Biomedical subjects

W J Bellini

Publications and source records attributed to W J Bellini.

84 records · Page 5Linked to original sources

PubMed1984

Positive identification of a measles virus cDNA clone encoding a region of the phosphoprotein.

A measles virus-specific cDNA clone, C1-G, that was previously assigned as a hemagglutinin-specific clone has been reassigned as a phosphoprotein-specific clone. The nucleotide sequence of C1-G was used to deduce the amino acid sequence. A synthetic peptide was constructed from a portion of the deduced sequence, and antisera were prepared. The antibodies directed against this synthetic peptide specifically precipitated the phosphoprotein of measles virus and not the hemagglutinin.

Amino Acid Sequence↗

PubMed1983

Biosynthesis of measles virus hemagglutinin in persistently infected cells.

The synthesis of the hemagglutinin (HA) glycoprotein of measles virus was investigated in a persistently infected cell line using a monoclonal anti-HA. The synthesis of the HA protein was shown to be associated with the rough endoplasmic reticulum. The unglycosylated (HA0) apoprotein is synthesized as a 65,000 dalton peptide and is inserted into the rough endoplasmic reticulum as a transmembrane protein with approximately 2 to 3000 daltons of the peptide exposed to the cytoplasmic membrane surface. Primary glycosylation of the HA protein was found to occur through the lipid-linked carrier, dolichol-phosphate, as determined by inhibition of glycosylation by tunicamycin. Glycosylation, however, was not a prerequisite for membrane insertion. Endo-beta-N-acetylglucosaminidase H digestion of the fully glycosylated HA protein indicated that both simple and complex oligosaccharides are present on the surface glycoprotein.

Antibodies, Monoclonal↗

PubMed1983

Cloned measles virus-specific T lymphocytes from a twin with multiple sclerosis.

A measles virus-specific T lymphocyte clone derived from a measles-responder twin with multiple sclerosis has been produced. The cloned cells proliferate in response to measles virus but not mumps, vaccinia, or canine distemper viruses. The clone recognizes an antigen that is distributed in both the membrane and cytoplasmic fractions of cells infected with measles virus. Antigen is presented to the clone equally well by irradiated mononuclear cells obtained from the autologous subject and from her healthy, measles-nonresponder, HLA-identical twin. Studies with a panel of HLA-typed irradiated mononuclear cells indicate that antigen is presented to the clone in the context of a gene product linked to, but not identical with, HLA-DRw2. The clone produces interleukin 2 and has surface determinants recognized by OKT-3, OKT-4, and anti-HLA-DR monoclonal antibodies, but not by OKT-8. It thus appears to belong to the helper/inducer subpopulation of T lymphocytes.

Antigens, Viral↗

PubMed1983

Antibody-mediated modification of encephalitis induced by hamster neurotropic measles virus.

The acute encephalopathy induced by hamster neurotropic (HNT) measles virus in BALB/c mice was abolished, and a subacute encephalitis was induced instead, when antibody to Edmonston (Ed) measles virus was administered three days after inoculation of HNT virus. Ascites fluid from 79XIC1, a monocolonal antibody to the hemaglutinin of strain Ed, had similar effects in vivo. However, other monoclonal antibodies to the hemagglutinin of Ed strain--79XVV17 and 80IIIB2--were ineffective in vivo at all doses tested. By viral neutralization, immunofluorescence, and radioimmunoprecipitation assays, it was shown that the hemagglutinin of HNT virus reacted with 79XIC1 antibody but lacked the epitopes recognized by 79XVV17 or 80IIIB2 antibody, a finding that explains their different reactivity in vivo. These observations also identified previously unrecognized antigenic differences between the hemagglutinin of Ed and HNT measles viruses.

Animals↗

PubMed1981

Immune reactivity of the purified hemagglutinin of measles virus.

The role of the immune response to measles virus in acute infection or in disease states associated with this virus is of major interest. The viral genome-specified surface antigens of measles, the hemagglutinin and fusion proteins, are likely to be of paramount importance with respect to the host immune response to the virus. This report describes initial studies aimed at assessing the immune response to the major surface glycoprotein, the hemagglutinin. This antigen was purified by affinity chromatography, using a monoclonal anti-hemagglutinin immobilized on Sepharose. The purified protein retained biological activity in hemagglutination assays. This activity could be specifically inhibited with a human antimeasles serum and with monoclonal antibody to the hemagglutinin. Lymphocytes from individuals known to proliferate to measles-infected monolayers also proliferated to the purified hemagglutinin. Thus, the immune-response to measles virus is, in part, directed to this surface antigen.

Antigens, Surface↗

PubMed1981

Idiotypes and biological activity of murine monoclonal antibodies against the hemagglutinin of measles virus.

