Gene expression profiling in peripheral blood mononuclear cells from patients with sporadic amyotrophic lateral sclerosis (sALS).

The aim of this study was to identify gene expression profiles in peripheral blood mononuclear cells (PBMCs) from sporadic amyotrophic lateral sclerosis (sALS) patients to gain insights into the pathogenesis of ALS. We found that upregulation of LPS/TLR4-signaling associated genes was observed in the PMBCs from sALS patients after short-term cultivation, and that elevated levels of gene expression correlated with degree of peripheral blood monocyte activation and plasma LPS levels in sALS. Similar patterns of gene expression were reproduced in LPS stimulated PBMCs from healthy controls.

Evidence for systemic immune system alterations in sporadic amyotrophic lateral sclerosis (sALS).

Sporadic amyotrophic lateral sclerosis (sALS) is a progressive neuroinflammatory disease of spinal cord motor neurons of unclear etiology. Blood from 38 patients with sALS, 28 aged-match controls, and 25 Alzheimer's disease (AD) patients were evaluated and activated monocyte/macrophages were observed in all patients with sALS and AD; the degree of activation was directly related to the rate of sALS disease progression. Other parameters of T-cell activation and immune globulin levels showed similar disease associated changes.

Hepatitis C virus E2 has three immunogenic domains containing conformational epitopes with distinct properties and biological functions.

Mechanisms of virion attachment, interaction with its receptor, and cell entry are poorly understood for hepatitis C virus (HCV) because of a lack of an efficient and reliable in vitro system for virus propagation. Infectious HCV retroviral pseudotype particles (HCVpp) were recently shown to express native E1E2 glycoproteins, as defined in part by HCV human monoclonal antibodies (HMAbs) to conformational epitopes on E2, and some of these antibodies block HCVpp infection (A. Op De Beeck, C.

Recognition of native hepatitis C virus E1E2 heterodimers by a human monoclonal antibody.

The majority of hepatitis C virus (HCV)-infected individuals progress from acute to chronic disease, despite the presence of a strong humoral immune response to the envelope glycoproteins E1 and E2. When expressed in mammalian cells, E1 and E2 form both noncovalently linked E1E2 heterodimers, believed to be properly folded, and disulfide-linked, high-molecular-weight aggregates that are misfolded. Previously, we identified 10 human monoclonal antibodies (HMAbs) that bind E2 glycoproteins from different genotypes.

Structural features of envelope proteins on hepatitis C virus-like particles as determined by anti-envelope monoclonal antibodies and CD81 binding.

The envelope glycoprotein E2 of hepatitis C virus (HCV) is a major component of the viral envelope. Knowledge of its topologic features and antigenic determinants in virions is crucial in understanding the viral binding sites to cellular receptor(s) and the induction of neutralizing antibodies. The lack of a robust cell culture system for virus propagation has hampered the characterization of E2 presented on the virion.

Epitope mapping of human monoclonal antibodies recognizing conformational epitopes within HTLV type 1 gp46, employing HTLV type 1/2 envelope chimeras.

The majority of the antibody response to HTLV-1 surface glycoprotein, gp46, is directed at conformational epitopes. However, the regions of HTLV-1 gp46 that contain conformational epitopes are poorly defined. We previously reported on human monoclonal antibodies (hMAbs) to conformational epitopes within the HTLV-1 surface glycoprotein (gp46) that inhibit HTLV-1-mediated syncytium formation (Hadlock KG, Rowe J, Perkins S, et al.

The B-cell receptor of a hepatitis C virus (HCV)-associated non-Hodgkin lymphoma binds the viral E2 envelope protein, implicating HCV in lymphomagenesis.

Hepatitis C virus (HCV) infection is associated with extrahepatic B-cell lymphoproliferative disorders. To determine whether a viral antigen drives this B-cell expansion, the B-cell receptors were cloned from HCV-associated lymphomas and were expressed as soluble immunoglobulins. The rescued immunoglobulins were then tested for their ability to bind the HCV-E2 envelope glycoprotein, an antigen that was previously implicated in the pathogenesis of HCV-associated B-cell diseases.

Cross-reactivity and clinical impact of the antibody response to hepatitis C virus second envelope glycoprotein (E2).

The genotype of hepatitis C virus (HCV) can profoundly affect the success of antiviral therapy for HCV infection. A possible contributing factor is a varied immune response elicited by infection with different HCV genotypes. In this study, full-length E2 proteins of HCV genotypes 1a, 1b, 2a, and 2b were used to determine the fraction of the humoral immune response to HCV E2 that is genotype specific.

