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Biomedical subjects

J S Wolinsky

Publications and source records attributed to J S Wolinsky.

At least 73 records · Page 4Linked to original sources

Monoclonal antibody to rubella virus capsid protein recognizes a beta-cell antigen.

The high frequency of insulin-dependent diabetes (IDDM) in children with congenital rubella suggests that the infectious agent may trigger the autoimmune process. To explore the immunologic relationship between rubella virus and IDDM, we examined a panel of mAb that recognizes rubella virus capsid and envelope glycoproteins for reactivity with islet cell Ag. One mAb, C9, which recognizes a defined domain within the capsid protein of rubella virus, was found to react with extracts from a rat beta-cell tumor and normal rat and human islets. Using one and two dimensional immunoblot analysis of rat beta-cell tumor extracts, the C9-like epitope was found to reside on a 52 kDa protein that is also the target of autoantibodies from human IDDM and nonobese diabetic mice. To confirm this cross-reactivity, antibodies in diabetic sera were absorbed to the recombinant rubella virus capsid protein, eluted, and then shown to react with the 52 kDa insulinoma protein. These data show that an immunogenic epitope on the rubella virus capsid protein is mimicked by a similar structure on a beta-cell protein. These findings suggest that rubella virus has the potential to sensitize susceptible individuals for an autoimmune response to beta-cell Ag and identify one mechanism that may contribute to beta destruction in IDDM.

Amino Acid Sequence↗

Mapping cell-mediated immunodominant domains of the rubella virus structural proteins using recombinant proteins and synthetic peptides.

Although it is known that rubella-immune individuals have T cells that proliferate in vitro in response to rubella virus (RV), the determinants that evoke this response have not been identified. This study utilized recombinant proteins that express overlapping sequences of the RV structural open reading frame to identify domains of the structural proteins that contain cell-mediated immunodominant sequences. Lysates enriched with RV fusion proteins (RecA-RV-LacZ) were prepared from Escherichia coli transformed with plasmids which contained specific RV cDNA inserts. Approximately 62% of RV-immune individuals gave RV-specific responses to one or more of the RV fusion proteins. Over 10% of immune individuals recognized the capsid sequence C1-C29. Lymphoproliferation data from studies using six overlapping synthetic peptides representing this sequence suggested that as much as 70% of the immune population may recognize this domain. An E1 sequence, E1(202)-E1(283), was recognized by 15% of the RV-immune individuals with the fusion proteins. Five synthetic peptides representing this sequence had an overall response rate of 50%. The sequence C64-C97 failed to evoke any RV-specific responses with the fusion proteins and synthetic peptides representing this sequence were used to verify that the RV fusion proteins and the criteria used to identify RV-specific responses were adequate. These peptides gave a response rate of only 6%. In general, significant responses to specific fusion proteins correlated with high responses (stimulation index > or = 4.0) to representative synthetic peptides. This study suggests that the recombinant proteins were beneficial in identifying cell-mediated immunodominant domains of the RV structural proteins which could be further characterized with synthetic peptides.

Adult↗

Rubella virus-specific cytotoxic T-lymphocyte responses: identification of the capsid as a target of major histocompatibility complex class I-restricted lysis and definition of two epitopes.

The role of major histocompatibility complex (MHC) class I-restricted CD8+ cytotoxic T lymphocytes in immunity to rubella virus (RV) infection is unknown. Lymphocytes of RV-immune individuals were prestimulated on an RV-infected MHC class I-matched (or partially matched) fibroblast monolayer which generated CD8+ lymphoblasts capable of lysing RV-infected fibroblast targets in a class I-restricted manner. Using an infectious Sindbis virus (SV) vector which expressed the RV capsid protein (SV/RubC), lymphocytes from 17 of 22 RV-immune individuals prestimulated on RV-infected fibroblast monolayers lysed SV/RubC-infected fibroblast targets. A sequence within the amino terminus of the capsid protein that was previously shown to contain immunodominant class II-restricted T-cell epitopes was evaluated for class I-restricted epitopes. Fibroblast targets pulsed with synthetic peptides representing subsequences within C1 to C29 (subscripts indicate amino acid positions) were lysed effectively when the targets and effectors matched at multiple class I alleles. By limiting the number of matching class I alleles, an A2-restricted epitope was identified within C9 to C22 and an epitope that could be presented by multiple class I molecules was identified within C11 to C29. A sequence such as C1 to C29 which contains both MHC class I- and MHC class II-restricted epitopes recognized by a heterologous human population may serve as a component of an effective synthetic vaccine.

