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J P Vaerman

Publications and source records attributed to J P Vaerman.

At least 109 records · Page 6Linked to original sources
PubMed1987

Complexes of albumin and alpha 1-antitrypsin with Fc-fragment of IgA monomer are disulfide-bound to penultimate C-terminal cysteine in the C alpha 3-domain.

Six IgA myeloma sera, containing albumin (ALB)-IgA and alpha 1-antitrypsin (alpha 1-AT)-IgA complexes (CXs), were gel-filtered on Ultrogel AcA22. The CXs were eluted between monomeric and dimeric IgA. The CX-containing fractions were digested with three IgA-proteases: ALB and alpha 1-AT remained bound to Fc alpha-, but not to Fab alpha-fragments. Short (less than 2 h) peptic digestion entirely released free ALB and alpha 1-AT from the CXs, indicating that these proteins are linked to the third constant domain of the alpha-chain. Identical results were obtained with anti-ALB immunosorbent-purified ALB-IgA CXs. Reduction-alkylation of ALB or alpha 1-AT bound to IgA or Fc alpha confirmed disulfide binding. The data support the binding of ALB and alpha 1-AT to the same penultimate C-terminal cysteine of the alpha-chain as that which binds the J-chain.

Alkylation↗
PubMed1987

Rat C3 conversion by rat anti-2,4,dinitrophenyl (DNP) hapten IgA immune precipitates.

Monomeric (m-) and polymeric (p-) anti-DNP monoclonal (MC) rat IgA antibodies (Ab) were tested for precipitation with DNP-bovine serum albumin (DNP-BSA) and C3 conversion in rat serum, with rat MC anti-DNP IgG2b used as reference. At equivalence, p-IgA rapidly precipitated DNP-BSA, with little antigen (Ag) left in the supernatant. In contrast, m-IgA at five-fold higher concentration precipitated Ag very slowly, with less than 50% of Ag precipitated at equivalence. The Ag/Ab weight ratio at equivalence was 0.13 for both m- and p-IgA, but the molar ratio was 0.3 for m-IgA and close to 1.0 for p-IgA, suggesting a higher avidity of p-IgA. Rat C3 conversion by rat IgA immune precipitates (IP) was about 20% with m-IgA and 40% with p-IgA. EGTA did not significantly affect these figures. Therefore, rat MC IgA IP activated the rat alternative C pathway. Neither rat nor mouse IgA anti-DNP IP activated C3 in normal human serum.

Animals↗
PubMed1986

The molecular organization of the protein HC-IgA complex (HC-IgA).

Complexes of protein HC and monoclonal IgA1 or IgA2 or polyclonal IgA were isolated from human blood plasma. Dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting showed that all complexes contain three types of chains: two light immunoglobulin chains, one regular IgA alpha-chain, and one chain with Mr = 90,000 carrying both alpha-chain and protein HC epitopes. The complexes were split into Fab alpha and Fc alpha fragments by bacterial IgA proteases. The protein HC epitopes were linked to the Fc fragments. Complexes of protein HC and an alpha-chain devoid of the variable region and the first heavy chain constant domain could also be demonstrated to be present in the blood plasma of a patient with alpha-heavy chain disease. Pepsin digestion of HC-IgA released a fragment containing all the protein HC epitopes and the C-terminal nonapeptide of the IgA alpha-chain. The light immunoglobulin chains, the regular alpha-chain, and the 90,000-Da chain from monoclonal HC-IgA1 were isolated by preparative dodecyl sulfate-polyacrylamide gel electrophoresis and by repeated gel filtration in dodecyl sulfate-containing buffer. The N-terminal amino acid sequence of the alpha-chain was identical with that of a regular human heavy immunoglobulin chain of subgroup III. Subtractive degradations of the 90,000-Da chain displayed 2 amino acid residues in each position in a pattern suggesting simultaneous degradations of a chain identical with the regular alpha-chain of HC-IgA and of uncomplexed, low molecular weight, protein HC. All the results are compatible with a model for HC-IgA in which a single low molecular weight protein HC polypeptide chain is covalently linked, side by side, to the C-terminal nonapeptide of one of the two alpha-chains of a regular monomeric IgA unit.

Alpha-Globulins↗
PubMed1986

Rat monoclonal antibodies. VI. Production of IgA secreting hybridomas with specificity for the 2,4-dinitrophenyl (DNP) hapten.

A simple method to obtain rat hybridomas producing specific IgA antibodies is reported. By fusing the IR983F rat myeloma cell line with mesenteric lymph node cells from LOU/C rats immunized via the Peyer's patches with DNP-Salmonella typhimurium, twenty hybrids secreting monoclonal IgA antibodies specific for DNP were produced and maintained as highly secreting transplantable ascitic tumors. The monoclonal IgA antibodies were easily purified by affinity chromatography on a DNP-immunosorbent and were found to comprise both monomers and polymers.

Animals↗
PubMed1986

Altered patterns of secretion of monomeric IgA and IgA subclass 1 by intestinal mononuclear cells in inflammatory bowel disease.

Intestinal mononuclear cells (MNC) from patients with inflammatory bowel disease (IBD) demonstrated altered patterns of spontaneous secretion of immunoglobulin A (IgA). Control intestinal MNC had markedly high spontaneous secretion of IgA compared to IBD intestinal MNC. Control intestinal MNC secreted predominantly dimeric IgA (only 31% monomeric IgA), whereas IBD intestinal MNC secreted increased amounts (43%-53%) of monomeric IgA. Control intestinal MNC secreted 61% IgA subclass 1 (IgA1), whereas IBD intestinal MNC secreted 71%-74% IgA1. Intestinal MNC from involved portions of resected specimens secreted more of both monomeric IgA and IgA1 than MNC from uninvolved areas of the same bowel. Therefore, intestinal MNC from involved IBD intestinal specimens secrete less total IgA but high percentages of monomeric IgA and IgA1 compared to control intestinal MNC. This could be caused by increased homing of monomeric IgA- and IgA1-producing cells into involved intestine, or the in situ proliferation of monomeric IgA and IgA1 precursor cells resulting from immunoregulatory alterations. These observations may represent the normal mucosal IgA immune response to infectious agents or inducing factors of either a primary or a secondary nature.

Cell Movement↗
PubMed1986

Monoclonal antibodies against isotypic and isoallotypic determinants of human IgA1 and IgA2: fine specificities and binding properties.

We have analysed and compared the fine specificity and behavior in various immunoassays of 10 mouse monoclonal antibodies, from three independent laboratories, directed against IgA1, IgA2 or non-IgA2m(2). The following observations were made. (1) Although all of the monoclonal antibodies were specific for a particular IgA subclass or isoallotype in a radioimmunoassay, three of them were not specific when tested in indirect immunofluorescence on plasma cells derived from pokeweed-activated peripheral blood lymphocytes. In this highly sensitive system, contrary to direct immunofluorescence previously performed using formalin-fixed lymphoid tissue, the anti-IgA1 69.114 reacted with some of the IgA2 plasma cells, the anti-IgA2 DLDB7 reacted with some of the IgA1 plasma cells and the anti-IgA2 16.512 dimly reacted with all IgM plasma cells. (2) Among the eight anti-IgA subclass antibodies, seven were directed against the CH2 domain of IgA whereas the anti-IgA1 1-155-1 recognised an epitope destroyed by Streptococcus sanguis IgA1 protease and localised in the hinge region of IgA1. The two anti-isoallotype antibodies were directed against epitope(s) probably localised in the 65 C-terminal amino acid residues of the alpha-CH3 domain. All of the 10 antibodies were able to react with endogeneously produced surface IgA on B-cells. (3) Using monoclonal anti-IgA subclass antibodies in radioimmunoassay may be hazardous in the absence of knowledge of their affinity constants and of careful control experiments: some of the antibodies were not sensitive in radioimmunoassays designed to measure the serum titer of specific IgA1 and IgA2 antibodies. Moreover, major differences were observed between the different monoclonal reagents with respect to the influence of the size of IgA on a solid-phase sandwich radioimmunoassay. While three of the anti-IgA1 underestimated dimeric IgA relative to monomeric IgA, the fourth anti-IgA1 and all the anti-IgA2 overestimated dimeric IgA relative to monomeric IgA, by a factor sometimes close to 7.

