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-Dependent, IFN-
Secretion by Bone Marrow-Derived Macrophages Controls an Intracellular Bacterial Infection
,
,
*
Microbiology and Tumorbiology Center,
Department of Microbiology, Pathology, and Immunology, Division of Biomedical Laboratory Technology, and Departments of
Rheumatology, Center of Molecular Medicine, and
Rheumatology, Astrid Lindgren’s Hospital, Karolinska Institutet, Stockholm, Sweden
 |
Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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. However, the biological relevance of
this finding is uncertain. We show in this study that bone
marrow-derived macrophages (BMMs) express IFN- at the mRNA and
protein level early after infection with Chlamydia
pneumoniae. Increased IFN- mRNA accumulation by
infected BMMs is early, transient, and requires both bacterial and host
protein synthesis. The induction of IFN- mRNA levels is independent
of IL-12 and was dramatically enhanced in IL-10-/- BMMs.
Such IL-10-/- BMMs contained less bacteria than the
wild-type controls, whereas IFN-R-/- BMMs showed
increased C. pneumoniae load. Inducible NO synthase
(iNOS) also participates in the control of bacterial load, as shown by
the enhanced numbers of C. pneumoniae in
iNOS-/- BMMs. However, the increased accumulation of iNOS
mRNA and NO in C. pneumoniae-infected BMMs depended on
the presence of IFN-
, but was independent of IFN-.
Interestingly, IFN- are also required for increased IFN- mRNA
accumulation in C. pneumoniae-infected BMMs.
Accordingly, IFN-R-/- BMMs showed higher levels of
C. pneumoniae than wild-type BMMs. Our findings unravel
an autocrine/paracrine macrophage activation pathway by showing an
IFN--dependent IFN- and iNOS induction in response to
infection, which protects macrophages against intracellular bacterial
growth. |
Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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regulates a variety of immunological programs. It is the predominant
cytokine during Th1-dominated immune reactions, and is the prototype
macrophage-activating cytokine. Macrophages infected by different
microorganisms secrete IL-12, which directs Th1 development and induces
IFN- production by NK and T cells (1). IFN- does act
on macrophages to augment IL-12 secretion (2) and to
produce NO that eradicates intracellular microbes (3). NO
release after IFN- stimulation is the result of increased de novo
synthesis of the inducible form of NO synthase
(iNOS).2 Studies using
neutralizing Abs against IFN- and mice genomically deficient of
IFN-, IFN-R, or IL-12 confirm the importance of these cytokines
in innate immunity and Th1 development, and consequently, for
controlling intracellular pathogens (4).
A few studies show that IFN- can be produced by macrophages in
response to stimulation with live bacteria (5), bacterial
components (5, 6), IL-12 (7, 8), a
combination of IL-12 and IL-18 (9, 10, 11), or IFN- itself
(12), suggesting presence of an autocrine loop. However,
the biological relevance of these findings, at variance with the
general assumption that NK and T cells are the sole IFN- producers,
is still unclear.
In the study presented in this work, we extend previous data by showing
that bone marrow-derived macrophage (BMM) cultures produce IFN- at
the mRNA and protein level, after infection with Chlamydia
pneumoniae, an obligate intracellular Gram-negative
bacterium. IFN- has been previously shown to play a protective role
during the in vitro and in vivo infection with Chlamydia
sp. (13, 14, 15, 16, 17). C. pneumoniae infects
and grows in macrophages, but bacterial load is controlled after
several days of infection (18, 19). We show in this study
that IFN- is transiently expressed early after in vitro infection of
BMMs with live bacteria, and is involved in control of intracellular
bacterial growth. Surprisingly, the expression of IFN- did not
depend on the presence of IL-12, but relied on IFN-R signaling.
IFN- have been shown to mediate defense mechanisms in an
important number of viral infections and possess numerous
immunoregulatory properties (reviewed in Ref. 20). In
addition, IFN- can in an IFN--independent manner induce iNOS
expression, adding to the control of intracellular bacterial growth.
Thus, we suggest a novel autocrine/paracrine loop by which BMMs are
induced by infection to produce IFN-, which in turn stimulates
IFN- secretion. In turn, this IFN- mediates the control of the
infecting bacteria.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Mutant mouse strains without IFN-R (21),
recombination-activating gene-1 (RAG-1), IL-10 (22),
IL-12p40 (23), IFN-R (24), iNOS
(25), and TNFR-I (26), generated by
homologous recombination in embryonic stem cells, were bred and kept
under specific pathogen-free conditions.
RAG-1-/-, IL-10-/-,
iNOS-/-, and
IFN-R-/- mice had been backcrossed with
C57BL/6 mice, which were used as controls. The 129Sv/Ev mice were used
as controls for experiments using IFNR- and TNFR-I-deficient
mice. All animal experiments have been approved by the Stockholm’s
Region Animal Research Ethical Board.
