Low-affinity IgE receptor (CD23) function on mouse B cells: role in IgE-dependent antigen focusing.

Publisher Website
Google Scholar
Abstract
B-cell surface immunoglobulin very efficiently focuses specific protein antigens for presentation to T cells. We have demonstrated a similar role in antigen focusing for the low-affinity Fc.epsilon. receptor (Fc.epsilon.RII) on mouse B lymphocytes. B cells treated with an IgE monoclonal antibody to 2,4,6-trinitrophenyl (TnP) (IgE-B cells) were 100-fold more effective than were untreated B cells in presenting low concentrations of TNP-antigen to T cells. Blocking the binding of IgE to Fc.epsilon.RII on IgE-B cells with a monoclonal antibody to Fc.epsilon.RII completely eliminated this increased effectiveness. Preformed complexes of IgE anti-TNP and TNP-antigen were more effectively presented (.apprxeq. 100-fold) than TNP-antigen in the presence of nonspecific IgE. In contrast, complexes of IgG1 anti-TNP and TNP-antigen, capable of binding to Fc.gamma. receptors on B cells, were presented less effectively than TNP-antigen in the presence of nonspecific IgG1. Antigens focused by means of Fc.epsilon.RII or by means of B-cell surface immunoglobulin receptors were presented at comparably low concentrations. For several reasons, Fc.epsilon.RII on B lymphocytes seems to be particularly effective in efficiently focusing IgE-antigen complexes.

This publication has 47 references indexed in Scilit: