| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Receptors1
Department of Microbiology and Immunology, Temple University School of Medicine, Philadelphia, PA 19140
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
R ligation. Macrophages
were stimulated in vitro with LPS, lipoteichoic acid, CD40 ligand, or
low molecular mass hyaluronic acid. All of these stimuli were
proinflammatory in character, inducing the production of high levels of
IL-12, but only modest amounts of IL-10. The coligation of FcR along
with these stimuli resulted in an anti-inflammatory profile,
abrogating IL-12 production and inducing high levels of IL-10. The
modulation of these two cytokines occurred by two independent
mechanisms. Whereas the abrogation of IL-12 biosynthesis was a property
shared by several macrophage receptors, the induction of IL-10 was
specific to the FcR. The biological relevance of these observations
was examined in murine models of endotoxemia, in which FcR ligation
induced the rapid production of IL-10 and prevented IL-12 synthesis.
Mice could be passively immunized with Abs to LPS to reverse
inflammatory cytokine production, and the transfer of macrophages whose
FcR had been ligated could rescue mice from lethal endotoxemia.
Thus, the ligation of the macrophage FcR can be exploited to prevent
inappropriate inflammatory cytokine responses. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
R) allow innate effector
cells, such as macrophages, to communicate with the specific, adaptive
immune response. The expression of all three classes of FcR
(FcRI, FcRII, and FcRIII) on macrophages facilitates the rapid
and efficient binding of IgG immune complexes to these cells (1, 2). Although phagocytosis is the most recognized sequella of
FcR cross-linking, signaling through FcR may influence other
responses such as Ag presentation, Ab-dependent cellular cytotoxicity,
and the release of inflammatory mediators (3).
IL-12 is a proinflammatory cytokine produced primarily by APCs.
Although transcribed and translated as separate gene products (p40 and
p35), the ascribed biologic activity of IL-12 occurs only when the two
subunits are joined and secreted as a disulfide-linked heterodimer
(p70) (4). IL-12 is essential for the development of an
efficient cell-mediated immune response to intracellular pathogens.
This occurs primarily through the induction of IFN-, leading to
macrophage activation and the biasing of Th cells toward a Th1
phenotype (5, 6, 7, 8). Although crucial for host defense to a
number of pathogens, the inappropriate overproduction of IL-12 can have
adverse affects. The contribution of IL-12 to organ-specific
autoimmunity has been documented in both murine and human forms of
multiple sclerosis (9, 10) as well as in diabetes, in
which macrophages were identified as the source of the pathogenic IL-12
(11). Studies have also implicated IL-12 and IL-12-induced
IFN- in the morbidity and mortality associated with endotoxemia
(12, 13, 14, 15). Therefore, the production of IL-12 must be
tightly controlled.
IL-10 is a pleiotropic cytokine produced by monocytes, macrophages, and lymphocytes (16, 17). It was originally identified by its ability to antagonize cellular immunity (18). Among its potent immunosuppressive qualities lies the ability of IL-10 to depress mononuclear cell activation through the prevention of inflammatory mediator production (19, 20, 21, 22) and the down-regulation of Ag-presenting (23) and costimulatory molecule (24) expression in vitro. The important immunomodulatory role of IL-10 in vivo is apparent during septic shock, a pathology that can be triggered by leukocyte activation in response to microbial products (25). Treatment with IL-10 diminishes inflammatory cytokine production and prevents lethality in several animal models of septic shock (26, 27, 28, 29, 30). Conversely, the removal of IL-10 via blocking Ab or gene targeting intensifies proinflammatory cytokine responses and lowers the threshold for induction of endotoxin lethality (31, 32, 33, 34, 35). In human models of endotoxemia, i.v. IL-10 administration reduces inflammatory cytokine responses (36), chemokine production (37), and activation of coagulation and fibrinolysis (38). In human patients suffering from severe Gram-negative septic shock, IL-10 was shown to inhibit the activation of monocytes (39).
Recently, we demonstrated that receptor ligation can influence
macrophage cytokine production in vitro (40, 41). We
showed that IL-12 production can be abrogated by ligating any one of
several macrophage receptors (40). There was a surprising
lack of receptor specificity to this effect, because the ligation of
the Fc, the complement, or the scavenger receptors was capable of
diminishing IL-12 production. We also showed that the specific ligation
of the FcR could increase the production of IL-10 in response to LPS
(41). Because macrophages are in position to effect both
innate and adaptive immune responses, we now further characterize
macrophage cytokine production following FcR ligation. We examine
the specificity and the kinetics of cytokine production and examine the
extent to which the in vitro observations that we have made could be
extended to in vivo applications.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Six- to 8-wk-old female C57BL/6 and
C57BL/6/IL-10-/- mice were purchased from
Taconic Farms (Germantown, NY).
