The JI Acurri Cytometers
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     
 

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kuroda, E.
Right arrow Articles by Yamashita, U.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kuroda, E.
Right arrow Articles by Yamashita, U.
The Journal of Immunology, 2001, 166: 1650-1658.
Copyright © 2001 by The American Association of Immunologists

Prostaglandin E2 Up-Regulates Macrophage-Derived Chemokine Production but Suppresses IFN-Inducible Protein-10 Production by APC1

Etsushi Kuroda, Tsutomu Sugiura, Kazumasa Okada, Kazuya Zeki and Uki Yamashita2

Department of Immunology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan


   Abstract
Top
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 References
 
PGE2 has been known to suppress Th1 responses. We studied the role of PGE2 in two representative chemokines, macrophage-derived chemokine (MDC) and IFN-inducible protein-10, production by LPS- or CD40-stimulated spleen cells. The production of MDC, one of the ligands for CCR4 preferentially expressed on Th2, was enhanced in nonstimulated, LPS-, CD40-, or CD3-stimulated spleen cells by the pretreatment with PGE2, while the production of IFN-inducible protein-10, a representative ligand for CXC chemokine receptor 3 expressed on Th1, was suppressed. MDC production was also enhanced by IL-4, IL-5, and intracellular cAMP-elevating agents such as dibutyryl cAMP and 3-isobutyl-1-methylxanthine, and the effect of IL-4, IL-5, and PGE2 was additive. However, the pretreatment with IL-6, IL-10, or TGF-{beta}, or the neutralization of IFN-{gamma} or IL-12 had no effect on MDC production. B cells, macrophages, and dendritic cells were main producers of MDC, while T cells produced only a small amount of MDC. MDC production by B cells was equally stimulated by LPS and anti-CD40 Ab, while that by macrophages and dendritic cells was more markedly stimulated by anti-CD40 Ab, and PGE2 further enhanced MDC production by these stimulated cells. These results indicate that PGE2 regulates Th1/Th2-related chemokine production by B cells, macrophages, and dendritic cells, and that this is a new function of PGE2 for the regulation of Th2 immune responses at the induction and activation stages.


   Introduction
Top
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 References
 
The activation of CD4+ T cell subsets, Th1 and Th2, is one of the most important factors to determine the characters of several immunological diseases. In general, the activation of Th1 promotes cellular immune responses via IFN-{gamma} production and is related with the elimination of intracellular pathogens, while the activation of Th2 enhances humoral immune responses via IL-4 and IL-5 and is related with allergic diseases. Th1 and Th2 are differentiated from naive T cells after the Ag recognition, which are influenced by surface molecules of APCs, Ag doses, and cytokines (1, 2, 3, 4, 5, 6). The selective recruitment of Th subset to an inflammatory site is also important to determine the character of immune responses. Although the mechanism of this selective recruitment still remained unclear, recent studies suggest that the patterns of chemokines and their receptors determine the selective recruitment of Th1 and Th2 (7, 8, 9, 10).

Th1 and Th2 express different chemokine receptors and respond to distinct types of chemokines. CXC chemokine receptor 3 (CXCR3)3 and CCR5 are highly expressed on Th1, and IFN-inducible protein-10 (IP-10, new nomenclature: CXCL10 (7)), which binds to CXCR3, induces chemotaxis of Th1, while CCR3 and CCR4 are preferentially expressed on Th2, and ligands for CCR4, macrophage-derived chemokine (MDC, CCL21 (7)), and thymus and activation-regulated chemokine (TARC, CCL17 (7)) promote the migration of Th2 (7, 8, 9, 10, 11, 12, 13). The relationship between chemokines and Th1/Th2 responses in vivo has been also investigated in several human diseases and mouse models. In multiple sclerosis and rheumatoid arthritis, which are Th1-related diseases, CCR5+ and CXCR3+ T cells are accumulated, and their ligands, macrophage-inflammatory protein (MIP)-1{alpha} (CCL3 (7)) and IP-10, are detected at inflammatory sites (14, 15). On the other hand, a higher expression of TARC is detected on Reed-Sternberg cells of Hodgkin’s lymphoma that have the characteristic feature of infiltration of Th2 (16). In murine models of allergic airway inflammation and atopic dermatitis, NC/Nga mouse, and endotoxin-induced liver injury, the accumulation of CCR4+ Th2 and the production of MDC and TARC play an important role in the induction of tissue injuries (17, 18, 19, 20).

