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J P Vaerman

Publications and source records attributed to J P Vaerman.

At least 145 records · Page 8Linked to original sources
PubMed1982

Selective transport of polymeric immunoglobulin A in bile. Quantitative relationships of monomeric and polymeric immunoglobulin A, immunoglobulin M, and other proteins in serum, bile, and saliva.

In 17 adults, serum, hepatic bile, and saliva samples were analyzed for their sedimentation profile of IgA and secretory component (SC), and for their concentrations of albumin, orosomucoid, transferrin, IgG, IgA, alpha 2-macroglobulin (alpha 2M), IgM, and SC. Polymeric IgA(p-IgA) averaged 13% (50-700 micrograms/ml) of total IgA in serum, 70% (43-88%) in bile, and 93% (74-98%) in saliva. Most of the p-IgA in bile sedimented with SC, which also occurred free (8-44%), and with IgM. In bile, albumin (155-1,485 micrograms/ml) was the predominant protein, followed by IgG (32-480 micrograms/ml), and total IgA (37-209 micrograms/ml). In saliva, p-IgA (72-902 micrograms/ml) predominated, followed by albumin (16-385 micrograms/ml) and IgG (9-178 micrograms/ml). Secretion-to-serum albumin-relative concentration ratios (S/S-ARCR = 1 for albumin) in bile averaged 22 for p-IgA, 1.91 for IgM, 1.28 for monomeric IgA (m-IgA), 0.70 for IgG, and 0.57 for alpha 2M, indicating for p-IgA, IgM, and to a lesser extent for m-IgA, a selective excretion into bile. In saliva, a 16-fold greater selective excretion of p-IgA (mean S/S-ARCR = 354) was found. Labeled m- and p-IgA were injected intravenously into five patients. Specific activities indicated that for p-IgA 50% was serum derived in bile, as compared with 2% in saliva, and to 85% for m-IgA in bile. In the patient with the highest excretion of 125I-p-IgA in bile, only 2.8% of the injected dose was recovered in bile within 24 h after injection. Compared with rats and rabbits, the serum-to-bile transport of p-IgA in humans is much smaller.

Bile↗
PubMed1982

Selective excretion of IgA in rat bronchial secretions: lack of significant contribution from plasma IgA.

Concentrated rat bronchial washings (BW) were analyzed by gel-filtration and immunochemical methods. BW contained mainly albumin, transferrin and IgG. Free secretory component and secretory IgA were identified in BW; the BW-IgA had the same three sedimentation coefficients, i.e. +/- 11 S, 13 S, 15 S by sucrose density gradient ultracentrifugation, as rat milk and rat bile IgA; the three peaks were secretory IgA. Compared to serum, and relatively to albumin, BW were significantly enriched in IgA, although much less than rat bile. Purified polyclonal rat polymeric 125I-IgA was injected intravenously into normal rats, and into rats with bile duct ligation or partial hepatectomy, which decrease the liver plasma-to-bile transfer of IgA. BW were then collected, one or four hours later, to assess the recovery of the 125I-IgA in BW and to estimate the contribution of serum IgA to BW-IgA. Very little 125I-IgA (less than 0.2%) was recovered in all BW. The specific activity, measured only in the rat with the highest recovery in BW, was 20 times lower in BW than in serum. The data demonstrate that rat serum IgA does not contribute significantly to IgA in BW.

Albumins↗
PubMed1982

Serum IgM-bound secretory component (sIgM) in liver diseases: comparative molecular state of the secretory component in serum and bile.

The sera of 15 patients with liver disease and high serum concentrations of secretory component (SC) were analyzed by density gradient ultracentrifugation and radioimmunoassays for SC, IgA, and IgM to determine the molecular state of SC and IgA. Results in serum were compared to those obtained by simultaneous analysis of bile in five of the patients, and to those in serum and bile of a case of total IgA deficiency. Free SC was virtually not found in sera, although it was well represented in all bile, up to 88 and 97% of total bile SC in a case of complete biliary obstruction and in IgA deficiency, respectively. IgM-bound SC was found in all sera, amounting to 91% and 100% of total serum SC, respectively, in a case of acute hepatitis with a very high serum IgM concentration and in IgA deficiency. The proportions of SC bound to IgM and to polymeric IgA (p-IgA) in the sera correlated with their IgM/p-IgA molar ratio. This suggests that during liver disease, the hepatobiliary tissues could release free SC into the circulation, where it binds to p-IgA and IgM according to their respective concentrations and affinities for SC. The proportion of p-IgA in serum was not increased in four cases of biliary obstruction, in contrast to our cases of cirrhosis and acute hepatitis, indirectly supporting a minor transfer of p-IgA from blood to bile in humans, in contrast to rats and rabbits.