Adult↗

Immunodominant T-cell epitopes of rubella virus structural proteins defined by synthetic peptides.

Sets of overlapping synthetic peptides containing predicted T-cell epitope motifs were designed from the murine monoclonal antibody-defined map of linear B-cell epitope domains within each of the structural proteins of rubella virus (RV). The peptides represented well-defined subsequences of two capsid domains (C1 to C29 and C64 to C97), of a domain of glycoprotein E1 containing neutralizing determinants (E1(202) to E1(283), and of a domain of glycoprotein E2 (E2(31) to E2(105). With the exception of peptides representing C64 to C97, each set of peptides stimulated varied but individually specific lymphoproliferative responses in peripheral blood mononuclear cells from 25 to 50% of a representatively large number of normal, RV-immune human donors with diverse human leukocyte antigen (HLA) backgrounds. Responses were mediated by CD4+ T cells in association with HLA class II antigens, though lymphoproliferative responses to a given peptide were usually not HLA-DR allele specific. Correlation analysis of responses to overlapping peptides suggests that there is an immunodominant T-proliferative epitope within C14 to C29 recognized by approximately 50% of the donor population. However, limiting-dilution analysis indicated much variability between individuals in lymphocyte recognition of this T-cell determinant, even within similar HLA-DR contexts. Thus, the fine specificity of relatively immunodominant T-cell epitopes may vary from individual to individual. Synthetic peptides with predicted T-cell motifs have proved to be useful probes of the molecular determinants of cellular immunity to RV and should expand the rational basis for the design of synthetic RV vaccines.

Amino Acid Sequence↗

An antibody- and synthetic peptide-defined rubella virus E1 glycoprotein neutralization domain.

We previously described a monoclonal antibody (MAb) library generated by infecting BALB/c mice with rubella virus (RV) and selected by an enzyme-linked immunosorbent assay (ELISA) using purified virion targets. Plasmid pARV02-01, which expresses the fusion protein RecA1-35-GIGDLGSP-E1(202)-E1(283)-GDP-LacZ9-1015 in Escherichia coli, was shown to be a ligand for MAbs E1-18 and E1-20 (J. S. Wolinsky, M. McCarthy, O. Allen-Cannady, W. T. Moore, R. Jin, S. N. Cao, A. Lovett, and D. Simmons, J. Virol. 65:3986-3994, 1991). Both of these MAbs neutralize RV infectivity. A series of five overlapping synthetic peptides was made to further explore the requirements of this MAb binding domain. One of these peptides (SP15; E1(208) to E1(239)) proved an effective ligand for both MAbs in the ELISA. Stepwise synthesis of SP15 defined the minimal amino-terminal requirement for binding MAb E1-18 as E1(221) and that of MAb E1-20 as E1(223); the minimal carboxyl-terminal requirement is uncertain but does not exceed E1(239). Immunization of mice and rabbits with SP15 induced polyvalent antibody reactive with SP15, with other overlapped and related but not unrelated synthetic peptides, and with RV. The rabbit anti-SP15 antibody showed neutralization activity to RV similar to that of MAbs E1-18 and E1-20 but lacked hemagglutination inhibition activity. These data define a neutralization domain on E1 and suggest that the RV epitopes conserved by SP15 may be critical for protective host humoral immune responses.

Amino Acid Sequence↗

Phagocytosis of latex beads is defective in cultured human retinal pigment epithelial cells with persistent rubella virus infection.

Phagocytosis, a secondary function of retinal pigment epithelial (RPE) cells essential to sight, was significantly decreased, when measured with latex beads, during persistent rubella virus (RV) infection of human cultured RPE cells. A target for RV in vivo, RPE cells infected with RV (RPE/RV) ingested fewer fluorescent microspheres (26%) than did uninfected RPE cells (68%) (P < 0.001), as measured by flow cytometry. In RPE/RV cells, with characteristic RPE monolayer appearance and normal growth during subculturing over 6 months, persistent RV infection was shown by specific RV antigen immunofluorescence, by the presence of the RV genome in RPE/RV cell messenger RNA, and by recovery of cell-free RV after cocultivation with Vero cells. The adhesion of latex beads to apical cell surfaces of RPE/RV and uninfected RPE cells appeared similar, as imaged by scanning electron microscopy. Cytoskeletal actin, a component of phagocytosis in RPE, appeared altered in 60 to 75% of RPE/RV cells by antiactin immunofluorescence staining, as previously described in other RV-infected cells, but its role in the disturbed phagocytosis of latex beads was not determined. Persistently RV-infected human RPE is an additional example of RV-associated secondary cellular dysfunction in the absence of cytopathic effects.

