| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
*
Department of Immunology and Bacteriology, University of Glasgow, Glasgow, United Kingdom; and
Department of Cell and Molecular Biology, AstraZeneca Lund, Lund, Sweden
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
but did not alter
IL-10 or NO production. Treatment of BMMs with sST2 down-regulated
expression of Toll-like receptors-4 and -1 but induced nuclear
translocation of NF-
B. Administration of sST2 in vivo after LPS
challenge significantly reduced LPS-mediated mortality and serum levels
of IL-6, IL-12, and TNF-. Conversely, blockade of endogenous ST2
through administration of anti-ST2 Ab exacerbated the toxic
effects of LPS. Thus, ST2 has anti-inflammatory properties that act
directly on macrophages. We demonstrate here a novel regulatory pathway
for LPS-induced shock via the ST2-Toll-like receptor 4 route. This may
be of considerable therapeutic potential for reducing the severity and
pathology of inflammatory diseases. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
, IL-1
, or
IL-1R antagonist (8, 9). Functional ligands for ST2 have
not been demonstrated, although ST2 binding proteins have been reported
(8, 9). In the mouse, differential mRNA processing within
the ST2 gene allows for the production of both a membrane-bound form of
ST2, which is expressed primarily by hemopoietic cells (ST2L), and a
soluble (s)4 form of
ST2, which is predominantly expressed by fibroblasts
(10). Hence, ST2 is identical with the extracellular
region of ST2L except for an additional nine amino acids, which are
present at the C terminus of ST2. More recently, another alternatively
spliced ST2 transcript has been described in humans, the functional
consequences of which are unclear (11). Transcription of
ST2/ST2L is controlled by two distinct promoters: an upstream promoter
directs transcription in hemopoietic cells such as mast cells,
while a promoter 10.5 kb downstream directs fibroblast-specific
expression (10). Regulation of ST2/ST2L expression between
mice and humans appears to be conserved, because two promoters also
control ST2/ST2L expression in human cells (12). Studies
using either anti-ST2 Abs or a recombinant s form of ST2 have
demonstrated important roles for this molecule in regulating
Th1/Th2-associated immune responses in vitro and in experimental
disease models in vivo (6, 13). Such data are supported by
studies using ST2-deficient mice (14).
Macrophages respond to bacterial products such as LPS, bacterial or
CpG-containing DNA, peptidoglycan, and muramyl dipeptide by producing a
cascade of proinflammatory cytokines including IL-1, IL-6, IL-12,
IL-18, and TNF-, adhesion molecules, and inflammatory mediators that
mediate innate immunity and prime the acquired immune response.
Systemic bacterial infections trigger dysregulated production of these
molecules, ultimately leading to disseminated intravascular
coagulation, multiple organ failure, and mortality. The toxic effects
of LPS in vivo are primarily conferred by macrophages
(15). LPS-mediated activation of macrophages involves
presentation of LPS by CD14 to members of the Toll-like receptor (TLR)
family, particularly TLR4 (16, 17, 18). Signaling through TLR
members involves recruitment of the IL-1R-associated kinase signaling
complex, leading to activation of NF-B and transcription of
responsive genes (19). It is clear that a multitude of
other signaling pathways including mitogen-activated protein kinase,
erk-1/2, p38, c-Jun N-terminal kinase, and ceramide-activated protein
kinase are also activated by LPS in macrophages, and these pathways are
critical in instigating and regulating the LPS response
(20).