IP-10 and MDC are mainly produced by APCs such as dendritic cells, monocytes, macrophages, and B cells, and highly regulated by Th1- and Th2-derived cytokines. In general, IFN-{gamma} up-regulates IP-10, but suppresses MDC production, while IL-4 and IL-13 have opposite effects (9, 12, 13, 21, 22, 23). Thus, Th1 and Th2 cytokines regulate Th1- and Th2-related chemokine (IP-10 and MDC) productions, and reversely these chemokines also regulate Th1/Th2 responses. However, there is no report about the role of PGE2 in Th1/Th2-related chemokine productions.

PGE2, an arachidonic acid metabolite, produced in various types of cells, regulates broad range of physiological functions (24). In the immune system, PGE2 is also mainly produced by APCs, and the effects are almost suppressive on Th1-related immune responses and augment Th2-related immune responses. PGE2 preferentially down-regulates IL-12R expression and inhibits the differentiation of Th1 (25, 26). PGE2 also suppresses LPS-induced IL-12 production by macrophages, and IL-12 and PGE2 derived from APCs down-regulate IFN-{gamma} production by T cells (27, 28). In B cell function, PGE2 enhances IgE production of IL-4- and LPS-stimulated B cells in vitro (29). In these reports, the effect of PGE2 is similar to IL-4 in immune responses.

In this study, we examined the effect of PGE2 on IP-10 and MDC productions in vitro, and demonstrate that PGE2 up-regulates MDC production, but down-regulates IP-10 production by APCs induced with LPS and CD40 stimulation. These results suggest that PGE2 plays an important role not only for the differentiation of Th2, but also for the recruitment of Th2 via the preferential production of Th2-related chemokines.


   Materials and Methods
Top
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 References
 
Mice

BALB/c male mice, 7–8 wk old, were purchased from Seac (Oita, Japan), and were maintained in our laboratory under specific pathogen-free condition.

Cytokines, chemokines, Abs, and other reagents

PGE2, indomethacin, dibutyryl cAMP (dbcAMP), 3-isobutyl-1-methylxanthine (IBMX), and o-phenylenediamine were purchased from Sigma (St. Louis, MO). Recombinant mouse IL-12, IFN-{gamma}, and MDC were purchased from R&D Systems (Minneapolis, MN). Recombinant mouse IL-4, IL-5, IL-6, and IL-10 were purchased from PeproTech (London, U.K.). Human TGF-{beta}, anti-mouse MDC, and anti-mouse CRG-2 (IP-10) Abs were purchased from Genzyme/Techne (Cambridge, MA). Anti-mouse IFN-{gamma} and anti-mouse IL-12 Abs were purchased from PharMingen (San Diego, CA). Recombinant mouse IP-10/CRG-2 was purchased from Dako Japan (Kyoto, Japan). Peroxidase-conjugated rabbit anti-goat IgG Ab was purchased from MBL (Nagoya, Japan).

Preparation of cell

Spleen cell suspension was prepared and maintained in RPMI 1640 medium (Nissui Pharmaceutical, Tokyo, Japan) supplemented with 10 mM HEPES, pH 7.2, and 10% FBS (BioWhittaker, Walkersville, MD). B cells (B220+ cells), macrophages (CD11b+ cells), dendritic cells (CD11c+ cells), and Th cells (CD4+ cells) were purified from spleen cells by magnetic cell sorting according to the manufacturer’s procedures (MACS; Miltenyi Biotech, Bergish-Gladbach, Germany). Purity of sorted cells was >95%, as determined by flow cytometry. In some experiments, B220-, CD11b-, and CD11c-negative cells were used as T cells (<5% Ig+, <5% Mac-1+, and >95% CD3+). The number of whole spleen cells and sorted cells was adjusted to 5 x 106/ml (whole spleen cells, B cells and T cells) or 2 x 106/ml (macrophages, dendritic cells, and macrophages/dendritic cells fraction), and used for experiments.

