like receptors (TLR), as certain TLR trigger immunity upon recognition of viral nucleic acids. On the basis of previous findings regarding viral double-stranded RNA and TLR3 in experimental lupus erythematosus, a similar role for TLR7 that recognizes viral single-stranded RNA was hypothesized. Immunostaining of kidney sections of nephritic MRLlpr/lpr mice revealed TLR7 expression in infiltrating ER-HR3-positive macrophages and few CD11c-positive dendritic cells but not in glomerular mesangial cells as observed for TLR3. This finding was consistent with the distribution pattern of intravenously injected single-stranded RNA in nephritic MRLlpr/lpr mice. TLR7 ligation activated monocytes and dendritic cells, both isolated from MRLlpr/lpr mice, to secrete IFN-alpha, IL-12p70, IL-6, and CCL2. In vivo, a single injection of the TLR7 ligand imiquimod increased serum levels of IL-12p70, IFN-alpha, and IL-6. A course of 25 microg of imiquimod given every other day from week 16 to 18 of age aggravated lupus nephritis in MRLlpr/lpr mice. This was associated with increased glomerular immune complex deposits as well as interstitial expression of CCL2 in imiquimod-treated MRLlpr/lpr mice. Different types of viral nucleic acids seem to modulate systemic autoimmunity through specific interactions with their respective TLR. Different TLR expression profiles on immune cell subsets and nonimmune parenchymal cell types determine the molecular mechanisms involved in viral infection-associated exacerbation of lupus nephritis and possibly other types of immune complex glomerulonephritis.

Aminoquinolines↗
PubMed1976

Pathogenesis of cytomegalovirus infection. Distribution of viral products, immune complexes and autoimmunity during latent murine infection.

During studies on the mechanisms of virus latency, reactivation and resultant tissue injury in mice infected with murine cytomegalovirus (MCMV) in utero or at birth, we found the occurrence of three distinct pathological groups. In the first group, mice died within 4 weeks of exposure to virus and showed evidence of tissue injury due to MCMV in multiple tissues and organs of the body. The second group consisted of mice which survived the initial infection and was composed of a minority (about 25%) which shed virus (chronically infected). The third group (about 75%) consisted of mice in which shedding of virus could not be detected (latently infected). Study of the latter group indicated that virus was not detected in brain, thymus, liver, kidneys, urine or serum by co-cultivation techniques or by cellular DNA-MCMV DNA hybridization. In contrast, virus could be activated from spleen cells by co-cultivation with allogenic but not syngeneic feeder cells and MCMV-DNA was detected in amounts equivalent to 3 to 4 virus genomes per 100 spleen cells. In both the latently infected and chronically infected mice, in all strains studied evidence of virus-antivirus immune complex deposits in the renal glomeruli occurred. Only one of the six infected strains (C57 Br/cdJ) studied showed manifestations of autoimmune disease with the formation of antibodies to nuclear antigens, DNA and soluble nucleoprotein.

Animals↗
PubMed2003

Does a viral infection cause complex regional pain syndrome?