C57BL/6J-RAG1-/- breeding pairs were purchased
from The Jackson Laboratory (Bar Harbor, ME). All mice were housed in
the Temple University School of Medicine Animal Facility. Bone
marrow-derived macrophages
(BMM
)3 were
established, as previously described (40). Briefly, femurs
were flushed with cation-free Dulbecco’s PBS containing 200 U/ml
penicillin G and 200 µg/ml streptomycin. Cells were grown in DMEM
containing 20% L929 cell-conditioned medium (as a source of M-CSF),
10% heat-inactivated FCS, 2 mM L-glutamine, 100 U/ml
penicillin G, and 100 µg/ml streptomycin. Cells were incubated at
37°C in 5% CO2 for 7–10 days until uniform
monolayers of macrophages were established. Twelve hours before use,
cells were removed from the original plastic petri dishes using 5 mM
EDTA and put in tissue culture-treated plates (Nunc, Naperville, IL) in
DMEM containing 10% heat-inactivated FCS, 2 mM
L-glutamine, 100 U/ml penicillin G, and 100 µg/ml
streptomycin (complete medium) with or without 200 U/ml murine
rIFN-.
Reagents
IgG-opsonized erythrocytes (E-IgG) were generated by combining
sheep erythrocytes (SRBC; Lampire, Pipersville, PA) with rabbit
anti-SRBC IgG (Cappel, Durham, NC) at nonagglutinating titers. This
suspension was gently rotated for 30 min at room temperature. E-IgG
were then washed with HBSS (Life Technologies, Gaithersburg, MD) and
resuspended at 2 x 108 cells/ml in HBSS.
Complement-opsonized erythrocytes (E-C3b/i) were generated by
incubating SRBC with rabbit anti-SRBC IgM (Cappel, Durham, NC) at
nonagglutinating titers in the presence of 5% C5-deficient mouse serum
for 40 min at room temperature. E-C3b/i were washed twice with HBSS and
resuspended at 2 x 108 cells/ml in HBSS.
Lipoteichoic acid (LTA) from Staphylococcus aureus, LPS
(Escherichia coli 0127:B8, 0128:B12, and K 235), and
cytochalasin D were purchased from Sigma (St. Louis, MO). An agonistic
Ab to CD40 was prepared from hybridoma supernatants of FGK115 cells.
Low molecular mass hyaluronic acid (LMW-HA; ICN, Aurora, OH) was
treated with polymyxin B-coated beads (Sigma) before use. IgG-LPS was
generated by incubating 10 µg/ml E. coli 0128:B12 LPS with
rabbit anti-LPS polyclonal antiserum (Calbiochem-Novabiochem, San
Diego, CA) at a 1/1 dilution for 15 min at 4°C. This dilution was
selected as the lowest amount of IgG that maximally stimulated
macrophage IL-10 production in vitro. Latex microspheres (2 µm) were
purchased from Duke Scientific (Palo Alto, CA). Recombinant murine
IL-10 and IFN- were purchased from R&D Systems (Minneapolis,
MN).
Macrophage stimulation and receptor ligation
For in vitro assays, stimuli were added to BMM at the
following concentrations, unless otherwise specified: LPS at 10 ng/ml,
LTA at 10 µg/ml, CD40 agonist at 20 µg/ml, IgG-LPS at 100 ng/ml,
LMW-HA at 250 µg/ml, murine rIL-10 at 2 ng/ml. For receptor
ligation/phagocytosis, E-IgG were added at a ratio of 10 erythrocytes
per macrophage. Latex microspheres were added at a ratio of 50
microspheres per macrophage. For phagocytosis studies, cells were
incubated with 10 µg/ml cytochalasin D. Unless otherwise specified,
inflammatory stimulation and FcR ligation were initiated
simultaneously.
In vivo assays
For passive immunization studies,
RAG1-/- mice (five per group) were injected
with anti-LPS Ab or saline in the peritoneum, followed 2 or 18
h later by 4 µg of LPS (0128:B12) i.v. (tail vein). Mice were bled by
retro-orbital puncture at the indicated time intervals, and serum
cytokine levels were determined by ELISA. For in vivo reconstitution
assays, a total of 1 x 106 BMM was
incubated with 1 x 107 E-IgG in the
presence of 5 ng/ml LPS (0127:B8) at 37°C in 1.5-ml Eppendorf tubes
for 30 min and then injected i.p. into C57BL/6 mice. Three and one-half
hours later, mice were injected i.p. with 300 µg of LPS (K 235).
Animals were then monitored at 12-h intervals for 6 days.
