Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.32 (bromelain)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Our previous studies have demonstrated that injection of rheumatoid arthritis (RA) synovial fluid (SF) induces a marked increase mainly of IgG1 antibody-producing cells in autoimmune disease prone (NZB x NZW)F1 mice but not in CBA mice. In the present study, the in vivo effect of RA-SF on autoantibody production was tested in different strains of mice. Injection of RA-SF induced the production of unorthodox autoantibodies (IgG1 rheumatoid factor, RF) in young (NZB x NZW)F1 mice as well as in their parental strains NZB and NZW, but not in normal mice (CBA) or in mice with severe combined immunodeficiency, indicating that the response is not caused by a conventional immune response against RA-SF material. IgG1 RF production was rapidly induced and reached high levels already on day 7 and lasted for more than 90 days. The induction of IgG1 RF was not the result of polyclonal activation, since RA-SF did not stimulate the production of other antibodies, such as autoantibodies against double-stranded DNA, bromelain-treated mouse red blood cells, myosin, transferrin, cytochrome c, thyroglobulin or myoglobin or antibodies reactive with the hapten TNP. To elucidate the identity of the active substance in RA-SF, responsible for IgG1 RF production, bound and unbound material of RA-SF, eluted from a protein-G column was injected into (NZB x NZW)F1 mice. Only the protein-G binding material was active, indicating that the effect is mediated by autoantibodies or immune complexes in the synovial fluid. Further studies demonstrated that identical concentrations of protein obtained from a pool of normal human IgG or SF from seronegative RA and non-RA arthritides patients did not contain the same activity.
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PMID:Protein-G binding material from synovial fluid of rheumatoid arthritis patients induces unorthodox autoantibodies (IgG1 rheumatoid factor) in NZB, NZW and (NZB x NZW)F1 mice. 812 37

We investigated whether autoimmune disregulation underlies the formerly reported induction of IgM hypergammaglobulinemia and lymphoid organ enlargement by hexachlorobenzene (HCB) in rats. To this end blood, liver, and lymphoid organs were collected from male Wistar rats after feeding a semisynthetic diet containing 0, 500, or 1000 mg HCB/kg for 3 weeks. Sera prepared from the blood were analyzed for total and (auto)antigen-specific antibody levels by ELISA, organs were weighed, and spleens were further investigated morphologically using immunohistochemically stained cryosections. Present experiments confirmed the ability of HCB to increase total IgM, but not IgG, levels and to increase relative spleen, lymph node, and liver weights. HCB treatment elevated IgM, but not IgG, levels against single-stranded DNA, native DNA, rat IgG (representing rheumatoid factor), and bromelain-treated mouse erythrocytes that expose phosphatidylcholine as a major autoantigen. Antibody levels against the foreign antigens sheep erythrocytes, tetanus toxoid, and bovine serum albumin remained unaffected. The IgM autoantibodies proved to be polyreactive. Morphometric analysis of spleen sections showed that HCB caused a proportionally equal expansion of all splenic compartments, but when individual spleen weights were taken into account a significantly larger expansion of the predominantly B cell-containing marginal zones could be noted. The latter compartment also contained an increased number of macrophages that can be recognized by the monoclonal antibody ED3. The ability of HCB to elevate serum antibody levels against autoantigens, but not foreign antigens, indicates that HCB probably does not act by polyclonal B cell activation. The IgM isotype, the repertoire, and the polyreactivity of the serum autoantibodies suggest that HCB activates a recently described B cell subset shown to be committed to the production of these autoantibodies and associated with various systemic autoimmune diseases. Since the marginal zone is considered to be the splenic lodging site of this B cell subset and since increases of ED3+ macrophages have been associated with autoimmune diseases in the rat, the observed changes of the marginal zones in HCB-treated rats is in line with this notion.
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PMID:Autoimmune effects of hexachlorobenzene in the rat. 821 5

In 1990 our group reported a patient with autoimmune hemolytic anemia and high titers of IgM anticardiolipin antibodies that cross-reacted with phosphatidylcholine (PTC). These autoantibodies also recognized bromelain-treated erythrocytes (BrE) and in vitro aged erythrocytes. The epitope exposed with this treatment is PTC. To detect and characterize antiphosphatidylcholine antibodies (anti-PTC) in a normal human population, we studied by ELISA the presence of serum anti-PTC (IgG and IgM) in clinically healthy human subjects. The most representative samples were also studied for IgG or IgM activity against BrE by flow cytometry, rheumatoid factor activity, anti-dsDNA, anti-ssDNA by ELISA and by indirect immunofluorecence (IIF) using HEp-2 line and a healthy human fibroblast strain as substratum. Eighty five percent of sera had IgM anti-PTC and none had IgG. IgM antibodies against BrE were inhibited by PTC micelles (mPTC). Anti-PTC were also inhibited by phosphorylcholine and phosphatidic acid. Aggregated gammaglobulin (AGG) reactivity was inhibited by dsDNA and mPTC. The IgM anti-dsDNA activity was inhibited by soluble dsDNA, AGG and mPTC. All sera gave intermediate filaments pattern by IIF and reacted against purified vimentin by dot blot and Western blot.Our study shows hemolytic IgM anti-PTC present in normal human serum. The main epitope recognized by these autoantibodies is phosphorylcholine. The physicochemical characteristics, crossreactivity with self-antigens and functional properties are typical features of natural autoantibodies.
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PMID:Characterization of anti-phosphatidylcholine polyreactive natural autoantibodies from normal human subjects. 1190 50