Apart from regulation of disease outcome through modulation of Th1/Th2
bias, there is indirect evidence to suggest that ST2 may also be
involved in inflammatory responses. ST2 expression was detected in
human monocytes after LPS stimulation in vitro and in the muscle and
spleen of mice after LPS injection (21). Proinflammatory
stimuli including TNF-, IL-1, and IL-1 induced ST2 expression
in 3T3 cells and, exposure to UV light triggered ST2 expression in vivo
(22). We have investigated the role of ST2 in regulating
the LPS response using a sST2-human (h)IgG-Fc fusion protein
(sST2). We report here that macrophages expressed a sST2-binding
activity that was up-regulated by LPS. Treatment of macrophages with
sST2 down-regulated expression of TLR4 and TLR1 but induced nuclear
translocation of NF-B. Furthermore, sST2 suppressed inflammatory
responses induced by LPS both in vitro and in vivo. Thus, sST2
represents a novel pathway for regulating endotoxic shock and may have
considerable therapeutic potential as an anti-inflammatory agent
through its ability to deactivate macrophages.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
RPMI 1640 medium (Life Technologies, Paisley, U.K.) containing 10% FCS, penicillin/streptomycin, and glutamine (complete medium) was used for culture of primary cells and cell lines. Murine bone marrow-derived macrophages (BMMs) were derived from cells of the femurs of adult BALB/c mice (Harlan Olac, Bichester, U.K.). Briefly, femurs were flushed with complete medium, and cells were plated in complete medium containing 104 U/ml rhCSF-1 (a gift from Chiron, Emeryville, CA, provided by D. Hume, Brisbane, Australia) on 10-cm bacteriological plastic plates (Bibby Sterilin, Staffordshire, U.K.) for 7 days in a 37°C incubator containing 5% CO2. In some experiments, 10% L929 cell-conditioned medium was used as a source of CSF-1 instead of rhCSF-1. The murine macrophage-like cell line RAW264 was obtained from American Type Culture Collection (Manassas, VA) and was cultured in complete medium on 10-cm bacteriological plastic plates. For in vitro experiments, LPS from Salmonella minnesota (Sigma, Poole, U.K.) was used at a concentration of 100 ng/ml in all cell culture experiments. For in vivo experiments, LPS from S. enteritidis (Sigma) was used at a dose of 18 mg/kg body weight. The sST2-IgG fusion protein was prepared as previously described (13). Briefly, a mammalian expression plasmid containing the sST2 cDNA linked to the hIgG1 constant region and containing the C5 signal sequence was stably transfected into Chinese hamster ovary cells. The sST2-IgG was purified from culture medium (low IgG) via protein A affinity chromatography, and purity was confirmed by SDS-PAGE. LPS was not detected in the sST2-IgG preparation (<0.01 ng/µg protein by an amoebocyte Limulus test; E-toxate, Sigma). The hIgG control protein (Sigma) was resuspended in PBS and stored at -20°C. Polyclonal rabbit anti-ST2 Ab and rabbit IgG control have been described previously (6). Monoclonal anti-ST2 Ab for flow cytometry was purchased from Morwell Diagnostics GmbH (Postfach, Switzerland). MTT assay reagent was from Sigma.
Flow cytometric analysis
BMMs were plated at 15 x 106 cells/15 ml complete medium in 10-cm bacteriological plastic plates and were treated with LPS or left untreated for 20 h. Adherent cells were harvested by scraping in ice-cold PBS, and 5 x 106 cells were resuspended in ice-cold complete medium and incubated at 4°C in the presence of 5 µg/ml of Fc block (BD PharMingen, San Diego, CA) for 20 min. The sST2-Ig fusion protein (25 µg/ml) or hIgG (25 µg/ml, purified as for ST2-Ig using a protein A column) was then added, and cells were incubated for 30 min at 4°C. Cells were then washed in FACS buffer (1x PBS supplemented with 2% FCS, 0.1% sodium azide) and stained with anti-hIgG1 mAb (26 µg/ml; Sigma). Cells were fixed and analyzed on a FACSCalibur flow cytometer (BD Biosciences, Mountain View, CA).
In vitro treatment of cells, ELISA, NO, and MTT assays
For all in vitro experiments, cells were plated in 24-well plates at 5 x 105 cells/well in 1 ml complete medium plus CSF-1 overnight. Cells were then treated with sST2, hIgG, or medium for 1 h (unless otherwise stated) followed by stimulation with LPS or medium alone. After 8 h (unless otherwise stated), supernatants were collected and stored at -20°C. ELISA was performed using paired Abs (BD PharMingen), and nitrite levels in culture medium were analyzed by Griess reagent (23). Cell viability was assessed by MTT assay (24).
