The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
To test the hypothesis that inefficient interactions of CXCR4 with CD4 and gp120 could affect HIV-1 entry, we incubated macrophages, monocytes, and lymphocytes with gp120 and coimmunoprecipitated CD4 by using anti-CXCR4 antibodies. CD4 was efficiently coimmunoprecipitated in lymphocytes and monocytes but not in macrophages. Overexpression of CD4 in macrophages resulted in detection of CD4–CXCR4 and...
Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is an important human pathogen. The envelope glycoprotein (Egp), a major structural antigen, is responsible for viral haemagglutination and eliciting neutralising antibodies. The three-dimensional structure of the Egp of JEV was predicted using the knowledge-based homology modeling approach and X-ray structure data of the Egp of tick-borne...
By the use of a mouse model, the enteropathic effects of the simian immunodeficiency virus (SIV) surface unit (SU) envelope glycoprotein were explored. Purified SU (0.01–0.45 nmol) was administered intraperitoneally to 6- to 8-day-old mouse pups and induced a dose-dependent diarrheal response. Surgical introduction of SU into adult mouse intestinal loops revealed fluid accumulation without histological...
Infection of CD4+ cells with HIV in vitro causes extensive cytopathicity. The mechanism that underlies this process is unclear and conflicting data exist regarding whether cytotoxicity is due to necrosis or apoptosis. It was previously reported and is shown here that the coculture of HIV glycoprotein-expressing cells with CD4+ cells results in apoptosis within several hours. This study demonstrates...
Hendra virus (HeV) is an emerging paramyxovirus first isolated from cases of severe respiratory disease that fatally affected both horses and humans. Understanding the mechanisms of host cell infection and cross-species transmission is an important step in addressing the risk posed by such emerging pathogens. We have initiated studies to characterize the biological properties of the HeV envelope glycoproteins...
Retroviral envelope proteins are heavily glycosylated. In some cases, glycosylation has been shown to be important for folding, protein stability, immune evasion, or receptor usage. The receptor-binding subunit (SU or gp85) of the envelope protein (EnvA) of the avian sarcoma/leukosis virus, subtype A (ASLV-A), contains 11 potential N-linked glycosylation sites (NXS/T). To address the importance of...
Little is known about the nature of foamy virus (FV) receptor molecules on target cells and their interaction with the viral glycoproteins. Similar to other viruses, cellular expression of the FV Env protein is sufficient to induce resistance to exogenous FV, a phenomenon called superinfection resistance (SIR). In this study we define determinants of the FV Env protein essential for mediating SIR...
Phage display libraries have provided an extraordinarily versatile technology to facilitate the isolation of peptides, growth factors, single chain antibodies, and enzymes with desired binding specificities or enzymatic activities. The overall diversity of peptides in phage display libraries can be significantly limited by Escherichia coli protein folding and processing machinery, which result in...
Display technology refers to methods of generating libraries of modularly coded biomolecules and screening them for particular properties. Retroviruses are good candidates to be a eukaryotic viral platform for the display of polypeptides synthesized in eukaryotic cells. Here we demonstrate that avian leukosis virus (ALV) provides an ideal platform for display of nonviral polyaeptides expressed in...
Induction of cross-reactive cellular and humoral responses to the HIV-1 envelope (env) glycoprotein was examined after DNA immunization of BALB/c mice with gp140 89.6 -derived constructs exhibiting partial or complete deletions of the V1, V2, and V3 domains. It was demonstrated that specific modification of the V3 loop (mV3) in combination with the V2-modified (mV2) or V1/V2-deleted...
HIV-1 infection is initiated by the interaction of the envelope glycoprotein gp120 with the cellular receptor CD4 that triggers conformational changes in gp120 necessary for subsequent interaction with a coreceptor CCR5 (or CXCR4). The CD4-induced (CD4i) conformation of gp120 can be mimicked by a full-length single chain (FLSC) protein consisting of gp120 linked with the D1D2 domains of CD4 by a 20-amino-acid...
The quantity of envelope glycoprotein molecules (Env) on HIV-1 particles is still an issue of debate and, depending on the strain of virus and the nature of the producer cells, it can vary greatly. Here, we have attempted to address how Env density influences HIV-1 fitness. To this aim, we have produced HIV-1-derived viral particles with various amounts of R5 Env (low Env: Env lo ; high Env:...
The fusion subunit of the SARS-CoV S glycoprotein contains two regions of hydrophobic heptad-repeat amino acid sequences that have been shown in biophysical studies to form a six-helix bundle structure typical of the fusion-active core found in Class I viral fusion proteins. Here, we have applied serine-scanning mutagenesis to the C-terminal-most heptad-repeat region in the SARS-CoV S glycoprotein...
The G2 fusion subunit of the Junín virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains...
The transmembrane (TM) subunit of the envelope (Env) glycoprotein of the simian immunodeficiency virus (SIV) contains an unusually long cytoplasmic domain of 164 amino acids. Previously, we identified domains in the SIV TM cytoplasmic tail that are necessary for Env incorporation into virions and viral infectivity. In this study, we investigated the relevance to Env function of the highly conserved...
A major challenge in developing an HIV-1 vaccine is to identify immunogens and their delivery methods that can elicit broad neutralizing antibodies against primary isolates of different genetic subtypes. Recently, we demonstrated that priming with DNA vaccines expressing primary HIV-1 envelope glycoprotein (Env) followed by recombinant Env protein boosting was successful in generating positive neutralizing...
The arenavirus envelope glycoprotein (GP-C) retains a cleaved and stable signal peptide (SSP) as an essential subunit of the mature complex. This 58-amino-acid residue peptide serves as a signal sequence and is additionally required to enable transit of the assembled GP-C complex to the Golgi, and for pH-dependent membrane fusion activity. We have investigated the C-terminal region of the Junín virus...
Primary human immunodeficiency type 1 viruses (HIV-1) resist antibody neutralization but become sensitive after passage through T cell lines. We and others previously reported an increased neutralization sensitivity of HIV-1 after prolonged culture on primary peripheral blood mononuclear cells (PBMC). Hence we hypothesized that adaptation to growth in T cell lines is in fact selection of a pre-existing...
The mature form of the envelope (Env) glycoprotein of lentiviruses is a heterodimer composed of the surface (SU) and transmembrane (TM) subunits. Feline immunodeficiency virus (FIV) possesses a TM glycoprotein with a cytoplasmic tail of approximately 53 amino acids which is unusually short compared with that of the other lentiviral glycoproteins (more than 100 residues). To investigate the relevance...
The genetic diversity of HIV-1 envelope glycoproteins (Env) remains a major obstacle to the development of an antibody-based AIDS vaccine. The present studies examine the breadth and magnitude of neutralizing antibody (NAb) responses in rhesus monkeys after immunization with DNA prime-recombinant adenovirus (rAd) boost vaccines encoding either single or multiple genetically distant Env immunogens,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.