TY - JOUR
T1 - Mucosa-specific targets for regulation of IFN-γ expression
T2 - Lamina propria T cells use different cis-elements than peripheral blood T cells to regulate transactivation of IFN-γ expression
AU - Gonsky, Rivkah
AU - Deem, Richard L.
AU - Bream, Jay H.
AU - Lee, Doo Han
AU - Young, Howard A.
AU - Targan, Stephan R.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2000/2/1
Y1 - 2000/2/1
N2 - Activation of lamina propria (LP) T cells via the CD2 pathway enhances IFN-γ (IFN-γ) secretion with further enhancement after CD28 coligation. The molecular mechanisms regulating IFN-γ expression in LP T cells remain unknown. Previous studies in PBL and T cell lines identified cis- and trans- regulatory elements in TCR-mediated expression of IFN-γ. This study examines CD2 and PMA/ionophore-responsive IFN-γ promoter elements. Activation of LPMC via CD2-induced IFN-γ secretion and a parallel up-regulation of mRNA expression. CD28 coligation enhanced mRNA stability without up-regulating transcription as measured by nuclear run-on. Transfection of a -2.7-kb IFN-γ promoter-reporter construct into PBL and LP mononuclear cells (LPMC) revealed significant promoter activity after CD2 activation, with additional transactivation after CD2/CD28 costimulation in PBL, but not in LPMC. Functional analysis using truncated promoter fragments identified distinct cis-regulatory regions selectively transactivating IFN-γ expression in PBL compared with LPMC. In PBL, CD2 activation elements reside within the -108- to +64-bp region. However, in LPMC the upstream region between -204 and -108 bp was essential. Transfection of the proximal and distal AP-1-binding elements, as well as TRE/AP-1 constructs, revealed functional activation of AP-1 subsequent to CD2 signaling, with activation critical in PBL but diminished in LPMC. Electromobility shift analysis using oligonucleotides encompassing the proximal, distal, and BED/AP-1-binding regions failed to demonstrate selective transactivation after CD2 signaling of LPMC. This report provides evidence that activation of LPMC results in transactivation of multiple promoter elements regulating IFN-γ expression distinct from those in PBL.
AB - Activation of lamina propria (LP) T cells via the CD2 pathway enhances IFN-γ (IFN-γ) secretion with further enhancement after CD28 coligation. The molecular mechanisms regulating IFN-γ expression in LP T cells remain unknown. Previous studies in PBL and T cell lines identified cis- and trans- regulatory elements in TCR-mediated expression of IFN-γ. This study examines CD2 and PMA/ionophore-responsive IFN-γ promoter elements. Activation of LPMC via CD2-induced IFN-γ secretion and a parallel up-regulation of mRNA expression. CD28 coligation enhanced mRNA stability without up-regulating transcription as measured by nuclear run-on. Transfection of a -2.7-kb IFN-γ promoter-reporter construct into PBL and LP mononuclear cells (LPMC) revealed significant promoter activity after CD2 activation, with additional transactivation after CD2/CD28 costimulation in PBL, but not in LPMC. Functional analysis using truncated promoter fragments identified distinct cis-regulatory regions selectively transactivating IFN-γ expression in PBL compared with LPMC. In PBL, CD2 activation elements reside within the -108- to +64-bp region. However, in LPMC the upstream region between -204 and -108 bp was essential. Transfection of the proximal and distal AP-1-binding elements, as well as TRE/AP-1 constructs, revealed functional activation of AP-1 subsequent to CD2 signaling, with activation critical in PBL but diminished in LPMC. Electromobility shift analysis using oligonucleotides encompassing the proximal, distal, and BED/AP-1-binding regions failed to demonstrate selective transactivation after CD2 signaling of LPMC. This report provides evidence that activation of LPMC results in transactivation of multiple promoter elements regulating IFN-γ expression distinct from those in PBL.
UR - http://www.scopus.com/inward/record.url?scp=0034142391&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034142391&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.164.3.1399
DO - 10.4049/jimmunol.164.3.1399
M3 - Article
C2 - 10640755
AN - SCOPUS:0034142391
SN - 0022-1767
VL - 164
SP - 1399
EP - 1407
JO - Journal of Immunology
JF - Journal of Immunology
IS - 3
ER -