Biotinylation of glycan chains in beta2 glycoprotein I induces dimerization of the molecule and its detection by the human autoimmune anti-cardiolipin antibody EY2C9.

Binding of beta2GPI (beta2 glycoprotein I), a human plasma protein, to AnPLs (anionic phospholipids) plays a key role in the formation of antiphospholipid antibodies involved in autoimmune diseases like antiphospholipid syndrome or systemic lupus erythematosus. We recently showed that binding of beta2GPI to AnPLs was enhanced by biotinylation of its glycan chains with biotin-hydrazide. In the present study, we investigated why this chemical modification of beta2GPI increased both its affinity for AnPLs and its recognition by anti-cardiolipin antibodies.

Oxidation and biotinylation of beta 2 glycoprotein I glycan chains induce an increase in its affinity for anionic phospholipids similar to that obtained by the addition of anti-beta 2 glycoprotein I or anti-cardiolipin antibodies.

Binding of beta 2 glycoprotein I (beta2GPI) to apoptotic cells plays a key role in the opsonization of apoptotic bodies and the formation of antiphospholipids antibodies. Here, we describe the binding of beta2GPI to apoptotic cells using beta2GPI labelled with biotin-hydrazide (beta2GPI-bh) after oxidation of its glycan chains. Flow cytometry analyses and confocal microscopy showed that beta2GPI-bh, contrary to native beta(GPI, bound to apoptotic cells, either permeable or non-permeable to propidium iodide (PI), as did annexin-V-FITC.

Hepatitis B virus Dane particles bind to human plasma apolipoprotein H.

Human apolipoprotein H (apo H) was found to bind specifically to hepatitis B surface antigen (HBsAg) from hepatitis B virus (HBV)-infected individuals. We used recombinant HBsAg proteins to analyze HBV domains recognized by apo H. We showed that the myristylated pre-S1 domain of HBsAg strongly interacted with apo H.

Human plasmatic apolipoprotein H binds human immunodeficiency virus type 1 and type 2 proteins.

Apolipoprotein H (apo H), isolated from human plasma albumin solution, was shown to capture HIV-1-related antigens from antigen-positive sera (HIV-1 AG+) of AIDS patients, by using HIV-1-specific polyclonal antibodies. In an enzyme-linked immunosorbent assay and ligand blot and dot assays, apo H was able to bind recombinant retroviral HIV antigens, especially Gag proteins p18 of HIV-1, p26 of HIV-2, and Env gp160 of HIV-1. Binding was shown to be pH and NaCl dependent, with an optimum at acidic pH and low ionic strength.

Antibodies against polypeptides of purified Epstein-Barr virus in sera from patients with connective tissue diseases.

Antibodies to Epstein-Barr virus (EBV) were investigated in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) by immunoblotting using purified virus. Compared with sera from Epstein-Barr virus seropositive healthy individuals who served as control, sera from patients less frequently recognized several polypeptides. In particular, a 100 kDa envelope polypeptide was recognized by 92% of healthy subjects and only 11% of patients (P less than 0.

[IgG autoantibodies against cellular p72 antigen crossing with (MLV) p15-gag antigen: presence in early HIV 1 infection, in HBV infection and in primary Gougerot-Sjögren].

IgG antibodies of autoimmune SLE (Systemic Lupus Erythematosus) serum S detected a HeLa hnRNP 72 kDa protein, cross-reacting with the retroviral (MLV) p15-gag polypeptide. Since serum S disclosed a ubiquitous 72 kDa antigen in HeLa cell fractions, was prepared the so-called cytoplasmic "X fraction", enriched for the 72 kDa protein, defined here as p72. This autoantigen was detected by antibodies of HIV 1+ patients, recently of seroconverted (RSC) asymptomatic subjects, of HBV+ sera, and of primary Gougerot-Sjögren (prGS) sera.

Antibody responses against polypeptide components of Epstein-Barr virus-induced early diffuse antigen in patients with connective tissue diseases.

The specific humoral response against polypeptide components of Epstein-Barr virus (EBV), the induced early diffuse antigen (EA-D), in patients with connective tissue diseases, including systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD), was investigated by using the immunoblotting technique. The EA(D)-positive sera from patients with infectious mononucleosis (IM), nasopharyngeal carcinoma (NPC), immunocompromised patients (renal transplant recipients and patients with AIDS) as well as the EA(D)-negative sera from patients with Burkitt's lymphoma and from clinically healthy subjects served as controls. Seven major antigenic polypeptides with molecular weights of 33 kDa, 35 kDa, 52 kDa, 54 kDa, 56 kDa, 58 kDa, and 134 kDa were detected reproducibly by the EA(D)-positive reference sera and, in particular, by each of the NPC sera tested.

Immunoblotting reactivity of human sera from various sources against purified Epstein-Barr virus.

The immunoblotting technique was used to analyse polypeptides of purified Epstein-Barr virus reacting with antibodies present in sera from clinically healthy individuals, from patients with infectious mononucleosis (IM) or AIDS, and from renal transplant recipients. Polypeptides with molecular sizes in the range of 40-290 kDa were detected. The 47- and 160-kDa nucleocapsid polypeptides, as well as the 72-, 74-, 140-, 220- and 290-kDa membrane polypeptides were the major viral proteins detected in the sera.

