Abstract
Binding of the purified anti-nRNP antibody and it's F (ab')2 fragment obtained from serum of a patient with mixed connective tissue disease to the normal human peripheral blood lymphocytes was studied flowcytometrically using fluorescence activated cell sortors.
In flowcytometer, T cells were identified by PE-conjugated anti-Leu l antibody and binding of the antibody was identified by FITC-conjugated anti-human IgG antibody.
The IgG fraction of anti-nRNP antibody bound mainly to the non-T cells, that is B cells.
When the anti-nRNP antibody was treated by pepsin to prepare F (ab')2 fragment of the antibody, the binding to lymphocytes was extremely reduced.
In addition, when the lymphocytes were treated by aggregated rabbit IgG, the binding of anti-nRNP antibody (IgG) was scarecely noted.
These results suggested that anti-nRNP IgG could bind to non-T, mainly B cells, through Fc receptors of lymphocytes.