Cytokine assays
Cell supernatants or serum were assayed for IL-12 p40, IL-12
p70, TNF-
, or IL-10 protein by ELISA. Macrophages were added to
24-well plates at 2 x 105 cells/well in 0.5
ml complete medium and stimulated for 8–24 h. Culture supernatants
were then collected and centrifuged at 13,000 x g, and
the supernatants were stored at -80°C. Ab pairs (IL-12 p40, C15.6
and C17.8; IL-12 p70, 9A5 and C17.8; TNF-, G281-2626 and MP6-XT3;
IL-10, JES-2A5 and JES-16E3) and recombinant standards were purchased
from BD PharMingen (San Diego, CA). To determine cytokine mRNA levels,
1.5 x 106 macrophages were added to
six-well plates in 2 ml complete medium. Cells were stimulated for
2.5 h, and total cellular RNA was harvested using TRIzol (Life
Technologies), according to manufacturer’s instructions. For RT-PCR
assays, RNA was reverse transcribed and amplified, as previously
described (40). For RNase protection assays, RNA was
prepared and assayed using multiprobe template sets mCK-2b and mCK-3b
(BD PharMingen), according to manufacturer’s instructions.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
R-mediated cytokine modulation is stimulus independent
To determine the extent to which receptor ligation could alter
macrophage cytokine production, murine BMM were stimulated in vitro
with the Gram-negative cell wall constituent LPS in the presence or
absence of E-IgG to ligate the FcR. Cells stimulated with LPS alone
produced high levels of IL-12 and TNF-, but only modest amounts of
IL-10 (Fig. 1
). The cross-linking of
FcR simultaneously with LPS stimulation changed the cytokine profile
of these cells. IL-12 production was essentially abrogated, and IL-10
production was dramatically increased (Fig. 1). TNF- production was
not affected by FcR ligation. These data confirm and extend two
previous independent observations (40, 41). This assay was
repeated with BMM that were primed with IFN- to induce the
production of high levels of IL-12 p70 (Fig. 2). Several stimuli in addition to LPS
were examined to determine whether they were also able to cooperate
with FcR ligation and modulate cytokine production. These stimuli
included the Gram-positive cell wall component LTA, the ligation of
macrophage CD40 with an agonistic Ab that mimics T cell CD40 ligand
(CD40), and CD44-mediated stimulation with LMW-HA. All of the
stimuli tested were proinflammatory in character and induced relatively
high levels of IL-12 (Fig. 2A, top graph), but
only modest levels of IL-10 (Fig. 2A, bottom
graph), comparable with stimulation with 10 ng/ml of LPS. The
coupling of all of these stimuli with FcR ligation resulted in a
decrease in IL-12 production to near-background levels (Fig. 2A,
top graph), and a dramatic increase in IL-10 production (Fig. 2A, bottom graph). LPS contamination of LMW-HA was excluded
as a potential source of macrophage stimulation by performing this
assay on C3H/Hej mice, which have a mutation in Toll-like receptor 4,
making them hyporesponsive to LPS. The response of macrophages from
these mice to LMW-HA ± E-IgG was not different from that of wild-type
mice (data not shown).
|
|
R ligation were also evident at the mRNA level (Fig. 2
B). By RNase protection, RNA levels for a number of
cytokine genes, including TNF-, IL-1, and IL-6, were increased
following stimulation of macrophages with LPS alone. The coupling of
stimulation with FcR ligation specifically diminished mRNA levels
for IL-12 p35 and p40 and increased IL-10 mRNA. Importantly, the
majority of the other cytokines that were analyzed remained relatively
unaffected by FcR ligation. Thus, the ligation of FcR does not
result in an indiscriminate down-regulation of all macrophage
cytokines, but rather a specific down-regulation of IL-12 and an
induction of IL-10.
Characterization of cytokine modulation following FcR ligation
To determine the receptor specificity of the effects demonstrated
in Fig. 1, BMM were stimulated with LPS, coupled with the ligation
of either FcR (E-IgG) or complement receptor (E-C3b/i) ligation
(Fig. 3). IL-12 levels were substantially
diminished following the ligation of either of these two receptor
classes, as previously described (40). However, the
induction of IL-10 was achieved only after FcR ligation (Fig. 3).
These results reveal a fundamental difference between the two receptor
classes with regard to the regulation of IL-10 biosynthesis, and
demonstrate that the induction of IL-10 is specific to the FcR,
whereas IL-12 inhibition is shared by a number of macrophage receptors,
as previously described (40). Thus, the reciprocal
alteration in cytokine production that was observed in Figs. 1 and 2 is
specific to the macrophage FcR.
|
). Latex beads
were also added to LPS-stimulated BMM to determine whether
nonreceptor-mediated phagocytosis could induce similar cytokine
alterations. Although several latex beads were rapidly engulfed by each
macrophage, this did not affect cytokine production in response to LPS;
LPS stimulation resulted in high IL-12 and low IL-10, and these levels
were not significantly altered by bead phagocytosis (Fig. 4). Thus,
phagocytosis is neither required nor sufficient to modulate LPS-induced
macrophage cytokine production in response to FcR ligation.
