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Max Planck Institut für Immunbiologie, Freiburg, Germany
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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,
and TNF-ß, whereas Th2 cells secrete IL-4, IL-5, IL-6, IL-10, and
IL-13. Th1 cells are mainly implicated in cell-mediated immune
reactions, macrophage activation, and the production of opsonizing Abs.
Th2 cells, on the other hand, are key players in humoral immunity and
activate mast cells and eosinophils. The Th1/Th2 balance within an
immune response is regulated by positive and negative feedback within
and between, respectively, both types of cells. The importance of
CD4+ T cell dichotomy is underlined by the growing body of
evidence that the outcome of numerous diseases critically depends on
the Th1/Th2 balance in the accompanying immune responses (2, 3).
Macrophages, in addition to having a role in innate immunity,
participate as effector cells in adaptive immune responses. Macrophages
induced in Th1-dominated immune responses secrete multiple
inflammatory mediators (e.g., IL-1, IL-6, and TNF-
) and are
therefore termed inflammatory macrophages. Inflammatory macrophages
possess cytotoxic and antimicrobial effector functions based on their
ability to produce nitric oxide
(NO)2 (4, 5). The production
of NO is catalyzed by the enzyme inducible NO synthase, which oxidizes
the substrate L-arginine to form NO and
L-citrulline. The fundamental importance of this metabolic
pathway in murine macrophages as a key defense element in various
infectious diseases as well as its role in diverse settings of
immunopathology is today firmly established (6, 7). In contrast, the
alternative pathway of macrophages to metabolize L-arginine
and the functions associated with macrophages using this pathway are
less well understood. This metabolic route is catalyzed by the enzyme
arginase and leads to the products L-ornithine and urea.
Little information about structure, function, and regulation of murine
macrophage arginase is available. The enzyme seems to act in trimeric
configuration, to be located in mitochondria, and to belong to the
family of extrahepatic arginases (AII), as opposed to the hepatic type
(AI), which is a component of the urea cycle (for review, see 8 .
We have previously demonstrated that the two enzymes are alternatively
induced by Th1 and Th2 cytokines (9, 10). IFN- up-regulates
exclusively iNOS, whereas IL-4 and IL-10 induce arginase activity.
Moreover, induction of one of the enzymes is accompanied by suppression
of the other, indicative of two competitive metabolic states in murine
macrophages. The present study extends these findings by showing that
the alternative states in macrophage metabolism are induced in cellular
coculture systems resembling established or early emerging Th1- or
Th2-type immune responses. The effects are mediated by cytokines
endogenously produced in these cultures, with synergistic action
leading to unexpectedly high arginase levels in Th2-dominated immune
responses.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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All cell cultures were performed in DMEM supplemented with 10% heat-inactivated FCS, 2 mM L-glutamine, 60 µM 2-ME, 1 mM sodium pyruvate, 1x nonessential amino acids, 100 U/ml penicillin, and 100 µg/ml streptomycin (Life Technologies, Paisley, U.K.).
Conalbumin and monensin were purchased from Calbiochem (La Jolla, CA);
N-monomethyl-L-arginine (L-NMMA) was
purchased from Alexis (San Diego, CA); PMA, Con A, A23187,
L-arginine, pigeon cytochrome c (PCC), Triton
X-100, -isonitrosopropiophenone, sulfanilamide,
N-(1-naphthyl)ethylenediamine dihydrochloride, and saponin
(lot P4170) were obtained from Sigma (Deisenhofen, Germany).
Streptavidin-PE was purchased from Life Technologies (Grand
Island, NY).
Cytokines and Abs
Recombinant murine IFN- was obtained from Genentech (South
San Francisco, CA); IL-2, IL-4, IL-5, IL-12, and IL-13 were purchased
from R&D Systems (Abingdon, U.K.); IL-1ß, IL-6, and IL-10 were
obtained from PeproTech (London, U.K.).
The following mAb were purchased from PharMingen (San Diego, CA):
FITC-conjugated anti-IL-4, PE-conjugated anti-IFN-,
PE-conjugated anti-TNF-, anti-IL-4, anti-IL-10, isotype
controls (FITC-conjugated rIgG2b, PE-conjugated rIgG1, rIgG2b, and
rIgG1), biotin-conjugated anti-V11, PE-anti-Vß3,
FITC-conjugated anti-CD44, and biotin-conjugated anti-CD62L.
Anti-CD3
mAb was purified from hybridoma (145-2C11) supernatant.
