Search results for "Cause"
showing 10 items of 6525 documents
Functional properties of a monoclonal antibody inhibiting the hepatitis C virus RNA-dependent RNA polymerase.
2001
The hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp), represented by nonstructural protein 5B (NS5B), has recently emerged as a promising target for antiviral intervention. Here, we describe the isolation, functional characterization, and molecular cloning of a monoclonal antibody (mAb) inhibiting the HCV RdRp. This mAb, designated 5B-12B7, binds with high affinity to a conformational epitope in the palm subdomain of the HCV RdRp and recognizes native NS5B expressed in the context of the entire HCV polyprotein or subgenomic replicons. Complete inhibition of RdRp activity in vitro was observed at equimolar concentrations of NS5B and mAb 5B-12B7, whereas RdRp activities of classica…
Replication of herpes simplex virus type 1 and 2 in the medulla of the adrenal gland after vaginal infection of mice.
1996
After vaginal infections of mice with neuroinvasive strains of herpes simplex virus type 1 and 2 (HSV-1, HSV-2) virus replicates in the epithelium of the vagina, in the paravaginal ganglia, in the spinal cord and finally in the brain and in the adrenal glands. However, viral antigens could be demonstrated only in the medulla of the adrenal glands but not in the cortex, as assessed by immunohistochemistry (IHC). HSV could not be isolated from liver, spleen, uterus, and ovaries. This contrasts to the intraperitoneal (i.p) route of infection with replication in different visceral organs including the adrenal gland's cortex.
Translocation of the nuclear autoantigen La to the cell surface of herpes simplex virus type 1 infected cells.
1992
Recently we developed a procedure to translocalize one of the extractable nuclear antigens (ENAs), the La protein, to the cell surface of CV-1 cells. Here we report that herpes simplex virus type 1 infection can also induce a translocation of the autoantigen to the cell surface. On the cell surface we detected La protein assembled with large protrusions. Within these protrusions La protein colocalized with virus particles. These protrusions are known to be released from the cell after virus infections. Such complexes consisting of self and virus could provide helper determinants for an anti-self response, and therefore be important in generation of autoimmunity.
The human autoantigen La/SS-B accelerates herpes simplex virus type 1 replication in transfected mouse 3T3 cells.
1998
SUMMARY Permanently transfected mouse cell lines which expressed different levels of the human autoantigen La/SS-B were infected with different strains of herpes simplex virus type 1, including the strains ANG, HSZP, 17syn+ and HFEM. During infection the localization of the human La protein was followed using an anti-La MoAb, which recognized only the human La protein but did not cross-react with either the endogenous mouse La protein or any viral encoded protein. After infection La protein was transported from the nucleus to the cytoplasm. The time course of translocation was dependent on the amount of human La protein expressed in the respective cell line. Moreover, acceleration of viral …
Papillomavirus assembly requires trimerization of the major capsid protein by disulfides between two highly conserved cysteines.
1998
ABSTRACT We have used viruslike particles (VLPs) of human papillomaviruses to study the structure and assembly of the viral capsid. We demonstrate that mutation of either of two highly conserved cysteines of the major capsid protein L1 to serine completely prevents the assembly of VLPs but not of capsomers, whereas mutation of all other cysteines leaves VLP assembly unaffected. These two cysteines form intercapsomeric disulfides yielding an L1 trimer. Trimerization comprises about half of the L1 molecules in VLPs but all L1 molecules in complete virions. We suggest that trimerization of L1 is indispensable for the stabilization of intercapsomeric contacts in papillomavirus capsids.
Single amino acid substitutions in the glycoprotein B carboxy terminus influence the fusion from without property of herpes simplex virus type 1.
1995
Syncytial mutations of herpes simplex virus type 1 (HSV-1) strains ANG, ANG path, HFEM, tsB5 and HSZP cause extensive cell fusion and were mapped to the cytoplasmic domain of glycoprotein B (gB), within the syn 3 locus. These strains are so far the only ones which show the phenotype ‘fusion from without’ (FFWO): 60 min after infection with high m.o.i., cells in a tissue culture are fused without transcription and translation of the viral genome. In this report we detected, using the recombinants 27/III and K-7, that an amino acid exchange from Ala to Val at aa position 854 of gB is the main determinant for FFWO activity of strains ANG, ANG path and recombinant K-7. The transfer of this muta…
Colonization of adrenal glands and ovaries of mice by variants of HSV 1 and 2
1991
The herpes simplex virus (HSV)-infected mouse model was used to correlate histopathological lesions in adrenal glands and ovaries with the localisation of viral nucleic acids and viral antigens, employing in situ hybridization and immunohistochemistry. In the adrenals, the lesions were mainly restricted to the zona fasciculata and the zona reticularis, sometimes extending to the medulla. In the ovaries, lesions were detected in follicles and in the stroma. During the course of infection, HSV nucleic acids could be detected earlier than HSV proteins. Next to the center of necrotic foci mainly HSV proteins were detected, whereas peripheral cells were found to contain viral nucleic acids. In s…
Human Papillomavirus Type 16 E7 Peptide-Directed CD8+ T Cells from Patients with Cervical Cancer Are Cross-Reactive with the Coronavirus NS2 Protein
2003
ABSTRACTHuman papillomavirus type 16 (HPV16) E6 and E7 oncoproteins are required for cellular transformation and represent candidate targets for HPV-specific and major histocompatibility complex class I-restricted CD8+-T-cell responses in patients with cervical cancer. Recent evidence suggests that cross-reactivity represents the inherent nature of the T-cell repertoire. We identified HLA-A2 binding HPV16 E7 variant peptides from human, bacterial, or viral origin which are able to drive CD8+-T-cell responses directed against wild-type HPV16 E7 amino acid 11 to 19/20 (E711-19/20) epitope YMLDLQPET(T) in vitro. CD8+T cells reacting to the HLA-A2-presented peptide from HPV16 E711-19(20)recogni…
Immune responses during COVID-19 infection
2020
International audience; Over the past 16 years, three coronaviruses (CoVs), severe acute respiratory syndrome CoV (SARS-CoV) in 2002, Middle East respiratory syndrome CoV (MERS-CoV) in 2012 and 2015, and SARS-CoV-2 in 2020, have been causing severe and fatal human epidemics. The unpredictability of coronavirus disease-19 (COVID-19) poses a major burden on health care and economic systems across the world. This is caused by the paucity of in-depth knowledge of the risk factors for severe COVID-19, insufficient diagnostic tools for the detection of SARS-CoV-2, as well as the absence of specific and effective drug treatments. While protective humoral and cellular immune responses are usually m…
SARS-CoV-2 envelope protein topology in eukaryotic membranes
2020
Coronavirus E protein is a small membrane protein found in the virus envelope. Different coronavirus E proteins share striking biochemical and functional similarities, but sequence conservation is limited. In this report, we studied the E protein topology from the new SARS-CoV-2 virus both in microsomal membranes and in mammalian cells. Experimental data reveal that E protein is a single-spanning membrane protein with the N-terminus being translocated across the membrane, while the C-terminus is exposed to the cytoplasmic side (Nt lum /Ct cyt ). The defined membrane protein topology of SARS-CoV-2 E protein may provide a useful framework to understand its interaction with other viral and ho…