Cells
BMMs were obtained as previously described (27). Briefly, mice were euthanized, and the femur and tibia of the hind legs were dissected. Bone marrow cavities were flushed with 5 ml cold, sterile PBS. The bone marrow cells were washed and resuspended in DMEM containing glucose and supplemented with 10% FCS, 20% L929 cell-conditioned medium (as a source of M-CSF), 100 µg/ml streptomycin, and 100 U/ml penicillin. Bone marrow cells (1.2 x 107 cells; 2 x 106 cells/ml) were plated in six-well plates and incubated for 7 days at 37°C, 5% CO2. Before use, BMM cultures were washed vigorously to remove nonadherent cells. Cells from several wells were also harvested and counted by trypan blue exclusion. Typically, bone marrow cells from one mouse yield 2–3 x 106 BMMs after 7 days in culture.
Immunostainings
BMMs were phenotypically characterized by FACS analysis. BMMs
were detached from plates using a cell scraper, and incubated with PBS
containing 10% normal goat serum (Sigma, St. Louis, MO) to block
unspecific binding of the secondary Ab. Cells were then incubated with
purified rat mAbs to F4/80, CD45, Mac-3, and CD80 for 30 min on ice.
Cells were then washed and incubated with 1/200 biotinylated goat
anti-rat serum for 30 min on ice. Anti-CD19, anti-CD11c,
anti-CD8, and anti-CD40 Abs were directly labeled with FITC.
Anti-CD3 and anti-CD4 Abs were directly labeled with PE. Anti-MHC
class I, anti-MHC class II, and anti-ICAM-1 (MALA-2) Abs were
biotinylated. Isotype-matched control rat Igs directly labeled with
FITC, PE, or biotin were used as controls. When staining with
biotinylated or directly labeled Abs, BMMs were preincubated with
anti-CD16/CD32 to block FcR. After incubation with biotinylated
Abs, cells were washed and stained with 1/1500 Neutroavidin Alexa
(Molecular Probes, Eugene, OR) before FACS analysis. All primary Abs
were purchased from PharMingen (San Diego, CA), except for F4/80
(Serotec, Oxford, U.K.).
When microscopic analysis was performed, BMMs grown on 13-mm2 coverslides were washed, fixed with 2% formaldehyde, and stained for the different cell surface markers, as indicated above. Thereafter, coverslides were washed, counterstained with 4',6'-diamidino-2-phenylindole (5 µg/ml), mounted, and analyzed in a fluorescent microscope
Bacteria and infectivity assay
Mycoplasma-free C. pneumoniae isolate Kajaani (28) was propagated in HL cells. Infected cells were sonicated, cell remnants were removed by centrifugation (6 min at 100 x g), and the bacteria were stored in small aliquots in sucrose-phosphate-glutamate (SPG) solution at -70°C until used. The infectivity as measured by inclusion-forming units (IFU) of bacterial preparation was determined in HL cells. BMM cultures were inoculated with 106 C. pneumoniae (bacteria to cell ratio 1:3) and centrifuged for 1 h at 500 x g. At different time points after infection, cells were washed with PBS, and thereafter lysates using SPG solution were obtained. Lysates were then diluted 10- and 100-fold in DMEM containing 5% FCS and 100 µg/ml streptomycin (DMEM 5% FCS). Infectious titers were assessed culturing 500 µl duplicate dilutions of lysates on confluent HL cells grown on round 13-mm2 coverslides in a shell vial. Inoculated cells were centrifuged for 1 h at 500 x g. Thereafter, supernatants were removed, DMEM 5% FCS containing 0.5 µg/ml cycloheximide was added, and cells were incubated at 35°C for 72 h, 5% CO2. Cells were then washed with PBS, fixed with methanol, and stained with a FITC-conjugated Chlamydia genus-specific mAb (Pathfinder Chlamydia Confirmation System; Kallestad Diagnostics, Chaska, MN). Inclusion bodies were counted by fluorescence microscopy. The existence of a linear regression between number of IFU recovered 3 days after infection and the number of infecting C. pneumoniae was proven in control experiments (data not shown).
Competitive RT-PCR assay
The accumulation of IFN-, IFN-, IL-12p40, iNOS, the gp91
component of the phagocyte NADPH oxidase complex (gp91-phox), TNF-,
IL-6, IL-1, and -actin mRNA in freshly extracted RNA from
C. pneumoniae-infected BMMs was visualized by RT-PCR and
measured by competitive PCR assays, as previously described
(29). Competitor fragments with a different length, but
using the same primers as the target DNA were constructed using
composite primers and an exogenous DNA fragment or by subcloning of
cytokine cDNA sequences mutated by deletion or ligation
(30). Competitors were purified (Qiagen, Studio City, CA)
and quantified in a spectrophotometer.
Three- or four-fold serial dilutions of the competitor were amplified in the presence of a constant amount of cDNA. Reactions were conducted for 28–45 cycles in a thermal cycler (PerkinElmer/Cetus, Norwalk, CT) using an annealing step at 60°C (except 65°C for IL-12, 56°C for gp91-phox, and 58°C for IL-10).
The primer sequences for the amplification of the cDNA in competitive
or noncompetitive RT-PCR are shown in Table I
.
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The amount of IFN- in the culture supernatants of C.
pneumoniae-infected BMMs was measured by ELISA, according to the
instructions of the manufacturer (R&D Systems, Abingdon,
U.K.).
