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J Roudier

Publications and source records attributed to J Roudier.

At least 55 records · Page 3Linked to original sources
PubMed1990

Altered immune response to glycine-rich sequences of Epstein-Barr nuclear antigen-1 in patients with rheumatoid arthritis and systemic lupus erythematosus.

Prior studies have shown that patients with rheumatoid arthritis (RA) have an increased number of circulating Epstein-Barr virus-infected B lymphocytes and elevated titers of antibody to Epstein-Barr nuclear antigen-1 (EBNA-1), the major nuclear antigen expressed in latently infected B cells. However, it is not known whether antibodies from RA patients recognize the same epitopes as antibodies from normal subjects. are directed at the glycine-alanine repeating region of the molecule. Antibodies specific for this region are also somewhat more prevalent in RA patients than in normal subjects. A panel of synthetic peptides derived from EBNA-1 was used to analyze the immune response to antigenic epitopes outside the glycine-alanine region, using the peptides as solid-phase antigen. Sera from RA patients and from systemic lupus erythematosus patients contained elevated levels of IgG antibodies to 2 non-glycine-alanine peptide and to 3 non-glycine-alanine peptides, respectively. Two of the 3 peptides are glycine-rich, but antibodies that react with them are distinct from each other, as well as from those that react with the glycine-alanine epitope. Eight other peptides from the C-terminal portion of EBNA-1 either do not react with sera or show no difference between normal subjects and patient groups. The antibodies to the glycine-alanine peptide are enriched with kappa light chains, whereas antibodies to epitopes outside the glycine-alanine region are not so restricted among kappa and lambda light chains. Thus, RA patients and systemic lupus erythematosus patients have different antibody responses than do normal subjects, both quantitatively and qualitatively.

Amino Acid Sequence↗
PubMed1989

Human T cell responses to the Epstein-Barr nuclear antigen-1 (EBNA-1) as evaluated by synthetic peptides.

A panel of synthetic peptides derived from Epstein-Barr virus (EBV) nuclear antigen 1 (EB-NA-1) was used to examine human T cell responses to this antigen. In six of seven normal persons with past EBV infection, T cell precursors specific for five peptides (P27, amino acid residues 83-101;P62, 148-166;E31, 353-367;E41, 368-381; and E11, 461-474) were detectable. The precursor frequencies were in the range of 1:20,000 to less than 1:100,000 peripheral blood mononuclear cells as determined by limiting dilution analyses. Only two of these peptides were predicted as alpha-helices; all peptides were glycine-rich. Four other peptides were not reactive in the seven individuals tested. T cell responses were not detectable in donors without prior EBV infection. Infectious mononucleosis patients investigated 4-6 weeks after diagnosis had likewise no detectable peptide-specific T cell precursors. Thus, it appears that T cells recognizing peptides from EBNA-1 arise and persist in people with past EBV infection.

Amino Acid Sequence↗
PubMed1989

Epstein-Barr virus and rheumatoid arthritis: cellular and molecular aspects.

Several lines of research have indicated a possible association of the Epstein-Barr virus and rheumatoid arthritis (RA). The earliest evidence suggested that RA patients develop a stronger humoral immune response to EBV nuclear antigens (EBNA) which may in part account for the increased titers of antibody to the RA nuclear antigen (RANA). It was then pointed out that mononuclear cells from RA patients may be impaired in their capacity to control EBV infection. This may be related to a decrease in the production of IFN gamma and a consequence of monocyte-derived inhibitory activities. These cellular defects, however, are not specific for RA and may rather be the result of chronic inflammatory responses. These findings and the lack of increased virus presence in RA tissues did not provide a strong basis for a possible association of EBV and RA. A new concept for this association is now being tested on the basis of the sequence homology between the genetic RA susceptibility determinant HLA DR4 and the EBV glycoprotein 110.

Amino Acid Sequence↗
PubMed1989

Susceptibility to rheumatoid arthritis maps to a T-cell epitope shared by the HLA-Dw4 DR beta-1 chain and the Epstein-Barr virus glycoprotein gp110.

Rheumatoid arthritis is associated with the HLA antigen HLA-DR4. Disease susceptibility maps to the amino acid sequence QKRAA located in the third hypervariable region of the DR beta-1 chain. This region is thought to be a site of recognition for the T-cell antigen receptor. We searched for an antigen in the human environment that could induce T-cell recognition of this sequence. An analysis of protein and DNA databases revealed that the Epstein-Barr virus glycoprotein gp110, which is encoded by the BALF4 open reading frame, contains the sequence QKRAAQRAA, which is highly homologous to the rheumatoid arthritis susceptibility determinant. Experiments using antibodies to synthetic peptides showed that the QKRAA determinant is expressed on the gp110 protein. Humans with serologic evidence of Epstein-Barr virus infection had serum antibodies to gp110 and peripheral blood T cells that recognized peptides from gp110 and HLA-Dw4 encompassing the QKRAA determinant.