Nuclear extract preparation and gel shift assays
Nuclear extract preparation and gel shift assays were performed
as described previously (25). Double-stranded
oligonucleotides (Sigma-Genosys, Poole, U.K.) used were NF-B
(26) corresponding to an element from the TNF- promoter
that contains an NF-B binding site
(5'-CAAACAGGGGGCTTTCCCTCCTC-3') and GATA corresponding to an
element from the ST2 promoter that contains a GATA-1 binding site
(5'-CCTGTAAGTAACTGATAAGGAACAGGAGGT-3'). Both strands of the NF-B
oligonucleotide were end-labeled with polynucleotide kinase and
[
-32P]ATP, annealed, separated on a
NAP-5 column (Sigma), and used for gel shift assays. Cold
competition analysis was performed by incubating binding reactions with
a 10-fold molar excess of either self (NF-B) or an unrelated
oligonucleotide (GATA). Supershift/Ab blocking experiments were
performed by addition of 1 µl of 100 µg/ml of either anti-p50,
anti-p52, anti-p65, or anti-c-rel Abs (BD PharMingen).
Quantification of mRNA
Total RNA was prepared using RNAzol B (Biogenesis, Poole, U.K.) according to the manufacturer’s instructions. RNA was treated with DNase 1 (Ambion, Austin, TX) and reverse transcribed to cDNA using Superscript reverse transcriptase (Life Technologies). Negative control samples (no first-strand synthesis) were prepared by performing reverse transcription reactions in the absence of reverse transcriptase. The cDNA levels of TLR4, TLR1, IL-12 p40, IL-12 p35, and hypoxanthine phosphoribosyltransferase (HPRT) were quantitated by real-time PCR using an ABI prism 7700 sequence detector according to the manufacturer’s instructions (Applied Biosystems, Foster City, CA). The cDNA levels during the linear phase of amplification were normalized against HPRT controls. Determinations were made in triplicate and expressed as mean ± SD. Primers and probes used were as follows: for TLR4, sense: 5'-AGGAAGTTTCTCTGGACTAACAAGTTTAGA-3', antisense: 5'-AAATTGTGAGCCACATTGAGTTTC-3', probe: 5'-GCCAATTTTGTCTCCACAGCCACCA-3'; for TLR1, sense: 5'-TGGATGTGTCCGTCAGCACTA-3', antisense: 5'-AGAGCAGCCCTGGTCTTCAA-3', probe: 5'-CACACACTTGATGTTAGACAGTTCCAAACCGAT-3'; for IL-12 p40, sense, 5'-GGAATTTGGTCCACTGAAATTTTAAA-3', anti-sense: 5'-CACGTGAACCGTCCGGAGTA-3', probe, 5'-AACAAGACTTTCCTGAAGTGTGAGCACCAAAT-3'; for IL-12 p35, sense: 5'-AAGACATCACACGGGACCAAA-3', antisense: 5'-CAGGCAACTCTCGTTCTTGTGTA-3', probe, 5'-CAGCACATTGAAGACCTGTTTACCACTGGA-3'; and for HPRT, sense: 5'-GCAGTACAGCCCCAAAATGG-3', antisense:5'-AACAAAGTCTGGCCTGTATCCAA-3', probe: 5'-TAAGTTGCAAGCTTGCTGGTGAAAAGGA-3'.
Induction of LPS shock in vivo
Age- and sex-matched BALB/c mice (10-wk-old male mice; n = 12/group) were injected i.p. with 18 mg/kg LPS then 1 h later were injected i.p. with 100 µg/mouse hIgG control or 100 µg/mouse sST2. Serum samples were collected from mice (n = 6), pooled, and stored at -20°C until subsequent cytokine estimation. For experiments using anti-ST2 Ab, age- and sex-matched BALB/c mice (8-wk-old male mice; n = 25/group) were pretreated with 250 µg/mouse rabbit anti-ST2 Ab or 250 µg/mouse normal rabbit IgG 1 day before LPS challenge, 1 h before LPS challenge, and 1 day after LPS challenge. Serum was collected from mice 2 h after LPS challenge, pooled, and cytokine levels estimated by ELISA (n = 6/group). Experiments were terminated on day 4 after LPS injection, as required by the guidelines for animal experimentation (Home Office, London, U.K.)
