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B and IFN-Regulatory Factor Transcription Factors1
Terry Fox Molecular Oncology Group, Lady Davis Institute for Medical Research, and Departments of Microbiology and Immunology, Medicine and Oncology, McGill University, Montreal, Canada
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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B via posttranslational
phosphorylation. In the present study, we further characterized the
regulatory control of RANTES transcription during virus infection using
in vivo genomic footprinting analyses. IRF-3, the related IRF-7, and
NF-B are identified as important in vivo binding factors required
for the cooperative induction of RANTES transcription after virus
infection. Using fibroblastic or myeloid cells, we demonstrate that the
kinetics and strength of RANTES virus-induced transcription are highly
dependent on the preexistence of IRFs and NF-B. Use of dominant
negative mutants of either IB-
or IRF-3 demonstrate that
disruption of either pathway dramatically abolishes the ability of the
other to bind and activate RANTES expression. Furthermore, coexpression
of IRF-3, IRF-7, and p65/p50 leads to synergistic activation of RANTES
promoter transcription. These studies reveal a model of virus-mediated
RANTES promoter activation that involves cooperative synergism between
IRF-3/IRF-7 and NF-B factors. |
Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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, and macrophage-inflammatory
protein-1ß, the natural ligands of HIV fusion cofactor CCR5 chemokine
receptor (7, 8, 9). Interestingly, RANTES is also targeted by
another unrelated virus, human CMV, which encodes a homologue of a CC
chemokine receptor gene (US28) that is capable of binding RANTES
(10, 11).
RANTES expression is increased following cellular activation of
fibroblasts, T cells, monocytes, and endothelial and epithelial cells
(12). Many cell types, including fibroblasts, epithelial
cells, and monocytes/macrophages, express RANTES within hours of
stimulation by proinflammatory stimuli, such as TNF- and IL-1ß
(13). Unlike other members of the chemokine family, which
are expressed early, RANTES mRNA is induced late (3–5 days) after T
cell activation (14). Recently, Song et al.
(15) reported the cloning and characterization of a late
transcription factor, designated RFLAT-1 (RANTES factor of late
activated T lymphocytes-1), that belongs to the TFIIIA-like zinc finger
protein superfamily, and that specifically binds to the RANTES
promoter. This protein is induced 3 days after T cell
activation, is a strong activator of RANTES promoter in T cells, and is
suggested to synergize with HMG(I/Y) and Rel family members to form an
enhanceosome that activates RANTES gene transcription
(15).
The RANTES promoter has been subdivided into five regions (A–E) based
upon deletion studies and reporter gene assays (see Fig. 1
A)
(13, 16, 17). In this promoter, four binding sites (Fig. 1A) for NF-B proteins are critical for induction by
proinflammatory cytokines TNF- or IL-1ß, or through the CD28
costimulatory pathway (18). The two proximal elements
(-54 to -45 and -40 to -31) are typical NF-B binding sites and
bind p65/p50 heterodimer, the third element called NF-AT (-230 to
-209) binds both NF-AT and NF-B, and the most distal CD28 response
element (-594 to -575) represents a binding site for p65/p50 or
p65/c-Rel heterodimers. Recently, a polymorphism in RANTES promoter (a
-28C to G mutation downstream of the first NF-B site) was
associated with reduced CD4+ lymphocyte depletion
rate in HIV-1-infected individuals (19). In contrast,
NF-B sites in the murine RANTES promoter failed to play a major role
in virus-mediated activation of this gene (12, 20).
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B and IFN-regulatory factors
(IRF)3 transcription
factor families participate in the virus-mediated activation of
cytokine gene transcription (21). Recent studies
demonstrated that in response to virus infection, type I IFN gene
activation required IRF-3 and IRF-7 gene products as direct
transcriptional regulators, but played different roles in the induction
of immediate-early vs delayed type I IFN gene (22, 23).
Previously, we demonstrated that IRF-3 plays a primary role in the
Sendai virus-inducible activation of the human RANTES gene
(24), based on the following data: 1) Tet-inducible
expression of a constitutively activated phosphomimetic form of IRF-3
increased endogenous RANTES mRNA levels, mediated through the ISRE
domain located between nucleotide -126 to -92 in the RANTES promoter
(Fig. 1
B); 2) mutations of the ISRE domain blocked
virus-mediated activation of RANTES promoter; and 3) a dominant
negative mutant of IRF-3 repressed virus-induced transcription of
endogenous RANTES mRNA. Moreover, a constitutively active form of IRF-7
transcription factor generated by our group constitutes a strong
activator of RANTES
promoter,4 suggesting
a role for a distinct IRF family member in virus-induced RANTES
transcription. In the present study, in vivo genomic footprinting
analysis was utilized in human embryonic kidney 293 and human myeloid
U937 cells to investigate protein-DNA contacts that mediate
virus-induced RANTES activation. IRF-3, the related IRF-7, and NF-B
were identified as important in vivo binding factors required for the
cooperative induction of RANTES transcription after virus infection.