In 1990 Omura, Y. reported that Herpes Simplex Virus Type 1 as the major cause of chronic intractable pain and its effective treatment using mixture of EPA & DHA with Selective Drug Uptake Enhancement Method. Subsequently among the other causes of pain, he included Chlamydia Trachomatis, Borrelia Burgdorferi, Mycobacterium Tuberculosis, human Herpes Virus type 6, and Circulatory Disturbances. In order to test possible involvement of viral infection in Complex Regional Pain Syndrome (CRPS), a disease which usually occurs in the extremities, we did a study of 17 patients with CRPS. They were examined for Herpes Simplex Virus (HSV) and Varicella Zoster Virus (VZV) by measuring IgG and IgM antibody titers, and 14 of these patients were also examined for Cytomegalo-Virus (CMV). As a control group 100 healthy Japanese employees at SRL, Inc. were also studied. In CRPS group, HSV IgG was positive in 12 of the 17 patients with an average antibody titer of 90.0 EIA value. VZV IgG was positive in all 17 patients with an average antibody titer of 26.8 EIA value. CMV IgG was positive in all 14 patients with an average antibody titer of 66.6 UA/ml. In control group, HSV IgG was positive in 54 subjects with an average antibody titer of 42.3 EIA value. VZV IgG was positive in 97 subjects with an average antibody titer of 26.2 EIA value. CMV IgG was positive in 82 subjects. There were no significant differences of positive rate of IgG antibody for the three viruses between patient and control groups. Although the difference was not significant, the average antibody titers of HSV in CRPS group were more than twice of those in healthy group. Antibody titers were almost equal in both groups for VZV. Possibly, some people in the control group who had latent virus, were also asymptomatic. In 2000, Takasaki, I. et al. in a separate animal study, inoculated with HSV Type-I the shin of the mouse causing allodynia and hyperalgesia (which are some of the characteristic findings seen in CRPS in humans). Also, VZV, which causes shingles which is sometimes followed by Post-Herpetic Neuralgia (PHN), is in the same family of HSV. As PHN resembles CRPS in symptoms, it is possible that HSV contributes to CRPS. Therefore, virus infection theory is an attractive hypothesis that accounts for many enigmas of CRPS.

Adolescent↗
PubMed2004

Complex patterns of viral load decay under antiretroviral therapy: influence of pharmacokinetics and intracellular delay.

We present a model of HIV dynamics under antiretroviral therapy that combines drug pharmacokinetics and intracellular delay. A two compartment pharmacokinetic model is employed to determine the time evolution of the intracellular concentrations of the active forms of drugs, and thereby drug efficacy. The viral replication period is divided into pre- and post-drug action parts, allowing for the introduction of an intracellular delay in drug action. The standard model of viral dynamics is modified to account for the drug dependence of intracellular delay and continuously varying drug efficacy. Model calculations reveal that viral load decay in HIV infected patients under monotherapy can exhibit remarkably complex patterns depending on the relative magnitudes of the pharmacokinetic, intracellular, and intrinsic viral dynamic time-scales. The commonly assumed exponential decay is only a special case. However, uncertainties in measurement and the low sampling frequencies employed in present clinical studies preclude the identification of these patterns from existing clinical viral load data.

Adenine↗
PubMedDate not supplied

In situ distribution of major histocompatibility complex products and viral antigens in chronic hepatitis B virus infection: evidence that HBc-containing hepatocytes may express HLA-DR antigens.

Using a double-staining immunohistochemical procedure, the topographical relationship between viral antigens on the one hand and the expression of major histocompatibility complex products by hepatocytes on the other hand was analyzed in a series of 19 liver biopsies from patients with chronic hepatitis B virus infection. In areas of piecemeal necrosis, periportal hepatocytes demonstrated Class I major histocompatibility complex products or HLA-A, B and C antigens, but did not show a preferential expression of either HBcAg or HBsAg. The cellular infiltrate of piecemeal necrosis consisted of helper/inducer and suppressor/cytotoxic T-lymphocytes, and was admixed in four cases with branching dendritic processes of sinusoidal lining cells which strongly expressed Class II major histocompatibility complex products or HLA-DR antigens. The latter surrounded small groups of periportal hepatocytes. In areas of spotty necrosis, the hepatocytes expressed HLA-A, B and C antigens in all cases, and were admixed with variable numbers of suppressor/cytotoxic T-lymphocytes. In 14 cases, the clustered hepatocytes in areas of spotty necrosis expressed HLA-DR antigens, associated in 11 of the cases with immunoreactive HBcAg in the nuclei of some of the HLA-DR-positive hepatocytes. Immunoelectron microscopy, performed in one such case, demonstrated the presence of HLA-DR antigen in a discontinuous pattern at the plasma membrane of some hepatocytes, together with the presence of core particles in the nucleus of HLA-DR-positive hepatocytes. Our findings further contribute to the growing evidence that HBcAg represents the major target antigen for T-cell attack in areas of spotty necrosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, Viral↗
PubMed1993

Application of the immune complex for immune protection against viral disease.

