1,721,069 research outputs found
Transient expression of human herpesvirus-8 (Kaposi's sarcoma-associated herpesvirus) ORF50 enhances HIV-1 replication
No full textOBJECTIVE: Human herpesvirus 8 (HHV-8) is the etiologic agent of Kaposi's sarcoma, the most common neoplasm in patients with acquired immunodeficiency syndrome. Current evidence indicates that activation of viral replication may be critical to the development of the disease. A key factor in the induction of HHV-8 lytic replication is ORF50, an immediate-early gene encoding a transactivating protein necessary for viral reactivation. We recently reported that ORF50 synergizes with HIV-1 TAT at a post-transcriptional level. To study the effects of these molecular interactions upon HIV replication and biology, cell lines of different origin were transiently transfected with ORF50 and subsequently infected with HIV. METHODS: Jurkat, BCBL-1 and A172 cells were transfected with ORF50 and subsequently infected with different MOI of HIV. The development of infection was evaluated by analyzing p24 antigen release, production of infectious HIV particles and the presence and transcription of HIV proviral DNA. RESULTS: ORF50 induced increased levels of HIV replication and production in CD4+ Jurkat T cells. Transfection of ORF50 into nonsusceptible B and glial cells (BCBL-1 and A172, respectively) increased cell susceptibility to infection and resulted in transient permissiveness to HIV replication. CONCLUSIONS: HIV replication can be significantly affected by the presence of HHV-8. Expression of ORF50 increases the efficiency of HIV infection in different cell types. This potentially could result in enhanced HIV spread within the infected organism and faster progression of the disease. Copyright 2003 S. Karger AG, Base
IMMUNIZZAZIONE PASSIVA CON SIERO POLICLONALE NELLA CHERATITE ERPETICA SPERIMENTALE
No full textDiversi studi sperimentali hanno dimostrato che anticorpi monoclonali diretti contro le principali glicoproteine virali sono in grado di proteggere il topolino dallo sviluppo di cheratite erpetica necrotizzante. Nel coniglio l'immunizzazione passiva è risultata meno efficace dell'immunoprofilassi attiva con vaccino a subunità (gB-1s) precedentemente sperimentato
Plaque dissociation of herpes sinplex viruses: biochemical and biological characters of the viral variants
No full textPolycaryocytogenic (P) and non-polycaryocytogenic, or aggregating (A), stable variants were selected from a herpes simplex virus type 1 (HSV-1) and from a herpes simplex virus type 2 (HSV-2) which had not been deliberately exposed to known mutagenic agents. The P variant of HSV-1 (FP) differed from the A variant (Fa) in polypeptides and glycoprotein patterns, but no gross differences were evident between the two variants of HSV-2 (GP and GA). Each P variant proved more ‘specific’ than each A variant in immune neutralization tests. At high multiplicity, GP produced polycaryocytes but FP did not. Virulence tests in mice showed FP to be much more virulent than FA but GA to be more virulent than GP. Finally, A and P variants of each type could not be differentiated with respect to thermal resistance of virions, capacity to grow at high temperature, and buoyant density of DNA. © 1975 by S. Karger AG, Basel
The heterogeneous regions in herpes simplex virus 1 DNA
No full textRestriction endonuclease analyses of herpes simplex virus (HSV-1) DNA's revealed variability in the electrophoretic migration of specific Bam HI and Kpn I fragments. The variable regions of the genome map at the ends and near the ends of both L and S components, near the L-S junction regio and in middle of the S component. The variability of the fragments was demonstrated by comparing the electrophoretic mobility patterns of DNAs from plaque-purified stocks originally derived from a common parental plaque-purified virus stock. Our analyses suggest that DNA sequences contained in the variable fragments can undergo accretion or deletion. So far the variability of HSV-DNA molecules has been explained in terms of number of copies of terminally reiterated sequences. Our results may be explained by unequal crossing over, slippage, because of the presence of reiterated sequences, or by the presence of transposable elements
HHV-6, HHV-7, HHV-8 in gingival biopsies from chronic adult periodontitis patients - A case-control study
No full textBACKGROUND: Recent reports have suggested that various herpesviruses may be involved in the occurrence and progression of different forms of periodontal disease. OBJECTIVE: The objective of the present study was to investigate the presence of the novel herpesviruses HHV-6, HHV-7 and HHV-8 in gingival biopsies from patients affected by chronic adult periodontitis. As control, gingival biopsies from periodontally healthy subjects were analysed. MATERIALS AND METHODS: Gingival biopsies were harvested from 23 volunteers: 13 patients affected by chronic adult periodontitis (CAP) and 10 periodontally healthy subjects. Each CAP patient contributed two biopsies involving the epithelium and connective tissue facing the sulcus/periodontal pockets: one biopsy from a site having a probing pocket depth (PPD) > or =5 mm and presenting with bleeding upon probing (affected site) at the time of biopsy collection, and the other biopsy from a site with PPD< or =3 mm and without bleeding on probing (nonaffected site). After DNA extraction, nested PCR was used in herpesvirus identification. RESULTS: HHV-6 DNA sequences were detected in one non-affected site (8%) and no affected sites (0%) of CAP patients. One biopsy (10%) in healthy subjects revealed HHV-6 positivity. Tissue specimens in 10/13 CAP patients (77%) and 7/10 healthy subjects (70%) contained HHV-7 DNA. HHV-7 prevalence in affected and nonaffected sites of CAP patients was 77% and 54%, respectively. HHV-8 was detected in 7.7% of CAP patients and 0% of healthy subjects. CONCLUSIONS: Gingival tissue may act as a reservoir for HHV-7. A high prevalence of HHV-7 was detected in both periodontally diseased and healthy individuals. The prevalence of HHV-6 and -8 was similarly low in both groups. Our data do not support an association of investigated herpesvirus species with destructive periodontal disease
Interazione molecolare tra l'herpesvirus linfotropico suino di tipo 1 (PLHV-1) a l'herpesvirus umano di tipo 8 (HHV-8): problematiche relative allo xenotrapianto
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EVIDENCE FOR GLYCOPROTEIN ABNORMALITY IN PLATELETS FROM PATIENTS WITH MAY-HEGGLIN ANOMALY
No full textProtein analysis on SDS-polyacrylamide gel electrophoresis (PAGE) has been used to study the glycoprotein pattern of the blood platelets of four members from a family affected by May-Hegglin anomaly. N,N'diallyltartardiamide (DATD) cross-linked gel electrophoresis was shown to improve the glycoprotein pattern resolution, although with the lactoperoxidase-iodination the glycoprotein characterization of May-Hegglin platelets overlapped the normal. With the immunoprecipitation the specific antiserum precipitated all the five major fractions of normal membrane glycoproteins, but it was shown to react quite poorly with the component V of the May-Hegglin glycoprotein pattern. Thus it could be argued that the component V is present on the surface of May-Hegglin platelets, but with different antigenic properties, which may be related to a change of the glycoproptein stereochemical set.
Therefore it could be suggested that the obbserved antigenic alteration of fraction V may contribute to explain the bleeding occasionally occuring in some patients affected by May-Hegglin anomaly
Human herpesvirus 8 enhances HIV replication in acutely infected cells and induces reactivation in latently infected cells
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