Lineage-specific expression of a T cell receptor variable gene promoter controlled by upstream sequences.
We have characterized the sequence contribution of DNA 5' of a functionally rearranged TCR promoter (V beta 8.1) on its T lineage-specific expression through the use of the chloramphenicol acetyl-transferase (CAT) reporter gene. A 230-bp fragment located 570 bp upstream of the determined transcription start site of the V beta 8.1 promoter confers a T lineage specificity of expression to a heterologous promoter. The inability of the V beta 8.1 promoter and its associated elements to function in B cells suggests the existence of a mechanism to prevent inappropriate V beta gene expression in B cells. Of considerable interest is the fact that both a B cell-specific and a nontissue-specific enhancer element were incapable of stimulating significant expression of this promoter in B cells. We discuss the implication of these results on the process of rearrangement of both Ig and TCR genes, and the differentiation of the lymphoid system.
Diamond
D J
DJ
Laboratory of Immunobiology, Dana-Farber Cancer Institute, Boston, Massachusetts.
Nelson
F B
FB
Reinherz
E L
EL
D001402:B-Lymphocytes / Q000502:physiology; D001483:Base Sequence; D004252:DNA Mutational Analysis; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011948:Receptors, Antigen, T-Cell / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D013601:T-Lymphocytes / Q000502:physiology*; D014158:Transcription, Genetic
D011948:Receptors, Antigen, T-Cell; D016693:Receptors, Antigen, T-Cell, alpha-beta