Clinical significance of anti-RNP and anti-Sm autoantibodies as determined by immunoblotting and immunoprecipitation in sera from patients with connective tissue diseases.

Antibodies to Sm and RNP antigens have been detected by immunoblotting and immunoprecipitation of small nuclear ribonucleoproteins in 168 sera from patients with connective tissue diseases previously characterized by immunodiffusion. Anti-RNP and anti-Sm antibodies immunoprecipitated U1 and U1-U6 snRNA respectively. By immunoblotting anti-Sm reacted with B-B' and D polypeptides and we have distinguished two types of anti-RNP sera: 1) 'full spectrum' anti-RNP sera reacted with the 68 kD, A, C and B-B' polypeptides; 2) 'partially reactive' anti-RNP sera reacted with various combinations of these polypeptides but not the four of them.

Human autoimmune serum antibodies against gag gene p30 retroviral protein also react with a U1-SnRNP 68K comigrant protein.

Using Immunoblotting procedure, we showed that autoimmune human antibodies reacting with mouse retrovirus gag-p30 also reacted with a HnRNP 68 Kd protein. Since U1-SnRNP 68 K and p30-gag proteins show 40% homology, the detected 68 Kd protein is likely to be the U1-RNA 68 K.

A human auto-immune antibody specifically recognizing initiator methionine tRNA from yeast and higher eucaryotes.

Analysis of sera from 168 patients with autoimmune disorders revealed that one patient with Sjôgren's syndrome produced antibodies against deproteinized initiator methionine tRNA in addition to those against La protein. This anti-tRNAimet recognizes also tRNAimet from yeast but not from Phaseolus vulgaris chloroplasts (bean) or E. coli.

Presence of circulating antibodies against gag-gene MuLV proteins in patients with autoimmune connective tissue disorders.

An immunoblotting procedure using viral proteins from purified murine sarcoma virus or MSV-(MLV) has been developed to characterize antiviral antibodies in sera from patients with autoimmune connective tissue disorders. Fifty-eight sera with anti-Sm, anti-RNP, anti-SS-B (La), and other undefined specificities were found to react with several major viral polypeptide bands. Most of them corresponded to gag-gene-encoded products: pr65gag, p40gag, p30, p15, p12 and p10.

[Study of caryotypes in 52 cases of chronic lymphocytic B-cell leukemia].

The karyotypes of 103 cases of B cell chronic lymphocytic leukemia were studied following stimulation or establishment of continuous cell lines using the Epstein-Barr virus. In 52 patients metaphases suitable for cytogenetic analysis were obtained; 30 revealed normal karyotypes and 22 abnormal karyotypes. The most frequently encountered abnormalities were 6 cases of extra chromosome 12, 4 cases of structured aberrations concerning chromosome 14, including 2 t(11;14), 4 translocations concerning chromosome 11, and 3 cases of extra chromosome 3.

Isochromosome 17q in cell lines of two cases of B cell chronic lymphocytic leukemia.

The cytogenetic study of lymphocytes stimulated by EB virus in two cases of B-CLL revealed an isochromosome 17q. This abnormality, well known in CML during the stage of blastic transformation, may not be specific to myeloid proliferation as it is also observed in malignant lymphomas and B- or T-CLL. The anomaly does not appear to have the same prognostic nature as in CML.

11;14 translocations in lymphoproliferative disorders. An analysis of three cases.

Our paper reports 3 cases of (11;14) (q13;q32) translocation during two B-cell chronic lymphocytic leukemias and one B-cell diffuse centrocytic malignant lymphoma. Relating to this subject, we briefly review observations of 11;14 translocations during lymphoid hemopathies.

Karyotype analysis of B-lymphocytes transformed by Epstein-Barr virus in 21 patients with B cell chronic lymphocytic leukemia.

The karyotypes of 21 patients with chronic B cell leukemia were studied using lymphoblastoid cell lines obtained with the aid of the Epstein-Barr virus. Ten patients had a normal karyotype and eleven patients, an abnormal. There is no single characteristic anomaly, but certain types were more frequent, i.

Relationship between snRNA species contained in nuclear antigens recognized by autoantibodies and the clinical profile in systemic rheumatic diseases.

Antibodies to extractable nuclear antigens (ENA) are generally used in the diagnosis of connective tissue diseases. Using a rapid, very sensitive method we have shown that extractable nuclear antigens, which are now well-characterized at the molecular level, differ by their RNA content. The method was applied to the sera of 17 patients suffering from different connective tissue diseases.

[Our experince with antiglobulin consumption (Dixon test) in the study of antibodies bound to platelets].

We measured the quantity of IgG bound to platelets (IgGP) by the antiglobulin consumption test (Dixon technic). In controls, the IgG level did not exceed 10 X 10(-15) g for one platelet. The amount of IgGP was often incraeased (more than 10 X 10(-l5) g) in some autoimmune diseases as lupus erythematosus, chronic lymphocytic leukemia and chronic active hepatitis.