In vitro culture and stimulation of cells

Whole spleen cells or sorted cells were cultured in 24-well culture plates (Falcon 3047; Becton Dickinson, Franklin Lakes, NJ) with or without PGE2 (1–100 nM), IL-4 (10 ng/ml), IFN-{gamma} (50 ng/ml), IL-12 (50 ng/ml), IL-5 (10 ng/ml), IL-6 (10 ng/ml), IL-10 (10 ng/ml), TGF-{beta} (4 ng/ml), dbcAMP (50 µM), IBMX (50 µM), anti-IFN-{gamma} Ab (1 µg/ml), or anti-IL-12 Ab (1 µg/ml) in the presence of indomethacin (1 µM) for 12 h, and then they were stimulated with LPS (10 µg/ml), anti-CD40 Ab (10 µg/ml), or anti-CD3 Ab (1 µg/ml) for an additional 24, 48, or 72 h. Purified CD4+ T cells were stimulated with plate-coated anti-CD3 Ab in the presence or absence of PGE2 or IL-4 for 48 h. In some experiments, cells were cultured without indomethacin for 12 h, and then stimulated. The culture supernatants were collected and used for the assay of chemokine or PGE2, as described below.

Chemokine mRNA analysis

mRNA expression was detected by RT-PCR. Total cellular RNA was extracted by TRIzol (Life Technologies, Rockville, MD), according to the manufacturer’s protocol. First strand cDNA was synthesized from 5 µg of total RNA by Superscript II RNase H-reverse transcriptase (Life Technologies), following the instruction of manufacturer using 0.25 µg of random primer (Life Technologies). One-tenth of synthesized cDNA was amplified by PCR using 50 pmol sense and antisense primers with 1 U of Taq polymerase (Boehringer Mannheim, Mannheim, Germany) in a total volume of 50 µl. PCR cycles were performed for 1 min at 94°C for denaturation, 1 min at 55°C for annealing, and 2 min at 72°C for extension, and at the first cycle, denaturation was run for 2 min at 94°C. The sequence of the sense and antisense primers, products size, and PCR cycles are as follows: {beta}-actin, 5'-ACCAACTGGGACGACATGGAGAA-3' and 5'-GTGGTGGTGAAGCTGTAGCC-3', 380 bp, 30 cycles; MDC, 5'-CTGGGTGAAGAAGCTACTCCAT-3' and 5'-TAGAAACTTGGGAGGTGTGTGG-3', 493 bp, 35 cycles; IP-10, 5'-GGGCCAGTGAGAATGAGGGC-3' and 5'-TGAGCTAGGGAGGACAAGGAG-3', 544 bp, 35 cycles. A 10 µl of PCR products was electrophoresed using a 1.5% agarose gel. After ethidium bromide staining (Sigma), PCR products were visualized by UV illumination.

Assay of chemokine

The concentrations of MDC in the supernatants were measured by competitive ELISA inhibition assay (30). In brief, ELISA plates (Nunc-Immuno Plate MaxiSorp; Nunc, Roskilde, Denmark) were coated with 100 µl of 250 ng/ml MDC in PBS at 4°C for 18 h. The wells were then washed and blocked with 300 µl of RPMI 1640 containing 10% FBS at 37°C for 30 min. Standard solutions (40,000~625 pg/ml in culture medium) or culture supernatants and equal volume of 400 ng/ml anti-MDC Ab were mixed well in microtubes and incubated at 37°C for 1 h. After incubation, 200 µl of prepared standard or sample solutions was transferred to each well of MDC-coated plates, and the plates were kept at 4°C for 18 h. The wells were washed and filled with 100 µl of peroxidase-conjugated rabbit anti-goat IgG Ab (diluted 1/2000 in PBS containing 0.05% Tween 20 and 1% BSA). The plates were incubated at 37°C for 2 h, washed, and then substrate (0.04% o-phenylenediamine, 0.01% H2O2 in 50 mM disodium hydrogen phosphate, and 150 mM citric acid, pH 5) was added to the wells. Thirty minutes later, the enzyme reaction was stopped by the addition of 25 µl of 8 N H2SO4, and the absorbance at 490 nm was measured. The results are expressed as mean ± SD of chemokine produced (pg/ml) in triplicate cultures. Competitive ELISA inhibition assay for IP-10 and TARC was also performed by a similar method except for Ab concentration. The concentration of anti-IP-10 Ab and anti-TARC Ab was used at 100 ng/ml. Detection limit of these assays is 1000 pg/ml.

PGE2 enzyme immunoassay

PGE2 in the culture supernatant was measured using STAT-PGE2 Enzyme Immunoassay Kit (Cayman Chemicals, Ann Arbor, MI), according to the manufacturer’s protocol.

Statistics

All experiments were repeated at least three times, and one representative result of each experiment is shown in figures. Statistical analyses were performed using the Student’s t test. A confidence level of <0.05 was considered significant (31).