Animals
Mice transgenic for the 2B4 ß-TCR (V11, Vß3),
recognizing PCC or moth cytochrome c
peptide88–103 bound to I-Ek (11) were derived
from a founder mouse provided by Dr. D. Mathis (Institut de
Génétique et de Biologie Moleculaire et Cellulaire du
Centre National de la Recherche Scientifique, Strasbourg, France). 2B4
mice (maintained as heterozygotes on a B10BR background) and AKR/N mice
were obtained from the specific pathogen-free animal facilities of the
Max Planck Institute and were used between 6 and 8 wk of age.
Determination of arginase activity
Arginase activity was measured in cell lysates with slight
modifications as previously described (12). Briefly, cells were lysed
with 100 µl of 0.1% Triton X-100. After 30 min on a shaker, 100 µl
of 25 mM Tris-HCl was added. To 100 µl of this lysate, 10 µl of 10
mM MnCl2 was added, and the enzyme was activated by
heating for 10 min at 56°C. Arginine hydrolysis was conducted by
incubating the lysate with 100 µl of 0.5 M L-arginine, pH
9.7, at 37°C for 15 to 120 min. The reaction was stopped with 800
µl of H2SO4
(96%)/H3PO4 (85%)/H2O (1/3/7,
v/v/v). The urea concentration was measured at 540 nm after addition of
40 µl of -isonitrosopropiophenone (dissolved in 100% ethanol)
followed by heating at 95°C for 30 min. One unit of enzyme activity
is defined as the amount of enzyme that catalyzes the formation of 1
µmol of urea per min.
NO measurement
NO was measured as nitrite using the Griess reagent. Culture supernatant was mixed with 100 µl of 1% sulfanilamide, 0.1% N-(1-naphthyl)ethylenediamine dihydrochloride, and 2.5% H3PO4. Absorbance was measured at 540 nm in a microplate reader (Molecular Devices, Ismaning, Germany).
Generation of bone marrow-derived macrophages
Bone marrow cells were obtained by flushing the femurs of mice.
Cells were cultured as previously described (13) in hydrophobic Teflon
bags (Biofolie 25, Heraeus, Hanau, Germany) in DMEM containing 10%
heat-inactivated FCS, 5% horse serum, and the supernatant of L929
fibroblasts at a final concentration of 15% (v/v) as a source of CSFs
that drive cell proliferation toward a >95% pure population of bone
marrow-derived macrophages (BMM
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Cells
D10G4 is a CD4+, ßTCR+,
I-Ak-restricted Th2 T cell clone recognizing conalbumin
residues 134 to 146 (14). AE7 (provided by Dr. M. Kopf, Basel Institute
for Immunology, Basel, Switzerland) is a CD4+,
ßTCR+, I-Ek-restricted Th1 T cell clone
recognizing the carboxyl-terminal fragment 81 to 104 of PCC (15). Both
T cell clones were maintained by biweekly stimulation with
30-Gy-irradiated splenocytes (AKR/N mice) and 50 µg/ml of the
appropriate Ag.
Ag presentation assays
BMM-T cell coculture experiments were set up in 96-well
flat-bottom plates (Costar, Cambridge, MA) in a final volume of 200
µl. Unless otherwise indicated, 5 x 104 BMM
were cultured together with 1 x 105 T cells in the
presence of the indicated concentrations of Ag. After 48 h,
supernatant was harvested for nitrite determination, and cell lysates
were prepared for arginase determination.
Intracellular cytokine staining of T cells
T cells were stimulated for 5 h in six-well plates (Costar)
with PMA (20 ng/ml), A23187 (300 ng/ml), and monensin (2.5 µM). After
blocking FcRII/III with culture supernatant of hybridoma 2.4G2,
cells were fixed with 4% paraformaldehyde (in PBS) for 30 min on ice.
After two washing steps in PBS/2% FCS, the cells were washed again in
PBS/2% FCS/0.1% saponin. During the subsequent staining (each FITC-
or PE-labeled Ab separately on ice for 30 min) and washing procedures,
saponin was always present at a concentration of 0.1%. Finally, the
cells were resuspended in PBS/2% FCS and analyzed on a FACScan (Becton
Dickinson, Mountain View, CA).
In vitro differentiation of naive T cells
CD4+ T cells from lymph nodes of 6- to 8-wk-old
2B4 TCR transgenic mice were isolated on a FACStarPlus
(Becton Dickinson), yielding purities of >98%. Sorted
V11+, Vß3+, CD62Lhigh,
CD44low CD4+ T cells (2 x
105) were primed in 24-well plates (Costar) in a final
volume of 1.5 ml with 6 x 106 irradiated (30 Gy)
AKR/N spleen cells/well and 50 µg/ml PCC. To promote Th1 development,
200 U/ml IL-12 were added, whereas 25 U/ml IL-4 were added to drive T
cells into a Th2 phenotype. At 72 h, the cells were diluted
10-fold in IL-2 (50 U/ml)-containing medium. On day 7, the T cells were
harvested, extensively washed to remove residual cytokines, and again
subjected to FACS analysis, revealing the Ag-experienced phenotype:
CD4+ (>98%), CD62Llow (>93%),
CD44high (>94%). In parallel, the cells were taken for
intracellular cytokine staining and the Ag presentation assays with
BMM.
