Premium
IgG2b Inducing Factor from Rheumatoid Arthritis Synovial Fluid Synergizes with Transforming Growth Factor‐β in Promoting IgG2b Antibody Production in Mouse B Lymphocytes
Author(s) -
LETTESJO¨ H.,
RIDDERSTAD A.,
MO¨LLER E.
Publication year - 1997
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.1997.d01-372.x
Subject(s) - antibody , immunology , synovial fluid , transforming growth factor , microbiology and biotechnology , rheumatoid factor , transforming growth factor beta , arthritis , biology , medicine , endocrinology , pathology , alternative medicine , osteoarthritis
Rheumatoid arthritis synovial fluid (RA‐SF) contains a distinct biological activity that selectively induces IgG2b production in LPS‐activated murine B blasts. This IgG2b inducing factor (IgG2bIF) acts directly on purified LPS‐activated B blasts from normal and Bruton's tyrosine kinase‐defective CBA/N mice. In order to test the possibility that TGF‐β and IgG2bIF in RA‐SF act in concert to induce IgG2b production, anti‐TGF‐β monoclonal antibodies and RA‐SF were added to LPS‐activated CBA B blasts, which led to a marked reduction of IgG2b‐producing cells. This result indicates that TGF‐β and IgG2bIF in RA‐SF synergize in the induction of IgG2b production. TGF‐β antibodies do not inhibit IgG2b production in CBA/N B blasts, further substantiating our earlier notion that CBA/N B blasts have a higher endogenous production of TGF‐β after LPS stimulation, which might be responsible for the aberrant reactivity in btk deficient CBA/N mice. RA‐SF is able to reconstitute the deficient IgG1 response in LPS‐ and IL‐4‐stimulated CBA/N B blasts. Addition of antibodies against TGF‐β had only a marginal effect on the IgG1 response, indicating that the reconstitution is mediated by another factor(s), which is present in RA‐SF.