Search results for "capsid"
showing 10 items of 248 documents
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…
Conformational and linear epitopes on virus-like particles of human papillomavirus type 33 identified by monoclonal antibodies to the minor capsid pr…
1995
The organization of epitopes on the minor capsid protein L2 of human papillomavirus (HPV) type 33 has been analysed using three monoclonal antibodies (MAbs) generated against a large fragment of the L2 protein (amino acids 82-259) expressed as a glutathione S-transferase fusion protein. The topology of the L2 epitopes has been investigated with respect to the structure of HPV-33 virus-like particles (VLPs). Two of the MAbs reacted with linear epitopes which were mapped to amino acids 153-160 and 163-170, respectively. These epitopes were accessible in denatured but not in native VLPs consisting of L1 and L2, suggesting an internal location. The third antibody was unable to detect denatured …
Immune status towards Epstein-Barr virus in a group of Sicilian children.
1989
The prevalence of antibodies to Epstein-Barr virus-determined antigens was studied in 17 children with acute infectious mononucleosis (IM) and in 263 children hospitalized for diseases unrelated to EBV infection. Antibodies against Epstein-Barr viral capsid antigens (VCA) were observed in 173 patients of the control group (66%), but 58 of them (33,5%) had not yet developed antibodies against Epstein-Barr virus-associated nuclear antigen (EBNA). IgM-specific antibodies were not found in any of the children of the control group but were present in all of the 17 patients with IM. The rates of positivity for IgA anti-VCA and IgG anti-early antigen (EA) were similar in all age groups. Anti-viral…
Induction of Type-Specific Neutralizing Antibodies by Capsomeres of Human Papillomavirus Type 33
2001
Abstract The immunogenicity of capsomeres of human papillomavirus type 33 was evaluated in a dose–response analysis. Capsomeres were obtained free of capsids by expression of L1 carrying the single point mutation C427S. Neutralizing antibodies were detected using an in vitro pseudoinfection assay. Capsomeres induced type-specific, neutralizing antibodies in mice even in the absence of adjuvant. The neutralization titers of immune sera raised without adjuvant were 10- to 20-fold lower than those of antisera to virus-like particles, but virtually identical using Freund's adjuvant. These data indicate that capsomeres may substitute for virus-like particles in future vaccines when used with an …
Cytoplasmic parvovirus capsids recruit importin beta for nuclear delivery
2020
Parvoviruses are an important platform for gene and cancer therapy. Their cell entry and the following steps including nuclear import are inefficient limiting their use in therapeutic applications. Two models exist on parvoviral nuclear entry: classical import of the viral capsid using nuclear transport receptors of the importin (karyopherin) family, or direct attachment of the capsid to the nuclear pore complex leading to local disintegration of the nuclear envelope. Here, by laser scanning confocal microscopy and in situ proximity ligation analysis combined with co-immunoprecipitation we showed that infection requires importin β-mediated access into the nuclear pore complex and nucleopori…
Evidence for Positive Selection in the Capsid Protein-Coding Region of the Foot-and-Mouth Disease Virus (FMDV) Subjected to Experimental Passage Regi…
2001
We present sequence data from two genomic regions of foot-and-mouth disease virus (FMDV) subjected to several experimental passage regimens. Maximum-likelihood estimates of the nonsynonymous-to-synonymous rate ratio parameter (dN/dS) suggested the action of positive selection on some antigenic sites of the FMDV capsid during some experimental passages. These antigenic sites showed an accumulation of convergent amino acid replacements during massive serial cytolytic passages and also in persistent infections of FMDV in cell culture. This accumulation was most significant at the antigenic site A (the G-H loop of capsid VP1), which includes an Arg-Gly-Asp (RGD) cellular recognition motif. Our …
Recombinant nanocapsid for targeted theranostic delivery
2017
Developments in diagnostic and therapeutic delivery are trending towards molecular level targeting with nano-platforms. Targeted delivery reduces generalized distribution by localizing diagnostic and/or therapeutic (theranostic) molecules to an intended target site. The first section of this thesis proposes Hepatitis E Virus (HEV) nanocapsids as a vector to stabilize and target theranostic delivery. Derived from the capsid protein of HEV, a feco-orally transmitted virus, HEV-like particles self-assemble in to non-infectious, nanocapsids that can withstand harsh protease and pH conditions in the mucosal system. The flexible nanocapsid surface protrusion domain is amenable to substantial modi…
Experimental Evolution Reveals a Genetic Basis for Membrane-Associated Virus Release
2021
Many animal viruses replicate and are released from cells in close association to membranes. However, whether this is a passive process or is controlled by the virus remains poorly understood. Importantly, the genetic basis and evolvability of membrane-associated viral shedding have not been investigated. To address this, we performed a directed evolution experiment using coxsackievirus B3, a model enterovirus, in which we repeatedly selected the free-virion or the fast-sedimenting membrane-associated viral subpopulations. The virus responded to this selection regime by reproducibly fixing a series of mutations that altered the extent of membrane-associated viral shedding, as revealed by fu…
Soft X-ray Tomography Reveals HSV-1-Induced Remodeling of Human B Cells.
2022
Upon infection, viruses hijack the cell machinery and remodel host cell structures to utilize them for viral proliferation. Since viruses are about a thousand times smaller than their host cells, imaging virus-host interactions at high spatial resolution is like looking for a needle in a haystack. Scouting gross cellular changes with fluorescent microscopy is only possible for well-established viruses, where fluorescent tagging is developed. Soft X-ray tomography (SXT) offers 3D imaging of entire cells without the need for chemical fixation or labeling. Here, we use full-rotation SXT to visualize entire human B cells infected by the herpes simplex virus 1 (HSV-1). We have mapped the temporo…