Cytokine determination
Cytokines (IL-4/IL-10/IFN-) in the supernatants were
determined by commercially available (PharMingen) sandwich ELISA tests
according to the manufacturers’ protocols. The measuring ranges of the
ELISA tests were the following: IFN-, 4 to 400 U/ml; IL-4, 0.1 to 10
U/ml; and IL-10, 0.2 to 50 U/ml.
T cell proliferation and stimulation
T cell proliferation in Ag presentation assays was assessed at
48 h by addition of 1 µCi [3H]thymidine
(DuPont, Boston, MA). After 16 h the cells were harvested on
glass-fiber filters (GF/A, Dunn Labortechnik, Asbach, Germany), and the
incorporated radioactivity was measured in an automatic beta counter
(Inotech, Asbach, Germany). In T cell proliferation assays, the BMM
were irradiated (30 Gy) to exclude a possible contribution to the
proliferative response.
To get supernatant of activated T cells, 96-well flat-bottom plates
(Costar) were precoated with 50 µl of anti-CD3 mAb (5 µg/ml
in PBS) for 2 h at 37°C. After washing with PBS, 105
T cells were added to each well in a final volume of 200 µl and
incubated for 48 h.
Statistical evaluation
Results were analyzed by analysis of variance without repeated measurement correction and by Dunnett’s multiple comparison test.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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In previous experiments we had demonstrated iNOS/arginase
dichotomy by cytokine stimulation of BMM of (BALB/c x
C57BL/6)F1 (H2d x H2b) mice
(9, 10). The T cell clones and TCR transgenic mice available for the
present study were restricted for H2k, so that we chose
strain AKR/N as the donor of BMM. Figure 1
shows that the previously described
alternative induction of iNOS and arginase by IFN- and IL-4,
respectively, holds true for strain AKR/N macrophages as well.
Moreover, additional cytokines were tested, and cytokine stimulation
was performed for 48 h in microtiter plates similar to the
cellular coculture systems described below. LPS alone stimulated both
pathways of macrophage arginine metabolism to moderate levels. IFN-
was the only cytokine inducing iNOS and failed to induce arginase
activity. Furthermore, IFN- enhanced the LPS-mediated induction of
iNOS and, at the same time, inhibited LPS-induced arginase activity
(10, 16). Conversely, up-regulation of arginase activity without iNOS
induction was seen with each of the typical Th2 cytokines, IL-4, IL-10,
and IL-13, with IL-4 consistently being the most potent inducer. All
other cytokines tested (IL1-ß, IL-2, IL-5, IL-6, and IL-12) had no
effect on L-arginine metabolism (data not shown).
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In the next set of experiments, iNOS or arginase induction was
determined in a cellular coculture system with AKR-BMM as APCs and
established Th1 (AE7) and Th2 (D10G4) CD4+ T cell
clones. The cytokine production patterns of both T cell clones were
confirmed by intracellular cytokine staining (Fig. 2A).
The data show that the two clones represent extremely polarized forms
of Th1 and Th2 cells. BMM were cocultivated with each of the T cell
clones and graded amounts of the appropriate Ag. Activation of the T
cells was determined by proliferation and cytokine secretion (Fig. 2, B and C), and the resulting phenotype of
macrophage L-arginine metabolism was measured by nitrite
production (Fig. 2D) or arginase activity (Fig. 2E). To exclude the possibility that the T cells
themselves contributed to iNOS or arginase induction in our coculture
system, we stimulated both T cell clones with all the above (Fig. 1
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mentioned cytokines as well as with Con A (5 µg/ml), PMA (1–100
ng/ml) plus A23187 (50–1000 ng/ml), or plate-bound anti-CD3 Abs
(see Materials and Methods); nitrites or arginase
activity were never detected (data not shown). The coculture system
yielded unambiguous results. In the presence of the Th1 T cell clone
AE7, an Ag dose-dependent up-regulation of iNOS activity (plateauing at
about 30 µM nitrites) without concurrent induction of arginase was
seen. Nitrite determination truly reflected iNOS activity, as
demonstrated by the addition of the iNOS inhibitor L-NMMA,
which nearly abolished detectable nitrites (Fig. 2D)
and at the same time restored the proliferative response of the T cell
clone (Fig. 2B), confirming the known inhibitory
effect of NO on T cell proliferation (17). Conversely, coculture with
the Th2 T cell clone D10G4 led to an exclusive induction of arginase
activity without induction of nitrites.