Statistical analysis
Statistical analysis was performed using Minitab software (Minitab, State College, PA). For in vivo trials, the two-tailed log-rank test was used, and the Student’s t test was used for cytokine determinations.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Using a sST2-hIgG fusion protein, we analyzed the ability of BMMs
to bind ST2. BMMs were initially preincubated with Fc block
(anti-CD16/anti-CD32) and then incubated with either sST2 or
hIgG. Cells were then analyzed by flow cytometry using an anti-hIgG
mAb. Cells incubated with normal hIgG had a staining pattern identical
with the isotype control. In contrast, cells incubated with sST2 were
markedly stained with anti-hIgG (Fig. 1
A). Hence, BMMs express a
cell surface binding activity for sST2. Importantly, this binding
activity was markedly enhanced by overnight exposure of BMMs to LPS
(Fig. 1B). In additional experiments, BMMs were incubated
with human IgG and then reacted with anti-ST2 Ab. Cells incubated
with hIgG showed no difference in binding between anti-ST2 Ab and
the isotype control, thus, indicating that macrophages do not express
detectable levels of cell surface ST2L (data not shown).
|
Because binding of sST2 to BMMs was up-regulated by LPS treatment,
we investigated the reciprocal involvement of sST2 in regulating the
LPS response. BMMs were pretreated for 1 h with sST2 or hIgG (both
at 50 µg/ml) or medium alone and then stimulated with LPS (100 ng/ml)
for up to 48 h. Culture supernatants were harvested at regular
intervals, and concentrations of cytokines were analyzed by ELISA.
Treatment with sST2 markedly inhibited the production of IL-6, IL-12,
and TNF- (Fig. 2). This was apparent
at all time points examined, indicating that inhibition by sST2 was not
overcome by persistent exposure to LPS. In contrast, NO and IL-10 (data
not shown) production in response to LPS was not inhibited by treatment
with sST2. Production of IL-6 and TNF-, but not IL-12, in response
to LPS in the murine macrophage-like cell line RAW264 was also
suppressed by sST2 treatment (data not shown). Hence, the inhibition
mediated by ST2 appears to be selective.
|
Although we have sometimes detected very low levels of expression of ST2L mRNA in BMMs by RT-PCR, we have been unable to detect membrane-bound ST2L by flow cytometry (data not shown). To confirm that the effect of sST2 on macrophages did not involve competition between sST2 and presumptive low levels of ST2L for an LPS-inducible protein, we pretreated BMMs for 2 h with sST2, washed the cells thoroughly to remove sST2 in culture medium, and then stimulated cells with LPS for 8 h. We found that sST2 inhibited LPS-induced IL-6 production irrespective of whether sST2 had been removed before stimulation with LPS (data not shown). Hence, sST2 appears to trigger anti-inflammatory signals in macrophages directly.
NF-B is activated in BMMs by sST2
One mechanism by which sST2 could suppress LPS-induced
proinflammatory cytokine production is by blocking LPS-initiated
nuclear translocation of NF-B or specifically mobilizing NF-B p50
homodimers, which can have inhibitory effects on gene expression
(27). To test this possibility, we assessed levels of
NF-B in BMMs pretreated with 50 µg/ml of hIgG or sST2 for 30 min
before stimulation with LPS for 45 min. Unexpectedly, sST2 was itself
able to activate NF-B in BMMs to the same extent as LPS, and no
additional activation or repression by LPS was observed (Fig. 3A). Cold competition analysis
indicated that the induced band was indeed NF-B, because unlabeled
self oligonucleotide, but not an unlabeled oligonucleotide containing a
GATA-1 site, could compete for binding (Fig. 3A). NF-B
induced by sST2 was primarily composed of p65, c-rel, and p50 as
assessed by supershift analysis (Fig. 3B). The inducible
complex did not contain the rel family member p52, because treatment
with an anti-p52 Ab did not alter binding. On the basis of
supershift analysis, LPS-induced NF-B could not be distinguished
from sST2-induced NF-B (data not shown). Hence, LPS and sST2, which
clearly have opposing effects on macrophage cytokine production, both
induced p65/c-rel/p50-containing NF-B.
