0000000000852138
AUTHOR
Gabriella Guarnotta
Inhibition of Fcγ Receptors in the Plasma of Subjects with Down's Syndrome
Abstract Subjects with Down's syndrome have several immunological abnormalities. We examined the sera of 29 subjects with Down's syndrome for the presence of Fcγ receptor blocking and for the presence of anti-ssDNA antibodies by EA rosette inhibition. Fifty-five percent of Down subjects had levels of inhibition above the upper limit of normality in comparison to 7% of normal controls. The finding that after polyethylene glycol precipitation of selected sera giving high levels of EA rosette inhibition there was a reduction or a disappearance of the EA rosette inhibition could indicate that the blocking factors detected behaved as immune complexes. Since almost all subjects with anti-ssDNA an…
Do Immune Complexes Formed with Autoantibodies Have a Role in the Maintenance of Immune Homeostasis Through Interaction with FC Receptors
Natural autoantibodies play an important regulatory role in the maintenance of immune homeostasis. They act as a first line of defense against environmental pathogens like toxins, bacteria and erythrocytes. In humans they are mainly produced by CD5+ B cells that are under the control of a regulatory T cell population. Fc-gamma receptors are involved in antigen recognition and signal transduction and tuning, and some of the members of the FcR family have structural similarity to MHC molecules; they may interact with multiple Ig ligands and with non-Ig ligands. We discuss the interactions between immune-complexes formed with natural autoantibodies and Fc-gamma receptors and suggest that such …