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From the Department of Medicine and Therapeutics, University of Aberdeen, Aberdeen, United Kingdom
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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(IFN-), tumor necrosis factor (TNF),
interleukin-4 (IL-4), or transforming growth factor-ß
(TGF-ß). Macrophages from normal glomeruli did not generate nitric
oxide (NO) spontaneously but only after treatment with IFN- and
TNF-
. NO generation by these macrophages was abrogated by
administering IL-4, TGF-ß, or TNF- before but not
after IFN- treatment. Glomerular macrophages also expressed
ß-glucuronidase, which was increased by TGF-ß and decreased
by IFN- and TNF. By contrast, glomerular macrophages from
rats with nephrotoxic nephritis did not express ß-glucuronidase even
after exposure to TGF-ß. Furthermore, they generated NO
spontaneously, and this spontaneous generation of NO was not
suppressed by IL-4, TGF-ß, or TNF-. Systemic
treatment of nephritic rats with IL-4 reduced NO generation by 40% but
did not prevent activation, which is similar to the effect of
IL-4 on bone marrow-derived macrophages in vitro when
given simultaneously with IFN-. We conclude that macrophages
infiltrating inflamed glomeruli have developed programmed
unresponsiveness to activating cytokines. This may enable them to
function appropriately in the complex conditions within an inflammatory
focus.
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Early studies by Mackaness,8
North,9
and their colleagues demonstrated that macrophages
elicited into the peritoneal cavity after injection of an irritant and
macrophages infiltrating the peritoneum as part of a T cell-mediated
response have different properties. These and many similar experiments
led to the distinction between elicited and activated macrophages and
to the identification of interferon- (IFN-) as the principal
macrophage-activating factor.10
Since then it has become
apparent that these are only two of many states that macrophages can
adopt and that macrophages can be alternatively activated by other
cytokines, for example by interleukin-4 (IL-4).11
It is
now clear that there are many other macrophage activation
states12,13
and that differently activated macrophages
cause tissue injury or facilitate its repair.
As the first step toward understanding these processes,
we14
and others15,16
have analyzed the effect
of specific cytokines on the development of complex macrophage
functions and have shown that IFN-, tumor necrosis factor-
(TNF-), transforming growth factor-ß (TGF-ß), and IL-4 committed
macrophages to sets of nonoverlapping and mutually exclusive properties
or programs. In each case the macrophage programming was determined by
the first cytokine to which the macrophages were exposed, and an
essential component of the program was the development of
unresponsiveness to alternatively activating cytokines.14
This is consistent with reports showing that inhibitory effects of
anti-inflammatory cytokines occur predominantly when macrophages are
pretreated.17,18
It is important whether programmed macrophages activated in vivo are also unresponsive to anti-inflammatory cytokines, because this could provide a mechanism for them to operate coherently within the chaotic environment of damaged tissue. Here they are exposed to an extreme variety of (often contradictory) receptor-mediated signals, including those derived from interactions with chemokines and adhesion molecules, immunoglobulins, and complement19,20 ; or contact with other cells (eg, through CD40, CD80, and CD86) or with the extracellular matrix (eg, via integrins and CD44). Analysis of these interactions requires an appropriate model, and accelerated nephrotoxic nephritis (NTN) in rats is particularly suited for this. It is characterized by acute macrophage-dependent injury,21 as demonstrated by macrophage depletion experiments.22 Injury is also attenuated by administration of anti-inflammatory cytokines with effects on macrophage function, such as IL-4, IL-6, and IL-10.23,24 The intensity of injury can be quantified functionally and morphologically, and macrophages can readily be purified from the inflamed glomeruli and studied ex vivo.