Three hybridomas, designated C2, V17, and B2, were produced from BALB/c mice after immunization with measles virus. All three were directed against the virus hemagglutinin (HA). The HA is a structural peptide of the virus and constitutes a major target for the host immune response during measles infection. The monoclonal anti-HA antibodies have biological functions such as (i) measles virus neutralization in vitro, (ii) binding to acutely and persistently infected cells, and (iii) inhibition of HA-mediated Rhesus monkey erythrocyte agglutination. Different idiotypes, designated HAMM-1, HAMM-2, and HAMM-3, were defined on C2, V17, and B2, respectively, by syngeneic anti-idiotype sera against those three monoclonal antibodies. A limited cross-reactivity with the HAMM-1 idiotype was detected in sera from some BALB/c mice immunized with measles virus. The anti-idiotype sera could significantly inhibit the biological functions of the HAMM-1 and HAMM-3 idiotypes bearing monoclonal anti-HA-antibodies. This suggests a possible role for auto-anti-idiotypes in the immune response after infection with measles virus.

Animals↗

PubMed1980

Monospecific antibody to the haemagglutinin of measles virus.

A hybrid between a murine myeloma cell line and spleen cells from a mouse immunized with measles has been produced. Two stable clones produce antibody with identical immunochemical and biological properties. This antibody reacts with the 76,000 mol. wt. protein present in the lysates and on the surface of cells persistently infected with measles. It exhibits HAI and neutralizing activity.

Animals↗

PubMed1980

Antibodies to the structural polypeptides of measles virus following acute infection and in SSPE.

A solid-phase radioimmunoassay was used to determine the specificity of IgG antibodies from normal sera, sera and CSF from patients with SSPE for the structural polypeptides of measles virus. The polypeptide specificity of antibodies from these sources were qualitatively similar; these results indicate antigenic cross-reactivity between SSPE-derived (Mantooth) and non-SSPE-derived strains of measles virus and stimulation of antibody formation by comparable antigens.

Adult↗

PubMed1979

Purification of measles virus with preservation of infectivity and antigenicity.

Measles virus Edmonston strain was purified by ultrafiltration followed by two successive sedimentations through sucrose. Purified virus retained infectivity and, when used as an immunogen, elicited high titred antibody to measles antigens by conventional serology. The measles preparations were examined by SDS-PAGE followed by staining. In addition, following PAGE, the purity of these preparations was assessed immunochemically using antisera directed to measles and host cell antigens. The results of these studies demonstrate the utility of the purification method for the preparation of milligram quantities of relatively pure measles virus.

Epitopes↗

PubMed1975

Metabolic characteristics of cells infected with a herpesvirus of turkeys.

Chicken embryo fibroblasts infected with the nononcogenic herpesvirus of turkeys (HVT) displayed an increased rate of glucose uptake, a pronounced alteration of the pH of the medium, and an increased production of lactic acid when compared to mock-infected cultures. Objective estimates of cytopathology (quantifiable neutral red uptake and cell protein determination) showed that cell deterioration was a slow process in HVT-infected cells when compared to infection by herpes simplex virus. Experiments with irradiated host cells demonstrated that HVT required functional cell DNA for replication. The inactivation of the necessary host cell function displayed multihit kinetics. In agreement with data on other herpesviruses, HVT damaged by UV light could be photoreactivated in chick cells. The results indicate that HVT shares biologic properties in common with other herpes and transforming viruses.

Animals↗

PubMedDate not supplied

Genetic diversity of wild-type measles viruses: implications for global measles elimination programs.

Wild-type measles viruses have been divided into distinct genetic groups according to the nucleotide sequences of their hemagglutinin and nucleoprotein genes. Most genetic groups have worldwide distribution; however, at least two of the groups appear to have a more limited circulation. To monitor the transmission pathways of measles virus, we observed the geographic distribution of genetic groups, as well as changes in them in a particular region over time. We found evidence of interruption of indigenous transmission of measles in the United States after 1993 and identified the sources of imported virus associated with cases and outbreaks after 1993. The pattern of measles genetic groups provided a means to describe measles outbreaks and assess the extent of virus circulation in a given area. We expect that molecular epidemiologic studies will become a powerful tool for evaluating strategies to control, eliminate, and eventually eradicate measles.

Genetic Variation↗

PubMedDate not supplied

Lack of evidence of endogenous avian leukosis virus and endogenous avian retrovirus transmission to measles, mumps, and rubella vaccine recipients.

The identification of endogenous avian leukosis virus (ALV) and endogenous avian retrovirus (EAV) in chick cell-derived measles and mumps vaccines in current use has raised concern about transmission of these retroviruses to vaccine recipients. We used serologic and molecular methods to analyze specimens from 206 recipients of measles, mumps, and rubella (MMR) vaccine for evidence of infection with ALV and EAV. A Western blot assay for detecting antibodies to endogenous ALV was developed and validated. All serum samples were negative for antibodies to endogenous ALV by Western blot analysis. Peripheral blood lymphocyte samples from 100 vaccinees were further tested by polymerase chain reaction for both ALV and EAV proviral sequences; all were negative. Matching serum samples were tested by reverse transcriptase polymerase chain reaction for ALV and EAV RNA, and all 100 samples were negative, providing no evidence of viremia. These findings do not indicate the presence of either ALV or EAV infection in MMR vaccine recipients and provide support for current immunization policies.

Animals↗