   Results
Top
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 References
 
PGE2 enhances MDC production, but suppresses IP-10 production in murine spleen cells

At first, we investigated the effect of PGE2 on Th1- and Th2-related chemokine (IP-10 and MDC, respectively) mRNA expression in murine spleen cells. Spleen cells were pretreated with PGE2 for 12 h, then stimulated with LPS, anti-CD3 Ab, or anti-CD40 Ab for an additional 24 h, and mRNA expression was detected by RT-PCR. As shown in Fig. 1Go, both IP-10 and MDC mRNA expressions were up-regulated following stimulation. The pretreatment with PGE2 suppressed the expression of IP-10 mRNA. On the contrary, the expression of MDC mRNA was enhanced by the pretreatment with PGE2.



View larger version (48K):
[in this window]
[in a new window]
  		FIGURE 1. PGE2 regulates IP-10 and MDC mRNA expression by spleen cells. A, Spleen cells were pretreated with or without 100 nM PGE2 in the presence of 1 µM indomethacin for 12 h, and then stimulated with indicated stimulators for additional 24 h. After stimulation, total RNA was extracted from cells and mRNA expression was assessed by RT-PCR. B, Relative amount of IP-10 expression normalized by {beta}-actin. C, Relative amount of MDC expression normalized by {beta}-actin.

 
Next, we assessed IP-10 and MDC protein productions in murine spleen cells. Spleen cells were pretreated with PGE2, IL-4, or IFN-{gamma} for 12 h, and then stimulated with LPS, anti-CD3 Ab, or anti-CD40 Ab for an additional 48 h. IP-10 and MDC in the supernatants were assessed by competitive ELISA inhibition assay. As shown in Fig. 2Go, in spleen cells without stimulation (PBS), MDC production was enhanced by PGE2 (~1.5-fold higher), but IP-10 production was not influenced. On the other hand, IFN-{gamma} suppressed MDC production, but enhanced IP-10 production. These findings were more clearly observed in stimulated spleen cells. In spleen cells stimulated with LPS (a model of bacterial stimulation), anti-CD40 Ab (a model of T-APC interaction), or anti-CD3 Ab (a model of T-APC interaction), PGE2 enhanced MDC production (about 3-fold higher), and this capacity was stronger than that of IL-4. On the other hand, IP-10 production was suppressed by the pretreatment with PGE2 or IL-4. IFN-{gamma} had quite opposite effects of IL-4 and PGE2, which was the same as previously reported (23). We also assessed MDC and IP-10 productions in spleen cells stimulated with soluble anti-CD3 Ab that is known to activate APC via CD40-CD40 ligand (CD40L) interaction (32). The pretreatment with PGE2 enhanced MDC production, and suppressed IP-10 production in anti-CD3 Ab-stimulated spleen cells the same as anti-CD40 stimulation. The amount of MDC was much higher in CD40-stimulated spleen cells than in LPS-stimulated ones, and was moderate in CD3-stimulated ones.



View larger version (37K):
[in this window]
[in a new window]
  		FIGURE 2. PGE2 regulates IP-10 and MDC production by spleen cells. Spleen cells were pretreated with PBS, PGE2, IL-4, or IFN-{gamma} in the presence of indomethacin for 12 h, and then stimulated with indicated stimulators for additional 48 h. After stimulation, cell culture supernatants were collected, and the amounts of IP-10 and MDC were detected by competitive ELISA inhibition assay. The results are expressed as mean ± SD of chemokines (pg/ml) produced by 5 x 106 spleen cells in triplicate cultures of a representative experiment. *, Significantly increased from PBS-pretreated group. #, Significantly decreased from PBS-pretreated group.

 
We also investigated the kinetics of PBS-, LPS-, or anti-CD40 Ab-induced MDC production. Spleen cells were pretreated with PGE2, and then stimulated. Supernatants were harvested at 24, 48, or 72 h after stimulation, and MDC in the supernatants were determined. As shown in Fig. 3Go, the amounts of MDC were increased in a time-dependent manner, and pretreatment with PGE2 clearly enhanced MDC production at 48 and 72 h.



View larger version (18K):
[in this window]
[in a new window]
  		FIGURE 3. Time course of MDC production by spleen cells. Spleen cells were pretreated with or without 100 nM PGE2 in the presence of indomethacin for 12 h, and then stimulated with indicated stimulators for additional 24, 48, and 72 h. Culture supernatants were collected, and the amount of MDC was detected by competitive ELISA inhibition assay. *, Significantly increased from PBS-pretreated group.

