Kinetic analysis of Ly-6 gene induction in a T lymphoma by interferons and interleukin 1, and demonstration of Ly-6 inducibility in diverse cell types.
The Ly-6 locus contains multiple genes encoding cell surface proteins, two of which, when cross-linked by antibodies, effect antigen-independent activation of T lymphocytes. In this study, cDNA for Ly-6-encoded antigens have been used as probes to examine RNA from various tissues and transformed cell lines for constitutive levels of Ly-6 RNA expression. Analyses of RNA prepared from several different tissues revealed a high level of expression of Ly-6 RNA in kidney, spleen, heart and thymus, with a more moderate level of expression in liver, brain and lung tissue cells. A survey of various cell lines demonstrated the presence of Ly-6 RNA in many, but not all T lymphocytic cell lines, in L cells, the Meth A fibrosarcoma, in the TCMK kidney cell line, and in the Neuro-2a neuroblastoma. We also evaluated the expression of Ly-6 RNA in cells after treatments with interferons (IFN) and interleukin 1 (IL1). Treatment of lymphoid cells with IFN (alpha/beta and gamma), known to increase cell surface Ly-6 antigen expression in normal T cells, was correlated with increases in Ly-6 RNA levels. Increases in levels of RNA correlated with increases in levels of the Ly-6A/E or Ly-6C antigens. Several T lymphoid cell lines exhibiting Ly-6 RNA inducibility by IFN were similarly inducible with IL1. Kinetic experiments using one such line, (YAC-1), showed that the induction of Ly-6 RNA mediated by IFN-alpha/beta occurred rapidly (within 4 h), while the induction by IL1 required relatively more time (approximately 8 h). Although the actions of IFN-alpha/beta were not blocked by cycloheximide, the presence of this protein synthesis inhibitor significantly attenuated the effects of IL1 and IFN-gamma on Ly-6 RNA transcription. Induction by IFN-gamma as well as IL1 could be blocked completely by co-culture with anti-IFN-gamma, implicating IFN-gamma as a mediator of the induction by IL1.
LeClair
K P
KP
Department of Biology, Yale University Medical School, New Haven, CT 06510.
Bridgett
M M
MM
Dumont
F J
FJ
Palfree
R G
RG
Hämmerling
U
U
Bothwell
A L
AL
D000818:Animals; D000950:Antigens, Ly / Q000235:genetics*; D003513:Cycloheximide / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D007158:Immunologic Techniques; D007372:Interferons / Q000235:genetics / Q000494:pharmacology*; D007375:Interleukin-1 / Q000494:pharmacology*; D007700:Kinetics; D008223:Lymphoma; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000235:genetics; D013601:T-Lymphocytes / Q000276:immunology*; D014018:Tissue Distribution; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D000950:Antigens, Ly; D007375:Interleukin-1; D012333:RNA, Messenger; D007372:Interferons; D003513:Cycloheximide