Regulation of in vivo Expression of Fc Receptors for IgE (FcεR) on Murine Lymphocytes

摘要

The induction of Fc receptors for IgE (FcεR) and its regulation were studied in BALB/c, SJL/J, and nude mice by a flow cytometric assay with the use of homologous monomeric IgE. Immunization of BALB/c mice with alum-absorbed antigen induced a remarkable increase in the expression of FcεR on spleen cells, whereas no enhancement of the FcεR expression was observed in SJL/J and nude mice after immunization. This increase was correlated with the elevation of serum IgE levels. However, the IgG antibody response, which is inducible even in SJL/J mice, was not associated with the induction of FcεR. The enhanced expression of FcεR in BALB/c mice observed in the primary or secondary IgE antibody response was detected in B cells with B220, surface IgM, and IgD, but not in T cells. The induction of FcεR in immunized BALB/c mice was inhibited by suppressive factor of allergy isolated from ascites fluids of SJL/J mice inoculated with complete Freund’s adjuvant. In addition, both cyclophosphamide and prednisolone had an inhibitory effect on the induction of FcεR. These results suggest that the FcεR induction is inhibited not only by suppressive factor of allergy, which is effective in inhibiting the IgE antibody response selectively, but also by some immunosuppressive agents which are capable of suppressing all