V(H)1-69 gene is preferentially used by hepatitis C virus-associated B cell lymphomas and by normal B cells responding to the E2 viral antigen.

Hepatitis C virus (HCV)-associated B cell lymphomas were previously shown to express a restricted repertoire of immunoglobulin V(H) and V(L) genes, V(H)1-69 and VkappaA27, respectively. Although this suggests a role for antigen selection in the pathogenesis of these lymphomas, the driving antigen involved in the clonal expansion has not been identified. B cell response to a viral antigen, the HCV envelope glycoprotein 2 (E2), was analyzed in an asymptomatic HCV-infected patient.

Human monoclonal antibodies that inhibit binding of hepatitis C virus E2 protein to CD81 and recognize conserved conformational epitopes.

The intrinsic variability of hepatitis C virus (HCV) envelope proteins E1 and E2 complicates the identification of protective antibodies. In an attempt to identify antibodies to E2 proteins from divergent HCV isolates, we produced HCV E2 recombinant proteins from individuals infected with HCV genotypes 1a, 1b, 2a, and 2b. These proteins were then used to characterize 10 human monoclonal antibodies (HMAbs) produced from peripheral B cells isolated from an individual infected with HCV genotype 1b.

The humoral immune response to human T-cell lymphotropic virus type 1 envelope glycoprotein gp46 is directed primarily against conformational epitopes.

Individuals infected with human T-cell lymphotropic virus type 1 (HTLV-1) develop a robust immune response to the surface envelope glycoprotein gp46 that is partially protective. The relative contribution of antibodies to conformation-dependent epitopes, including those mediating virus neutralization as part of the humoral immune response, is not well defined. We assess in this report the relationship between defined linear and conformational epitopes and the antibodies elicited to these domains.

Large granular lymphocyte leukaemia occurring after renal transplantation.

Post-transplantation lymphoproliferative disorders (PTLD) are a clinicopathologically heterogeneous group of lymphoid proliferations. The majority are of B-cell origin and associated with Epstein-Barr virus (EBV) infection. In contrast, the development of T-cell PTLD is much less common and EBV does not appear to be involved in pathogenesis.

Epitope mapping of HTLV envelope seroreactivity in LGL leukaemia.

Sera from approximately 50% of patients with large granular lymphocyte (LGL) leukaemia react with a recombinant human T-cell leukaemia/lymphoma virus (HTLV) transmembrane envelope protein, p21e. Two immunodominant epitopes within env p21e have been defined by reactivity against recombinant proteins GD21 and BA21. In this study sera from 41 patients with LGL leukaemia were examined for reactivity against these recombinant HTLV env proteins.

Seroreactivity to an envelope protein of human T-cell leukemia/lymphoma virus in patients with CD3- (natural killer) lymphoproliferative disease of granular lymphocytes.

Natural killer (NK) cells are CD3- large granular lymphocytes (LGL) responsible for immunity against viral infections. A chronic lymphoproliferative disorder of NK cells has been described in which the expanded NK cells display a restricted phenotype and cytotoxic activity. These data raise the hypothesis that proliferating LGL in these patients result from discrete expansions of NK cells responding to an unknown, perhaps viral, antigen.

Neutralizing human monoclonal antibodies to conformational epitopes of human T-cell lymphotropic virus type 1 and 2 gp46.

Ten human monoclonal antibodies derived from peripheral B cells of a patient with human T-cell lymphotropic virus (HTLV)-associated myelopathy are described. One monoclonal antibody recognized a linear epitope within the carboxy-terminal 43 amino acids of HTLV gp21, and two monoclonal antibodies recognized linear epitopes within HTLV type 1 (HTLV-1) gp46. The remaining seven monoclonal antibodies recognized denaturation-sensitive epitopes within HTLV-1 gp46 that were expressed on the surfaces of infected cells.

Chromatin structure and factor site occupancies in an in vivo-assembled transcription elongation complex.

The chromatin structure specific to the SV40 late transcription elongation complex as well as the occupancy of several sites that bind transcription factors have been examined. These features have been determined by assessing blockage to restriction enzyme digestion. Cleavage specific to the elongation complex has been quantified using ternary complex analysis.

Enhanced specificity of truncated transmembrane protein for serologic confirmation of human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 infections by western blot (immunoblot) assay containing recombinant envelope glycoproteins.

