TY - JOUR
T1 - Reduced expression of nuclear cyclic adenosine 5′-monophospate response element-binding proteins and IFN-γ promoter function in disease due to an intracellular pathogen
AU - Samten, Buka
AU - Ghosh, Paritosh
AU - Yi, Ae Kyung
AU - Weis, Stephen E.
AU - Lakey, David L.
AU - Gonsky, Rivkah
AU - Pendurthi, Usha
AU - Wizel, Benjamin
AU - Zhang, Yueru
AU - Zhang, Ming
AU - Gong, Jianhua
AU - Fernandez, Marilyn
AU - Safi, Hassan
AU - Vankayalapati, Ramakrishna
AU - Young, Howard A.
AU - Barnes, Peter F.
PY - 2002/4/1
Y1 - 2002/4/1
N2 - Mycobacterium tuberculosis-induced IFN-γ protein and mRNA expression have been shown to be reduced in tuberculosis patients, compared with healthy tuberculin reactors. To determine whether this decrease was associated with reduced activity of the IFN-γ promoter, we first studied binding of nuclear proteins to the radiolabeled proximal IFN-γ promoter (-71 to -40 bp), using EMSAs with nuclear extracts of freshly isolated peripheral blood T cells. Nuclear extracts of T cells from most tuberculosis patients showed markedly reduced expression of proteins that bind to the proximal IFN-γ promoter, compared with findings in nuclear extracts of T cells from healthy tuberculin reactors. These DNA-binding complexes contained CREB proteins, based on competitive EMSAs, supershift assays, and Western blotting with an anti-CREB Ab. Transient transfection of PBLs with a luciferase reporter construct under the control of the IFN-γ promoter revealed reduced IFN-γ promoter activity in tuberculosis patients. Transient transfection of Jurkat cells with a dominant-negative CREB repressor plasmid reduced IFN-γ promoter activity. These data suggest that reduced expression of CREB nuclear proteins in tuberculosis patients results in decreased IFN-γ promoter activity and reduced IFN-γ production.
AB - Mycobacterium tuberculosis-induced IFN-γ protein and mRNA expression have been shown to be reduced in tuberculosis patients, compared with healthy tuberculin reactors. To determine whether this decrease was associated with reduced activity of the IFN-γ promoter, we first studied binding of nuclear proteins to the radiolabeled proximal IFN-γ promoter (-71 to -40 bp), using EMSAs with nuclear extracts of freshly isolated peripheral blood T cells. Nuclear extracts of T cells from most tuberculosis patients showed markedly reduced expression of proteins that bind to the proximal IFN-γ promoter, compared with findings in nuclear extracts of T cells from healthy tuberculin reactors. These DNA-binding complexes contained CREB proteins, based on competitive EMSAs, supershift assays, and Western blotting with an anti-CREB Ab. Transient transfection of PBLs with a luciferase reporter construct under the control of the IFN-γ promoter revealed reduced IFN-γ promoter activity in tuberculosis patients. Transient transfection of Jurkat cells with a dominant-negative CREB repressor plasmid reduced IFN-γ promoter activity. These data suggest that reduced expression of CREB nuclear proteins in tuberculosis patients results in decreased IFN-γ promoter activity and reduced IFN-γ production.
UR - http://www.scopus.com/inward/record.url?scp=0036533614&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.168.7.3520
DO - 10.4049/jimmunol.168.7.3520
M3 - Article
C2 - 11907114
AN - SCOPUS:0036533614
SN - 0022-1767
VL - 168
SP - 3520
EP - 3526
JO - Journal of Immunology
JF - Journal of Immunology
IS - 7
ER -