 
Enhancement of MDC production by PGE2 is mediated by the accumulation of intracellular cAMP

A representative activity of PGE2 is the elevation of intracellular cAMP (24). We examined whether the enhanced production of MDC is mediated by intracellular accumulation of cAMP in stimulated spleen cells. Spleen cells were pretreated with 1–100 nM PGE2, dbcAMP (membrane-permeable cAMP analogue), or IBMX (cAMP phosphodiesterase inhibitor), and then stimulated with LPS or anti-CD40 Ab for 48 h. As shown in Fig. 4Go, A and B, in both stimuli, the pretreatment with dbcAMP or IBMX also enhanced MDC production the same as PGE2 treatment, but the degree of increase in IBMX treatment was lower than PGE2 or dbcAMP. This difference seems to be caused by a different mechanism of cAMP accumulation between PGE2 and IBMX.



View larger version (61K):
[in this window]
[in a new window]
  		FIGURE 4. Enhanced production of MDC by PGE2 depends on the elevation of intracellular cAMP, but not the activation or suppression of other cytokine production. A and B, Spleen cells were pretreated with PBS, PGE2, dbcAMP, or IBMX in the presence of indomethacin for 12 h, and then stimulated with LPS (A) or anti-CD40 Ab (B) for additional 48 h. C and D, Spleen cells were pretreated with PBS, PGE2, IL-4, IL-5, IL-6, IFN-{gamma}, IL-12, IL-10, TGF-{beta}, anti-IFN-{gamma} Ab, or anti-IL-12 Ab for 12 h, and then stimulated with LPS (C) or anti-CD40 Ab (D) for additional 48 h. Culture supernatants were collected, and the amount of MDC was detected by competitive ELISA inhibition assay. *, Significantly increased from PBS-pretreated group.

 
PGE2 is a potent inhibitor of IFN-{gamma} and IL-12, and an inducer of IL-10 (25, 26, 27, 28). Next, we examined whether the enhanced production of MDC is due to a secondary effect of the suppression of IFN-{gamma} and IL-12 or the induction of IL-10. As shown in Fig. 4Go, C and D, neutralization of IFN-{gamma} or IL-12 was not sufficient to enhance MDC production in LPS- or anti-CD40 Ab-stimulated spleen cells. Moreover, the pretreatment with IL-10 suppressed MDC production. Another representative inhibitory cytokine, TGF-{beta}, had no effect on MDC production. Interestingly, IL-5 also enhanced MDC production the same as IL-4, but IL-4 and IL-5 were not detected in PGE2-treated spleen cells stimulated with LPS or anti-CD40 Ab (data not shown). However, IL-6, another Th2 cytokine, had no effect on MDC production. IFN-{gamma} suppressed MDC production the same as previously reported (23), but IL-12 had no effect.

Enhanced production of MDC by PGE2 is mainly mediated by B cells, macrophages, and dendritic cells

It has been reported that MDC is produced by various types of cells, such as B cells, T cells, and macrophages (33, 34, 35, 36, 37, 38). We investigated the producer of MDC by LPS- or anti-CD40 Ab-stimulated spleen cells in the presence of PGE2. Spleen cells were separated into B cells (B220+ cells), macrophages/dendritic cells (CD11b+ or CD11c+ cells), and T cells (B220-, CD11b-, and CD11c- spleen cells). Purified cell fractions were pretreated with PGE2 or IL-4 for 12 h, and then stimulated with LPS or anti-CD40 Ab for 48 h. PGE2-pretreated B cells produced a higher amount of MDC as compared with nontreated cells in both LPS and anti-CD40 Ab stimulation (Fig. 5Go, A and B). The amount of MDC is much higher in CD40-stimulated macrophages/dendritic cells than other types of cells, and PGE2 pretreatment further enhanced MDC production in macrophages/dendritic cells treated with anti-CD40 Ab (Fig. 5GoD). Contrary to our expectation, however, PGE2 pretreatment slightly reduced MDC production in LPS-stimulated macrophages/dendritic cells (Fig. 5GoC). Macrophages and dendritic cells were further purified, and MDC production was assessed. Dendritic cells produced higher amount of MDC than macrophages did after LPS stimulation, but PGE2 pretreatment had no effect on MDC production in both cells (Fig. 5GoE). Macrophages and dendritic cells produced the same amount of MDC after anti-CD40 Ab stimulation, and PGE2 pretreatment similarly enhanced MDC production in both cells (Fig. 5GoF). It has been reported that CD4+ T cells, especially Th2, are MDC-producing cells. Although we could not detect MDC production in LPS-, anti-CD40 Ab-, or plate-coated anti-CD3 Ab-stimulated T cells (Fig. 5GoG, and data not shown), purified CD4+ T cells produced only a small amount of MDC following the stimulation with immobilized anti-CD3 Ab in the presence of PGE2 (Fig. 5GoH). IP-10 production was also assessed. IP-10 production was not detectable in B cells, T cells, and CD4+ T cells stimulated with anti-CD40 Ab, LPS, or anti-CD3 Ab (data not shown). Macrophages/dendritic cells produced high amount of IP-10 after stimulation with LPS or anti-CD40 Ab, and PGE2 pretreatment suppressed, but IFN-{gamma} pretreatment enhanced IP-10 production in these cells the same as spleen cells (Fig. 5Go, I and J). These results indicate that PGE2 mainly affects APCs (B cells, macrophages, and dendritic cells) to enhance MDC production and to suppress IP-10 production.