Immunoassays based on the highly immunogenic transmembrane protein of human T-cell lymphotropic virus type 1 (HTLV-1) (protein 21c) are capable of detecting antibodies in all individuals infected with HTLV-1 and HTLV-2. However, because of antigenic mimicry with other cellular and viral proteins, such assays also have a large proportion of false-positive reactions. We have recently identified an immunodominant epitope, designated GD21-I located within amino acids 361 to 404 of the transmembrane protein, that appears to eliminate such false positivity.

Delineation of an immunodominant and human T-cell lymphotropic virus (HTLV)-specific epitope within the HTLV-I transmembrane glycoprotein.

Antibody reactivity to the transmembrane region of human T-cell lymphotropic virus type I (HTLV-I) envelope, gp21, is observed in virtually all individuals infected with HTLV-I or HTLV-II. Recombinant proteins encoding selected portions of gp21 are described and used to define two immunogenic regions. The first epitope (designated GD21-I) contains amino acids 361 to 404 of the HTLV-I envelope and reacted with all of 54 sera from HTLV-I- and HTLV-II-infected individuals.

Complete nucleotide sequence of an Amerindian human T-cell lymphotropic virus type II (HTLV-II) isolate: identification of a variant HTLV-II subtype b from a Guaymi Indian.

The complete nucleotide sequence of a human T-cell lymphotropic virus type II (HTLV-II) isolate from a Panamanian Guaymi Indian was determined and analyzed. When this new viral isolate (HTLV-IIG12) was compared with prototypic HTLV-IIMoT, the overall nucleotide sequence similarity was 95.4%, while the predicted amino acid sequence similarity was 97.

Isotypic and IgG subclass restriction of the humoral immune responses to human T-lymphotropic virus type-I.

We have investigated the isotypic and IgG subclass profile of the antibody response to HTLV-I structural proteins (gag and env) in patients with HTLV-I-associated myelopathy (HAM; n = 20), adult T-cell leukemia (ATL; n = 15), and HTLV-I-positive asymptomatic carriers (ASY; n = 21). IgG, IgM, and IgA were the predominant antibody responses in all HTLV-I-infected individuals; minimal IgE response was detectable in the HAM and ATL groups. Among the IgG subclasses, IgG1 was the most predominant antibody detected in responses to HTLV-I antigens, followed by IgG3 and IgG2; IgG4 could not be detected in any patient group.

Evaluation of an immunoblot assay for serological confirmation and differentiation of human T-cell lymphotropic virus types I and II.

The confirmation of infection with human T-cell lymphotropic virus type I (HTLV-I) and type II (HTLV-II) currently involves multiple assays. These include Western blot (immunoblot) (WB) and/or radioimmunoprecipitation assay for detection of antibodies to HTLV-specific viral proteins and polymerase chain reaction and/or peptide-based enzyme immunoassays for differentiating between the two viruses. We undertook an evaluation of a modified WB assay that includes native HTLV-I viral proteins from MT-2 cells spiked with an HTLV-I transmembrane glycoprotein (recombinant p21e) and the HTLV-I- and HTLV-II-specific recombinant proteins MTA-1 and K55.

Immune responsiveness to the immunodominant recombinant envelope epitopes of human T lymphotropic virus types I and II in diverse geographic populations.

The heterogeneity of immune responsiveness to the immunodominant epitopes of human T lymphotropic virus (HTLV) types I (MTA-1(162-209)) and II (K-55(162-205)) were determined in natural infections with HTLV-I and -II from diverse geographic areas (n = 285). Of the HTLV-I specimens confirmed by polymerase chain reaction (PCR), all North American (n = 37) and Peruvian (n = 19) specimens reacted with MTA-1. Of HTLV-II specimens confirmed by PCR, 44 (96%) of 46 from North American blood donors, 28 (97%) of 29 from native Americans, and all from intravenous drug users (n = 29) reacted with K-55.

Cloning and analysis of a recombinant antigen containing an epitope specific for human T-cell lymphotropic virus type II.

An immunodominant HTLV-I-specific epitope in the HTLV-I envelope glycoprotein (GP) 46 has been described. To determine if the analogous region of HTLV-II contains a similarly immunogenic and specific epitope, the polymerase chain reaction (PCR) was used to amplify HTLV-II DNA fragments encoding various portions of the putative epitope. The synthesized DNAs were cloned into lambda-phage gt11 and screened for production of immunoreactive fusion protein using sera from HTLV-II- or HTLV-I-infected individuals.