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with individual
cytokines (see Fig. 1) (10). Moreover, considerable arginase activity
was induced at Ag concentrations (
1 µg/ml conalbumin) that
appeared too low to result in detectable production of IL-4 in the
culture. This raises the question of whether cytokine secretion alone
or additional mechanisms are responsible for arginase induction by Th2
cells (see also below, Fig. 3).
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early in a developing
immune response
The T cell clones D10G4 and AE7 represent the extreme endpoints of
CD4+ T cell polarization. The in vivo situation of a
developing immune response (18) may be characterized by more moderately
polarizing conditions. To mimic the latter, we chose as a model the in
vitro differentiation of naive 2B4 TCR transgenic CD4+ T
cells in the presence of Ag/APC and either IL-4 or IL-12, without
blocking endogenously produced IL-12 or IL-4, respectively. FACS-sorted
naive CD62Lhigh CD4+ T cells were cultured for
1 wk (as described in Materials and Methods), and the
resulting T cell populations were analyzed by intracellular cytokine
staining (Fig. 3A). Furthermore, they were used as
responding T cells in Ag presentation assays with BMM as APC (Fig. 3, B–D). The moderately polarizing conditions were
reflected in the resulting phenotype of the T cells; the IL-12 primed
population consisted of about 6% IL-4+, 31%
IFN-+, and 54% TNF-+ T cells, and the
IL-4-primed population consisted of about 30% IL-4+, 1%
IFN-+, and 38% TNF-+ T cells (Fig. 3A). Furthermore, IL-10, which can be secreted by T
cells or by macrophages (19), was detectable in the culture supernatant
during Ag presentation assays with both types of polarized T cells
(Fig. 3B). Thus, as expected, polarization remained
incomplete in the Th1- and Th2-like cell populations. Nevertheless,
their presence during Ag presentation assays resulted in macrophage
phenotypes that were strongly polarized in L-arginine
metabolism (Fig. 3, C and D). Depending on
the Ag concentration, the IL-12-primed T cells induced high levels of
nitrites in the culture (plateau at about 60 µM) without
up-regulating macrophage arginase. The opposite holds true for the
IL-4-primed T cells. Again, arginase levels reached a plateau at about
2000 mU/106 cells, a level severalfold greater than upon
addition of IL-4 alone. No nitrites were detected until arginase
activity had reached plateau levels. However, further increased
concentrations of Ag were accompanied by iNOS induction, presumably
reflecting the incomplete polarization of the IL-4-primed T cells.
IFN--producing cells (1.35%) could clearly be detected by
intracellular cytokine staining, although simultaneous cytokine
determinations by ELISA (Fig. 3B) in the culture
supernatant revealed no detectable IFN-. Furthermore, TNF-
produced by the IL-4-primed T cell population (38.51%
TNF-+ cells) may synergize with low amounts of IFN-
in iNOS induction. Essentially the same dichotomous pattern of enzyme
induction was seen if peptide (moth cytochrome c peptide)
was used as Ag instead of PCC (data not shown).
Soluble factors, most importantly IL-4 and IL-10, are responsible for arginase induction during a Th2-dominated immune response
As shown by the results in Figures 2 and 3, Th2 cell-induced
arginase activity reached levels considerably greater than those
inducible by the strongest soluble agonist, IL-4. Moreover, induction
took place at Ag concentrations significantly lower than those required
for induction of IL-4 to levels detectable by ELISA. Because
interactions between macrophages and T cells include direct
cell-to-cell contact (20), we considered that such direct interactions,
possibly by costimulatory molecules, were involved in the induction of
arginase in our coculture system. The role of soluble factors was
ascertained by transfer of the 48 h supernatant of a D10G4-BMM Ag
presentation assay (Fig. 4A) onto fresh BMM.
The resulting levels of arginase induction in the second culture (Fig. 4, B and C) were comparable to those found
in the first, even if the supernatant was used at a final concentration
of only 25%. Moreover, the supernatant of plate-bound
anti-CD3-stimulated D10G4 cells induced arginase in BMM to
levels comparable to those reached in the cellular coculture system
(Fig. 4D).