An immune complex (IC), composed of antigenic subunits of the Newcastle disease virus (NDV) and specific polyclonal allogeneic antibodies, was used to protect chickens against NDV. Antibodies in the IC were chicken immunoglobulin G. The antibody:antigen ratio in IC was 2.03. The IC was prepared at equivalence by direct mixing of NDV-infected allantoic fluid, treated with Triton X-100, and chicken anti-NDV serum. In order to bind NDV antigenic subunits to specific antibodies, previous isolation and purification of antigen is not required. Chickens were immunized with 1 mg IC, containing 0.3788 mg of viral antigens. The IC, prepared in the form of an oil-emulsion, was administered intramuscularly. The IC generated high levels of anti-NDV antibodies and successfully protected chickens against live virus challenge. Therefore, the IC could be recommended as a safe and environmentally convenient vaccine.

Animals↗
PubMed2005

Purification, crystallization and preliminary X-ray diffraction analysis of the human major histocompatibility antigen HLA-B*2703 complexed with a viral peptide and with a self-peptide.

The product of the human leukocyte antigen (HLA) gene HLA-B*2703 differs from that of the prototypical subtype HLA-B*2705 by a single amino acid at heavy-chain residue 59 that is involved in anchoring the peptide N-terminus within the A pocket of the molecule. Two B*2703-peptide complexes were crystallized using the hanging-drop vapour-diffusion method using PEG 8000 as a precipitant. The crystals belong to space group P2(1) (pVIPR peptide) or P2(1)2(1)2(1) (pLMP2 peptide). Data sets were collected to 1.55 A (B*2703-pVIPR) or 2.0 A (B*2703-pLMP2) resolution using synchrotron radiation. With B*2705-pVIPR as a search model, a clear molecular-replacement solution was found for both B*2703 complexes.

Antigen-Antibody Complex↗
PubMed2006

Need for tripeptidyl-peptidase II in major histocompatibility complex class I viral antigen processing when proteasomes are detrimental.

CD8(+) T lymphocytes recognize infected cells that display virus-derived antigenic peptides complexed with major histocompatibility complex class I molecules. Peptides are mainly byproducts of cellular protein turnover by cytosolic proteasomes. Cytosolic tripeptidyl-peptidase II (TPPII) also participates in protein degradation. Several peptidic epitopes unexpectedly do not require proteasomes, but it is unclear which proteases generate them. We studied antigen processing of influenza virus nucleoprotein epitope NP(147-155), an archetype epitope that is even destroyed by a proteasome-mediated mechanism. TPPII, with the assistance of endoplasmic reticulum trimming metallo-aminopeptidases, probably ERAAP (endoplasmic reticulum aminopeptidase associated with antigen processing), was crucial for nucleoprotein epitope generation both in the presence of functional proteasomes and when blocked by lactacystin, as shown with specific chemical inhibitors and gene silencing. Different protein contexts and subcellular targeting all allowed epitope processing by TPPII as well as trimming. The results show the plasticity of the cell's assortment of proteases for providing ligands for recognition by antiviral CD8(+) T cells. Our observations identify for the first time a set of proteases competent for antigen processing of an epitope that is susceptible to destruction by proteasomes.

Acetylcysteine↗
PubMed1975

Synthesis of fibroma viral deoxyribonucleic acid complexes in rabbit kidney cells.

Cytoplasmic extracts of primary rabbit kidney cells inoculated with fibroma virus revealed 2 peaks of DNA complexes (120S and greater than or equal to 410S) in a linear sucrose gradient. Pulse-chase experiments demonstrated a shift in the gradient profile of lighter complexes toward heavier complexes. Synthesis of DNA complexes was inhibited by adding puromycin or actinomycin D. The DNA from virus-infected cultures hybridized 7 to 9 times greater with fibroma virus DNA than did the DNA from noninfected cultuures. The DNA complexes became increasingly resistant to deoxyribonuclease digestion as a function of time during viral growth cycle and produced tumors in rabbits.

DNA, Viral↗