C. pneumoniae DNA extraction and PCR amplification
DNA was extracted from 150 µl SPG BMM lysates, 5 days after infection with C. pneumoniae. Lysates were centrifuged for 10,000 x g, 35 min, at 4°C, and 0.5 ml lysis buffer (10 mM Tris-HCl, pH 7.6, 1 mM EDTA, pH 7.6, 1% SDS) containing 200 µg/ml proteinase K (Life Technologies, Paisley, U.K.) was added to the pellet. The samples were then incubated for 3 h at 50°C. Thereafter, DNA was extracted by use of Tris-saturated phenol, chloroform, and isoamyl alcohol (25:24:1; Sigma). DNA was then precipitated, washed, and quantified spectrophotometrically. The amplification of 16S RNA gene from C. pneumoniae was performed by PCR, as previously described (31).
The primer sequences for the amplification of the C. pneumoniae DNA were: sense-16S RNA, 5'-TGA CAA CTG TAG AAA TAC AGC-3'; antisense-16S RNA, 5'-CGC CTC TCT CCT ATA AAT-3'.
A PCR product of 465 bp was electrophoresed and visualized in a 1.5% ethidium bromide-stained agarose gel.
Detection of intracellular IFN- protein by immunostaining
BMMs were fixed at different time points after infection with
C. pneumoniae with 2% (v/v) formaldehyde in PBS at pH 7.4
for 10 min and subsequently stored at -70°C until required for
staining. Detection of intracellular IFN- production was made using
indirect staining (32, 33). Briefly, permeabilization of
cell membranes was performed using BSS (Earle’s BSS; Life
Technologies) supplemented with 0.1% saponin in all subsequent washes
and incubation steps. The slides were then blocked with BSS containing
2% FCS for 5 min at 37°C. Endogenous cellular biotin was blocked
with avidin for 30 min and biotin for an additional 15 min
(avidin/biotin blocking kit; Vector, Burlingame, CA), both supplemented
with 0.1% saponin. Subsequently, the cells were incubated overnight
with 5 µg/ml mouse IFN--specific rat mAb (clone XMG1.2, kindly
provided by J. Abrams, DNAX Research Institute, Palo Alto, CA). Slides
were then washed and incubated for 30 min with a biotinylated
second-step Ab (goat anti-rat; Vector) diluted 1/500. Finally, a
developing step with 2 µg/ml Oregon Green coupled to avidin D
(Molecular Probes) was applied for 30 min. The slides were air dried
and mounted with PBS-buffered glycerol and examined in a Polyvar UV
microscope (Reichert-Jung, Vienna, Austria).
Specificity controls were based on parallel staining studies omitting the primary Ab or using primary isotype-matched Ig of irrelevant Ag specificity at the same concentration as the cytokine-detecting Abs.
Nitrite assay
Nitrite concentrations were measured in BMM culture supernatants using the Greiss reagent in a previously described colorimetric assay (34). Fifty-microliter aliquots of culture medium were mixed in 96-well plates with an equal volume of 0.5% sulfanilamide dihydrochloride and 0.05% naphthylethylenediamide dihydrochloride in 2.5% phosphoric acid. OD540 was determined using a Dynatech MR700 plate reader (Chantilly, VA). Sodium nitrite, dissolved in DMEM, was used to generate a standard concentration curve. The lower limit of detection of the assay was 1 µM.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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protein and increases IFN- mRNA levelsWe first phenotypically characterized uninfected BMMs by immunostaining, followed by FACS and/or microscopic analysis. BMMs were found to be homogeneously positive for macrophage markers as F4/80, Mac-3, and CD14. BMMs were also positive for CD45, and expressed low MHC class II, MHC class I, B7, and ICAM-1 levels. The T cell Ags CD3, CD4, and CD8, and the pan B cell Ag CD19 were uniformly negative (data not shown). BMMs were also negative for CD11c and CD40.
In a second series of experiments, BMMs were infected with C.
pneumoniae, and the presence of IFN- mRNA was measured at
several time points after infection. Infection of BMMs with C.
pneumoniae resulted in increased IFN- mRNA accumulation.
Increased levels of IFN- transcripts could be detected at 30 min and
waned 24 h after infection (Fig. 1, A and B). IFN- protein was also detected in
supernatants from infected BMMs. IFN- was detected at 6 h,
peaked at 24 h, and was low or undetectable (<4 pg/ml) at later
time points after infection (Fig. 1C). Moreover, BMMs after
18 h of infection with C. pneumoniae, but not BMMs
6 h and 26 h after infection or uninfected controls, were
stained intracellularly with anti-IFN- Abs (Fig. 1D).
Infected RAG-1-/- BMMs depleted or not of NK
cells by anti-asialo-GM1 and complement
treatment showed similar levels of IFN- mRNA as wild-type (WT)
controls, indicating that neither T, nor B, nor NK cells are necessary
for chlamydial-induced IFN- mRNA expression (Fig. 1F).
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mRNA required infectious bacteria and
host cell protein synthesis. UV or heat inactivation of C.
pneumoniae dramatically diminished the steady state level of
IFN- mRNA in infected BMMs. The same was observed when
coculture of C. pneumoniae and BMMs was done in presence of
chloramphenicol, which inhibits bacterial protein synthesis (Fig. 2).
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mRNA accumulation by
BMMs is IL-12 independent and is controlled by IL-10
To determine whether host cell proteins are involved in the
increased IFN- mRNA in BMMs, cycloheximide, an eukaryotic protein
synthesis inhibitor, was applied. Addition of cycloheximide during
coculture of bacteria and BMMs reduced IFN- mRNA levels (Fig. 2
).
IL-12 has been shown to increase IFN- gene expression by NK and T
cells (2). However, we found that C.
pneumoniae-infected IL-12-/- BMMs showed
similar levels of IFN- mRNA as WT controls (Fig. 3). Hence, IL-12 does not appear to
mediate C. pneumoniae-induced IFN- mRNA expression
in BMMs.
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in infected BMMs was an unforeseen
characteristic. IL-10 has been shown to inhibit IFN- mRNA expression
(35). IL-10 mRNA levels were increased in WT BMMs after
infection with C. pneumoniae (Fig. 4A). Moreover, IFN- mRNA
levels were substantially increased in infected
IL-10-/- BMMs as compared with WT BMMs (Fig. 4B). Presence of IL-10 also explains the low IL-12p40 mRNA
levels measured after chlamydial infection, because IL-12p40 mRNA
titers were significantly increased in C.
pneumoniae-infected IL-10-/- BMMs (Fig. 4C).
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secreted by infected BMMs diminishes the
intracellular bacterial growth
We then investigated whether IFN- secretion by infected BMMs
could alter the course of the infection. For this purpose, we compared
the susceptibility of IFN-R-/-,
IL-10-/-, and WT BMMs to infection with
C. pneumoniae. IFN-R-/- BMMs
showed higher numbers of bacteria (Fig. 5A) and bacterial DNA levels
(Fig. 5B) than WT controls. On the contrary,
IL-10-/- BMMs showed diminished numbers of
C. pneumoniae than WT BMMs (Fig. 5A).
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and iNOS expression by C.
pneumoniae-infected BMMs are dependent on IFN-
We next analyzed whether infection of BMMs with C.
pneumoniae also affected the levels of IFN-, IL-1, IL-6,
TNF-, iNOS, and IFN--inducible gp91-phox transcripts. Increased
levels of IFN-, IL-1, IL-6, TNF-, and iNOS, but not of
gp91-phox mRNA, were observed in BMMs after infection with C.
pneumoniae (Fig. 6).
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have been shown to increase as well as decrease IFN- gene
expression in different viral infections. Because IFN- mRNA levels
were increased in infected BMMs, the expression of IFN- mRNA and
protein was studied in IFN-R-/- BMMs.
IFN- mRNA and protein levels were not raised in
IFN-R-/- BMMs after infection with
C. pneumoniae, indicating that IFN- expression in
infected BMMs is controlled by IFN- (Fig. 7, A and B).
TNF- has been shown to act as a cofactor together with IL-12 in
inducing IFN- production (36, 37). However, signaling
through the main receptor for TNF (TNFR-I) was not necessary for
IFN- expression, because infected TNFR-I-/-
BMMs showed unaltered IFN- mRNA accumulation as compared with
infected WT controls (Fig. 7A).
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-mediated
control of C. pneumoniae infection in BMMs was iNOS
dependent. IFN- was not necessary for increased iNOS mRNA and
nitrite accumulation, because iNOS transcripts were not diminished in
infected IFN-R-/- BMMs (Fig. 8, A and B). Also,
expression of IL-12 was not necessary for induction of iNOS mRNA and NO
release (Fig. 8, A and B). On the contrary, iNOS
mRNA and nitrite levels were dramatically diminished in infected
IFN-R-/- BMM as compared with infected
controls (Fig. 8, C–E).
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mediate control of infection with C.
pneumoniae in BMMs
Our results thus suggest an important role of IFN--mediated
mechanisms in the macrophage control of chlamydial infection. To test
this hypothesis, IFN-R-/- BMMs were
infected and the bacterial load compared with that of WT controls.
IFN-R-/- BMMs showed higher numbers of
intracellular C. pneumoniae (Fig. 9B).
iNOS-/- BMMs also showed diminished control of
infection (Fig. 9A).
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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secretion by cells other than T or NK cells (6, 38, 39, 40).
We now report that in vitro infection of BMMs with C.
pneumoniae induces both the release of low levels of IFN-
protein and an early and transient increase in IFN- mRNA levels.
BMM-derived IFN- probably functions in a paracrine/autocrine manner,
because 1) IFN- expression was not altered in BMM cultures lacking T
or NK cells and 2) IFN- expression had a profound effect on
chlamydial control by BMMs. Confirming our data, expression of IFN-
by macrophages from RAG-2-/- mice has been
recently observed (11).
Acellular chlamydial components including whole chlamydial lysates,
LPS, or heat shock proteins have all been shown to stimulate production
of different cytokines and chemokines by mouse or human cells
(41, 42, 43, 44). However, in our experimental model, infection
with live bacteria and bacterial protein synthesis were required for
the increased IFN- mRNA accumulation in BMMs 6 h after
infection. However, IFN- could be induced after stimulation with
different conentrations of inactivated bacteria or at later time points
after coincubation.
