HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Satoguina, J. S. Articles by Hoerauf, A. Search for Related Content PubMed PubMed Citation Articles by Satoguina, J. S. Articles by Hoerauf, A.

T Regulatory-1 Cells Induce IgG4 Production by B Cells: Role of IL-10¹

Judith S. Satoguina^*,, Esther Weyand, John Larbi and Achim Hoerauf^2,*,

^* Institute of Medical Parasitology, Friedrich Wilhelm University of Bonn, Bonn, Germany; and Department of Helminthology, Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany

The study was aimed to find out whether T cells with a regulatory profile could regulate the secretion of IgG4. Using tetanus Ag we found that PBMC of healthy human donors responded to exogenous IL-10 by down-regulating IgG1 and increasing IgG4 secretion. IgE was not affected. To investigate the direct effect of IL-10-producing T cells on B cells, we generated T cell clones (TCC) with two different cytokine profiles: first, IL-10^high, IL-2^low, IL-4^low TCC, and second, IL-10^low, IL-2^high, IL-4^high. The T cell-dependent Ab secretion was measured by coculturing purified CD19⁺ B cells and the TCC. Interestingly, we found that IgG4 production in the coculture correlated with the TCC production of IL-10 (r² = 0.352, p = 0.0001), but not with IL-2, IL-4, nor IFN-. IgE showed only a trend with regard to IL-4. Further, there was decreased Ab secretion in the absence of T-B cell contact. IL-10 also induced IgG4 when added to a Th1 TCC-B cell coculture system. The present study thus shows that in T-B cell coculture, IL-10, if induced by the TCC or added to the system, down-regulates the immune response by inducing IgG4 secretion. This establishes a direct implication of IL-10 in humoral hyporesponsiveness, particularly in compartments where the T-B cell interplay determines the subsequent immune response. The correlation between IgG4 and IL-10 (r² = 0.352) indicates that IL-10 is an important but not the only factor for IgG4 induction.