Animals↗
PubMed1986

Autoantibodies of the IgM class against a human myeloma protein IgE(DES). I. Occurrence.

We report on the natural occurrence of human serum antibodies with specificity for a human monoclonal myeloma IgE(DES). These antibodies were of the IgM class, based on their susceptibility to reduction, sedimentation in sucrose gradients, gel filtration and inhibition of agglutination by anti-IgM antiserum. Autoantibody levels were studied in several groups of patients by particle-counting immunoassay using latex particles to which purified monoclonal IgE(DES) was coupled. Only sera of patients suffering from parasitosis had significantly higher levels (p less than 0.0005) than those of healthy blood donors. Cord sera had very low levels, followed by an age-dependent increase during early infancy. There was no relation (p greater than 0.10) between serum IgE and IgM antibody level. On the other hand, significant relations between IgM anti-IgE(DES) levels and serum IgM (p less than 0.0005), serum IgA (p less than 0.001) and serum IgG (p less than 0.05) were observed suggesting that high levels were caused by or related to polyclonal activation of the immune system.

Antibodies, Anti-Idiotypic↗
PubMed1986

Autoantibodies of the IgM class against a human myeloma protein IgE(DES). II. Specificity.

Five different monoclonal IgE proteins, papain and pepsin fragments of myeloma protein IgE(DES) and particle-counting immunoassay were used to study in detail the epitope(s) of IgE(DES) involved in the agglutination with IgM anti-IgE(DES) antibodies. The specificity of these autoantibodies was restricted to IgE(DES) as they did not react with latex particles coated with four other IgE myeloma proteins. Antibodies reactive with latex-IgE other than latex-IgE(DES), when present, were also of restricted specificity as shown by criss-cross absorption experiments. These differences between IgE myeloma proteins could not be attributed to the light chain type nor to the Em(1)-allotype. The epitope(s) of IgE(DES) participating in the reaction was heat-resistant (56 degrees C, 2 h) and localized in the pepsin F(ab')2 epsilon fragment, but was absent in the papain Fc epsilon and Fab epsilon fragments. Further degradation by pepsin of the F(ab')2 epsilon fragment (molecular weight 145,000 daltons) to 5S epsilon (90,000 daltons) and Fc" epsilon fragments (30,000 daltons) destroyed the reacting epitope. These results indicate that the IgM antibodies were not directed against kappa chain or idiotypic determinants of IgE(DES), but to some epitope(s) in the undegraded hinge region. Therefore, it seems that some kind of antigenic heterogeneity, perhaps related to the carbohydrate moieties, is present in IgE myeloma proteins besides the known idiotypic, allotypic and isotypic ones.

Antibodies, Anti-Idiotypic↗
PubMed1986

Induction of rat secretory IgA antibodies against cholera toxin by a synthetic peptide.

There is accumulating evidence concerning the possible importance of secretory IgA antibodies in defence mechanisms against infections of the gastrointestinal tract, including cholera. Intestinal IgA antibodies are also thought to play a major role in protection against the diarrhoeogenic effects of cholera toxin. We therefore attempted to induce secretory IgA antibodies towards a reactive synthetic peptide from the cholera toxin B subunit sequence. We report that rat biliary secretory IgA antibodies against the CTP3 peptide (residues 50-64 of the B subunit) were obtained by three intra-Peyer's patch immunizations, at 2-week intervals, with CTP3 conjugated to tetanus toxoid in complete Freund's adjuvant. Purified secretory IgA fractions from bile of such immunized rats reacted with the carrier toxoid, but also with the CTP3 peptide, and with the native cholera toxin, they also partially neutralized its biological activity, as assayed by inhibition of in vitro cholera toxin-induced cAMP production in mouse thymocytes.

Animals↗
PubMed1985

Hepatobiliary transport of plasma IgA in the mouse: contribution to clearance of intravascular IgA.