This study was to determine whether macrophages infiltrating glomeruli
of rats with NTN become programmed and, if so, whether programming
could be influenced by exogenously delivered cytokines. The results
show that macrophages from normal glomeruli behave like uncommitted
bone marrow-derived macrophages (BMDMs), whereas those from nephritic
glomeruli have the characteristics of IFN--primed, TNF-activated
macrophages. They generate large amounts of NO spontaneously and do not
express ß-glucuronidase, properties that cannot be modulated by
ex vivo incubation with TGF-ß or IL-4. Analysis of NO
generation by glomerular macrophages from nephritic rats treated
systemically with IL-4 suggests that programming occurs after
macrophages localize to the nephritic kidney. These results provide a
further insight into the function of inflammatory macrophages and have
obvious implications for the use of cytokine therapy to modulate acute
immunologically mediated inflammation.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Nephrotoxic serum, rabbit antiserum to rat glomerular basement
membrane (GBM), was prepared as described
previously.25
Recombinant human TNF-, recombinant human
TGF-ß, and recombinant rat IFN- were obtained from Boehringer
(Ingelheim, Germany), Sigma Chemical Co. (Dorset, UK), and Bradsure
Biologicals Ltd. (Loughborough, UK), respectively. Recombinant rat IL-4
was produced in house as described previously,23
using a
Chinese hamster ovary cell line generously donated by Dr. Neil Barclay
(MRC Cellular Immunology Unit, Oxford, UK).
Induction of Accelerated Autologous Phase of NTN
Male Sprague-Dawley rats were immunized by subcutaneous injection of 1 mg of normal rabbit immunoglobulin G (Sigma Chemical Co., St. Louis, MO) in Freund’s complete adjuvant (Difco). The rats (weight 180–200 g) were injected intravenously 7 days later with 1 ml of nephrotoxic serum. Groups of rats were killed 48 and 96 hours after induction of nephritis, for histological studies and preparation of glomerular macrophages. Urine was collected by placing rats in metabolic cages over night for 18 hours before induction of nephritis and every subsequent night. Albuminuria was quantified by rocket immunoelectrophoresis as previously described.26
Administration of Recombinant Rat IL-4
Recombinant rat IL-4 (8 µg in 0.5 ml of cell culture supernatant) was administered intraperitoneally twice daily starting the day before induction of nephritis and continuing until rats were sacrificed on day 4. Control rats received the same volume of cell culture supernatant from the parent Chinese hamster ovary-K1 cell line.
Morphology and Immunohistology
First the kidneys were perfused in vivo with phosphate-buffered saline at 4°C through a cannula inserted into the abdominal aorta. Samples of renal tissue were either snap-frozen in liquid nitrogen or fixed in formalin for light microscopy and immunohistochemistry as previously described.23,24 Macrophages were identified in formalin-fixed sections by alkaline phosphatase anti-alkaline phosphatase (APAAP) staining with monoclonal antibody ED1 (Serotec, Oxford, UK).
Purification of Glomerular Macrophages
Glomeruli were isolated from kidneys perfused in vivo with 50 ml sterile phosphate-buffered saline, by a standard sieving technique. Isolated glomeruli were enzymatically digested to single-cell suspensions with trypsin, collagenase, DNase, and ethylenediaminetetraacetic acid (Sigma) as previously described.27 The macrophages were isolated from the single-cell suspension by adherence in 24-well plates at an approximate density of 1 x 106 macrophages per well. The cells were then counted, and the results were corrected for differences in cell number. In addition all wells that contained less than 8 x 105 or more than 1.2 x 106 cells per well were excluded from the experiments. The purity of the macrophage population always exceeded 90%, and there was no significant mesangial cell or endothelial cell contamination. The macrophages were washed and incubated for 48 hours in Dulbecco’s modified Eagle’s medium (DMEM) containing 2 mmol/L glutamine, 100 U/ml penicillin, and 100 U/ml streptomycin and 10% heat-inactivated fetal calf serum alone or in medium containing cytokines.
Isolation and Culture of BMDMs
Rat BMDMs were obtained using a technique previously described in detail.28 Briefly, bone marrow cells were flushed aseptically from the dissected femurs of male Sprague-Dawley rats with a jet of complete medium directed through a 25-gauge needle to form a single-cell suspension. The cells were cultured in 75-mm tissue culture flasks (Corning, NY) adherent to plastic, in DMEM containing 2 mmol/L glutamine, 100 U/ml penicillin, and 100 U/ml streptomycin; 10% heat-inactivated fetal calf serum; and 10% L929-conditioned medium as a source of macrophage-colony stimulating factor. After 7 days in culture, the cells were carefully removed using 1% tripsin-ethylenediaminetetraacetic acid and dispensed into 24-well culture plates (Corning) at a concentration of 1 x 106 cells/well, and they rested for 24 hours in macrophage-colony stimulating factor-free medium before they were washed and incubated with the cytokines. When combinations of cytokines were used, the initial cytokine was given 4 hours before the second cytokine, and the cytokines were not removed from the medium until macrophage function was assessed.
