Differential glycosylation of two glycoproteins synthesized by murine B cells in response to IL-4 plus IL-5.
We sought to determine whether selected cytokines, known to stimulate profoundly B-cell activation and differentiation, also have as yet unrecognized effects upon the glycosylation of secreted Ig and/or membrane-associated proteins. The glycosylation of both secreted IgM and membrane-bound MHC Class-I synthesized by CH12LX cells was detected by enzyme-lectin conjugates in immunoabsorption assays. Stimulation of B cells with IL-4 plus IL-5 significantly decreases the terminal glycosylation of secreted IgM, whereas LPS has a minor effect, despite the fact that both stimuli are equipotent for IgM secretion. Neither LPS nor IL-4 plus IL-5 affect MHC Class-I expression. However, IL-4 plus IL-5 substantially increases the terminal glycosylation of MHC Class-I produced from both mIgM(+)and mIgA(+)CH12LX cells. LPS has no or a modest effect on the terminal glycosylation of MHC Class-I produced from CH12LX cells. These results suggest that Th(2)-derived cytokines differentially influence the glycosylation of secreted and membrane-associated glycoproteins of B cells. In turn, this might elucidate the basis of aberrant glycosylation reported in conditions such as IgA nephropathy, cancer and rheumatoid arthritis.
Chintalacharuvu
S R
SR
Institute of Pathology, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Emancipator
S N
SN
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D006031:Glycosylation; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000378:metabolism*; D006825:Hybridomas; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000378:metabolism*; D015847:Interleukin-4 / Q000276:immunology*; D015848:Interleukin-5 / Q000276:immunology*; D051379:Mice; D014407:Tumor Cells, Cultured
D015395:Histocompatibility Antigens Class I; D007075:Immunoglobulin M; D015848:Interleukin-5; D015847:Interleukin-4