Labeled monomeric and polymeric (pIgA) mouse monoclonal IgA were injected intravenously into mice which were either sequentially bled for plasma turnover studies of IgA, or cannulated at their common bile duct, with excluded gallbladder, for quantitation of plasma-to-bile transport of pIgA. Our data show that mice do display a relatively high rate of biliary transport of plasma pIgA (22-28% of the injected 125I-labeled pIgA over 3 h), which accounts for approximately 90% of the total amount of pIgA (8.8 mg/kg/day) daily delivered by hepatic bile into the duodenal fluid of this species. However, in mice the absolute biliary output of pIgA does not exceed that of IgG (9.5 mg/kg/day) and the kinetics of the hepatobiliary transport of plasma pIgA appear to be slower than in the rat. Furthermore, as plasma survival studies of 125I-labeled pIgA yielded a plasma turnover of pIgA averaging 20.6 mg/kg/day, it can be approximated that the hepatobiliary pathway contributes for only 38% to the elimination of intravascular pIgA from mouse plasma, a figure to be compared to 89.8% in the rat and approximately 8.9% in man. We conclude that internal catabolism plays a dominant role in the clearance of intravascular pIgA in the mouse which appears as a model intermediate between rats and humans. Supporting this conclusion, serum pIgA two days after common bile duct ligation in 6 mice was increased by 2.5-fold vs. greater than 14-fold in ligated rats and 1.1-fold in humans with complete biliary obstruction.

Albumins↗
PubMed1985

Double precipitin arcs of IgA myeloma sera on immunoelectrophoresis. Origin and suggestion of IgA2m(2) allotype.

The serum from two patients with IgA myeloma displayed double precipitin arcs upon immunoelectrophoresis with class-specific (light chain absorbed) anti-IgA antisera obtained by immunization with monoclonal IgA1, but not IgA2 proteins. Both sera contained large amounts of monoclonal IgA2m(2) together with some polyclonal IgA1. No incomplete IgA molecules were found. The double precipitin arcs resulted from the reaction of large amounts of monoclonal IgA2m(2) with class-specific antibodies, and of small amounts of polyclonal IgA1 with subclass-specific anti-IgA1 antibodies of the same antiserum. Such double arcs, if not due to incomplete IgA molecules, could indicate the IgA2m(2) nature of the monoclonal IgA in these rare sera.

Aged↗
PubMed1985

Neutralization of cholera toxin by rat bile secretory IgA antibodies.

IgA-antibody (AB) activities have been elicited in rat bile against several antigens such as bacteria, erythrocytes, tumour cells, haptens and proteins (Lemaître-Coelho, Jackson & Vaerman, 1978; Hall et al., 1979; Montgomery, Lemaître-Coelho & Vaerman, 1980; Peppard et al., 1982). However, their biological significance, except for plasma clearance of immune complexes (Peppard et al., 1982) and bacterial agglutination, remains conjectural, despite their possible major contribution to rat intestinal immunity. The importance of local intestinal immunity in protection against cholera is today widely admitted (Jertborn, Svennerholm & Holmgren, 1984). Intraintestinally given cholera toxin (CT) is a potent immunogen in rats whose intestinal mucosa then harbours numerous anti-CT IgA plasma cells (Pierce, 1978). Since bile IgA in rats is largely, but not entirely, derived from intestinal synthesis (Vaerman, Lemaître-Coelho & Jackson, 1978; Manning et al., 1984), rats intestinally immunized with CT could display high levels of anti-CT IgA AB in their bile, and these AB might neutralize CT in the biologically relevant intestinal loop assay (Lange & Holmgren, 1978).

Animals↗
PubMed1984

Typing of subclasses and light chains of human monoclonal immunoglobulins by particle counting immunoassay (PACIA).

The subclasses of monoclonal IgGs and IgAs were identified by particle-counting immunoassay. The principle of the test is the inhibition of the agglutinating activity of either specific antisera or monoclonal antibodies (for IgA only) on latex particles coated with a monoclonal IgG or IgA of known subclass. The feasibility of assay of polyclonal Ig subclasses was demonstrated. However, the anti-IgG2 antiserum cross-reacted with an allotype (nG4m(b)) of IgG4. The possibility of typing monoclonal Igs for light chains by the same technique was also demonstrated. Results are obtained in 30 min, and the method requires only small amounts of purified immunoglobulins (Igs) and antisera or monoclonal antibodies.

Agglutination Tests↗