Identification of cis sequences controlling efficient position-independent tissue-specific expression of human major histocompatibility complex class I genes in transgenic mice.
We previously reported that genomic major histocompatibility complex class I human leukocyte antigen (HLA)-B7 gene constructs with as little as 0.66 kb of 5'- and 2.0 kb of 3'-flanking DNA were expressed efficiently and appropriately in transgenic mice. To identify and characterize the relevant cis-acting regulatory elements in more detail, we have generated and analyzed a series of transgenic mice carrying native HLA-B7 genes with further 5' truncations or intronic deletions and hybrid constructs linking the 5'-flanking region of B7 to a reporter gene. We were unable to detect a specific requirement for sequence information within introns 2 to 7 for either appropriate constitutive or inducible class I expression in adult animals. The results revealed the presence of cis-acting regulatory sequences between -0.075 kb and -0.66 kb involved in driving efficient copy number-dependent constitutive and gamma interferon-enhanced tissue-specific expression. The region from -0.11 to -0.66 kb is also sufficient to prevent integration site-specific "position effects," because in its absence HLA-B7 expression is frequently detected at significant levels at inappropriate sites. Conserved sequence elements homologous to the H-2 class I regulatory element, or enhancer A, and the interferon response sequence are located between about -151 and -228 bp of the B7 gene. Our results also indicate the existence of sequences downstream of -0.11 kb which can influence the pattern of tissue-specific expression of the HLA-B7 gene and the ability of this gene to respond to gamma interferon.
Chamberlain
J W
JW
Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada.
Vasavada
H A
HA
Ganguly
S
S
Weissman
S M
SM
D000818:Animals; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D015870:Gene Expression; D005786:Gene Expression Regulation / Q000187:drug effects; D005805:Genes, MHC Class I; D005809:Genes, Regulator; D015793:HLA-B7 Antigen / Q000235:genetics*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D011994:Recombinant Proteins; D014158:Transcription, Genetic / Q000187:drug effects
D015793:HLA-B7 Antigen; D011994:Recombinant Proteins; D012313:RNA; D007371:Interferon-gamma; D004247:DNA