Our results reveal a model of RANTES promoter activation that involves
cooperative synergism between IRF-3/IRF-7 and NF-B factors. |
Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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RANTES/pGL3 luciferase reporter and the mutated form of RANTES
promoter (see Fig. 1B) were prepared by cloning
BglII-SalI fragment (-397 to +5, filled in with
Klenow enzyme) from RANTES/chloramphenicol acetyltransferase reporter
plasmid (25) into the NheI site (filled in with
Klenow enzyme) of the pGL3-basic vector, as previously described
(24). The IRF-3, IRF-7, p65/p50, and CBP expression
plasmids used in cotransfection experiments have been previously
described (24, 26).
Cell culture, transfections, and luciferase assays
The 293 cells stably expressing either IRF-3, IRF-3(
N),
IRF-7, or IB-2N were described previously (24, 25, 27). Transfections for luciferase assay were conducted in human
embryonic kidney 293 cells grown in MEM media (Life Technologies,
Burlington, Canada) supplemented with 10% FBS, glutamine, and
antibiotics. Subconfluent cells were transfected with 0.2 µg of
pRL-TK reporter (Renilla luciferase for internal control)
and 1 µg of pGL3 reporter (Firefly luciferase, experimental reporter)
by calcium phosphate coprecipitation method, as previously described
(28). For coexpression experiments, 0.5 µg of each
expressing plasmid was added to the reporter plasmid. Sixteen hours
after transfection, cells were stimulated with Sendai virus (80 HAU/ml)
for 8 h and harvested. Reporter gene activity was measured by
dual-luciferase reporter assay, following the instructions of Promega
Technical Manual. The experiments were performed in triplicate, and the
average fold induction was calculated.
Ribonuclease protection analysis
The 293-expressing cells were pretreated with DOX for 48 h. The 293 or U937 wild-type or expressing cells were either left untreated, or infected with Sendai virus (80 HAU/ml) for the times indicated. Total RNA was prepared from the cell pellets using the Qiagen (Chatsworth, CA) RNeasy kit. A total of 5 µg of RNA was subjected to RNase protection assay using hCK-5 chemokine template of RiboQuant multiprobe RPA kit, following the manufacturer’s instructions (PharMingen, San Diego, CA).
In vivo genomic footprinting
For in vivo methylation by dimethyl sulfate (DMS; Aldrich
Chemical, Milwaukee, WI), U937 cells (108) were
harvested and resuspended in 1 ml of RPMI, 10% FBS, while 293 adherent
cells were exposed to DMS directly in the plate containing 4 ml of
MEM, 10% FBS. For both cell types, complete medium was supplemented
with 20 mM HEPES (pH 7.3) and 10 µl/ml of concentrated DMS during 1
min, followed by two washes in cold PBS containing 2% 2-ME to stop the
reaction. Cells were then lysed to extract genomic DNA, as previously
described (29). For each genomic DNA sample, the cleavage
of methylated G residues (or A residues) was performed using 20 µl of
piperidine (Aldrich Chemical) for 200 µl of DNA for 30 min at 90°C.
To provide control, DNA (naked DNA) cells were first lysed to extract
genomic DNA and then submitted to DMS treatment, precipitated in
ethanol, and treated to piperidine cleavage to allow methylation and
cleavage to all G residues of the sequence. For each sample, 5 µg of
DNA was submitted to LM-PCR using Vent DNA polymerase (New England
Biolabs, Mississauga, Canada), as described (30, 31). To
ensure elongation of different fragment sizes, PCR amplification step
was 2 min for the first cycle and was progressively increased to 10 min
in the last cycle, with a total of 18 cycles for DNA amplification. The
third primer was radiolabeled by end labeling using T4 polynucleotide
kinase (Pharmacia Biotech, Uppsala, Sweden) and
[
-32P]ATP (ICN Pharmaceuticals, Costa Mesa,
CA). Two more PCR cycles were performed to radiolabeled elongated DNA.