The observed secretion of BMM-derived IFN- depended on host protein
synthesis. IL-12, a cytokine produced by macrophages and dendritic
cells in response to protozoan and bacterial infections, can induce
IFN- gene expression (45, 46, 47, 48). Exogenous IL-12 has been
shown to induce expression of IFN- in macrophages (7, 8, 9, 10, 11, 49). Surprisingly, IL-12 neither played a role in the
chlamydial-induced enhancement of IFN- mRNA levels in BMMs, nor in
the control of bacterial load (data not shown). The low IL-12p40 mRNA
and IL-12p70 protein levels (<40 pg/ml) secreted by C.
pneumoniae-infected BMMs might not be adequate to induce the
release of IFN-.
A striking feature of chlamydial-induced IFN- mRNA accumulation in
BMMs was the early and transient expression. IL-10, a cytokine released
by many cell types, including monocytes in response to activation with
bacterial components, can inhibit IFN- synthesis by T cells
(50). Macrophages are also primary targets of IL-10 with
prominent effects on morphology, phenotype, and cytokine secretion
(35). Our data indicate that endogenous IL-10 diminishes
IFN- mRNA levels in Chlamydia-infected BMMs. IL-10 has
been previously shown to reduce IFN- expression in macrophages
(8, 64). As IL-10 was also found to inhibit accumulation
of IL-12p40 mRNA, IL-12 might account for the prolonged accumulation of
IFN- mRNA in infected IL-10-/- BMMs. In
contrast, infected IL-10-/- BMMS showed no changes in
IFN- or iNDS mRNA and nitrite levels compared to WT controls (data
not shown).
IFN- cytokines play essential roles in many antiviral immune
responses. The role of IFN- in the defense against nonviral
agents is considerably less studied, but functional relationships have
been issued (51). Produced by macrophages and other cells,
IFN- enhance NK cell cytotoxicity (52, 53), regulate
lymphocyte proliferation (54), stimulate or inhibit
macrophage activation (55), and regulate differentiation
of Th cells into Th1 cells. In the latter case, IFN- may inhibit
or enhance IFN- gene expression in murine and human T cells
(56, 57, 58, 59, 60), a dichotomy probably regulated by STAT-1
activity (61). In accordance with previous studies on
Chlamydia trachomatis-infected fibroblasts
(62), we show that IFN- mRNAs are induced after
C. pneumoniae infection of BMMs. Our data also suggest that
endogenous IFN- participate in the control of intracellular
chlamydial infection by allowing IFN- release.
NO produced after cell activation by IFN- is important for killing
or inhibiting growth of different microorganisms (3). iNOS
mRNA and nitrite levels were increased in C.
pneumoniae-infected BMMs, but BMM-derived IFN- was not
necessary for iNOS induction. Interestingly, iNOS mRNA induction and NO
release depended on IFN-R signaling. We also showed that iNOS was
necessary for effective chlamydial clearance by BMMs. This is in
agreement with previous studies in which NO release was stimulated by
coculture of IFN- with Leishmania major-infected
macrophages (55, 62). Infection of fibroblasts with
C. trachomatis (57) or stimulation of
macrophages with LPS (63) do also induce NO synthesis via
an IFN--mediated pathway. Thus, IFN- signaling in infected
BMMs appears to independently induce bothIFN- and iNOS, also
suggesting that a bidirectional IFN- and IFN- induction
(65) does not occur in this experimental model. Both iNOS
and IFN- are necessary for the control of intracellular chlamydial
growth. At this stage, it remains to unravel details of
IFN--mediated mechanisms of chlamydial control in infected BMMs. In
contrast to our results, endogenous IFN- inhibited IFN-
release by macrophages when IL-12 was used as a stimulus
(10).
In summary, we propose that C. pneumoniae infection can
stimulate an IFN--mediated pathway of autocrine/paracrine macrophage
activation. IFN- expression is independent of IL-12 and TNFR-I, but
depends on IFN-R signaling (Fig. 10). IFN- are also involved in
chlamydial control via inducing increased accumulation of iNOS
transcripts. A biological role for macrophage release of IFN- in the
control of infection with Toxoplasma gondii has recently
been shown (8). IFN- release in such model was the
result of exogenous addition of IL-12 and IL-18, and thereby strikingly
different from the model proposed in this study. In a microbial
infection, a pathway of macrophage activation via autocrine IFN-
release would be alternative or complementary to paracrine NK
cell-secreted IFN-, and thus important for an early stage of innate
immune response.
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Acknowledgments |
|---|
R-/- mice were provided by Dr. M. Aguet
(Swiss Institute of Experimental Cancer Research, Lausanne,
Switzerland). |
Footnotes |
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2 Abbreviations used in this paper: iNOS, inducible NO synthase; BMM, bone marrow-derived macrophage; IFU, inclusion-forming unit; RAG, recombination-activating gene; SPG, sucrose-phosphate-glutamate; WT, wild type.
