Isolation of mutant T lymphocytes with defects in capacitative calcium entry

• Published in: Immunity (Cambridge, Mass.) Vol. 3; no. 2; pp. 239 - 250
• Main Authors: Serafini, Andrew T., Lewis, Richard S., Clipstone, Neil A., Bram, Richard J., Fanger, Christopher, Flering, Steve, Herzenberg, Leonard A., Crabtree, Gerald R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-1995
• Subjects: Base Sequence; Calcineurin; Calcium - physiology; Calmodulin-Binding Proteins - physiology; Cell Compartmentation; Cell Line; Cell Nucleus - metabolism; Corynebacterium diphtheriae; DNA-Binding Proteins - metabolism; Gene Expression Regulation; Humans; Lymphocyte Activation; Molecular Sequence Data; Mutation; NFATC Transcription Factors; Nuclear Proteins; Oligodeoxyribonucleotides - chemistry; Phosphoprotein Phosphatases - physiology; T-Lymphocytes - physiology; Transcription Factors - metabolism
• ISSN: 1074-7613; 1097-4180
• DOI: 10.1016/1074-7613(95)90093-4

Calcium and calcium-binding proteins play important roles in the signaling cascade leading from the initial engagement of TCRs on T cells to the fully activated state. To undertake a molecular dissection of this cascade, we first isolated a Jurkat T cell line derivative containing the NF-AT promoter element driving transcription of the diphtheria toxin A chain gene (
dipA), resulting in rapid cell death. Selecting viable cells that fail to activate NF-AT-dependent transcription, we isolated two independent cell lines possessing defects in capacitative Ca
2+ entry. NF-AT-dependent transcription can be restored in these cells by expression of a constitutively active calcineurin, but not by overexpression of the Ca
2+ regulatory protein CAML, which can normally replace the Ca
2+ signal. The defect in these cell lines probably lies between CAML and calcineurin in the T cell activation cascade.