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demonstrates that each of the two Abs
alone inhibited the induction of arginase partially. Inhibition was
enhanced if both Abs were added together. However, considerable
arginase activity remained detectable even if both Abs were added. This
may be due to the existence of other known (e.g., IL-13) or unknown
arginase-inducing cytokines. Together, the experiments in Figures 4 and 5 suggest that cytokines produced by the T cells are mainly (if not
exclusively) responsible for the induction of arginase, although
autoregulatory cytokine secretion of the macrophages (e.g., production
of IL-10) is not formally ruled out.
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We suspected synergistic mechanisms to account for the superior
efficacy of Th2 cells over Th2 cytokines in the induction of arginase
in macrophages. Synergistic effects in iNOS induction among Th1-type
cytokines have been described (21); IL-2, TNF-, and TNF-ß are
unable to induce iNOS activity on their own, but increase the
IFN--induced iNOS activity (see also Fig. 1 for synergism between
IFN- and TNF-). We investigated possible additive or synergistic
effects among the Th2-type cytokines, IL-4, IL-5, IL-6, IL-10, and
IL-13, in arginase induction in BMM. In a pilot experiment (not
shown) it was determined that arginase levels induced in AKR-BMM by
IL-4, IL-10, and IL-13 individually plateaued at around 400, 200, and
300 mU/106 cells, respectively (see also Fig. 1). In
subsequent experiments one cytokine was held constant (at 10 U/ml), and
a second cytokine (0–50 U/ml) was titrated into the culture system.
When IL-4 was held constant (Fig. 6A), addition of minimal
concentrations of IL-10 pushed arginase levels to >1000
mU/106 cells, and a plateau at about 3000
mU/106 cells was reached. Similar plateau arginase levels
were obtained in the reverse combination, although at higher
concentrations of IL-4. (Fig. 6B), IL-13 alone was less
effective in arginase induction compared with IL-4 (Fig. 1), as
reflected in the lower arginase activity reached during synergism of
IL-13 with IL-10, which plateaued at about 1000 mU/106
cells (Fig. 6, B and C). IL-4 and IL-13
showed no cooperation, not even additive effects; when arginase was
already up-regulated by a fixed concentration of IL-4 (10 U/ml), IL-13
had no further influence on arginase activity. When the IL-13
concentration was fixed, the addition of IL-4 increased the response to
a level similar to that reached by IL-4 alone (Fig. 6, A and
C). IL-13 had no augmenting influence on IL-4- plus
IL-10-induced arginase activity; IL-5 and IL-6 showed no modulating
influence on Th2 cytokine-induced arginase up-regulation (data not
shown). Together the data suggest an impressive synergism among
Th2-type cytokines in the induction of arginase that is most pronounced
between IL-4 and IL-10 and, to a lesser degree, between IL-13 and
IL-10. In quantitative terms, the synergistic arginase response to
combinations of IL-4 and IL-10 appears to be sufficient to account for
the unexpectedly high arginase levels induced by Th2 cells.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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induces specifically iNOS, and the Th2-type cytokines
IL-4 and IL-10 (9, 10) as well as IL-13 (this study) up-regulate
arginase. Furthermore, a mutual negative feedback between both pathways
suggested a competitive regulation; IFN- was found to suppress
arginase activity in macrophages stimulated with LPS or IL-4 (10),
whereas the iNOS-suppressing activities of IL-4 and IL-10 are well
established (19, 25). Interestingly,
N-hydroxy-L-arginine, the intermediate during NO
synthesis, was a strong inhibitor of liver and macrophage arginase
(26). The scenario of two alternative and competitive modes of
L-arginine metabolism in macrophages was further completed
by our demonstration of two distinct signal transduction pathways:
protein kinase A in arginase induction as opposed to protein kinase C
in iNOS up-regulation (27). The competitive nature of the regulation of
L-arginine metabolism in macrophages described in this
paper may point toward a biologic significance of arginase or its
products, similar to that of iNOS and NO. The demonstration of
up-regulated iNOS within intratumor macrophages during tumor rejection
as opposed to induced arginase during progressive tumor growth (28) as
well as the reciprocal regulation of both enzymes during wound healing
(29) further support this idea.
