Search results for " REPLICATION"

Nuclear entry and egress of parvoviruses.

2022

Parvoviruses are small non-enveloped single-stranded DNA viruses, which depend on host cell nuclear transcriptional and replication machinery. After endosomal exposure of nuclear localization sequence and a phospholipase A2 domain on the capsid surface, and escape into the cytosol, parvovirus capsids enter the nucleus. Due to the small capsid diameter of 18–26 nm, intact capsids can potentially pass into the nucleus through nuclear pore complexes (NPCs). This might be facilitated by active nuclear import, but capsids may also follow an alternative entry pathway that includes activation of mitotic factors and local transient disruption of the nuclear envelope. The nuclear entry is followed b…

Commentary: Misguided Effort with Elusive Implications, and Sifting Signal from Noise with Replication Science

2016

2018

Tetraspanins (Tspans) are a family of four-span transmembrane proteins, known as plasma membrane “master organizers.” They form Tspan-enriched microdomains (TEMs or TERMs) through lateral association with one another and other membrane proteins. If multiple microdomains associate with each other, larger platforms can form. For infection, viruses interact with multiple cell surface components, including receptors, activating proteases, and signaling molecules. It appears that Tspans, such as CD151, CD82, CD81, CD63, CD9, Tspan9, and Tspan7, coordinate these associations by concentrating the interacting partners into Tspan platforms. In addition to mediating viral attachment and entry, these …

TLR7 controls VSV replication in CD169(+) SCS macrophages and associated viral neuroinvasion

2019

Vesicular stomatitis virus (VSV) is an insect-transmitted rhabdovirus that is neurovirulent in mice. Upon peripheral VSV infection, CD169+ subcapsular sinus (SCS) macrophages capture VSV in the lymph, support viral replication, and prevent CNS neuroinvasion. To date, the precise mechanisms controlling VSV infection in SCS macrophages remain incompletely understood. Here, we show that Toll-like receptor-7 (TLR7), the main sensing receptor for VSV, is central in controlling lymph-borne VSV infection. Following VSV skin infection, TLR7−/− mice display significantly less VSV titers in the draining lymph nodes (dLN) and viral replication is attenuated in SCS macrophages. In contrast to effects o…

Cell Cycle: The Life Cycle of a Cell

2013

“Where a cell arises, there must be a previous cell”. This early statement of Rudolf Virchow already points to the process that is called cell cycle. It describes a series of events leading to cell division and duplication and can be sectioned into phases that are controlled by a collection of proteins interacting with each other, the cyclines and the cycline-dependent kinases. It is mandatory that DNA replication is conservative meaning that its structure and sequence remain unaltered while the DNA is duplicated before the cell actually divides. Checkpoints are responsible for the supervision, proteins such as p53 and RB being the key protagonists in cell cycle control. Upon DNA damage rec…

Generation of multifunctional murine monoclonal antibodies specifically directed to the VP1unique region protein of human parvovirus B19.

2007

Little is known about the VP1unique region (VP1u), a part of one major capsid protein of human parvovirus B19 (B19), concerning its involvement in viral replication and infection cycle. Showing a phospholipase A2 (PLA2)-like activity, which is discussed to be necessary for viral release from host cell, its precise function remains unclear. The purpose of this study was to generate multifunctional monoclonal antibodies (mabs) for different applications that may be useful in investigating VP1u's relevance. To establish antiVP1u antibodies, spleen cells from Balb/c mice immunized with purified recombinant viral protein were used for generating antibody-producing hybridoma cell lines. Usability…

Replication and extension of framing effects to compliance with health behaviors during pandemics

2021

Outbreaks of infectious diseases represent a significant challenge for health authorities around the world Public cooperation and compliance with health recommendations constitute critical steps to stop the spread of such diseases But how should these recommendations be framed to achieve the most desirable outcomes? Across two experiments, we show that the classic Asian Disease Problem (Tversy and Kahneman, 1981) is replicable, regardless of disease type (real vs hypothetical) Thus, people are less (vs more) willing to take risks when information is positively (negatively) framed, irrespective of disease type, although they are generally more risk-averse in real pandemics Furthermore, peopl…

Treatment of chronic hepatitis C

1991

alpha-Interferon given subcutaneously at doses between 1-3 million units leads to responses in about 50% of patients suffering from chronic hepatitis C. A 24-week treatment is frequently (approx. 50%) followed by relapses reducing the percentage of lasting responders to approx. 20%. The patients who relapse are sensitive to retreatment with interferon-alpha. A better understanding of HCV replication and of the interferon action in this viral disease might help to further improve treatment schedules. Side effects of interferon were frequently mild and readily reversible after cessation of treatment. At present interferon treatment should not be recommended in asymptomatic patients or individ…

Studies on a measles virus variant inducing persistent infections in cultured cells

1976

Attempts were made to characterized by a plaque assay two variants of the Edmonston strain of measles virus and to obtain plaque purified virus populations. The UP non-cytocidal variant, in all the examined cell systems, mainly produced small but also large plaques; the DP cytocidal variant always large plaques. Three clones, UP-SP4, UP-LP4 and DP-LP4, were derived by plaque purfication respectively of the UP small plaque, UP large plaque and DP large plaque forming particles. The virus populations of the clones could be distinguished by some other biological and physical characters: cytopathic effect in roller tube cultures, growth potential in HeLa cells, thermal stability at 45 degrees C…

Neurotropism in newborn hamsters of plaque purified measles virus clones

1976

Three plaque purified measles virus clones displayed a different neurotropism in newborn hamsters.