The final labeled PCR product was analyzed on a 5% Explorer sequencing
gel (Baker, Phillipsburg, NJ) in 1x TBE at 65 W, and exposed from 12
to 36 h with a BioMax sensitive film (Kodak, Rochester, NY). For
the LM-PCR, several sets of oligonucleotides were used. For the
noncoding strand: primer 1, 5'-CAC CAT TGG TGC TTG GTC A-3',
Tm 60°C; primer 2, 5'-GAT GAG CTC
ACT CTA GAT GAG AGC-3', Tm 63°C; and
primer 3, 5'-TCT AGA TGA GAG AGC AGT GAG GGA GAG AC-3',
Tm 66°C.
Electrophoretic mobility shift assay (EMSA)
Nuclear extracts were prepared from 293 cells after induction
with Sendai virus (80 HAU/ml) for times ranging from 2 to 12 h, as
previously described (32). A total of 10 µg of
extracts was subjected to EMSA by using
32P-labeled probes, DNA-binding buffer (10 mM
HEPES, pH 7.9, 2% glycerol (v/v), 40 mM KCl, 1 mM EDTA, pH 8, 0.2 mM
MgCl2, 1 mM DTT, 0.05 mM PMSF), 0.2% Nonidet
P-40, 0.5 µg of BSA, and 1 µg of poly(dI:dC). Incubation was
performed for 30 min at room temperature using DNA oligonucleotide
corresponding to the -50 to -26 NF-B region of RANTES
promoter: 5'-ACT CCC CTT AGG GGA TGC CCC TCA A-3'. The resulting
protein-DNA complexes were resolved on 5% polyacrylamide (37.5:1) TBE
0.25x gels and exposed for 16 h. Supershift analysis was
performed by preincubating 1 µl of anti-p65, anti-p50, and
anti-c-Rel Abs with extracts and binding buffer for 30 min at 4°C
before adding probe (Santa Cruz Biotechnology, Santa Cruz,
CA).
RT-PCR analysis of IRF-7 mRNA expression
Total RNA isolated from U937, 293, and IRF-7-expressing 293
cells was treated with 1 U of RNase-free DNase (RQ1 Dnase; Promega,
Madison, WI) for 30 min at 37°C and ethanol precipitated. Reverse
transcriptase was performed on 5 µg of total RNA and 0.2 pmol of
random hexamers using 200 U of Moloney murine leukemia virus reverse
transcriptase (Life Technologies) in buffer containing 50 mM Tris-HCl,
pH 8.3, 75 mM KCl, 10 mM DTT, 3 mM MgCl2, 500 nM
dNTP, 0.1 mg/ml BSA, and 272.5 U/ml RNase inhibitors (Amersham
Pharmacia Biotech, Piscataway, NJ). PCR assays were performed using 24
µl and 1 µl of reverse-transcriptase product for IRF-7 and GAPDH
mRNA amplification, respectively, in 100 mM Tris-HCl, pH 8.4, 500 mM
KCl, 15 mM MgCl2, 200 mM dNTP, 15 pmol of
[-32P]-labeled primers, and 1.25 U of
Taq DNA polymerase (Amersham Pharmacia Biotech).
Nucleotide sequence of primers used is as follows: F7/1, 5'-CAG CTG CGC
TAC ACG GAG-3', and F7/2, 5'-GCC AGC TCT AGG TGG GCT-3'. The PCR
reaction mixture was subjected to 25 cycles of denaturation for 1 min
at 95°C, annealing for 2 min at 58°C, and polymerization for 2 min
at 72°C. PCR products were analyzed on a 5% denaturing
polyacrylamide gel. Primers for GAPDH were used as described previously
(33).