Quantitation of NO Synthesis
Generation of NO was estimated by assaying culture supernatants for nitrite, a stable reaction product of NO. Of each cell-free culture, two 200-µl aliquots per well of supernatant were incubated with 50 µl of Griess reagent (0.5% sulfanilamide, 0.05% N-(1-naphthyl) ethylenediamine dihydrochloride in 2.5% phosphoric acid) in 96 flat-bottomed tissue culture plates for 10 minutes at room temperature. The optical densities of the assay samples were then measured at 540 nm, using a solution of phenol red-free DMEM. In most experiments, nitrite was measured after 24 and 48 hours in culture. A nitrite standard was included in all experiments, and the results for a single experiment are the means of four aliquots taken from duplicate wells after 48 hours. The addition of the nonspecific NO synthase-competitive inhibitor L-monomethyl arginine at 100 µm largely inhibited IFN-induced NO generation in BMDMs and glomerular macrophages.
Quantitation of ß-Glucuronidase Expression
ß-Glucuronidase is a lysosomal hydrolase that is strongly
expressed and released in bacterial infections or when macrophages
ingest particulate matter such as group A streptococcal cell walls,
zymosan particles, or ß-1-3-glucan. TGF-ß primes macrophages to
express lysosomal hydrolases in response to particulate
stimuli,29
and a series of studies suggests that the
induction of lysosomal hydrolase synthesis and secretion may actively
contribute to the debridement phase of the inflammatory
response.7
At higher concentrations, IFN- decreases
ß-glucuronidase expression in vitro and abrogates the
effects of TGF-ß.12,13
ß-Glucuronidase was visualized by an enzymatic staining method in
which ß-glucuronidase catalyzed the reaction of -naphthol AS-BI
ß-D-glucuronide into the red-soluble chromogenic naphthol
AS-BI-HPR complex.30
Cytospin preparations of macrophages
harvested from the 24-well tissue culture plates were fixed in a
gluteraldehyde-acetone solution, and the sections were air-dried. They
were then stained with ß-glucuronidase staining solution and
counterstained with methylene blue before being mounted with aqueous
medium. Slides were coded, and 1000 cells per slide were scored by our
standard system,14
using the following scale: 0, no
staining; 1, equivocal positive staining; 2, weak positive staining; 3,
moderate positive staining; 4, strong positive staining. The score
represents an overall change in the density of staining.
Statistical Analysis
Differences between the groups in NO generation and scoring of ß-glucuronidase were analyzed by the Wilcoxon rank sum test and Kruskal Wallis analysis of variance.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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Uncommitted BMDMs do not generate NO spontaneously but can be
programmed to do so by administering IFN- followed by TNF. Once
programmed, NO generation is unaffected by IL-4 or
TGF-ß.14
Macrophages isolated from normal glomeruli
responded to cytokines in exactly the same way and did not generate NO
spontaneously or when stimulated individually with IL-4, TGF-ß, or
TNF-. However, they generated an amount of NO similar to that of
uncommitted BMDMs when incubated with IFN- followed 4 hours later by
TNF (Table 1)
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. Expression increased after
incubation with TGF-ß and was attenuated by IFN- followed by
TNF-; neither TNF- nor IL-4 alone had any effect (Table 1)
. These
data indicate that normal glomerular macrophages and uncommitted BMDMs
respond identically to the cytokines. It is important that they also
demonstrate that the isolation procedure neither primed nor activated
the macrophages. This validates use of this approach to analyze the
properties of macrophages purified from inflamed glomeruli. Functional Properties of Macrophages Isolated from Inflamed Glomeruli
Macrophages were purified from acutely inflamed glomeruli of
nephritic rats at various times after induction of nephritis. Unlike
normal glomerular macrophages, these macrophages generated large
amounts of NO spontaneously in culture. This activity was maximal in
macrophages harvested on day 2 after induction of nephritis (Figure 1)
. Incubation with IFN- followed by
TNF further enhanced NO generation at each of the time points, whereas
IL-4, TGF-ß, and TNF alone had no effect (Figure 1)
. These responses
are identical to those of BMDMs that have been programmed in
vitro by IFN- and TNF.14,31
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, which again is similar to results
found in BMDMs programmed by IFN- and TNF.14
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Effect of in Vivo Injection of IL-4 on Normal and Nephritic Rats
Systemic treatment with IL-4 attenuates injury in rats with
NTN,23
