Correlation of presentation of insulin with surface I-Ad and A alpha and A beta mRNA expression by cloned B lymphoma hybridoma variants.
We investigated the relationship between Ia expression and antigen presentation in cloned B cells, using variants of TA3 antigen presenting cells. Two TA3 subclones were selected as high presenters and 5 as low presenters of insulin to pork insulin/I-Ad restricted T cells. All TA3 subclones express the surface I-Ak, I-Ek, I-Ad and I-Ed Ia antigens characteristic of the parental cell line. However, surface I-Ad levels correlated best with the ability to present insulin, since high presenters express 2- to 4-fold more I-Ad than low presenters. High presenters possess 2- to 4-times more A alpha and A beta Ia mRNA than low presenters and also transcribe these mRNAs 2- to 5-fold faster than most low presenters. Thus, the correlation noted between I-Ad surface density and capacity to present insulin by our panel of TA3 variants is regulated at the level of transcription and not translation of I-Ad specific mRNAs.
Bernard
N F
NF
Banting and Best Department of Medical Research, University of Toronto, Ontario, Canada.
Reid
P C
PC
Phillips
M L
ML
Delovitch
T L
TL
D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D002999:Clone Cells / Q000276:immunology; D005786:Gene Expression Regulation; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D006825:Hybridomas / Q000276:immunology; D007328:Insulin / Q000276:immunology*; D008223:Lymphoma / Q000235:genetics / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics*; D014158:Transcription, Genetic
D000949:Histocompatibility Antigens Class II; D007328:Insulin; D012333:RNA, Messenger