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Footprinting primers were designed to analyze in vivo
protein-DNA interactions occurring in the proximal -10 to -130 region
of the RANTES promoter (primers 1, 2, 3 for the noncoding strand; Fig. 1A). Sendai virus-infected
cells were submitted to DMS (dimethyl sulfate) treatment which
methylates G residues and to a lesser extent A residues; genomic DNA
was then extracted and submitted to piperidine treatment to cleave
methylated residues. Piperidine-cleaved DNA was then amplified by
ligation-mediated PCR using specific primers for the RANTES promoter,
as detailed in Fig. 1A. A G-specific sequence ladder was
also generated as reference and analyzed by sequencing. Initial
footprinting experiments in U937 cells revealed that only the ISRE
(-124 to -97) and NF-B (-46 to -30) sites were targeted by
constitutive or virus-inducible binding activities (Fig. 2A). A weak constitutive
protection was observed at the NF-B sites, reflected by an increase
in the methylation of -33 and -43 G residues and accompanied by a
decrease in -44 to -45 G methylation (Fig. 2A, compare
lanes 1 and 2). This protection correlated with
constitutive RANTES mRNA production detected by RPA in uninfected U937
cells (Fig. 2B, lane 1). Following virus
infection, protection of the NF-B sites and hypermethylation of the
-43G residue strongly increased by 2 h after induction and peaked
between 6 and 10 h (Fig. 2A, lanes 3–7). In
other experiments, protection of the NF-B sites was detected as
early as 30 min after virus infection (data not shown); the induced
protection was sustained but decreased after 12 and 24 h of
induction (Fig. 2A, lanes 8 and 9). A
similar virus-inducible occupancy of the ISRE site was also
detected, as indicated by increased methylation of -107, -113,
and -119A residues, as well as the decrease in methylation of -105,
-111, and -118 G residues (Fig. 2A, lanes
2–7). The kinetics of binding to the ISRE region followed the
same pattern as the NF-B sites: protein-DNA interaction appeared
after 2 h of induction and peaked between 6 and 10 h of virus
induction. Protection was reduced after 12 h and disappeared by
24 h, indicating a more transient in vivo binding to the ISRE site
(Fig. 2A, lanes 8 and 9). Changes in
the coding strand methylation pattern of RANTES promoter were also
examined using specific primers (data not shown); modifications were
not observed at either the NF-B or ISRE site, suggesting that the
protein-DNA interaction may be asymmetric, as discussed previously
(29).
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B and ISRE binding correlated with the
rapid induction of endogenous RANTES transcription; RANTES mRNA
progressively increased 5- to 7-fold at 2 h after virus
infection to a maximum of 30- to 40-fold between 6 and 10 h.
RANTES mRNA levels were subsequently sustained at 12 and 24 h
after infection (Fig. 2B, lanes 2–8). These
results demonstrate a correlation between transcription of the RANTES
gene and the in vivo occupancy of both ISRE and NF-B sites, with an
expected delay between binding of transcription factors and production
of mRNA. Differential in vivo binding on RANTES promoter in virus-infected 293 cells
Genomic footprinting analyses performed with 293 cells revealed
distinct patterns of in vivo binding to NF-B and ISRE sites (Fig. 3A). No constitutive
protection was observed in nonstimulated cells at either site (Fig. 3A, comparison of lanes 1 and 2).
Following virus infection, protection of the NF-B sites and
increased methylation of -33 and -43 G residues were observed (Fig. 3A, lane 3 compared with lane 2). In
contrast to U937 cells, in which -33G is constitutively methylated and
remained unchanged in virus-induced cells, methylation at both the -33
and -43G residues was modified by virus infection of 293 cells (Fig. 3A, comparison of lanes 3 and 5).
Increased methylation of -101, -107, and -113 A residues of the ISRE
region was detected initially at 4 h postinfection and was further
increased after 6–10 h (Fig. 3A, lane 3 compared
with lane 2, and data not shown). Protection was reduced at
12 h and disappeared by 24 h postinduction, indicating again
a transient in vivo binding to the ISRE site (data not shown). In
contrast to virus induction, TNF- treatment led to the appearance of
NF-B-binding, but not ISRE-binding activity in U937 (Fig. 3A, comparison of lanes 3 and 5 with
lane 6). Furthermore, in the absence of ISRE binding in
TNF--treated U937 cells, only a 2- to 3-fold increase in RANTES gene
expression was detected compared with the 40-fold increase after virus
induction (Fig. 3B, lanes 4 and
5).
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B sites appeared after 4 h, further
increased at 6 h (Fig. 4A, lanes 4 and
5 compared with lane 2), and was sustained even
after 24 h, although a slight decrease in methylation intensity of
the -33 and -43 G residues was observed (Fig. 4A,
lanes 6–9). Concomitant with modifications in protein-DNA
occupancy on both ISRE and NF-B sites, RANTES mRNA was undetectable
before infection, but appeared at 8 h after infection (Fig. 4B, lanes 1–5); RANTES mRNA levels further
increased 5-fold at 10 h, and 30-fold at 12 and 24 h of virus
induction (Fig. 4B, lanes 6–8). Using the -50
to -26 NF-B region of RANTES promoter in EMSA, the p50-p65 complex
was identified as responsible for in vivo binding activity induced by
either TNF- or Sendai virus (34) (Fig. 4C).
These data indicate that although the NF-B complex was induced and
participated in virus induction of the RANTES promoter, only the
ISRE-binding activity was specifically targeted by virus infection.