|
Because members of the TLR family, particularly TLR4, are
essential for macrophage responses to LPS, we examined the effect of
sST2 on TLR mRNA levels in BMMs using quantitative real-time PCR. Fig. 4 shows that treatment of BMMs with
either sST2 or LPS down-regulated expression of TLR4 mRNA 
3-fold,
and the combination of these stimuli suppressed TLR4 mRNA levels
further. Interestingly, TLR1, which may also be involved in the
response to LPS (28), was differentially regulated by LPS
and sST2; sST2 repressed TLR1 mRNA levels 4-fold, whereas LPS
induced TLR1 expression 2-fold. To confirm that sST2 inhibited
LPS-induced proinflammatory gene expression in the same RNA samples,
mRNA levels of IL-12 p40 and IL-12 p35 were also assessed. Both IL-12
p40 and p35 mRNA levels were almost undetectable in unstimulated cells
or cells treated with sST2. LPS induced expression of both IL-12 p40
and p35, and sST2 repressed this LPS-induced expression (p40, 2.6-fold
and p35, 5.5-fold).
|
The observation that sST2 could inhibit LPS-induced
proinflammatory cytokine production in vitro suggested that this
molecule might have therapeutic potential as an LPS antagonist. To test
this hypothesis, a murine LPS shock model was used. Mice were injected
i.p. with LPS and then treated 1 h later with either sST2 or hIgG.
Although only 4 of 12 mice in the control hIgG-treated group survived
over a 4-day period, mice treated with sST2 had a significantly
enhanced survival rate (10 survived of 12; p < 0.01)
(Fig. 5A). Treatment with sST2
clearly down-regulated the levels of serum IL-6, IL-12, TNF-, and
IFN- in LPS-challenged mice (Fig. 5B). No significant
differences in IL-10 levels were seen between sST2- and hIgG-treated
mice. Because there is evidence that IL-18 may be involved in
controlling the onset of LPS shock (29), we also measured
serum IL-18 in the two groups. IL-18 levels were not altered by
treatment with sST2 (Fig. 5B).
|
The above-described data demonstrate that sST2 has potent
anti-inflammatory activity and blocks LPS shock in vivo. Therefore,
it might be expected that inhibition of endogenous sST2 action would
exacerbate mortality. We tested this hypothesis by examining the
effects of an anti-ST2 Ab that has been used previously to block
Th2 responses in vivo (6). Mice were injected i.p. with
either anti-ST2 Ab or an isotype control on day -1, 0, and +1 of
LPS challenge. Although 9 of 25 from the control group succumbed to
LPS-induced shock, the level of mortality in the anti-ST2
Ab-treated group was significantly higher (20 of 25; p
< 0.01) than in the control group (Fig. 6A). Levels of the
proinflammatory cytokines IL-6, TNF-, and IFN- were also elevated
in sera from mice treated with anti-ST2 Ab compared with the
control group (Fig. 6B). The level of IL-10 was similar in
both groups (3.5 vs 3.8 ng/ml).
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
, and TNF-. Therefore, sST2 may be a novel
therapeutic agent for endotoxic shock. The receptor on macrophages responsible for binding sST2 is at present unknown. Although sST2 has significant homology with IL-1R, it did not bind to known members of the IL-1 family (8, 9, 30). Others have isolated a cDNA that encodes a ST2-binding protein (9). Although they were unable to demonstrate signaling through ST2L-bearing 3T3 cells in response to this protein, signaling in cells expressing the ST2-binding protein in response to sST2 (the reverse interaction) was not investigated. Given that the ST2-binding protein contains a transmembrane domain and a short 12 amino acid intracellular domain, it is possible that it is involved in recognition of sST2 by macrophages and subsequent signaling. We have detected expression of the ST2 binding protein in BMMs by RT-PCR (data not shown). Alternatively, it may be that sST2 binds to an as yet unidentified member of the IL-1R family. This is currently being addressed.