|
BMM from mice genetically deficient in IL-10
(IL-10-/-) were examined to determine whether
the down-regulation of IL-12 was dependent on the enhanced production
of IL-10. The addition of E-IgG to LPS-stimulated
IL-10-/- macrophages resulted in a dramatic
down-regulation of IL-12 production (Fig. 5, main graph). The extent of
down-regulation was similar to that observed in parallel monolayers of
wild-type BMM (Fig. 5, inset). Thus, the induction of
IL-10 that accompanies macrophage FcR ligation is not required for
the ablation of IL-12 biosynthesis. However, the addition of exogenous
rIL-10 to macrophages of both genotypes potently inhibited IL-12
production (Fig. 5). Taken together, these data indicate that both
IL-10 dependent and IL-10 independent mechanisms exist to inhibit
macrophage IL-12 production.
|
R ligation is a potent inducer of IL-10
To determine the extent to which FcR ligation was able to
induce IL-10, macrophages were incubated with increasing concentrations
of LPS in the presence or absence of E-IgG. LPS is a relatively
inefficient inducer of IL-10 from macrophages, and at low doses (below
1 ng) LPS failed to elicit the production of detectable levels of
IL-10, even when the assays were performed in the presence of serum, as
these were (Fig. 6). High doses of LPS
consistently induced IL-10 production, but the levels of production
rarely exceeded 500 pg/ml in these assays, which used a total of 2
x 105 macrophages per 0.5 ml. However, the
combination of LPS and E-IgG was a potent inducer of IL-10. Even low
doses of LPS, which alone failed to produce detectable IL-10,
synergized with FcR ligation to induce high levels of IL-10. This
represents a true synergy, because E-IgG alone also failed to induce
detectable IL-10. The IL-10 levels that we routinely measure following
FcR ligation of stimulated macrophages (2–10 ng/ml) make this the
most potent inducer of macrophage IL-10 that we have observed.
|
We examined the kinetics of LPS-induced IL-12/IL-10 production
with and without FcR ligation (Fig. 7). Total cytokine accumulation over time
was determined (main graphs), as was cytokine production
during specific time intervals (insets). Following
stimulation by LPS alone (
), IL-12 p40 accumulated in a fairly
linear fashion over the entire 24-h observation period (Fig. 7, top graph). IL-10 production was close to the limit of
detection (Fig. 7, bottom graph, ). However, following
FcR ligation (
), there was a rapid and substantial accumulation
of IL-10, which increased linearly for approximately the first 8 h
and then began to plateau (Fig. 7, bottom main graph). An
analysis of IL-10 production during individual 4-h time intervals
(insets) revealed that the kinetics of IL-10 production
following FcR ligation were quite rapid, with the majority of
cytokine being produced within the first 4 h of stimulation. Thus,
FcR ligation not only induced the production of large amounts of
IL-10, but also caused this cytokine to be produced very rapidly
following stimulation.
|
Two different models were used to examine the effect of
FcR ligation on macrophage cytokine production in vivo. In the first
series of studies, IgG-opsonized LPS was used as the stimulus instead
of E-IgG + LPS. In vitro studies (Fig. 8, A and B) confirmed that IgG-LPS specifically
induced the production of IL-10 and diminished IL-12 production, at
both the protein (Fig. 8A) and the mRNA (Fig. 8B)
level. To determine the physiological significance of this in vitro
observation, in vivo studies (Fig. 8C) were undertaken, in
which mice were passively immunized with Ab to LPS, 2 and 18 h
before the i.v. administration of LPS. Serum was collected at various
intervals thereafter, and cytokine levels were assayed by ELISA. Mice
receiving Ab 2 h before i.v. injection of LPS produced
significantly lower levels of IL-12 (Fig. 8C, left
graph) and higher levels of IL-10 (Fig. 8C, right
graph) relative to mice receiving LPS alone. The IL-10 that was
produced by IgG-LPS was only detected at 2 h poststimulation,
confirming the rapidity with which this cytokine was produced in vitro.
Mice receiving Ab to LPS at 18 h before stimulation exhibited
intermediate levels of IL-12, but retained a high production of IL-10
at 2 h poststimulation (Fig. 8C). Thus, the in vivo
administration of anti-LPS IgG before LPS stimulation decreases the
production of IL-12 and induces IL-10 production.
|
R ligation
in preventing LPS toxicity used the i.p. administration of lethal doses
of LPS (300 µg/ml) to C57BL/6 mice. This dose is well in excess of
the LD90 of 50–100 µg/ml. Consequently, all
mice receiving this dose of LPS succumbed within 3 days of
administration (data not shown). To test our model, 4 h before LPS
administration, a total of 1 x 106
macrophages was transferred i.p. into mice. Before transfer,
macrophages were exposed to low doses of LPS (5 ng/ml) in the presence
or absence of E-IgG to ligate FcR. All of the mice that received
macrophages pretreated with LPS alone succumbed to endotoxic shock
within 3 days postadministration, whereas all of the mice that
received macrophages treated with E-IgG and LPS survived (Fig. 9). The mice in the latter group remained
relatively well groomed and continued to move about the cage when their
counterparts in the previous group were moribund. To demonstrate that
this effect was due to IL-10 production, similar experiments were
performed with macrophages from IL-10-/- mice.