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Recent studies indicate that two members of the IRF family, IRF-3
and IRF-7, participate in the virus induction of type I IFN genes via
an autostimulatory mechanism (22). The involvement of
IRF-7 in virus-inducible transcription of RANTES was determined by RPA
in 293 cells expressing a dominant negative IRF-7 mutant carrying a
deletion in the N-terminal DNA binding domain (Fig. 5A). Expression of N IRF-7
inhibited by more than 70% the virus-induced levels of RANTES mRNA
(Fig. 5A, lanes 2 and 4). To assess
whether IRF-7 can account for the differences in RANTES induction
between U937 and 293 cells, the level of IRF-7 expression was
determined by RT-PCR analysis (Fig. 5B). Interestingly, a
low level of IRF-7 mRNA was detected in U937 in the absence of
infection, whereas no IRF-7 mRNA was amplified in nonstimulated 293
cells (Fig. 5B, lanes 1 and 3). As
expected, infection of both cell types with Sendai virus further
enhanced IRF-7 gene expression, with a higher level in infected U937
cells (Fig. 5B, lanes 2 and 4). As a
control, high levels of IRF-7 mRNA were detected in 293 cells inducibly
expressing IRF-7, and were dramatically increased after virus infection
(Fig. 5B, lanes 5 and 6). These
observations indicate that differences in IRF-7 expression exist
between 293 and U937 cells and may be responsible in part for the
constitutive expression of RANTES observed in unstimulated U937 cells.
The absence of constitutive expression of IRF-7 in 293 cells also
suggests that virus-induced RANTES transcription is dependent on de
novo synthesis of the IRF-7 gene product.
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Next, genomic footprinting was performed in 293 cells inducibly
expressing either IRF-3 or IRF-7. Although IRF-3 binds to the ISRE site
after infection and is required for virus induction of the RANTES
promoter, overexpression did not affect the methylation pattern of the
RANTES promoter after Sendai virus infection (Fig. 6A, lanes 4 and
5). In contrast, IRF-7 overexpression in 293 cells induced
significant changes in the protection pattern of the ISRE site after
virus infection (Fig. 6A, lanes 6 and
7). A strong decrease in the methylation of -106, -111,
and -118 G residues was detected (Fig. 6A, lanes
3 and 7), leading to a pattern similar to that observed
in Sendai-infected U937 cells (see Fig. 2A, lane
7). Furthermore, subtle changes were also observed in
nonstimulated cells expressing IRF-7, such as hypermethylation of -113
A usually detected after virus induction of cells, as well as slight
increase in -101 and -102 A methylation (Fig. 6A,
comparison of lanes 2 and 6). This pattern
suggests that IRF-7 binds to the RANTES ISRE site and activates the
RANTES promoter (Fig. 6B, lane 5). Activation of
IRF-7 by virus widened the observed protection at the ISRE site and
further increased RANTES expression by 8-fold, which was a 2-fold
higher level than in the absence of IRF-7 expression (Fig. 6B, comparison of lanes 2 and 6).
These results also highlight the necessity for virus induction to
mediate IRF-3 activation (26), binding, and
transactivation ability, whereas expression of IRF-7 is sufficient to
confer binding and transactivation activities.
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B factors is required for virus
induction of the RANTES promoter
To determine the individual participation of the two virus-induced
pathways, genomic footprinting was performed on 293 cells expressing
dominant negative forms of IRF-3 or IB, i.e., IRF-3(N) or
IB- 2N, respectively (Fig. 7A). Overexpression of
IRF-3(N) completely abolished virus-induced protection at the ISRE
site; surprisingly, protection at the NF-B site was also completely
inhibited (Fig. 7A, compare lanes 3 and
5). However, normal virus-induced NF-B binding was
observed in EMSA performed with 293 cells expressing the IRF-3(N)
mutant, demonstrating that this dominant negative mutant does not
directly affect the activation and binding of the NF-B complex (data
not shown). Reciprocally, overexpression of the IB- dominant
negative not only blocked protection at the NF-B site, but also
blocked virus-induced ISRE-binding activity (Fig. 7A,
compare lanes 3 and 7). Overexpression of either
IRF-3(N) or IB- 2N reduced RANTES mRNA levels by 90% (Fig. 7B, lanes 4 and 6 compared with
lane 2). These results demonstrate that NF-B and IRF
closely cooperate in the induction of RANTES gene transcription by
virus and disruption of either pathway dramatically abolishes the
ability of the other to bind and activate RANTES expression.
