Cellular localization of rheumatoid factor idiotypes.

Suppression of in vitro monoclonal human rheumatoid factor synthesis by antiidiotypic antibody. Target cells and molecular requirements.

“…In agreement with animal studies (5)(6)(7)(8), the capacity of antiidiotypic antibody to suppress human idiotype expression has been demonstrated both in vitro (32)(33)(34) and in vivo (35) (Fig. 3), the IgG fraction was approximately five times more effective than the F(ab')2 preparation in suppressing in vitro IgM RF release by the patient's blood MNL.…”

“…In this regard, the recent studies of Bonagura et al (34) indicating that antiidiotype is capable of suppressing the appearance of idiotype-positive plasma cells in a pokeweed mitogen driven system are of considerable interest. The observation that F(ab')2 antiidiotype suppressed both extracellular and intracellular IgM and IgM RF in our patient suggest that antiidiotype suppresses synthesis, not secretion, of idiotype.…”

Monomeric (7S) IgM found in the serum of rheumatoid arthritis patients share idiotypes with pentameric (19S) monoclonal rheumatoid factors.

“…Anti-RCRI antibodies raised in Flanders Giant rabbits were obtained as previously described in detail (17,18). In short, Ea monoclonal pentameric IgM (RF+, member of the major RCRI group) was injected subcutaneously in complete Freund's adjuvant into rabbits.…”

“…Utilizing indirect immunofluorescence (17) and hemagglutination inhibition assays (15,16), we observed that 7S IgM molecules obtained from RF+ patients' sera inhibit polyclonal anti-major RCRI antibodies from binding RCRI+ molecules in the cytoplasm of peripheral blood lymphocyte (PBL)-derived, pokeweed mitogen (PWM)-induced plasma cells from RA patients, or from reacting with prototypic reduced and alkylated 19S IgM RFs placed on the surface of sheep red blood cells (SRBC). The reaction of anti-RCRI antibodies with RCRI' monoclonal IgM RF was not inhibited in either assay by seronegative (RF-) 7S IgM obtained from one "RA" patient, or by reduced and alkylated polyclonal normal IgM.…”

Complete protein sequences of the variable regions of the cloned heavy and light chains of a human anti-cytomegalovirus antibody reveal a striking similarity to human monoclonal rheumatoid factors of the Wa idiotypic family.

“…This is analogous to the restricted use of immunoglobulin variable region gene segments in murine antigen specific systems, many of which bear cross-reactive idiotypes. The relationship between these monoclonal RFs and the RFs present in RA was demonstrated by Pernis and his colleagues, who showed that the plasma cells of patients with RA contained idiotype-positive material (29). Some of the autoantibodies produced during the course of RA thus are structurally similar to the antibodies so extensively studied in mixed cryoglobulinemia (30).…”