The induction of murine B cell Ia by IgE-antigen complexes is dependent on protein synthesis and preceded by class II mRNA accumulation.
Complexes of murine monoclonal anti-DNP IgE and DNP-OVA interact with murine B cells to stimulate expression of cell surface Ia antigens. Enhanced membrane expression of class II MHC antigens was accompanied by a threefold increase of I-A and I-E transcripts, as measured by Northern blot. Peak accumulation of Ia mRNA were detected after 6 hr of incubation with IgE-antigen complexes and returned to control levels after 12 hr of incubation. Hence, induction of Ia mRNA by IgE-antigen complexes was compatible with cell surface Ia expression, both quantitatively and with regard to the time frame. The Ia-inductive effects of both IL-4 and IgE-antigen complexes were inhibited by cycloheximide and actinomycin-D. However, whereas actinomycin-D and cycloheximide blocked IL-4 induction of Fc epsilon RII expression, inhibition of transcription or protein synthesis did not abrogate the increased expression of Fc epsilon R associated with IgE-antigen complexes. These results suggest that the IgE-antigen-induction of B cell Ia expression follows from activation of transcription and de novo synthesis of Ia antigens.
Richards
M L
ML
Division of Immunology, Medical Biology Institute, La Jolla, California 92037.
Liu
F T
FT
Katz
D H
DH
D000818:Animals; D000936:Antigen-Antibody Complex / Q000378:metabolism*; D000943:Antigens, Differentiation / Q000235:genetics; D001402:B-Lymphocytes / Q000276:immunology*; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism*; D007073:Immunoglobulin E / Q000378:metabolism*; D015847:Interleukin-4 / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D011961:Receptors, Fc / Q000235:genetics; D017452:Receptors, IgG; D013154:Spleen / Q000166:cytology
D000936:Antigen-Antibody Complex; D000943:Antigens, Differentiation; D000949:Histocompatibility Antigens Class II; C024138:I-E-antigen; D012333:RNA, Messenger; D011961:Receptors, Fc; D017452:Receptors, IgG; D003609:Dactinomycin; D015847:Interleukin-4; D007073:Immunoglobulin E; D003513:Cycloheximide