doi: 10.1093/ndt/gfq325 Original Article Down-regulation of core 1 β1,3-galactosyltransferase and Cosmc by

Background. Patients with IgA nephropathy (IgAN) have an increased amount of abnormally O-glycosylated IgA1 in circulation, in glomerular deposits and produced by tis-sue cells in vitro. Although increased production of Th2 cytokines by peripheral blood lymphocytes and a function-al abnormality of core 1 β1,3-galactosyltransferase (C1β3Gal-T) have been proposed as mechanisms under-lying pathogenesis of IgAN, they are still obscure and are not connected. Methods. To clarify the effect of T-cell cytokines, we ana-lysed the mRNA levels of C1β3Gal-T and its molecular chaperone Cosmc, C1β3Gal-T activity and subsequent O-glycosylation of IgA1 in a human B-cell line stimulated with these cytokines. The surface IgA1-positive huma