The purpose of the present study was to determine whether the
iNOS/arginase balance in macrophages was regulated by Th1/Th2 cells in
a similar fashion as by the corresponding cytokines. We chose
well-known Th1 and Th2 CD4+ T cell clones as
representatives of completely polarized immune responses. These cells
were stimulated in vitro by their specific Ag using BMM as APCs. In
a recent report it has been demonstrated that Th1, but not Th2, cell
clones were able to induce NO production in murine macrophages (in this
case in ANA-1 macrophages and thioglycolate-elicited peritoneal
macrophages) (30). Conversely, we now demonstrate that a Th2, but not a
Th1, cell clone up-regulated arginase. Moreover, we confirm the
differential effects of Th1 vs Th2 cell clones on NO production. We
could not detect nitrites or arginase activity under different modes of
stimulation of the T cells used in this study. We, therefore, do not
think that in our experiments T cells contributed to the production of
iNOS, as described in one earlier report for malaria-specific Th1 T
cell clones (31), or arginase activity. Furthermore, our experiments
with in vitro polarized naive T cells suggest that the competitive
induction of the two L-arginine-metabolizing pathways may
be established early in a developing immune response and is not a
phenomenon restricted to highly polarized, long term cultured T cell
clones. The in vitro polarized Th1 and Th2 T cells carried the same
clonal TCR, excluding that the induced dichotomy in macrophage
metabolism depends on factors contributed by the Ag. Furthermore, the
phenomenon appears to be independent of the genetic background of the
macrophages: BMM of C3H, B10BR, and CBA/N mice gave essentially
similar results as the AKR/N mice used here (data not shown). As an
indicator of iNOS induction, we determined the accumulation of nitrite,
one of NO’s stable degradation products, in the supernatant at the end
of the cell culture period. Arginase activity, on the other hand, was
measured at the end of the culture period in the cell lysate as an
end-point enzymatic assay under optimal conditions (unlimited substrate
availability, optimum pH 9.5). We are aware of the fact that our
results do not therefore allow for a direct quantitative comparison of
the absolute fluxes of L-arginine through either of the two
metabolic pathways. This indeed was not the aim of our work and should
be investigated by future radioactive labeling studies. The essential
finding of our study, namely the clear-cut Th1/Th2-mediated all-or-none
induction of either of the two enzymes, is in our view not impaired by
this restriction of quantification.
A striking feature of the cellular coculture assays was that the Th2
cell-induced arginase activity exceeded by far the levels reached after
stimulation of the macrophages with individual cytokines. We considered
three possible explanations for this pronounced quantitative
difference: the participation of cell membrane-bound structures, the
existence of as yet unknown potent arginase-inducing cytokines, and
synergism among Th2-type cytokines in arginase induction. An earlier
report demonstrated the participation of membrane-bound structures on T
cells in iNOS induction in macrophages (32), and a recent report showed
the participation of the CD40-CD40 ligand interaction during the early
phase of this iNOS induction (33). We found that arginase induction was
fully transferable by culture supernatants, including supernatants of
anti-CD3-activated Th2 cells. Thus, direct cell-cell interactions
may not be required in arginase induction by T cells. An unresolved
problem is the relatively high background of arginase in the coculture
assays with the established Th2 cell clone D10G4. Even without addition
of Ag, a remarkable up-regulation of arginase activity in the
macrophages (in the range of 400 mU/106 cells) was
consistently found. Possible explanations include cell membrane-bound
cytokines or other structures on the T cells as well as minute amounts
of secreted cytokines by not completely resting T cells. Nevertheless,
the conclusion that soluble factors predominate during Th2 T
cell-mediated arginase induction is further strengthened by our
Ab-blocking experiments (Fig. 5), demonstrating a pivotal role for IL-4
and IL-10 in Th2 cell-induced arginase activity in BMM.
The excessive arginase induction by Th2 cells is fully accounted for by
synergism between IL-4 and IL-10 and, to a lesser degree, between IL-13
and IL-10. This Th2 cytokine synergism also seems to be the explanation
for the pronounced up-regulation of arginase by low or even
undetectable individual cytokine concentrations (Figs. 2 and 3), making
arginase activity a high sensitivity Th2 read-out system. The lack of
synergism between IL-4 and IL-13 was no surprise, since IL-4 and IL-13
are known to partially share the same receptor and signal transduction
pathways and exert similar biologic functions (34, 35). Few reports in
the literature have demonstrated synergism among IL-4 and IL-10,
including the inhibition of schistosomulum killing and NO production by
IFN--activated murine macrophages (36) or the inhibition of
delayed-type hypersensitivity to Leishmania majorin mice (37) by an unknown mechanism. These reports fit into the
prevailing view on Th2 cytokines as macrophage-deactivating agents. In
particular, IL-4 was demonstrated to potently inhibit NO synthesis by
inflammatory murine macrophages (25, 38), whereas IL-10 preferably
suppresses the macrophage release of TNF- and reactive oxygen
intermediates (39). Furthermore, IL-4 and IL-10 were recently shown to
inhibit killing of Leishmania spp. in human macrophages by
decreasing NO generation (40). In an extension of these findings, we
clearly demonstrate that the down-regulating activities of IL-4, IL-10,
and IL-13 are intimately associated with alternative macrophage
activation. The role of Th2 cytokines as an alternative class of
macrophage-activating agents is underscored by the findings that IL-4
and IL-13 potently enhance murine macrophage MHCII (35, 41) as well as
mannose receptor expression (35, 42). Even for IL-10, generally
considered an immunoinhibitory cytokine (19, 39), published data
demonstrate immunostimulatory properties as well (43). Interestingly,
TGF-ß, a cytokine not attributable to either the Th1 or Th2 subset of
T cells (2), was reported to suppress murine macrophage NO release (44)
and to stimulate arginase activity in rats (45).