Acute Disease↗
PubMed1982

Secretory component (SC): preferential binding to heavy (greater than 11S) IgA polymers and IgM in serum, in contrast to predominance of 11S and free SC forms in secretions.

The origin and molecular form(s) of the small amounts of secretory component (SC) found in serum are but poorly known. Using sensitive immunoradiometric assays for SC, we studied its molecular distribution after ultracentrifugation of native sera containing various proportions of IgA and IgM, with SC levels (sIgA equivalents) ranging from 4 to 25 micrograms/ml. Large proportions of SC were found bound to IgM and IgA polymers heavier than the classical 11S sIgA, in contrast to saliva and bile where SC was found mainly in the 11S region and in the free form. A comparative study of the ultracentrifugal distribution of labelled free SC, incubated in vitro with sera containing various proportions of IgA and IgM, yielded similar results, indicating a direct relationship between the proportion of IgM-bound SC and the IgM concentration. Free SC in serum was only found in the in vitro experiments. The data suggest that the epithelial cells synthesizing SC not only release (secrete?) SC as pre-assembled SC-Ig complexes in lymph or plasma, but also directly release some SC in free form.

Bile↗
PubMed1981

A solid phase, direct competition, radioimmunoassay for quantitation of secretory IgA in human serum.

A solid phase radioimmunoassay is described for measurement of secretory IgA (sIgA) in human serum. The assay is based on direct competition between sIgA in serum and purified labelled milk sIgA for anti-secretory-component antibodies coated on disposable plastic cups. The assay is relatively rapid, reproducible and of adequate sensitivity. A wide range of sIgA concentrations (5--120 microgram/ml) can be tested with the same dilution of human serum. The arithmetic mean +/- S.D. of the serum sIgA levels of 120 random blood donors (both sexes) was 10.9 +/- 4.6 microgram/ml. Compared to previously published methods and results of quantitation of sIgA in human sera, the present assay is an improvement which should yield interesting data in human hepatic physiopathology.

Blood Proteins↗
PubMed1981

The induction and expression of IgA anti-DNP antibodies in rat bile and secretions.

Pregnant rats were immunized with dinitrophenylated type III-pneumococcal vaccine by the intravenous, gastric, or intramammary routes. Anti-DNP antibody responses in the IgA, IgG and IgM isotypes were measured in serum, secretions and bile. Gastric intubation was most effective at eliciting IgA antibody responses in bile and secretions, whereas the other routes were more effective at inducing IgG responses in serum and bile. IgM antibody responses were infrequent and were found in fluids most closely associated with the immunization route. Isoelectric focusing studies of IgA antibodies appearing in secretions and bile revealed that the gastric route consistently elicited antibody spectrotypes with shared components. Intravenous and intramammary immunization resulted in IgA spectrotypes possessing less homology, suggesting that these protocols lead to independent antibody responses triggered in spleen, draining lymph nodes, or secretory sites. After gastric stimulation, the appearance of IgA antibodies with identical spectral components in secretions and bile favours the concept that IgA precursor cells with identical clonotype potential migrate from the gastrointestinal area to secretory sites. Antibody expression in bile appears to result from the selective transfer of IgA populations gaining access to serum after synthesis at a secretory site.

Animals↗
PubMed1981

Increased serum IgA levels in rats after portacaval shunt but not after portacaval transposition.

Groups of rats were submitted to end-to-side portacaval shunt, portacaval transposition or a control sham operation. There was an 18-fold increase of the IgA level in the serum of portacavally shunted rats (n = 7) at 3-6 weeks after surgery. Gel filtration revealed that this increase was predominantly due to dimeric and polymeric IgA. The serum IgM of these shunted rats, but not the IgG, was also significantly increased (twofold) above their control values. In rats subjected to portacaval transposition (n = 6), there was no significant increase of serum IgA, IgM or IgG when compared with their control values. These data confirm the active transfer, by the healthy rat liver, of IgA and, to a lesser extent, of IgM from the blood into bile. Impairment of this function, leading to the accumulation of polymeric IgA and IgM in the serum, in portacavally shunted but not portacavally transposed animals, may be related to impairment of hepatic flood flow and hepatic atrophy, shown earlier to occur in portacavally shunted but not transposed rats. Such reduction in liver cell mass could also explain the fall in transferrin levels in shunted rats.