Received for publication June 1, 2001. Accepted for publication September 20, 2001.
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References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
in monocytic cells. J. Exp. Med. 183:147.. Annu. Rev. Immunol. 15:749.[Medline]
interferon production in human alveolar macrophages by Mycobacterium tuberculosis. Infect. Immun. 65:5149.[Abstract]
in macrophages by lipopolysaccharide. Int. Immunol. 5:1383. expression and secretion in mouse peritoneal macrophages. J. Immunol. 159:3490.[Abstract]
upon combined stimulation with interleukin (IL)-12 and IL-18: a novel pathway of autocrine macrophage activation. J. Exp. Med. 187:2103. and IL-18 exert opposite regulatory effects on the IL-12 receptor expression and IL-12-induced IFN- production in mouse macrophages: novel pathways in the regulation of the inflammatory response of macrophages. J. Leukocyte Biol. 68:707. by IL-12/IL-18-activated macrophages requires STAT4 signalling and is inhibited by IL-4. J. Immunol. 166:3075. up-regulates its own gene expression in mouse peritoneal macrophages. J. Exp. Med. 179:1731. interferon-mediated chlamydial persistence. Infect. Immun. 62:3705.-dependent and -independent pathways. J. Immunol. 158:3344.[Abstract]
: role of tryptophan catabolism. J. Infect. Dis. 177:1326.[Medline]
interferon receptor-deficient mice despite a strong local immunoglobulin A response. Infect. Immun. 65:1032.[Abstract]
receptor. Science 259:1742. production and type 1 cytokine responses. Immunity 4:471.[Medline]
are costimulators of interferon production by natural killer cells in severe combined immunodeficiency mice with listeriosis, and interleukin 10 is a physiologic antagonist. Proc. Natl. Acad. Sci. USA 90:3725. production and lethality in lipopolysaccharide-induced shock in mice. Eur. J. Immunol. 25:672.[Medline]
production by CD8+ lymphoid dendritic cells. J. Exp. Med. 189:1981. production from activated B cells. Proc. Natl. Acad. Sci. USA 94:3948. following IL-12 treatment but not in response to IgE-mediated activation. J. Immunol. 157:2123.[Abstract]
and matrix metalloproteinase expression. Circulation 98:300. in the innate resistance to infection with Chlamydia pneumoniae. J. Immunol. 164:4812. interferon in murine Chlamydia pneumoniae infection. Infect. Immun. 68:2245. and IL-18 synergistically enhance IFN- gene expression in human T cells. J. Immunol. 160:6032. inhibition of interleukin 12 and interferon- production in vitro and endogenously during viral infection. Proc. Natl. Acad. Sci. USA 94:634., and TNF effects on antiviral state and NK cell responses during murine cytomegalovirus infection. J. Immunol. 156:4746.[Abstract]
by NK cells. Immunol. Lett. 59:1.[Medline]
/- and interleukin 12-mediated pathways in promoting T cell interferon responses during viral infection. J. Exp. Med. 189:1315./-mediated inhibition and promotion of interferon : STAT1 resolves a paradox. Nat. Immun. 1:70.
/ interferon and dependent nitric oxide synthesis during Chlamydia trachomatis infection of McCoy cells in the absence of exogenous cytokine. Infect. Immun. 64:3951.[Abstract]
mediates the lipopolysaccharide-induced activation of transcription factor Stat1 in mouse macrophages: pivotal role of Stat1 in induction of the inducible nitric oxide synthase gene. J. Immunol. 161:4803. interferon, and interleukin-10 mRNA production in murine macrophages. Infect. Immun. 65:3239.[Abstract]
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A. G. Rothfuchs, J. G. Egen, C. G. Feng, L. R. V. Antonelli, A. Bafica, N. Winter, R. M. Locksley, and A. Sher In Situ IL-12/23p40 Production during Mycobacterial Infection Is Sustained by CD11bhigh Dendritic Cells Localized in Tissue Sites Distinct from Those Harboring Bacilli J. Immunol., June 1, 2009; 182(11): 6915 - 6925. [Abstract] [Full Text] [PDF]
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 N. Rodriguez, R. Lang, N. Wantia, C. Cirl, T. Ertl, S. Durr, H. Wagner, and T. Miethke Induction of iNOS by Chlamydophila pneumoniae requires MyD88-dependent activation of JNK J. Leukoc. Biol., December 1, 2008; 84(6): 1585 - 1593. [Abstract] [Full Text] [PDF]
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U. M. Nagarajan, D. Prantner, J. D. Sikes, C. W. Andrews Jr., A. M. Goodwin, S. Nagarajan, and T. Darville Type I Interferon Signaling Exacerbates Chlamydia muridarum Genital Infection in a Murine Model Infect. Immun., October 1, 2008; 76(10): 4642 - 4648. [Abstract] [Full Text] [PDF]