ST2 expression was induced by IL-1, IL-1, and TNF- in
fibroblasts (22) and in muscle and spleen following LPS
challenge (21). We have now shown that LPS enhanced the
binding of sST2 to macrophages. Thus, macrophages respond to LPS by
both producing cytokines that can induce sST2 expression and by
enhancing the expression of a putative sST2 receptor. This would
provide an effective mechanism by which sST2 could regulate the
inflammatory response through its interaction with macrophages.
We also demonstrated that both LPS and sST2 could reduce TLR4 mRNA levels in BMMs. The ability of LPS to transiently repress mRNA levels of TLR4 in macrophages has been reported (31, 32) and, more importantly, LPS triggered a rapid and sustained down-regulation of cell surface TLR4 expression, thus providing one potential mechanism of endotoxin tolerance (31). Similarly, the ability of sST2 to down-regulate TLR4 expression may explain, at least in part, how sST2 suppresses LPS-induced proinflammatory cytokine production by macrophages. TLR1 expression was differentially regulated by the two stimuli. LPS induced, whereas sST2 markedly suppressed, TLR1 mRNA levels. This result also excludes the possibility that the effect of sST2 was due to any potential contaminating LPS. Others have recently reported that TLR1 can bind to LPS and can enhance the LPS response of HeLa cells after cotransfection with TLR2 (28), and we have found that TLR1 is expressed at much higher levels than other TLR family members in BMMs (data not shown). Thus, it is possible that down-regulation of TLR1 may also contribute to inhibition of LPS responsiveness by ST2 in macrophages.
One might expect that down-regulation of TLR4 by sST2 would prevent
subsequent mobilization of NF-B in response to LPS. Macrophages from
LPS nonresponder mice (C3H/HeJ) still respond to LPS with NF-B
activation (33), implying that, although TLR4 is required
for LPS-inducible gene expression, it is not essential for NF-B
mobilization in response to LPS. Indeed, TNF- induction by LPS in
RAW264 cells is primarily a post-transcriptional event
(34), and the mechanism of IL-6 regulation in BMMs or
RAW264 cells is yet unknown.
The anti-inflammatory signals triggered by sST2 leading to
down-regulation of TLR4 and TLR1 and suppressed production of
proinflammatory cytokines are at present unclear. It appears that sST2
acts directly rather than via the action of an intermediary factor,
because LPS-induced NO and IL-10 levels were not altered by sST2
treatment, and we were unable to detect significant levels of TGF-1
in sST2-treated BMMs (data not shown). Furthermorre, kinetic studies
showed that sST2-mediated suppression was apparent 4 h after LPS
treatment at the protein level. This is consistent with the effect of
sST2 in vivo, where IL-6, IL-12, IFN-, and TNF- levels were
suppressed 2 h after administration of sST2. Similarly, IL-6,
TNF-, and IFN- levels in the serum were markedly elevated in mice
treated with anti-ST2 Ab 2 h after LPS challenge.