Animals↗
PubMed1981

In vivo experiments involving secretory component in the rat hepatic transfer of polymeric IgA from blood into bile.

Human or rat purified secretory IgA (sIgA) injected intravenously (i.v.) into rats is transferred to bile much less (seven to twenty-four times) than human or rat polymeric IgA (pIgA) devoid of secretory component (SC). A polymeric Fc alpha (pFc alpha) fragment of a human IgAl myeloma protein, obtained by IgA-protease digestion, bound in vitro to rat SC and was actively transferred in vivo into bile, in contrast to the corresponding Fab alpha. The IgA recovered in bile was not degraded, as judged by sedimentation in density gradients. Purified rabbit IgG anti-rat SC antibody was also efficiently transported in vivo into bile, about forty times more than normal rabbit IgG. The biliary transport of anti-Sc antibody could be reduced and retarded by the simultaneous i.v. injection of purified rat SC or human pIgA. The transfer of rat 125I-pIgA into bile was also significantly reduced and retarded by the concomitant i.v. injection of purified rat or human SC. Moreover, i.v. injection of purified rat or human SC induced a marked and prolonged decrease of the sIgA level in the bile. Rat SC was more effective than human SC in this respect. All these in vivo experiments confirm the in vitro findings of Orlans, Peppard, Fry, Hinton : Mullock, (1979) and Socken, Jeejeebhoy, Bazin & Underdown, (1979) showing that Sc is the IgA-receptor on the hepatocyte membrane for the transfer of pIgA from rat plasma into bile.

Animals↗
PubMed1981

Reassessment of levels of secretory IgA in pathological sera using a quantitative radioimmunoassay.

Serum levels of sIgA were quantitated by a new radioimmunoassay in patients with a variety of diseases, lactating women and clinically healthy blood donors. Significantly elevated levels compared to controls were found in lactating women, patients with Crohn's disease and patients with cirrhosis, but not in patients with rheumatoid arthritis, IgA myeloma or neoplastic disease. Patients with inflammatory disease and serum IgA levels at least two-fold greater than the normal mean and patients with a variety of other diseases did not show elevated levels of sIgA. In the two latter groups, patients with hepatic disease were excluded. High levels of sIgA were found in four patients with liver metastases from extrahepatic neoplasms. The results indicate that the liver is important for the maintenance of normal serum levels of sIgA.

Arthritis, Rheumatoid↗
PubMed1980

Synthesis of secretory component by rat hepatocytes in culture.

Normal rat hepatocytes were isolated and cultivated in vitro. Synthesis of secretory component was demonstrated by its accumulation in the culture medium, as measured by radioimmunoassay; by incorporation of 14C-leucine in the protein specifically precipitated with anti-secretory component antiserum; and by a positive precipitin reaction of concentrated culture medium with the same antiserum. The results explain the high levels of secretory component found in rat bile and render plausible a mechanism of hepatic IgA transfer involving secretory component as the hepatocyte membrane receptor for polymeric IgA.

Animals↗
PubMed1980

A common mucosal immune system. Antibody expression in secretions following gastrointestinal stimulation.

Isoelectric focusing was used to probe the expression of IgA anti-DNP antibodies in secretions of rats receiving gastrointestinal immunization. The identity of the IgA antibody spectrotypes suggest that cells with identical clonotype potential seed various secretory surfaces following gastrointestinal stimulation. The data are discussed in terms of a common mucosal immune system linked by migrating populations of IgA precursor cells.

Animals↗
PubMed1980

Molecular diversity of secretory IgA anti-DNP antibodies elicited in rat bile.

Dinitrophenylated-type III pneumococcus has been used to induce biliary IgA anti-DNP antibody responses in rats. A solid phase radioimmunoassay was employed to quantitate the biliary IgA anti-DNP antibodies after subcutaneous, i.v., or intragastric immunization. All routes were shown to effectively elicit biliary IgA antibody responses. The microscale sucrose isoelectric focusing technique was employed to assess molecular diversity of the secretory IgA anti-DNP antibodies in bile. Subcutaneous and intragastric immunization resulted in complex antibody spectrotypes whereas i.v. immunization yielded restricted antibody spectrotypes, demonstrating that the route of immunization influenced the molecular diversity of the biliary secretory IgA antibodies. These findings are discussed in terms of mechanisms governing the induction of secretory antibodies.

Animals↗