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D. Takeuchi, V. C. Jones, M. Kobayashi, and F. Suzuki Cooperative Role of Macrophages and Neutrophils in Host Antiprotozoan Resistance in Mice Acutely Infected with Cryptosporidium parvum Infect. Immun., August 1, 2008; 76(8): 3657 - 3663. [Abstract] [Full Text] [PDF]
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H. Qiu, Y. Fan, A. G. Joyee, S. Wang, X. Han, H. Bai, L. Jiao, N. Van Rooijen, and X. Yang Type I IFNs Enhance Susceptibility to Chlamydia muridarum Lung Infection by Enhancing Apoptosis of Local Macrophages J. Immunol., August 1, 2008; 181(3): 2092 - 2102. [Abstract] [Full Text] [PDF]
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M. Kobayashi, T. Yoshida, D. Takeuchi, V. C. Jones, K. Shigematsu, D. N. Herndon, and F. Suzuki Gr-1+CD11b+ cells as an accelerator of sepsis stemming from Pseudomonas aeruginosa wound infection in thermally injured mice J. Leukoc. Biol., June 1, 2008; 83(6): 1354 - 1362. [Abstract] [Full Text] [PDF]
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T. Yang, P. Stark, K. Janik, H. Wigzell, and M. E. Rottenberg SOCS-1 Protects against Chlamydia pneumoniae-Induced Lethal Inflammation but Hampers Effective Bacterial Clearance J. Immunol., March 15, 2008; 180(6): 4040 - 4049. [Abstract] [Full Text] [PDF]
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M. Eickhoff, J. Thalmann, S. Hess, M. Martin, T. Laue, J. Kruppa, G. Brandes, and A. Klos Host Cell Responses to Chlamydia pneumoniae in Gamma Interferon-Induced Persistence Overlap Those of Productive Infection and Are Linked to Genes Involved in Apoptosis, Cell Cycle, and Metabolism Infect. Immun., June 1, 2007; 75(6): 2853 - 2863. [Abstract] [Full Text] [PDF]
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C. Trumstedt, E. Eriksson, A. M. Lundberg, T.-b. Yang, Z.-q. Yan, H. Wigzell, and M. E. Rottenberg Role of IRAK4 and IRF3 in the control of intracellular infection with Chlamydia pneumoniae J. Leukoc. Biol., June 1, 2007; 81(6): 1591 - 1598. [Abstract] [Full Text] [PDF]
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L. Li, L. Huang, S.-s. J. Sung, P. I. Lobo, M. G. Brown, R. K. Gregg, V. H. Engelhard, and M. D. Okusa NKT Cell Activation Mediates Neutrophil IFN-{gamma} Production and Renal Ischemia-Reperfusion Injury J. Immunol., May 1, 2007; 178(9): 5899 - 5911. [Abstract] [Full Text] [PDF]
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A. A. Byrnes, D.-Y. Li, K. Park, D. Thompson, C. Mocilnikar, P. Mohan, J. P. Molleston, M. Narkewicz, H. Zhou, S. F. Wolf, et al. Modulation of the IL-12/IFN-{gamma} axis by IFN-{alpha} therapy for hepatitis C J. Leukoc. Biol., March 1, 2007; 81(3): 825 - 834. [Abstract] [Full Text] [PDF]
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 K. Sakai, H. Suzuki, H. Oda, T. Akaike, Y. Azuma, T. Murakami, K. Sugi, T. Ito, H. Ichinose, S. Koyasu, et al. Phosphoinositide 3-Kinase in Nitric Oxide Synthesis in Macrophage: CRITICAL DIMERIZATION OF INDUCIBLE NITRIC-OXIDE SYNTHASE J. Biol. Chem., June 30, 2006; 281(26): 17736 - 17742. [Abstract] [Full Text] [PDF]
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A. G. Rothfuchs, C. Trumstedt, F. Mattei, G. Schiavoni, A. Hidmark, H. Wigzell, and M. E. Rottenberg STAT1 Regulates IFN-{alpha}beta- and IFN-{gamma}-Dependent Control of Infection with Chlamydia pneumoniae by Nonhemopoietic Cells. J. Immunol., June 1, 2006; 176(11): 6982 - 6990. [Abstract] [Full Text] [PDF]
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 A. Bafica, C. A. Scanga, C. G. Feng, C. Leifer, A. Cheever, and A. Sher TLR9 regulates Th1 responses and cooperates with TLR2 in mediating optimal resistance to Mycobacterium tuberculosis J. Exp. Med., December 19, 2005; 202(12): 1715 - 1724. [Abstract] [Full Text] [PDF]
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S. P. Lad, E. Y. Fukuda, J. Li, L. M. de la Maza, and E. Li Up-Regulation of the JAK/STAT1 Signal Pathway during Chlamydia trachomatis Infection J. Immunol., June 1, 2005; 174(11): 7186 - 7193. [Abstract] [Full Text] [PDF]
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C. S. Little, A. Bowe, R. Lin, J. Litsky, R. M. Fogel, B. J. Balin, and K. L. Fresa-Dillon Age Alterations in Extent and Severity of Experimental Intranasal Infection with Chlamydophila pneumoniae in BALB/c Mice Infect. Immun., March 1, 2005; 73(3): 1723 - 1734. [Abstract] [Full Text] [PDF]