In this group, LPS + E-IgG-treated macrophages failed to protect mice;
four of the five animals succumbed to endotoxemia within the first 3
days, and the fifth animal remained viable but moribund until it was
euthanized at day 4. Thus, FcR-induced IL-10 is able to prevent
lethality induced by endotoxin.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
In previous studies, we had begun to examine cytokine production by
stimulated macrophages following the ligation of phagocytic receptors.
We (40) and others (43, 44, 45, 46, 47, 48, 49) have demonstrated
that the ligation of a variety of macrophage receptors could result in
a decrease in IL-12 production in response to bacterial products. We
also previously showed that the specific ligation of the FcR could
cause an induction of IL-10 in response to LPS (41).
Together, these studies suggested that we could reliably and
predictably influence the cytokine profile of a macrophage simply by
ligating the correct receptor class. In the present study, we extend
and characterize these observations, and we test their therapeutic
potential.
We studied the effects of FcR ligation on cytokine production using
several types of leukocyte stimuli. All of the stimuli tested yielded
identical results; FcR ligation prevented the induction of IL-12 and
dramatically up-regulated the production of IL-10. This cytokine
modulation occurs whether the inflammatory signal was set off by the
innate pattern recognition of Gram-negative or Gram-positive bacterial
extracts (LPS or LTA through Toll-like receptor) (50), an
acquired immunity ligand on the surface of activated T cells
(CD40L-CD40) (51), or a component of the extracellular
matrix (LMW-HA through CD44) (13). Each of these stimuli
induced IL-12 synthesis, and all of them were down-regulated by FcR
ligation. The common pathway that allows all of these diverse stimuli
to synergize with FcR to induce IL-10 is less obvious, and studies
to identify this pathway are currently underway.
We have begun to define the requirements for altered macrophage
cytokine production. Studies using cells treated with cytochalasin D or
incubated with latex beads demonstrate that phagocytosis is neither
necessary nor sufficient for FcR-mediated cytokine modulation. To
address the somewhat controversial issue regarding the ability of
complement receptors to up-regulate IL-10 (41, 52), we
assayed culture supernatants from macrophages stimulated with LPS in
the presence of E-C3b/i. In this study, the down-regulation of IL-12 by
complement receptor ligation provided the necessary internal control,
and indicated that the failure of complement receptors to induce IL-10
was not due to a lack of receptor signaling. Thus, the reciprocal
alteration in cytokine production that we identify is specific to the
macrophage FcR.
Our data reveal several important practical aspects of
FcR-induced cytokine modulation. We demonstrate that there are
actually two independent mechanisms for down-regulating IL-12 following
FcR ligation. It is clear that signaling through FcR prevents
IL-12 production independently of IL-10, as studies using
IL-10-/- macrophages show that these cells fail
to produce IL-12 following FcR ligation. However, a second mechanism
that can also contribute to the decrease in IL-12 production is the
induction of IL-10 following FcR ligation. We show that exogenous
IL-10 can effectively halt IL-12 production (Fig. 5), as previously
reported (53). These two mechanisms may cooperate to
maximally inhibit the production of IL-12 at inflammatory sites. The
first mechanism exerts a direct effect on the cells whose FcR have
been cross-linked, whereas the second mechanism may also influence the
activation state of surrounding cells. It is undoubtedly this second
mechanism that accounts for the data shown in Fig. 9, in which a
relatively small number of macrophages can rescue mice from LPS
lethality.
We also examined the kinetics of cytokine production and observed a
surprising acceleration in the biosynthesis of IL-10 following FcR
ligation. Previous studies (19) have shown that
macrophages stimulated with LPS experience a lag in IL-10 production,
generally producing IL-10 only after these cells have made ample
amounts of inflammatory cytokines. These kinetics would suggest that
the primary role of macrophage-derived IL-10 is to control the
overproduction of inflammatory mediators, allowing damage to the
pathogen, while limiting damage to the host. However, the coupling of
this stimulation with FcR ligation revealed a fundamental change in
these kinetics. The majority of IL-10 production occurred during the
first 4 h of stimulation. This production is as rapid as any
cytokine that we have observed, including TNF-, the earliest
cytokine present in the endotoxic cascade. Thus, whereas LPS-stimulated
macrophages usually secrete IL-10 as part of a negative feedback cycle
subsequent to inflammatory cytokine production (i.e., TNF-)
(19, 54), FcR ligation induces early IL-10 production,
positioned for the prevention rather than the down-regulation of
inflammation.