Actins↗

Antibody response to rubella virus antigen and structural proteins in retinitis pigmentosa.

Elevated serum ELISA IgG antibodies to rubella virus (RV) were found by three independent determinations in 41 (72%) of 57 adults with the retinal degeneration retinitis pigmentosa, while antibody responses to five other common neurotropic viruses were normal. However, these patients lacked clinical signs of active RV infection or known recent RV exposure, and 56 lacked IgM anti-RV antibody. Unusual relative percentages of IgG antibody to RV structural proteins compared with those of controls were found in patients' sera by radioimmunoprecipitation assay. For retinitis pigmentosa patients, percentage of RV envelope glycoprotein E1 antibody was similar to, of RV envelope glycoprotein E2 antibody was greater than, and of antibody to RV nucleocapsid C protein was lower than control percentages. Abnormal immunity to RV was also suggested by a lack of increased proliferation of lymphocytes to RV antigen despite elevated anti-RV antibody in patients with retinitis pigmentosa. Not associated with age or particular genetic pattern, these divergences from normal immunity suggest an unusual association between RV proteins and retinitis pigmentosa.

Adolescent↗

Monoclonal antibody-defined epitope map of expressed rubella virus protein domains.

An expanded library of murine monoclonal antibodies (MAbs) was generated by infecting BALB/C mice with the Therien strain of rubella virus (RV) and selecting secreting hybrids by enzyme-linked immunosorbent assay (ELISA) using purified virion targets. A panel of plasmids containing specified RV cDNA fragments was also constructed by using a variety of strategies with pGE374- and pGE374-derived expression vectors. Hybrid RecA-RV-beta-galactosidase (LacZ)- or RecA-RV-truncated LacZ-containing proteins collectively representing the entire open reading frame of the structural proteins of RV were overexpressed in Escherichia coli. Bacterial lysates were then probed by ELISA with selected MAbs and by immunoblot following separation by electrophoresis under denaturing conditions. With this approach, MAbs that appeared to react with linear determinants defined epitopes localized within the following domains: MAbs C-1, C-2, and C-8 bind epitopes within the predicted amino-terminal 21 amino acids of the capsid region C9 to C29; MAb C-9 binds to a domain bounded by C64 and C97; MAbs E2-1 through E2-6 bind to the E2 glycoprotein backbone region from E2(1) to E2(115); MAbs E1-18 and E1-20 bind to the E1 glycoprotein region from E1(202) to E1(283). MAb E1-18 neutralizes RV infectivity; MAb E1-20 neutralizes infectivity and modestly inhibits hemagglutination. Analyses with selected synthetic peptides have confirmed several of the molecular domains deduced with the expressed proteins. These plasmid constructions and peptides have proven useful in beginning to unravel the molecular organization of several antigenic sites of this human pathogen.

Animals↗

Antibody response to rubella virus structural proteins in multiple sclerosis.

The antibody response to the structural proteins of rubella virus was studied in patients with multiple sclerosis (MS). Irrespective of the antibody titer to whole rubella virus, the relative proportion of the IgG response to the surface glycoprotein E1 was diminished, and that to the surface glycoprotein E2 was elevated in MS patients when compared to a matched control population of normal health individuals or a group of patients with systemic lupus erythematosus and other collagen vascular diseases. No difference was observed in the response to the core protein of rubella virus on comparing the MS and normal control groups. This divergence in the relative antibody response to the viral surface proteins suggests that the vigorous antibody response to rubella virus reported in MS is not simply an expression of a nonspecific polyvalent B-cell response.

Adult↗

Proton magnetic resonance spectroscopy in multiple sclerosis.

Regional in vivo proton magnetic resonance spectroscopy provides quantitative data on selected chemical constituents of brain. We imaged 16 volunteers with clinically definite multiple sclerosis on a 1.5 tesla magnetic resonance scanner to define plaque-containing volumes of interest, and obtained localized water-suppressed proton spectra using a stimulated echo sequence. Twenty-five of 40 plaque-containing regions provided spectra of adequate quality. Of these, 8 spectra from 6 subjects were consistent with the presence of cholesterol or fatty acids; the remainder were similar to those obtained from white matter of normal volunteers. This early experience with regional proton spectroscopy suggests that individual plaques are distinct. These differences likely reflect dynamic stages of the evolution of the demyelinative process not previously accessible to in vivo investigation.

Adult↗

Immune studies in human immunodeficiency virus infection with myasthenia gravis: a case report.