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 U. Schleicher, A. Hesse, and C. Bogdan Minute numbers of contaminant CD8+ T cells or CD11b+CD11c+ NK cells are the source of IFN-{gamma} in IL-12/IL-18-stimulated mouse macrophage populations Blood, February 1, 2005; 105(3): 1319 - 1328. [Abstract] [Full Text] [PDF]
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H. K. Maxion, W. Liu, M.-H. Chang, and K. A. Kelly The Infecting Dose of Chlamydia muridarum Modulates the Innate Immune Response and Ascending Infection Infect. Immun., November 1, 2004; 72(11): 6330 - 6340. [Abstract] [Full Text] [PDF]
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S. B. Pruett, C. Schwab, Q. Zheng, and R. Fan Suppression of Innate Immunity by Acute Ethanol Administration: A Global Perspective and a New Mechanism Beginning with Inhibition of Signaling through TLR3 J. Immunol., August 15, 2004; 173(4): 2715 - 2724. [Abstract] [Full Text] [PDF]
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G. Schiavoni, C. Mauri, D. Carlei, F. Belardelli, M. Castellani Pastoris, and E. Proietti Type I IFN Protects Permissive Macrophages from Legionella pneumophila Infection through an IFN-{gamma}-Independent Pathway J. Immunol., July 15, 2004; 173(2): 1266 - 1275. [Abstract] [Full Text] [PDF]
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M. G. Netea, B. J. Kullberg, L. E. H. Jacobs, T. J. G. Verver-Jansen, J. van der Ven-Jongekrijg, J. M. D. Galama, A. F. H. Stalenhoef, C. A. Dinarello, and J. W. M. Van der Meer Chlamydia pneumoniae Stimulates IFN-{gamma} Synthesis through MyD88-Dependent, TLR2- and TLR4-Independent Induction of IL-18 Release J. Immunol., July 15, 2004; 173(2): 1477 - 1482. [Abstract] [Full Text] [PDF]
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J. Mattner, A. Wandersee-Steinhauser, A. Pahl, M. Rollinghoff, G. R. Majeau, P. S. Hochman, and C. Bogdan Protection against Progressive Leishmaniasis by IFN-{beta} J. Immunol., June 15, 2004; 172(12): 7574 - 7582. [Abstract] [Full Text] [PDF]
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A. G. Rothfuchs, C. Trumstedt, H. Wigzell, and M. E. Rottenberg Intracellular Bacterial Infection-Induced IFN-{gamma} Is Critically but Not Solely Dependent on Toll-Like Receptor 4-Myeloid Differentiation Factor 88-IFN-{alpha}{beta}-STAT1 Signaling J. Immunol., May 15, 2004; 172(10): 6345 - 6353. [Abstract] [Full Text] [PDF]
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A. G. Rothfuchs, M. R. Kreuger, H. Wigzell, and M. E. Rottenberg Macrophages, CD4+ or CD8+ Cells Are Each Sufficient for Protection against Chlamydia pneumoniae Infection through their Ability to Secrete IFN-{gamma} J. Immunol., February 15, 2004; 172(4): 2407 - 2415. [Abstract] [Full Text] [PDF]
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T. Katakura, M. Miyazaki, M. Kobayashi, D. N. Herndon, and F. Suzuki CCL17 and IL-10 as Effectors That Enable Alternatively Activated Macrophages to Inhibit the Generation of Classically Activated Macrophages J. Immunol., February 1, 2004; 172(3): 1407 - 1413. [Abstract] [Full Text] [PDF]
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E. Eriksson, L. Dons, A. G. Rothfuchs, P. Heldin, H. Wigzell, and M. E. Rottenberg CD44-Regulated Intracellular Proliferation of Listeria monocytogenes Infect. Immun., July 1, 2003; 71(7): 4102 - 4111. [Abstract] [Full Text] [PDF]
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H. A. Papadaki, A. G. Eliopoulos, T. Kosteas, C. Gemetzi, A. Damianaki, H. Koutala, J. Bux, and G. D. Eliopoulos Impaired granulocytopoiesis in patients with chronic idiopathic neutropenia is associated with increased apoptosis of bone marrow myeloid progenitor cells Blood, April 1, 2003; 101(7): 2591 - 2600. [Abstract] [Full Text] [PDF]
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M. A. Freudenberg, T. Merlin, C. Kalis, Y. Chvatchko, H. Stubig, and C. Galanos Cutting Edge: A Murine, IL-12-Independent Pathway of IFN-{gamma} Induction by Gram-Negative Bacteria Based on STAT4 Activation by Type I IFN and IL-18 Signaling J. Immunol., August 15, 2002; 169(4): 1665 - 1668. [Abstract] [Full Text] [PDF]
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T. Hayashi, T. Kaneda, Y. Toyama, M. Kumegawa, and Y. Hakeda Regulation of Receptor Activator of NF-kappa B Ligand-induced Osteoclastogenesis by Endogenous Interferon-beta (INF-beta ) and Suppressors of Cytokine Signaling (SOCS). THE POSSIBLE COUNTERACTING ROLE OF SOCSs IN IFN-beta -INHIBITED OSTEOCLAST FORMATION J. Biol. Chem., July 26, 2002; 277(31): 27880 - 27886. [Abstract] [Full Text] [PDF]
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