In conclusion, apart from acting as a marker for Th2 cells and directly
modulating Th1/Th2 balance by influencing Th2 cell functions (6, 7), the gene encoding T1/ST2 may also have an important
regulatory role in the inflammatory response by acting directly on
macrophages. Fig. 7 summarizes the
regulatory pathway of sST2 in LPS-induced inflammatory responses. LPS
activates macrophages via TLR4, inducing production of proinflammatory
cytokines including IL-1 and TNF-, which activate fibroblasts and
other cell types to produce sST2. Then sST2 binds to macrophages via a
yet undefined receptor and directly and selectively represses the
expression of proinflammatory cytokines, including IL-6, IL-12, and
TNF-, possibly through the down-regulation of TLR4. Thus, sST2 may
function as an important mediator in this negative feedback loop for
preventing uncontrolled inflammatory reactions. Consistent with this is
our demonstration that ST2-IgG, an effective surrogate of ST2, markedly
blocked LPS-induced shock and down-regulated proinflammatory cytokine
production in vivo. Conversely, anti-ST2 Ab, which neutralized ST2,
exacerbated LPS-mediated mortality and enhanced production of
proinflammatory cytokines in vivo. However, it should be noted that the
ST2-Fc construct used here may exist as a dimeric molecule, which may
or may not be identical with native sST2. Nevertheless, it would be of
considerable interest to define the ST2 receptor and the mechanism by
which it transmits signal leading to the inhibition of TLR4 expression.
These data also strongly suggest that ST2-IgG could be a novel
therapeutic agent against septic shock and other inflammatory
diseases.
|
|
Acknowledgments |
|---|
|
Footnotes |
|---|
2 Current address: Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Belgrade, Yugoslavia.
3 Address correspondence and reprint requests to Prof. Foo Y. Liew or Dr. Damo Xu, Department of Immunology and Bacteriology, University of Glasgow, Glasgow, G11 6NT, U.K. E-mail addresses: F.Y.Liew@clinmed.gla.ac.uk or dx1c{at}clinmed.gla.ac.uk
4 Abbreviations used in this paper: s, soluble; TLR, Toll-like receptor; h, human; BMMs, bone marrow-derived macrophages; HPRT, hypoxanthine phosphoribosyl transferase.
Received for publication September 22, 2000. Accepted for publication March 21, 2001.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
primes macrophage responses to bacterial DNA. J. Interferon Cytokine Res. 18:263.[Medline]
promoter in primary macrophages. J. Immunol. 147:1694.[Abstract]
B element located downstream of the tumor necrosis factor gene: distinct NF-B binding pattern and enhancer activity in LPS activated murine macrophages. Oncogene 11:97.[Medline]
B. J. Leukocyte Biol. 57:174.[Abstract]
This article has been cited by other articles:
|
|
 |
|
  J Kwakkel, O Chassande, H C van Beeren, W M Wiersinga, and A Boelen Lacking thyroid hormone receptor {beta} gene does not influence alterations in peripheral thyroid hormone metabolism during acute illness J. Endocrinol., April 1, 2008; 197(1): 151 - 158. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. P. Klieverik, H. P. Sauerwein, M. T. Ackermans, A. Boelen, A. Kalsbeek, and E. Fliers Effects of thyrotoxicosis and selective hepatic autonomic denervation on hepatic glucose metabolism in rats Am J Physiol Endocrinol Metab, March 1, 2008; 294(3): E513 - E520. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. A. Verri Jr., A. T. G. Guerrero, S. Y. Fukada, D. A. Valerio, T. M. Cunha, D. Xu, S. H. Ferreira, F. Y. Liew, and F. Q. Cunha IL-33 mediates antigen-induced cutaneous and articular hypernociception in mice PNAS, February 19, 2008; 105(7): 2723 - 2728. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Miller, D. Xu, D. L. Asquith, L. Denby, Y. Li, N. Sattar, A. H. Baker, I. B. McInnes, and F. Y. Liew IL-33 reduces the development of atherosclerosis J. Exp. Med., February 18, 2008; 205(2): 339 - 346. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. P. Gantier, S. Tong, M. A. Behlke, D. Xu, S. Phipps, P. S. Foster, and B. R. G. Williams TLR7 Is Involved in Sequence-Specific Sensing of Single-Stranded RNAs in Human Macrophages J. Immunol., February 15, 2008; 180(4): 2117 - 2124. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. H. Ho, T. Ohno, K. Oboki, N. Kajiwara, H. Suto, M. Iikura, Y. Okayama, S. Akira, H. Saito, S. J. Galli, et al. IL-33 induces IL-13 production by mouse mast cells independently of IgE-Fc{epsilon}RI signals J. Leukoc. Biol., December 1, 2007; 82(6): 1481 - 1490. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Rui, X. Liu, N. Li, Y. Jiang, G. Chen, X. Cao, and J. Wang PECAM-1 Ligation Negatively Regulates TLR4 Signaling in Macrophages J. Immunol., December 1, 2007; 179(11): 7344 - 7351. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 X. Huang, W. Du, R. P. Barrett, and L. D. Hazlett ST2 Is Essential for Th2 Responsiveness and Resistance to Pseudomonas aeruginosa Keratitis Invest. Ophthalmol. Vis. Sci., October 1, 2007; 48(10): 4626 - 4633. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Hayakawa, M. Hayakawa, A. Kume, and S.-i. Tominaga Soluble ST2 Blocks Interleukin-33 Signaling in Allergic Airway Inflammation J. Biol. Chem., September 7, 2007; 282(36): 26369 - 26380. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J Kwakkel, W M Wiersinga, and A Boelen Interleukin-1{beta} modulates endogenous thyroid hormone receptor {alpha} gene transcription in liver cells J. Endocrinol., August 1, 2007; 194(2): 257 - 265. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Divanovic, A. Trompette, L. K. Petiniot, J. L. Allen, L. M. Flick, Y. Belkaid, R. Madan, J. J. Haky, and C. L. Karp Regulation of TLR4 signaling and the host interface with pathogens and danger: the role of RP105 J. Leukoc. Biol., August 1, 2007; 82(2): 265 - 271. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Wang, T. Chen, C. Han, D. He, H. Liu, H. An, Z. Cai, and X. Cao Lysosome-associated small Rab GTPase Rab7b negatively regulates TLR4 signaling in macrophages by promoting lysosomal degradation of TLR4 Blood, August 1, 2007; 110(3): 962 - 971. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Amatucci, T. Novobrantseva, K. Gilbride, M. Brickelmaier, P. Hochman, and A. Ibraghimov Recombinant ST2 boosts hepatic Th2 response in vivo J. Leukoc. Biol., July 1, 2007; 82(1): 124 - 132. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. M. Ripoll, K. M. Irvine, T. Ravasi, M. J. Sweet, and D. A. Hume Gpnmb Is Induced in Macrophages by IFN-{gamma} and Lipopolysaccharide and Acts as a Feedback Regulator of Proinflammatory Responses J. Immunol., May 15, 2007; 178(10): 6557 - 6566. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K.-i. Arimoto, H. Takahashi, T. Hishiki, H. Konishi, T. Fujita, and K. Shimotohno Negative regulation of the RIG-I signaling by the ubiquitin ligase RNF125 PNAS, May 1, 2007; 104(18): 7500 - 7505. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. T. Fagundes, F. A. Amaral, A. L. S. Souza, A. T. Vieira, D. Xu, F. Y. Liew, D. G. Souza, and M. M. Teixeira ST2, an IL-1R family member, attenuates inflammation and lethality after intestinal ischemia and reperfusion J. Leukoc. Biol., February 1, 2007; 81(2): 492 - 499. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Boelen, J Kwakkel, W M Wiersinga, and E Fliers Chronic local inflammation in mice results in decreased TRH and type 3 deiodinase mRNA expression in the hypothalamic paraventricular nucleus independently of diminished food intake J. Endocrinol., December 1, 2006; 191(3): 707 - 714. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. MENSAH-BROWN, A SHAHIN, K. PAREKH, A AL HAKIM, M AL SHAMISI, D.K HSU, and M.L LUKIC Functional Capacity of Macrophages Determines the Induction of Type 1 Diabetes Ann. N.Y. Acad. Sci., November 1, 2006; 1084(1): 49 - 57. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Boelen, J Kwakkel, X G Vos, W M Wiersinga, and E Fliers Differential effects of leptin and refeeding on the fasting-induced decrease of pituitary type 2 deiodinase and thyroid hormone receptor {beta}2 mRNA expression in mice. J. Endocrinol., August 1, 2006; 190(2): 537 - 544. [Abstract] [Full Text] [PDF] |