Amino Acid Sequence↗
PubMed1987

Do viruses play an etiologic role in ankylosing spondylitis or psoriatic arthritis?

High venous blood levels of 2-5A, an adenylic acid polymer synthesized in the presence of double-stranded RNA and considered as a viral replication indicator, have been found in blood samples from ankylosing spondylitis and psoriatic arthritis patients, but not from patients with seropositive rheumatoid arthritis or acute chondrocalcinosis. These findings suggest the possibility that ankylosing spondylitis and psoriatic arthritis might be virus-induced diseases.

Adenine Nucleotides↗
PubMed1986

IgM antiplatelet antibodies in 7 out of 20 rheumatoid arthritis sera. A new antiplatelet antibody ELISA. Reverse correlation with anti-B-lymphocyte antibodies in the same sera.

In a previous work, we had found that anti-B lymphocyte antibodies exist in rheumatoid arthritis. To investigate whether these antibodies were directed against surface immunoglobulins or not we have investigated if RA sera could recognize similar structures on other targets such as platelets (on which immunoglobulins and immune complexes are present) by a new ELISA method. No IgG antiplatelet antibody was found in 20 RA sera. But 7 out of these 20 RA sera had IgM antiplatelet antibodies when tested on platelets from 5 donors. The comparison of the positivities of these sera on B lymphocytes and platelets from the same donors showed a statistically significant reverse (X2 = 20,008, p much less than 0.0001) correlation. The target antigen and the meaning of these IgM antiplatelet antibodies, which seem to be associated with severe RA, is still under investigation.

Antibody Specificity↗
PubMed1985

[Antiplatelet antibodies of the IgM class detected by ELISA in the serum of 20 patients with rheumatoid polyarthritis. Inverse correlation with the presence of anti-B lymphocyte antibodies].

In an earlier study, the authors demonstrated IgM anti-B lymphocyte antibodies in the sera of patients with rheumatoid arthritis. In an attempt to identify the target antigen, we studied the reactivity of these same sera to other cells, by means of a recently developed ELISA micro-method. 7 of the 20 sera contained IgM anti-platelet antibodies. There is an inverse correlation between the presence of anti-platelet antibodies and anti-B lymphocytes antibodies. The detection of anti-platelet antibodies in the serum of patients with rheumatoid arthritis may correspond to the recognition of aggregated immunoglobulins or specific immune complexes bound to receptors on the surface of the platelets.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Molecular polymorphism of various HLA-D subregions and rheumatoid arthritis.

In Caucasian populations, rheumatoid arthritis (RA) is generally associated with serologic HLA-DR4 specificity. In order to refine this correlation in the HLA-D region, we used six different probes pertaining to this locus: DR beta, DQ beta, DQ alpha, DO beta, DP beta and DP alpha. In this step, pooled RA and control DNA were hybridized with DR beta and DQ beta probes after digestion with 12 different endonucleases. Some bands appeared specific in the RA pool. In fact, with genomic DNA from 13 unrelated typed RA patients and 12 matched or partially matched control cells, these bands were revealed to be related to DR4 and/or DR1, with DR beta and DQ beta probes hybridizing BamHI, EcoRV, PvuII and StuI digests. With other probes, no differences could be related to RA disease. The polymorphism detected by these probes was suggestive of a gradient of decreasing complexity from DR beta to DO beta through DQ beta and DP beta, which could reflect discrete functions of each subregion.

Arthritis, Rheumatoid↗
PubMedDate not supplied

[Autoimmune pathology and esthetic surgery. Apropos of a case].

The authors report the case of a 46-year old woman who, 7 years after bilateral implantation of a silicone breast prosthesis, presented with a seropositive rheumatoid arthritis involving the shoulders, wrists, metacarpophalangeal and interphalangeal joints of both hands, as well as the knees and ankles. Six months after the onset of the arthritis, she developed a Raynaud's syndrome and a lacrymal and salivary dry syndrome with unilateral axillary lymphadenopathy. No regression followed the removal of the breast prostheses, one of which was found broken.

Autoimmune Diseases↗
PubMedDate not supplied

Serological and structural analysis of HLA class I molecules: beta 2-microglobulin interacts with the two external domains of the HLA class I heavy chain.

The serological reactivities of HLA class I molecules were studied in relation to structural modifications of these molecules, including shuffling of external exons and exchange of human beta 2-microglobulin for beta 2-microglobulin from different species. Two major clusters (I and II) of monomorphic and polymorphic antigenic determinants could be delineated. beta 2-Microglobulin participates in the formation of the two clusters, indicating that the light chain interacts tightly with the two external domains of the HLA class I heavy chain. However, external molecules can modify these interactions and alter the antigenic structure of the overall molecule. Thus, fixation on HLA class I molecules of the Fab fragment of a monoclonal antibody directed at antigenic determinants associated with cluster II resulted in enhanced fixation of a monoclonal antibody (B10.6) related to cluster I. The structural and functional implications of these results are discussed.

Antibodies, Monoclonal↗