IMMUNOGLOBULIN-G COMPLEX INTERACTIONS WITH RHEUMATOID-FACTOR AND NEUTROPHILS - (CRCL3)-CR-51 LABELING AND (CO2)-C-14 HEXOSE MONOPHOSPHATE SHUNT STUDIES

  • 1 January 1976
    • journal article
    • research article
    • Vol. 3  (4) , 329-336
Abstract
The interactions of soluble and insoluble Ig[immunoglobulin]G complexes with macromolecular rheumatoid factor (RF) and neutrophils were examined in an in vitro system allowing the separate assay of the biologic activities of these elements in the rheumatoid inflammatory process. Studies utilizing soluble and insoluble 51CrCl3 labeled human IgG complexes demonstrated uptake of only the insoluble complexes by human neutrophils. A burst of hexose monophosphate shunt activity, as evidenced by increased oxidation of glucose-1-14C to 14CO2, occurred only when neutrophils were exposed to these insoluble complexes. High titer RF sera added to the insoluble complexes prior to their incubation with neutrophils did not affect the uptake of the complexes or the magnitude of hexose monophosphate shunt activity. Native IgG and soluble IgG complexes were not taken up by the neutrophils and did not stimulate hexose monophosphate shunt activity in the presence or absence of rheumatoid sera. The addition of high titer RF sera to soluble IgG complexes produced precipitation of RF-IgG complexes which were capable of stimulating hexose monophosphate shunt activity in normal neutrophils. RF changes functionally inactive soluble complexes into functionally active insoluble complexes capable of stimulating normal neutrophils. Neutrophil stimulation by insoluble complexes may be important in the continuing inflammatory process occurring in the joints of patients with rheumatoid arthritis.