Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present studies were undertaken to characterize the affinity of CMV-induced Fc receptors for each of the subclasses of human IgG and to define the specific region of the IgG Fc fragment interacting with such receptors. To do this, we infected confluent human embryonic lung (HEL) cell monolayers with CMV (strain AD169) and then used a double radiolabel assay to measure adherence of antibody-coated E. coli 06 to such monolayers. Preincubating monolayers with each of the 4 subclasses of human IgG (but not IgA, IgM, or human or bovine albumin) abrogated the enhancing effect of CMV infection on adherence of antibody-coated E. coli 06 to HEL monolayers. Pepsin-derived, purified Fc fragments of human IgG had a similar abrogative effect. Preincubating these with staphylococcal protein A did not reduce their capacity to interfere with binding of antibody-coated E. coli to CMV-induced Fc receptors. These observations establish a broad range of immunoreactivity for CMV-induced Fc receptors, that encompasses all 4 subclasses of human IgG. They also provide indirect evidence that the reaction site of CMV-induced Fc receptors is in the CH2 domain of the Fc fragment.
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PMID:Immunoreactivity of cytomegalovirus-induced Fc receptors. 282 62

We previously reported that rheumatoid factors (RFs) might bear the internal image of Fc gamma-binding proteins (FcBPs) of herpes family viruses, suggesting the possibility that some RFs may be produced as antiidiotypic antibodies to anti-viral FcBP antibodies. Since human cytomegalovirus (HCMV) has been implicated in the pathogenesis of RA, we made an attempt to detect antibodies to 65 KD major HCMV FcBP in sera and synovial fluid from patients with RA. Western blotting was performed using HCMV-infected MRC-5 cell lysate as the antigen. Eleven of 23 patients with RA possessed strong serum antibodies to HCMV-65 KD protein, whereas such antibodies were found in only 2 of 23 normal controls. In the synovial fluid, 10 of 19 RA patients showed anti-HCMV 65 KD reactivity. Pepsin-digested IgG retained anti-65 KD reactivity, indicating that false-positive reaction due to the presence of IgG Fc portion and/or RF was unlikely. 65 KD protein was shown to be different from human heat shock proteins (hsps) using monoclonal antibodies against human hsps. Patients' IgG F(ab')2 also reacted with the 65 KD protein of purified HCMV virion itself. These results support the possibility that some RFs could be produced as antiidiotypic antibodies to anti-viral FcBP antibodies.
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PMID:Antibodies to human cytomegalovirus 65-kilodalton Fc binding protein in rheumatoid arthritis: idiotypic mimicry hypothesis of rheumatoid factor production. 821 29