A patient with human immunodeficiency virus infection had cellular and humoral immune responses studied longitudinally from the onset of generalized myasthenia gravis. Progressive decline in CD4+, CD45R+ and CD4+, CDw29+ T-cells, cellular immune responses to alloantigen and mitogen stimulation, and acetylcholine receptor antibody titers were associated with clinical improvement of all myasthenic symptoms.

Adult↗

Anti-idiotypic antibodies to rubella virus.

Polyclonal and monoclonal anti-idiotypic (Ab2) and monoclonal anti-anti-idiotypic antibodies were generated against rubella virus-specific neutralizing and/or hemagglutination inhibiting monoclonal antibodies. None of the characterized Ab2's recognized the putative rubella virus receptor.

Antibodies, Anti-Idiotypic↗

Effect of cyclosporine on rubella virus-specific immune responses in chronic progressive multiple sclerosis.

Cyclosporine A (CsA) has been used in putative autoimmune diseases after sensitization to unknown antigens. We have previously shown that CsA prevented continued activation of T-cells in chronic progressive multiple sclerosis (CPMS) patients. The current study was undertaken to determine whether CsA, or CsA and prednisone (CsA + P) could suppress immune responses to a common recall antigen. Serum antibody levels were higher in all CPMS patients than age-matched normal controls. However, rubella antibody titers in the CsA or CsA + P groups were no different from a placebo-treated CPMS patient group. The lymphocyte responses to inactivated rubella virus of CsA and CsA + P-treated CPMS patients were lower than placebo and control but not statistically different. Therapy with both CSA and CSA + P was associated with significantly lower panel mixed leukocyte responses and Ta1 expression than in the placebo-treated group; CD3, CD4, CD8 antigen expression and active rosette formation by T-cells were similar for the three CPMS groups. These results suggest that while CsA exerts measurable effects on non-specific indicators of cellular immunity in CPMS patients, it may not be as effective in suppressing pre-existent specific immune responses.

Antibodies, Viral↗

Sequence determination of the mumps virus HN gene.

The hemagglutinin-neuraminidase protein (HN) of mumps virus was purified by immunoaffinity chromatography and fragmented by the combined action of CNBr and trypsin. The resulting peptides were separated by HPLC and sequenced by automated Edman degradation. Using this HN-specific amino acid sequence data, a degenerate oligonucleotide was produced and subsequently used to screen a mumps virus cDNA library to isolate HN-specific clones. The complete nucleotide sequence of the HN gene was determined. The monocistronic HN mRNA is approximately 1900 nucleotides long and encodes a single open reading frame of 582 amino acids. The HN protein has a unique hydrophobic stretch of 19 amino acids at its N-terminus that apparently anchors the protein in the viral envelope. A comparison of the mumps virus HN protein sequence with the sequences of the other known paramyxovirus HNs indicates that mumps virus is most closely related to SV-5, followed in decreasing order by NDV, parainfluenza virus 3, and Sendai virus.

Amino Acid Sequence↗

Serial immune evaluation of cyclosporine- and placebo-treated multiple sclerosis patients.

During an ongoing clinical trial of cyclosporine (CsA) immunosuppression therapy for chronic progressive multiple sclerosis (MS), a comparison was made of the immune responses of 18 CsA- and 18 placebo (P)-treated MS patients. Patients randomized to receive either CsA or P had identical entry immune profiles. However, these MS patients displayed significantly increased T-helper:T-suppressor (TH:TS) ratios (P less than 0.01), percentage (%) active-T (P less than 0.01), % Ia+-T (P less than 0.05) and % Ta1+-T (P less than 0.01) cell phenotypes when compared to age-matched normal controls. Further, the MS-P-treated patients displayed significant increases (all P less than 0.01) in % pan-T, % helper-T, % active-T and % Ta1+-T cell phenotypes as well as panel mixed lymphocyte culture (panel MLC) functional responsiveness from entry to cumulative 12-month study data. In contrast, the MS-CsA-treated patients only displayed an increased % pan-T cell phenotype. The cumulative 12-month follow-up data showed that the MS-P-treated patients displayed significantly higher immune parameters than the MS-CsA-treated patients for % pan-T (P less than 0.05), % helper-T (P less than 0.01), TH:TS ratio (P less than 0.05), % active-T (P less than 0.01), % Ta1+-T cells (P less than 0.01) and panel MLC stimulation index (P less than 0.01). Thus, MS-CsA-treated patients did not display the progressive immune activation seen on serial evaluation during the follow-up time period that characterized the placebo-treated MS group.

Acute Disease↗