Finally, we adapted our model to study murine endotoxemia in vivo. First, mice were passively immunized with Abs to LPS and then given an i.v. bolus of LPS 2 or 18 h later. It should be noted that these initial in vivo studies were done in RAG-/- mice, which, unlike normal mice, lack naturally occurring Abs to LPS. It is for this reason that these mice are hypersusceptible to LPS (55). Mice that were passively immunized with Ab to LPS produced dramatically less IL-12 and more IL-10 than did mice receiving LPS alone. The IL-10 was only detectable at 2 h postinjection, whereas the differences in IL-12 were evident throughout the 24-h observation period. These data may have practical implications, as a prophylactic treatment with Abs to LPS could benefit patients at risk for endotoxemia. Similar approaches have been previously attempted, using IgM Abs (56, 57), which we have shown to be unable to modulate cytokine production in our in vitro system (data not shown). We hypothesize that an IgG Ab to LPS would prove most effective in ameliorating endotoxemia due to both the accelerated clearance of LPS and the reciprocal alteration in cytokine production.
Our second animal model demonstrates the powerful immunosuppressive
effects of FcR-induced IL-10. In this study, delivery of
FcR-ligated macrophages protected C57BL/6 mice from a lethal dose of
LPS. The addition of only one million macrophages whose FcR had been
ligated was enough to overcome the inflammatory response mounted by
endogenous cells whose receptors were obviously not ligated.
Importantly, the administration of FcR-ligated macrophages from
IL-10-/- mice failed to rescue the mice. This
failure suggests that it is the production of IL-10 that is primarily
responsible for preventing endotoxic shock in this model. Thus,
although several studies have reported that the ligation of macrophage
FcRs induces inflammatory cytokine production in vitro
(3), these in vivo models of murine endotoxemia
demonstrate a dominant physiological anti-inflammatory effect of
FcR ligation. This effect is mediated primarily by the production of
IL-10, accompanied by the abrogation of IL-12 synthesis. These
observations establish the biological relevance of FcR-induced
cytokine modulation.
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. David M. Mosser, Department of Cell Biology and Molecular Genetics, 1104 Microbiology Building, College Park, MD 20742. E-mail address: dm268{at}umail.umd.edu
3 Abbreviations used in this paper: BMM, bone marrow-derived macrophage; E-C3b/i, complement-opsonized erythrocytes; E-IgG, IgG-opsonized erythrocytes; LMW-HA, low molecular mass hyaluronic acid; LTA, lipoteichoic acid.
Received for publication December 20, 2000. Accepted for publication March 23, 2001.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
receptors. Microbes Infect. 3:131.[Medline]
production and type 1 cytokine responses. Immunity 4:471.[Medline]
in host defense against mycobacteria and salmonella in mice and men. Curr. Opin. Immunol. 11:346.[Medline]
interferon. Infect. Immun. 62:4244. production and lethality in lipopolysaccharide-induced shock in mice. Eur. J. Immunol. 25:672.[Medline]
-dependent shock. Infect. Immun. 65:4734.[Abstract]
-activated macrophages. J. Immunol. 148:1792.[Abstract]
and tumor necrosis factor production during experimental endotoxemia. Eur. J. Immunol. 24:1167.[Medline]
receptor type I. J. Exp. Med. 188:217.