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B and IRF transcription
factors, coexpression experiments were performed using the RANTES
promoter (-397 to +5) linked to the luciferase reporter gene (Fig. 8). In the absence of virus induction,
coexpression of IRF3, IRF-7, and p65/p50 increased RANTES promoter
transcription by 160-fold, whereas transfection of IRF-3, IRF-7, or
p65/p50 alone led only to a 5- to 30-fold induction, respectively (Fig. 8A, open bars). Interestingly, in unstimulated cells,
coexpression of both IRF-7 and p65/p50 resulted in a similar induction
of RANTES promoter transcription (130-fold), while cotransfection of
p65/p50 and IRF-3 or IRF-3 and IRF-7 caused a 25- to 30-fold increase
(Fig. 8A, open bars). These results indicate that in the
absence of virus induction, cooperation between NF-B and IRF-7
produced a synergistic activation of RANTES promoter, whereas
expression of IRF-3 alone or together with other activators resulted in
a relatively modest effect on RANTES transcription. Synergism between
IRFs and NF-B was also observed in virus-induced cells: RANTES
promoter activity was increased by more than 300-fold when NF-B,
IRF-3, and IRF-7 were coexpressed together compared with the 30- to
150-fold increase observed when combinations such as IRF3 + p65/p50 or
IRF-7 + p65/p50 were coexpressed (Fig. 8A, black bars).
Although the requirement for coactivator recruitment for this
transcriptional synergism is not excluded, no effect of CBP expression
was observed on the synergistic activation of RANTES promoter when
NF-B, IRF-3, and/or IRF-7 were coexpressed (Fig. 8A).
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B and
ISRE sites of the RANTES promoter, similar coexpression experiments
were performed using NF-B- or ISRE-mutated RANTES promoters (Fig. 8, B and C). As expected, no activation or no
further increase of NF-B-mutated RANTES promoter transcription was
observed when p65/p50 were transfected either alone or in combination
with IRF-3 and/or IRF-7, indicating that disruption of the NF-B
binding abolished the synergistic activation observed with the
wild-type promoter (Fig. 8B). Interestingly, coexpression of
both IRF-7 and NF-B resulted in a 70–80% inhibition of the
NF-B-mutated RANTES transcription levels observed when IRF-7 was
transfected alone, in both unstimulated and virus-induced cells (Fig. 8B). This observation indicates that in the absence of
binding to its site, NF-B is able to interfere with IRF-7-mediated
transcription of NF-B-mutated RANTES promoter. Coexpression of IRF-3
together with IRF-7 abolished the inhibition by NF-B. Surprisingly,
CBP expression increased by more than 2-fold transcription of
NF-B-mutated RANTES by IRF-3 and IRF-7 in virus-induced cells (Fig. 8B, black bars). Moreover, this synergy between CBP and
IRF-3/IRF-7 was not observed when p65/p50 was coexpressed, indicating
again an interference of IRF-mediated activation by NF-B when
not bound to its NF-B site in RANTES promoter. Finally,
transcriptional activation of the ISRE-mutated RANTES promoter was
observed only when p65/p50 was expressed alone or in combination with
IRFs (Fig. 8C). Again, interference between NF-B and IRF
activation pathways was observed because IRF-7 coexpression with
p65/p50 inhibited by 70% the NF-B-mediated activation of the
ISRE-mutated RANTES promoter in unstimulated cells (Fig. 8C,
open bars). Altogether, these results demonstrate that synergistic
cooperation among IRF-3, IRF-7, and NF-B is required for the
activation of RANTES promoter transcription. |
Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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B factors and IRF-3 in the
regulation of RANTES promoter. The present study identified IRF-3,
IRF-7, and NF-B as important in vivo binding factors required for
the cooperative induction of RANTES transcription after virus
infection. Genomic footprinting data suggest a correlation between the
transcription of RANTES gene and the in vivo occupancy of both ISRE and
NF-B sites. Moreover, the transient inducibility of RANTES
transcription appears to correlate with ISRE-binding activities,
whereas sustained transcription is due to the in vivo occupancy of the
NF-B sites only. Using fibroblastic or myeloid cells, we showed that
the kinetics and the strength of RANTES virus-induced transcription are
highly dependent on the preexistence of IRFs and NF-B, highlighting
cell type specificity in the role of RANTES production following virus
infection. The constitutive level and rapid induction of RANTES
expression observed in myeloid U937 cells are most likely due to
presence of both IRF-7 expression and NF-B-binding activity in
unstimulated cells. In contrast, virus-induced RANTES transcription in
293 cells is dependent on virus induction of NF-B activity and on de
novo synthesis of IRF-7 gene product. Genomic footprinting and EMSA
further demonstrated that although NF-B complex is induced and
participates in virus induction and TNF stimulation of the RANTES
promoter, only the ISRE-binding activity is specifically targeted by
virus infection. This ISRE-mediated activity was further shown to be
due to both IRF-3 and IRF-7 binding and transcriptional activities, the
former being strictly virus inducible, whereas the latter was both
constitutive and virus inducible.
