The role of shedding in the activity of immunocompetent cells with the reagin protective mechanism

The data on the content of soluble and membrane forms of CD23 antigen in healthy subjects are presented. Three groups were distinguished: the first group with low contents of both free and membrane CD23; the second group with increased contents of both forms; and the third group with an increased content of CD23 and a significantly decreased sCD23 concentration. The conclusion has been drawn that proteolytic shedding of CD23 was carried out by activated cells against a background of an increase in the CD23+ phenotype frequency in lymphocytes. An increase in the expression of CD23+ by lymphocytes was associated with an increase in the concentration of IL-6 and IFN-γ cytokines and the natural mitogen α-fetoprotein. Shedding of CD23 by cells and an increase in sCD23 occurred upon an excessive increase in IgE and antiinflammatory cytokine IL-10. The ratio between the membrane and free forms of CD23 was determined by the activity of the expression and shedding and level of an associate formation.