B down-regulation in transcriptional repression of the p40 gene. J. Clin. Invest. 101:252.[Medline]
-primed and lipopolysaccharide-challenged human monocytes. J. Immunol. 162:6763. production by suppressing natural killer cell stimulatory factor/IL-12 synthesis in accessory cells. J. Exp. Med. 178:1041. in human monocyte IL-10 synthesis. J. Immunol. 151:6853.[Abstract]
This article has been cited by other articles:
|
|
 |
|
  H. Huang, G. R. Ostroff, C. K. Lee, J. P. Wang, C. A. Specht, and S. M. Levitz Distinct Patterns of Dendritic Cell Cytokine Release Stimulated by Fungal {beta}-Glucans and Toll-Like Receptor Agonists Infect. Immun., May 1, 2009; 77(5): 1774 - 1781. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. G. Nair, Y. Du, J. G. Perrigoue, C. Zaph, J. J. Taylor, M. Goldschmidt, G. P. Swain, G. D. Yancopoulos, D. M. Valenzuela, A. Murphy, et al. Alternatively activated macrophage-derived RELM-{alpha} is a negative regulator of type 2 inflammation in the lung J. Exp. Med., April 13, 2009; 206(4): 937 - 952. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Edwards, X. Zhang, and D. M. Mosser The Expression of Heparin-Binding Epidermal Growth Factor-Like Growth Factor by Regulatory Macrophages J. Immunol., February 15, 2009; 182(4): 1929 - 1939. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. J. Maglione, J. Xu, A. Casadevall, and J. Chan Fc{gamma} Receptors Regulate Immune Activation and Susceptibility during Mycobacterium tuberculosis Infection J. Immunol., March 1, 2008; 180(5): 3329 - 3338. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-E. Ghia, F. Galeazzi, D. C. Ford, C. M. Hogaboam, B. A. Vallance, and S. Collins Role of M-CSF-dependent macrophages in colitis is driven by the nature of the inflammatory stimulus Am J Physiol Gastrointest Liver Physiol, March 1, 2008; 294(3): G770 - G777. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. N. Forthal, G. Landucci, J. Bream, L. P. Jacobson, T. B. Phan, and B. Montoya Fc{gamma}RIIa Genotype Predicts Progression of HIV Infection J. Immunol., December 1, 2007; 179(11): 7916 - 7923. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Polumuri, V. Y. Toshchakov, and S. N. Vogel Role of Phosphatidylinositol-3 Kinase in Transcriptional Regulation of TLR-Induced IL-12 and IL-10 by Fc{gamma} Receptor Ligation in Murine Macrophages J. Immunol., July 1, 2007; 179(1): 236 - 246. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P L E M van Lent, A B Blom, L Grevers, A Sloetjes, and W B van den Berg Toll-like receptor 4 induced Fc{gamma}R expression potentiates early onset of joint inflammation and cartilage destruction during immune complex arthritis: Toll-like receptor 4 largely regulates Fc{gamma}R expression by interleukin 10 Ann Rheum Dis, March 1, 2007; 66(3): 334 - 340. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Rodriguez, C. Mold, M. Kataranovski, J. A. Hutt, L. L. Marnell, J. S. Verbeek, and T. W. Du Clos C-Reactive Protein-Mediated Suppression of Nephrotoxic Nephritis: Role of Macrophages, Complement, and Fc{gamma} Receptors J. Immunol., January 1, 2007; 178(1): 530 - 538. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Edwards, X. Zhang, K. A. Frauwirth, and D. M. Mosser Biochemical and functional characterization of three activated macrophage populations J. Leukoc. Biol., December 1, 2006; 80(6): 1298 - 1307. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. D. Iankov, M. Pandey, M. Harvey, G. E. Griesmann, M. J. Federspiel, and S. J. Russell Immunoglobulin g antibody-mediated enhancement of measles virus infection can bypass the protective antiviral immune response. J. Virol., September 1, 2006; 80(17): 8530 - 8540. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K.-J. Huang, Y.-C. Yang, Y.-S. Lin, J.-H. Huang, H.-S. Liu, T.-M. Yeh, S.-H. Chen, C.-C. Liu, and H.-Y. Lei The dual-specific binding of dengue virus and target cells for the antibody-dependent enhancement of dengue virus infection. J. Immunol., March 1, 2006; 176(5): 2825 - 2832. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. A. W. Verreck, T. de Boer, D. M. L. Langenberg, L. van der Zanden, and T. H. M. Ottenhoff Phenotypic and functional profiling of human proinflammatory type-1 and anti-inflammatory type-2 macrophages in response to microbial antigens and IFN-{gamma}- and CD40L-mediated costimulation J. Leukoc. Biol., February 1, 2006; 79(2): 285 - 293. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