Synergistic activation of RANTES transcription by NF-B and IRF
pathways
Use of the dominant negative mutant of either IB- or IRF-3
demonstrated that disruption of either pathway dramatically abolishes
the ability of the other to bind and activate RANTES expression. This
cooperation was further confirmed by transfection experiments
showing that coexpression of IRF-3, IRF-7, and p65/p50 leads to maximal
induction of RANTES promoter transcription even in the absence of viral
infection. Use of NF-B- or ISRE-mutated RANTES promoters
demonstrated that this synergism is dependent on binding of these
factors to their respective sites. As expected, cooperation between
NF-B and IRF-7 was observed in the absence of virus induction,
whereas cooperation between IRF-3 and NF-B was only observed after
virus induction, highlighting again the requirement of virus-inducible
activation of IRF-3 for its transcriptional activity. The ability of
IRF-7 to induce RANTES transcription in the absence of viral infection
was confirmed by both coexpression and RNase protection assays
performed in IRF-7-expressing 293 cells. Although our results are
slightly different from the modest effect of ectopic expression of
IRF-7 on IFN-ß gene expression (22), they most likely
reflect the fact that these experiments were performed in stably
transfected 293 cells and not in transiently transfected cells. These
results indicate that IRF-7 gene expression has to be tightly
controlled before induction, and that an abundant accumulation of the
IRF-7 protein is required for full induction of RANTES. However, an
induction of IRF-7 gene transcription by the IFN-regulatory loop seems
to be unlikely, because RANTES gene expression is not inducible by type
I IFN either in transient transfection experiments (data not shown), or
by RPA (24). The intriguing possibility that IRF-3
or NF-B transcription factors can directly induce transcription of
IRF-7 gene expression is under current investigation.
Formation of an enhanceosome on the RANTES promoter
Using cells derived from mice in which the IFN signaling pathway
is disrupted, several groups recently proposed a two-step model of IFN
gene activation (22, 23). Following virus infection,
IRF-3, NF-B, and the activating transcription factor-2/c-Jun complex
are activated by posttranslational phosphorylation and cooperate to
form a transcriptionally active enhanceosome complex, at the promoter
of the immediate early IFN-ß gene, in association with the CBP/p300
coactivator and the chromatin-associated HMG proteins (35, 36). Secreted IFN produced as a consequence of this protein
synthesis-independent mechanism acts through an autocrine or paracrine
loop to activate the Jak/STAT pathway. IFN activation of ISGF3 (latent
cytosolic transcription factor) induces the expression of the IRF-7
gene (22, 37). In the second step, virus-activated IRF-7
participates with IRF-3 in the transcriptional induction of
delayed-type IFN- genes (22). In the case of RANTES
promoter, formation of an enhanceosome composed of NF-B and/or
IRF-3/IRF-7 and potential coactivators such as CBP/p300 is supported by
the cooperativity between the NF-B and IRF pathways. Synergism
between IRF and NF-B proteins is emphasized by the complete
inhibition of both ISRE- and NF-B-dependent in vivo activities by
dominant negative forms of IB or IRF-3. However, the persistence
of virus-induced NF-B binding in 293 cells expressing the
IRF-3(N) mutant argues against a direct effect of this dominant
negative mutant on the NF-B activation pathway. Similarly, the
absence of activation of IRF-3 after induction by known activators of
the NF-B pathway such as TNF- or IL-1 (38), as well
as the inability of the IB kinase (IKK) complex to phosphorylate
IRF-3 either in vivo or in vitro (data not shown), is inconsistent with
a direct inhibition of the IRF-3 activation pathway by IB- 2N.
These data rather indicate that cooperation between NF-B and IRF
occurs at the promoter level and involves direct or indirect contacts
between subunits of the NF-B complex and at least IRF-3, but also
probably IRF-7. Remarkably, both NF-B and IRF-3 interact with the
coactivators CBP/p300 (39, 40), and Wathelet et al.
(36) demonstrated that virus infection leads to an
unusually stable association of IRF-3 and IRF-7 with CBP/p300.
