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. This binding involved phospholipid components of the HBV envelope because their removal by detergent prevented apo H-HBsAg interaction. The opposite effects of iron and zinc metal ions on binding suggest that the oxidation of phospholipids also affects apo H-HBsAg interaction. After fractionation of viral particles on a sucrose gradient, and their addition to microtiter plates coated with apo H or anti-HBsAg, we observed that the maximal anti-HBsAg capture activity corresponded to a sucrose concentration of 36%, whereas the maximal apo H capture activity corresponded to a concentration of 39%. Electron microscopy and polymerase chain reaction (PCR) Southern blot studies of these fractions showed that the fraction with maximal apo H binding predominantly contained full Dane particles. Finally, we studied apo H-HBsAg binding relative to the presence of hepatitis B virus markers and observed that apo H binding activity for HBsAg was higher in sera from patients in the active virus replication phase.

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. Specificity was demonstrated by saturation of this binding and inhibition either by homologous competition or by specific antisera. Binding was also observed in cell line-harvested viral proteins. The mechanism of this apo H-polyspecific binding is discussed in relation to conformational changes due to the influence of lipids or detergents.

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 0.001). On the other hand, 62% of the patient sera had antibodies to the 42 kDa envelope polypeptide, whereas these antibodies were only present in 4% of the sera from the control subjects (P less than 0.001). These results could reflect either perturbations of the immune response associated with connective tissue disorders or a possible pathogenic role of EBV.

[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]. / Autoanticorps IgG contre un antigène cellulaire p72 croisant avec l'antigène (MLV) p15-gag: présence dans l'infection HIV 1 précoce, dans l'infection HBV et le Gougerot-Sjögren primitif.

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. The presence of these autoantibodies in different autoimmune and infectious pathologies raises the question of the involvement of p72 in the immune processes and in the early HIV1 infection.

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. The EA(D)-positive sera from the other groups showed various combinations of detection patterns and few samples reacted with all the major EA(D) polypeptides. Seventy-three percent of sera from SLE and 47% of sera from MCTD were found to react with EA(D). Sixty-one percent of sera from SLE vs. 5% from MCTD detected all the EA(D) polypeptides. These results could either reflect perturbations of the immune response linked to the autoimmune disease or suggest a possible pathogenic role of EBV.

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. Sera from clinically healthy individuals contained antibodies directed against all EBV membrane and nucleocapsid antigens. Sera from renal transplant recipients, from patients with IM and from patients with AIDS failed to react with certain nucleocapsid and membrane antigens; in particular, sera from AIDS patients and renal transplant recipients did not react with the 220-kDa polypeptide, one of the major membrane antigens, while sera from subjects with IM and from healthy individuals did. A high proportion of sera from patients with IM (38% vs 5% of clinically healthy individuals and 0-5% of the AIDS patients and renal transplant recipients) reacted with a 42-kDa polypeptide, suggesting its possible role in acute EBV infection.

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. A strong specificity of anti-Sm antibodies for systemic lupus erythematosus (SLE) was found with all three methods but immunoblotting was more sensitive and detected anti-Sm in 76% of SLE sera. Sera containing a high titer of 'full spectrum' anti-RNP without anti-Sm activity were only detected in mixed connective tissue disease (MCTD) whereas anti-68 kD antibodies alone seemed to be less specific. This strong association between 'full spectrum' anti-RNP antibodies and MCTD supports the hypothesis that MCTD is a distinct clinical entity associated with a specific serologic marker.

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. It appears therefore that the epitope could be located in the TF loop in which an A residue in position 60 and the AUCG sequence are the only common features in yeast and human tRNAimet.

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. Other bands with molecular weights averaging 90K, 60K, 45K, and 28K were recognized by a few sera. Immunological specificity of the reaction was assessed by reproducing the tests with IgG purified from sera and from corresponding F(ab')2 fragments. Moreover, the specificity of the reaction with gag proteins was confirmed by repeating the tests with p30 and p15 prior purified by immunoprecipitation with anti-p30 and anti-p15 goat sera. Furthermore, the gag polypeptides were recognized by human sera by replacing MSV-(MLV) by three other murine retroviruses of different origin. An indirect confirmation of these results was obtained by applying this method to sera of MRL lpr/lpr mice which develop an autoimmune syndrome comparable to that of human systemic lupus erythematosus. In agreement with previously published results (C. Rordorf, C. Gambke, and J. Gordon (1983), J. Immunol. Methods 59, 105-112), we found that anti-gag-gene antibodies were present in the sera of individual mice. Patterns of reactivity were found to vary with the age of the animals. No retroviral polypeptide was significantly detected in the great majority (80%) of sera from normal donors. However, 5 out of 25 sera showed faint bands although to a lesser extent than pathological sera. These five sera also reacted with HeLa cell purified HnRNPs, suggesting that their normal status should be reconsidered.

[Study of caryotypes in 52 cases of chronic lymphocytic B-cell leukemia]. / Etude du caryotype de 52 leucémies lymphoïdes chroniques B.

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. No relationship appears to exist between the abnormalities observed and the clinical profile or prognosis.

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.e., 14q+ as a result of a translocation 11;14, trisomy 12, and an isochromosome 17q. Abnormalities in these same three chromosomes have been found in other hematologic malignancies. It is postulated that loci with control cell proliferation are present on chromosomes 12, 14, and 17.

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. The results show that mixed connective tissue disease (MCTD) and other mild connective tissue diseases are characterized by the presence in the antigen of U1 small nuclear RNA (U1 snRNA) only. On the other hand, antibodies from 6 out of 8 patients tested with Systemic Lupus Erythematosus (SLE) recognize antigens exhibiting a more complex RNA pattern. Three of them precipitated all five snRNAs U2, U1, U4, U5, U6 whereas some snRNAs were lacking or quantitatively less important in precipitates obtained with the three others.

[Our experince with antiglobulin consumption (Dixon test) in the study of antibodies bound to platelets]. / Notre expérience de la consommation de l'antiglobuline (test de Dixon) dans la recherche des anticorps fixés sur les plaquettes.

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. Among 26 patients presenting an idiopathic thrombocytopenic purpura (ITP) with a low number of platelets, 21 (77%) had a high titer of IgGP. In 6 ITP in remission, the IgGP titer was normal. After a review of the different technics detecting the IgG bound to platelets, we explain why we choose the antiglobulin consumption. This test is excellent for the research of anti-platelets auto-antibodies in ITP. Yet, the reaction remains negative in a minority of ITP. Several explanations are possible: low quantity of IgGP, presence of other anto-antibodies as IgM or IgA, cellular auto-immunity anti-platelets without antibodies, non immunologic ITP.