and IL-4 has profound effects on IFN-–induced
priming of BMDMs in vitro, in that IL-4 prevents priming
when given before IFN- modulates it when given at the same
time, but has no effect if given afterward.14
We therefore
assessed the effect of systemic treatment with IL-4 on glomerular
macrophages. The IL-4-treated rats with NTN had less severe injury both
functionally and morphologically throughout the course of the
experiment. Albuminuria was 945.3 ± 307 mg/day on day 2 in
controls and 356.4 ± 138 mg/day in IL-4-treated rats, and at
autopsy the percentages of glomeruli with capillary thrombi were 92%
± 5.2 in untreated nephritic rats and 70% ± 20 in IL-4-treated rats
(Table 3)
. There were significantly fewer
glomerular macrophages in IL-4-treated rats: 21.4 ± 3.1
ED1-positive cells per glomerulus in untreated nephritic rats
and 5.3 ± 0.4 ED1-positive cells per glomerulus in IL-4-treated
rats (Table 3)
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and TNF,
which results in 60% less NO generation (Figure 2)
and a smaller reduction in
ß-glucuronidase expression than that of macrophages isolated from
glomeruli of untreated rats (Table 2)
. Macrophages isolated from
nephritic rats treated continuously with IL-4, starting 14 hours before
induction of NTN, generated significantly less NO at days 2 and 4 of
NTN compared with macrophages from diseased but untreated rats (Figure 2)
. However these macrophages were not refractory to treatment. IFN/TNF
ex vivo still increased NO, albeit to a lesser extent than
in untreated nephritic rats, and the maximum amount of NO generated was
also significantly less in the IL-4-treated rats. It is interesting
that NO generation by the macrophages isolated from the IL-4-treated
rats was not altered when the cells were incubated with IL-4, TGF, or
TNF ex vivo (Figure 2)
. There was significantly greater
ß-glucuronidase expression in macrophages isolated from glomeruli of
IL-4-treated rats at day 4 of NTN than by untreated nephritic controls
(Table 2)
. These results are both qualitatively and quantitatively
similar to those obtained for BMDMs treated simultaneously with IL-4
and IFN- followed by activation with TNF,14
and they
suggest a similar temporal sequence in vivo.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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NTN provided an ideal model for these studies because macrophages can be easily isolated from normal and nephritic glomeruli, and the results showed that the isolation procedure neither activated nor programmed the macrophages, thus demonstrating the suitability of the model for analyzing macrophage activation. Injury in this model is macrophage-dependent, but we cannot exclude that some of the protective effects of IL-4 described here are on neutrophils because injury in this model is also neutrophil-dependent.32 However it is unlikely that the effects of IL-4 on glomerular macrophages reported here can be explained on this basis because the effects were evident well after the glomerular neutrophil infiltration had resolved. NO generation and ß-glucuronidase expression were chosen as measures of macrophage function primarily because they are complex functions that have been used to characterize macrophage programming in vitro.12,14,16,28 Furthermore, the cytokines that induce them in vitro are present in inflamed glomeruli,33 and glomeruli isolated from nephritic rats produce NO ex vivo.34 Thus we were able to determine whether macrophages that have infiltrated an inflammatory focus in vivo are still able to respond to cytokines.
Macrophages from normal glomeruli responded to cytokines in exactly the
same way as uncommitted BMDMs. Both could be programmed to generate NO
by incubation with IFN- followed by TNF, and, once programmed, NO
generation was unaffected by IL-4 or TGF-ß. By contrast, macrophages
isolated from inflamed glomeruli generated NO spontaneously, and this
was not inhibited by IL-4, TGF-ß, or TNF—results identical to those
of BMDMs activated with IFN- followed by TNF.14
The
large quantity of NO that was produced indicated that a substantial
proportion of the macrophages contributed to NO generation. Analysis of
ß-glucuronidase expression confirmed that macrophages from normal and
nephritic glomeruli behaved like uncommitted and IFN/TNF macrophages,
respectively. This assay has the additional advantage of enabling
macrophage function to be examined at the single-cell level, and it
showed that the macrophages purified from a given kidney behaved as a
single population with little cell-cell variation in ß-glucuronidase
expression either spontaneously or after exposure to cytokines. Thus,
inflammatory macrophages purified from nephritic glomeruli are
uniformly programmed and cannot be reprogrammed by anti-inflammatory
cytokines ex vivo.