Similarly, binding of IRF-3 and IRF-7 to the ISRE site may permit an
indirect interaction with NF-B via association with CBP/p300
coactivators. This interaction would result in the in vivo assembly of
a highly specific multicomponent enhancer complex on the RANTES
promoter, thus insuring transcriptional activation in response to virus
infection. Furthermore, activation of both IRF-3 and IRF-7 as well as
NF-B has been observed in different primary cells, including mouse
embryonic fibroblasts and monocytes/macrophages (22 and
data not shown). Thus, a common virus-induced mechanism of RANTES
regulation involving synergism among IRF-3, IRF-7, and NF-B is also
active in primary cell models. Interestingly, virus transcription of
another member of the chemokine family, the IFN--inducible
protein-10 (-IP-10) gene, also requires cooperation of the ISRE
elements with the adjacent NF-B site (41). As in the
case of RANTES, -IP-10 mRNA is induced by virus in 293 cells and by
TNF- and virus in U937 cells, and is also strongly inhibited by both
IRF-3(N) and IB- 2N overexpression (data not shown). Such
interactions between IRF and NF-B families represent the point
of convergence between these two virus-inducible pathways and denote a
recurrent theme in the coordinate regulation of virus-inducible
cytokine genes.
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Acknowledgments |
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Footnotes |
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2 Address correspondence and reprint requests to Dr. John Hiscott, Lady Davis Institute for Medical Research, 3755 Cote Ste. Catherine, Montreal, Quebec, Canada H3T1E2.
3 Abbreviations used in this paper: IRF, IFN-regulatory factor; CBP, CREB-binding protein; DMS, dimethyl sulfate; DOX, doxycycline; HAU, hemagglutinating unit; I-B-, inhibitor of NF-B; ISRE, IFN-stimulated response element; LM-PCR, ligation-mediated PCR; RPA, RNase protection analyses.
4 R. Lin, P. Giening, Y. Mamane, and J. Hiscott. Submitted for publication.
Received for publication December 6, 1999. Accepted for publication March 6, 2000.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
and MIP-1ß in rat experimental autoimmune encephalomyelitis by in situ hybridization. J. Neuroimmunol. 77:17.[Medline]
, and MIP-1ß as the major HIV-suppressive factors produced by CD8+ cells. Science 270:1811.. J. Biol. Chem. 271:17161.B potently up-regulates the promoter activity of RANTES, a chemokine that blocks HIV infection. J. Immunol. 158:3483.[Abstract]
genes by positive feedback through interferon regulatory factor-7. EMBO J. 17:6660.[Medline]
B mediated inhibition of virus-induced interferon ß transcription. J. Virol. 73:2694.B in the C-terminal PEST domain by casein kinase II affects intrinsic protein stability. Mol. Cell. Biol. 16:1401.[Abstract]
B and Sp1 that regulates the IB promoter. Mol. Cell. Biol. 19:6140.B repressor mutants interferes with NF-B activity and HIV-1 replication in Jurkat T cells. J. Biol. Chem. 273:7431.B site but not IRF-1 or viral transcription. J. Interferon Cytokine Res. 18:987.[Medline]
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|
|
|
|
|
|
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|
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|
|
|
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|
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J. B. Sundstrom, L. K. McMullan, C. F. Spiropoulou, W. C. Hooper, A. A. Ansari, C. J. Peters, and P. E. Rollin Hantavirus Infection Induces the Expression of RANTES and IP-10 without Causing Increased Permeability in Human Lung Microvascular Endothelial Cells J. Virol., July 1, 2001; 75(13): 6070 - 6085. [Abstract] [Full Text] [PDF]
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S. J. Polyak, K. S. A. Khabar, D. M. Paschal, H. J. Ezelle, G. Duverlie, G. N. Barber, D. E. Levy, N. Mukaida, and D. R. Gretch Hepatitis C Virus Nonstructural 5A Protein Induces Interleukin-8, Leading to Partial Inhibition of the Interferon-Induced Antiviral Response J. Virol., July 1, 2001; 75(13): 6095 - 6106. [Abstract] [Full Text] [PDF]
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T. Yamada, S. Fujieda, S. Yanagi, H. Yamamura, R. Inatome, H. Yamamoto, H. Igawa, and H. Saito IL-1 Induced Chemokine Production Through the Association of Syk with TNF Receptor-Associated Factor-6 in Nasal Fibroblast Lines J. Immunol., July 1, 2001; 167(1): 283 - 288. [Abstract] [Full Text] [PDF]
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R. Lin, Y. Mamane, and J. Hiscott Multiple Regulatory Domains Control IRF-7 Activity in Response to Virus Infection J. Biol. Chem., October 27, 2000; 275(44): 34320 - 34327. [Abstract] [Full Text] [PDF]
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R. Lu, W.-C. Au, W.-S. Yeow, N. Hageman, and P. M. Pitha Regulation of the Promoter Activity of Interferon Regulatory Factor-7 Gene. ACTIVATION BY INTERFERON AND SILENCING BY HYPERMETHYLATION J. Biol. Chem., October 6, 2000; 275(41): 31805 - 31812. [Abstract] [Full Text] [PDF]
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