To summarize, in the present study we were able to demonstrate for the first time that arginase activity in murine macrophages is exclusively up-regulated during Th2 (as opposed to Th1)-dominated immune reactions. This process of Th2 cell-induced, Ag-dependent up-regulation of arginase activity is mediated by cytokines (especially IL-4 and IL-10). Finally, we demonstrated a previously unknown mechanism of synergy among Th2-type cytokines that fully accounts for the extraordinarily high arginase levels (as opposed to stimulation by individual Th2 cytokines) in the cellular coculture systems. Taken together with the known Th1-mediated up-regulation of iNOS, our results corroborate the hypothesis of two alternative L-arginine-metabolizing enzymatic pathways, reflecting the two alternative functional modes of the CD4+ T cell compartment.
One possible function of Th2 cytokine-induced arginase might be to divert the common substrate L-arginine away from iNOS and thereby to suppress NO output (10, 23). Further speculations concern the arginase product L-ornithine, the precursor amino acid for the synthesis of polyamines (spermine, spermidine, and putrescine) that participate in the process of cell growth and are known to interact with DNA and RNA and to influence protein synthesis (46). Interestingly, spermine was shown to suppress NO production in LPS-stimulated macrophages (47) as well as to inhibit specifically the synthesis of proinflammatory cytokines in human mononuclear cells (48). The macrophage is capable of adopting extraordinarily diverse metabolic and functional phenotypes (49). The specific, high level induction of arginase in macrophages (as demonstrated here) might indeed turn out to be a key effector mechanism by which Th2 T cells regulate proinflammatory immune responses. Furthermore, it might be fruitful to investigate the role of up-regulated arginase in host-protective (50), Th2-driven immune responses as well as during allergy.
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2 Abbreviations used in this paper: NO, nitric oxide; iNOS, inducible nitric oxide synthase; L-NMMA, N-monomethyl-L-arginine; PCC, pigeon cytochrome c; PE, phycoerythrin; BMM, bone marrow-derived macrophages.
Received for publication October 31, 1997. Accepted for publication February 4, 1998.
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|
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|
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|
|
|
|
|
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|
|
|
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|
|
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|
|
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|
|
|
|
|
|
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|
|
|
|
|
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|
|
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|
|
|
|
 |
|
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|
|
|
|
|
|
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|
|
|
|
|
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|
|
|
|
 |
|
 S. G. Correa, C. E. Sotomayor, M. P. Aoki, C. A. Maldonado, and G. A. Rabinovich Opposite effects of galectin-1 on alternative metabolic pathways of L-arginine in resident, inflammatory, and activated macrophages Glycobiology, February 1, 2003; 13(2): 119 - 128. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
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|
|
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|
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G. Raes, P. De Baetselier, W. Noel, A. Beschin, F. Brombacher, and G. Hassanzadeh Gh. Differential expression of FIZZ1 and Ym1 in alternatively versus classically activated macrophages J. Leukoc. Biol., April 1, 2002; 71(4): 597 - 602. [Abstract] [Full Text] [PDF]
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D. Tzachanis, A. Berezovskaya, L. M. Nadler, and V. A. Boussiotis Blockade of B7/CD28 in mixed lymphocyte reaction cultures results in the generation of alternatively activated macrophages, which suppress T-cell responses Blood, February 15, 2002; 99(4): 1465 - 1473. [Abstract] [Full Text] [PDF]
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Y. Murata, T. Shimamura, and J. Hamuro The polarization of Th1/Th2 balance is dependent on the intracellular thiol redox status of macrophages due to the distinctive cytokine production Int. Immunol., February 1, 2002; 14(2): 201 - 212. [Abstract] [Full Text] [PDF]
