Induction of immunoglobulin mu mRNA in a B cell transfectant stimulated with interleukin-5 and a T-dependent antigen.
We have established an Ag-specific in vitro system for studying the roles of Ag and IL-5 in B cell differentiation and Ig production. The murine B cell leukemia, BCL1B1, was transfected with mu and kappa genomic sequences and VS107 V regions that conferred a T15 Id and phosphocholine-binding specificity upon the cells. Transfected cells were treated with both the T-dependent Ag phosphorylcholine-key-hole limpet hemocyanin (PC-KLH), and 0.5 ng/ml purified IL-5. After 3.5 days steady state mu-mRNA levels increased three- to fourfold over mu-mRNA levels obtained from untreated cultures, or cultures treated with IL-5 or PC-KLH alone. IL-5 alone caused increased Ig secretion and a nearly twofold increase in proliferation. Additionally, cells treated with PC-KLH alone were able to process the Ag and present it to T cells as shown by subsequent lymphokine production. Thus, both Ag and IL-5 used singly appear to interact with their respective receptors, although neither Ag nor IL-5 increased mu-mRNA levels when used singly. The production of increased mu-mRNA levels obtained with Ag plus IL-5 required polymerase II transcription, suggesting that they may act to increase Ig transcription directly.
Webb
C F
CF
Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235.
Das
C
C
Coffman
R L
RL
Tucker
P W
PW
D000818:Animals; D000918:Antibody Specificity; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D000939:Epitopes / Q000276:immunology; D005786:Gene Expression Regulation; D005803:Genes, Immunoglobulin; D006241:Haptens / Q000276:immunology*; D006433:Hemocyanins / Q000276:immunology; D007148:Immunoglobulin mu-Chains / Q000096:biosynthesis*; D015848:Interleukin-5 / Q000494:pharmacology*; D008213:Lymphocyte Activation; D051379:Mice; D010767:Phosphorylcholine / Q000276:immunology; D012333:RNA, Messenger / Q000096:biosynthesis*; D014158:Transcription, Genetic; D014162:Transfection
D000939:Epitopes; D006241:Haptens; D007148:Immunoglobulin mu-Chains; D015848:Interleukin-5; D012333:RNA, Messenger; D010767:Phosphorylcholine; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin