title: Characterization of cystic fibrosis factor and its interaction with human immunoglobulin.
abstract: Cystic fibrosis factor activity (CFFA), assayed as the ability to stop oyster ciliary movement, was present in serum-free medium from actively growing cystic fibrosis skin fibroblast cultures. CFFA was associated with a low molecular weight, negatively charged molecule that contained no uronic acid and was heat and pH labile. When CFFA-positive media were mixed with human IgG1, the CFFA was chromatographically displaced and emerged with the IgG1 fraction on column chromatography. Experiments in which various immunoglobulins were added to CFFA-positive culture media and then incubated with specific anti-immunoglobulins suggested that CFFA binding was class specific for human IgG, subclass specific for IgG1 and IgG2, and occurred with intact unaggregated heavy chains but not with kappa- and lambda-light chains, or Fab, Fc, and F(ab')(2) fragments. The serum protein beta(2)-microglobulin, which has structural homology to IgG, also bound CFFA.
mesh_terms: D000367:Age Factors; D000937:Antigen-Antibody Reactions; D002460:Cell Line; D002478:Cells, Cultured; D003550:Cystic Fibrosis / Q000276:immunology*; D005347:Fibroblasts / Q000032:analysis / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007136:Immunoglobulins / Q000032:analysis*; D012867:Skin / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007136:Immunoglobulins