In vitro, BMDMs are programmed by the first cytokine they
encounter,14
which raises the question whether
administration of cytokines in vivo can divert infiltrating
macrophages down an alternative programming pathway for therapeutic
gain. We investigated this possibility by administering IL-4 starting
14 hours before the induction of NTN. IL-4 was chosen for these
experiments first because it attenuates injury in NTN, with fewer
infiltrating macrophages expressing the macrophage activation marker
sialoadhesin, recognized by the monoclonal antibody
ED323,35
; second, because IL-4 has been shown to reduce NO
generation by whole glomeruli isolated from rats with
NTN36
; and, third, because in vitro IL-4
prevents priming for NO generation when given 4 hours before IFN-,
modulates NO generation when given at the same time as IFN-, and has
no effect when given after IFN-. Thus the responses of glomerular
macrophages to systemic IL-4 administration would be expected to differ
depending on whether monocytes/macrophages were programmed before or
after infiltrating the kidney. The results show that IL-4 did not
prevent programming because macrophages from treated rats generated NO
and were unresponsive to IL-4 and TGF-ß ex vivo. However
the infiltrating macrophages generated significantly less NO and thus
behaved like BMDMs simultaneously exposed to IFN- and
IL-4.14
This implies that circulating monocytes are not
susceptible to programming and only become so after localization to the
inflamed site. Currently we are conducting experiments to examine this
hypothesis, but various differences in responses of monocytes and
macrophages to IL-4 and other cytokines have already been
described,37-39
and adherence is important for
facilitating the altered responsiveness.40,41
Recently,
Bonder et al42
showed that cultured human monocytes do not
express the IL-2 receptor chain, a component of the IL-4 receptor,
whereas macrophages do, and that some of the anti-inflammatory
responses to IL-4, such as their ability to down-regulate
lipopolysaccaride-induced TNF- production, are lost. This suggests
that, under the experimental conditions reported here, the macrophages
were programmed in the inflammatory focus and not in the circulation
when, as monocytes, they were first exposed to IL-4.
Finally, the results raise the question of how macrophage function alters with time during the resolution of inflammation. This could occur if inflammatory macrophages regained the ability to be programmed once the original programming stimulus had been removed, as occurs in vitro when BMDMs are rested for 48 hours after exposure to IL-4.14 Alternatively, programmed macrophages could be removed from an inflammatory focus either by apoptosis or migration to the local lymph nodes43 and be replaced by newly infiltrating macrophages that are differently programmed. This would require a substantial flux of macrophages through an inflammatory focus even though total numbers within the infiltrate show little change.44 Our recent work with ß-galactosidase–expressing macrophages and fluorescently labeled macrophages supports the idea of a substantial flux of macrophages through inflamed glomeruli.45
In conclusion, our experiments demonstrate how macrophages could maintain a coordinated response to the local environment without being overwhelmed by the multitude of signals impinging on their receptors. If correct, this would have obvious implications for the role of macrophages in the control of inflammation and for the use of cytokine therapy.
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Acknowledgements |
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Footnotes |
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Supported by the Deutsche Forschungsgemeinschaft (ER 254/1–1 to L.-P. R.). This work was performed in the context of European Union Contract EMH4B MH4-CT98–3631.1: Chronic Inflammation Leading to Scarring: the Major Cause of Renal Failure.
Accepted for publication September 16, 1999.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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as a critical macrophage chemoattractant in murine wound repair. J Clin Invest 1998, 101:1693-1698[Medline]
, the activated macrophage, the host defence against microbial challenge. Ann Intern Med 1988, 108:595-608
and interleukin-10. Immunology 1997, 91:104-108[Medline]
(TNF ) by interferons: implications for the pleiotropic activities of TNF . J Clin Invest 1994, 93:1661-1669
-dependent mechanism in murine macrophages. J Clin Invest 1993, 91:2368-2377
and prostaglandin E2. J Immunol 1995, 155:2123-2133[Abstract]
, by human macrophages. J Immunol 1998, 160:3513-3521-chain in the control by IL-4 of human monocyte and macrophage proinflammatory mediator production. J Immunol 1998, 160:4048-4056This article has been cited by other articles:
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