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T. Ravasi, C. Wells, A. Forest, D. M. Underhill, B. J. Wainwright, A. Aderem, S. Grimmond, and D. A. Hume Generation of Diversity in the Innate Immune System: Macrophage Heterogeneity Arises from Gene-Autonomous Transcriptional Probability of Individual Inducible Genes J. Immunol., January 1, 2002; 168(1): 44 - 50. [Abstract] [Full Text] [PDF]
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M. Hesse, M. Modolell, A. C. La Flamme, M. Schito, J. M. Fuentes, A. W. Cheever, E. J. Pearce, and T. A. Wynn Differential Regulation of Nitric Oxide Synthase-2 and Arginase-1 by Type 1/Type 2 Cytokines In Vivo: Granulomatous Pathology Is Shaped by the Pattern of L-Arginine Metabolism J. Immunol., December 1, 2001; 167(11): 6533 - 6544. [Abstract] [Full Text] [PDF]
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F. H. Falcone, P'n. Loke, X. Zang, A. S. MacDonald, R. M. Maizels, and J. E. Allen A Brugia malayi Homolog of Macrophage Migration Inhibitory Factor Reveals an Important Link Between Macrophages and Eosinophil Recruitment During Nematode Infection J. Immunol., November 1, 2001; 167(9): 5348 - 5354. [Abstract] [Full Text] [PDF]
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V. Iniesta, L. C. Gomez-Nieto, and I. Corraliza The Inhibition of Arginase by N{omega}-Hydroxy-L-Arginine Controls the Growth of Leishmania Inside Macrophages J. Exp. Med., March 19, 2001; 193(6): 777 - 784. [Abstract] [Full Text] [PDF]
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B. Namangala, P. De Baetselier, W. Noël, L. Brys, and A. Beschin Alternative versus classical macrophage activation during experimental African trypanosomosis J. Leukoc. Biol., March 1, 2001; 69(3): 387 - 396. [Abstract] [Full Text]
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R. Rutschman, R. Lang, M. Hesse, J. N. Ihle, T. A. Wynn, and P. J. Murray Cutting Edge: Stat6-Dependent Substrate Depletion Regulates Nitric Oxide Production J. Immunol., February 15, 2001; 166(4): 2173 - 2177. [Abstract] [Full Text] [PDF]
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I. B. Kremer, M. P. Gould, K. D. Cooper, and F. P. Heinzel Pretreatment with Recombinant Flt3 Ligand Partially Protects against Progressive Cutaneous Leishmaniasis in Susceptible BALB/c Mice Infect. Immun., February 1, 2001; 69(2): 673 - 680. [Abstract] [Full Text] [PDF]
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M. Hesse, A. W. Cheever, D. Jankovic, and T. A. Wynn NOS-2 Mediates the Protective Anti-Inflammatory and Antifibrotic Effects of the Th1-Inducing Adjuvant, IL-12, in a Th2 Model of Granulomatous Disease Am. J. Pathol., September 1, 2000; 157(3): 945 - 955. [Abstract] [Full Text] [PDF]
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M. Munder, K. Eichmann, J. M. Moran, F. Centeno, G. Soler, and M. Modolell Th1/Th2-Regulated Expression of Arginase Isoforms in Murine Macrophages and Dendritic Cells J. Immunol., October 1, 1999; 163(7): 3771 - 3777. [Abstract] [Full Text] [PDF]
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P. Bobe, K. Benihoud, D. Grandjon, P. Opolon, L. L. Pritchard, and R. Huchet Nitric Oxide Mediation of Active Immunosuppression Associated With Graft-Versus-Host Reaction Blood, August 1, 1999; 94(3): 1028 - 1037. [Abstract] [Full Text] [PDF]
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J. J. Lasarte, F. J. Corrales, N. Casares, A. Lopez-Diaz de Cerio, C. Qian, X. Xie, F. Borras-Cuesta, and J. Prieto Different Doses of Adenoviral Vector Expressing IL-12 Enhance or Depress the Immune Response to a Coadministered Antigen: the Role of Nitric Oxide J. Immunol., May 1, 1999; 162(9): 5270 - 5277. [Abstract] [Full Text] [PDF]
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 C. A. Louis, V. Mody, W. L. Henry Jr., J. S. Reichner, and J. E. Albina Regulation of arginase isoforms I and II by IL-4 in cultured murine peritoneal macrophages Am J Physiol Regulatory Integrative Comp Physiol, January 1, 1999; 276(1): R237 - R242. [Abstract] [Full Text] [PDF]
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F. Facchetti, W. Vermi, S. Fiorentini, M. Chilosi, A. Caruso, M. Duse, L. D. Notarangelo, and R. Badolato Expression of Inducible Nitric Oxide Synthase in Human Granulomas and Histiocytic Reactions Am. J. Pathol., January 1, 1999; 154(1): 145 - 152. [Abstract] [Full Text] [PDF]
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