V. Fronhofer, M. R. Lennartz, and D. J. Loegering Role of PKC isoforms in the Fc{gamma}R-mediated inhibition of LPS-stimulated IL-12 secretion by macrophages J. Leukoc. Biol., February 1, 2006; 79(2): 408 - 415. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Hamerman and L. L. Lanier Inhibition of Immune Responses by ITAM-Bearing Receptors Sci. Signal., January 31, 2006; 2006(320): re1 - re1. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. B. Mann, D. Wolfe, E. Latz, D. Golenbock, A. Preston, and E. T. Harvill Comparative Toll-Like Receptor 4-Mediated Innate Host Defense to Bordetella Infection Infect. Immun., December 1, 2005; 73(12): 8144 - 8152. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Lucas, X. Zhang, V. Prasanna, and D. M. Mosser ERK Activation Following Macrophage Fc{gamma}R Ligation Leads to Chromatin Modifications at the IL-10 Locus J. Immunol., July 1, 2005; 175(1): 469 - 477. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. J. Scotton, F. O. Martinez, M. J. Smelt, M. Sironi, M. Locati, A. Mantovani, and S. Sozzani Transcriptional Profiling Reveals Complex Regulation of the Monocyte IL-1{beta} System by IL-13 J. Immunol., January 15, 2005; 174(2): 834 - 845. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Casadevall and L.-a. Pirofski New Concepts in Antibody-Mediated Immunity Infect. Immun., November 1, 2004; 72(11): 6191 - 6196. [Full Text] [PDF]
|
|
|
|
|
|
P. B. Mann, K. D. Elder, M. J. Kennett, and E. T. Harvill Toll-Like Receptor 4-Dependent Early Elicited Tumor Necrosis Factor Alpha Expression Is Critical for Innate Host Defense against Bordetella bronchiseptica Infect. Immun., November 1, 2004; 72(11): 6650 - 6658. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Xiong, H. Li, Y. Chen, J. Zhao, and J. C. Unkeless Interaction of TRAF6 with MAST205 Regulates NF-{kappa}B Activation and MAST205 Stability J. Biol. Chem., October 15, 2004; 279(42): 43675 - 43683. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Whitsett, C. J. Bachurski, K. C. Barnes, P. A. Bunn Jr., L. M. Case, D. N. Cook, D. Crooks, M. W. Duncan, L. Dwyer-Nield, R. C. Elston, et al. Functional Genomics of Lung Disease Am. J. Respir. Cell Mol. Biol., August 1, 2004; 31(2/S1): S1 - S81. [Full Text] [PDF]
|
|
|
|
|
|
T. H. Sulahian, P. A. Pioli, K. Wardwell, and P. M. Guyre Cross-linking of Fc{gamma}R triggers shedding of the hemoglobin-haptoglobin scavenger receptor CD163 J. Leukoc. Biol., July 1, 2004; 76(1): 271 - 277. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. C. Morrison, C. B. Wilson, M. Ray, and P. H. Correll Macrophage-Stimulating Protein, the Ligand for the Stem Cell-Derived Tyrosine Kinase/RON Receptor Tyrosine Kinase, Inhibits IL-12 Production by Primary Peritoneal Macrophages Stimulated with IFN-{gamma} and Lipopolysaccharide J. Immunol., February 1, 2004; 172(3): 1825 - 1832. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Esnault and J. S. Malter Hyaluronic Acid or TNF-{alpha} Plus Fibronectin Triggers Granulocyte Macrophage-Colony-Stimulating Factor mRNA Stabilization in Eosinophils Yet Engages Differential Intracellular Pathways and mRNA Binding Proteins J. Immunol., December 15, 2003; 171(12): 6780 - 6787. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Colmenares, P. E. Kima, E. Samoff, L. Soong, and D. McMahon-Pratt Perforin and Gamma Interferon Are Critical CD8+ T-Cell-Mediated Responses in Vaccine-Induced Immunity against Leishmania amazonensis Infection Infect. Immun., June 1, 2003; 71(6): 3172 - 3182. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. N. Gantner, R. M. Simmons, S. J. Canavera, S. Akira, and D. M. Underhill Collaborative Induction of Inflammatory Responses by Dectin-1 and Toll-like Receptor 2 J. Exp. Med., May 5, 2003; 197(9): 1107 - 1117. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. M. Mosser The many faces of macrophage activation J. Leukoc. Biol., February 1, 2003; 73(2): 209 - 212. [Full Text] [PDF]
|
|
|
|
|
|
C. Mold, W. Rodriguez, B. Rodic-Polic, and T. W. Du Clos C-Reactive Protein Mediates Protection from Lipopolysaccharide Through Interactions With Fc{gamma}R J. Immunol., December 15, 2002; 169(12): 7019 - 7025. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. F. Anderson, J. S. Gerber, and D. M. Mosser Modulating macrophage function with IgG immune complexes Innate Immunity, December 1, 2002; 8(6): 477 - 481. [Abstract] [PDF]
|
|
|
|
|
|
G. S. Deepe, Jr., and R. S. Gibbons Cellular and Molecular Regulation of Vaccination with Heat Shock Protein 60 from Histoplasma capsulatum Infect. Immun., July 1, 2002; 70(7): 3759 - 3767. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. F. Anderson and D. M. Mosser A novel phenotype for an activated macrophage: the type 2 activated macrophage J. Leukoc. Biol., July 1, 2002; 72(1): 101 - 106. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. K. Varma, C. Y. Lin, T. E. Toliver-Kinsky, and E. R. Sherwood Endotoxin-Induced Gamma Interferon Production: Contributing Cell Types and Key Regulatory Factors Clin. Vaccine Immunol., May 1, 2002; 9(3): 530 - 543. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. F. Anderson and D. M. Mosser Cutting Edge: Biasing Immune Responses by Directing Antigen to Macrophage Fc{gamma} Receptors J. Immunol., April 15, 2002; 168(8): 3697 - 3701. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