View larger version (39K):
[in this window]
[in a new window]
  		FIGURE 5. IP-10 and MDC were mainly produced by APCs in spleen cells. B cells (A and B) and macrophages (M{phi})/dendritic cells (DC) (C, D, I, and J) were pretreated with PGE2, IL-4, or IFN-{gamma} in the presence of indomethacin, and then they were stimulated with LPS (A, C, and I) or anti-CD40 Ab (B, D, and J) for additional 48 h. Macrophages and dendritic cells (E and F) were purified from spleen cells, respectively. Each cell was pretreated for 12 h, and then stimulated for 48 h, as described above. T cells (G) and CD4+ T cells (H) were stimulated with plate-coated anti-CD3 Ab in the presence or absence of PGE2 or IL-4 for 48 h. Culture supernatants were collected, and the amount of MDC and IP-10 was assessed by competitive ELISA inhibition assay. *, Significantly increased from PBS-pretreated group. #, Significantly decreased from PBS-pretreated group.

 
Modulation of enhanced production of MDC in PGE2-treated APCs by cytokines

Next we investigated the effect of cytokines on PGE2-enhanced MDC production in B cells, macrophages, and dendritic cells. As shown in Fig. 6Go, PGE2, IL-4, and IL-5 alone once again enhanced MDC production. The combination of PGE2 and IL-4 or IL-5 had additive effect on MDC production in B cells and macrophages/dendritic cells. The combination of PGE2 and IL-5 was the strongest in MDC production in both cell types, especially in macrophages/dendritic cells. IFN-{gamma}, IL-10, and TGF-{beta} suppressed MDC production, as shown in Fig. 4Go. These cytokines also suppressed the enhanced production of MDC by PGE2 in B cells and macrophages/dendritic cells. IL-6 had no effect on the PGE2-induced enhanced production of MDC. Leukotriene B4 (LTB4), another arachidonic acid derivative, alone or in combination with PGE2, had only a little effect on MDC production in macrophages/dendritic cells.



View larger version (22K):
[in this window]
[in a new window]
  		FIGURE 6. Effect of Th1 or Th2 cytokines on enhanced production of MDC by PGE2-treated cells. B cells (5 x 106/ml, A and B) or macrophages (M{phi})/dendritic cells (DC) (2 x 106/ml, C) were pretreated with IL-4, IL-5, IL-6, IL-10, IFN-{gamma}, TGF-{beta}, or LTB4 in the presence of PGE2 and indomethacin for 12 h, and then stimulated with LPS (A) or anti-CD40 Ab (B and C) for 48 h. Culture supernatants were collected, and the amount of MDC was assessed by competitive ELISA inhibition assay. *, Significantly increased from PGE2-pretreated group. #, Significantly decreased from PGE2-pretreated group.

 
Endogenous PGE2 also serves as an enhancing factor for MDC production

In all experiments to date, cells were pretreated with indomethacin to inhibit endogenous production of PGE2 after stimulation. PGE2 was mainly produced by APCs such as macrophages and dendritic cells. Then we investigated the effect of endogenous PGE2 from macrophages/dendritic cells on MDC production. Splenic macrophages/dendritic cells were pretreated with PBS, PGE2, indomethacin, or PGE2 plus indomethacin for 12 h, and then stimulated with anti-CD40 Ab for an additional 48 h. As shown in Fig. 7Go, indomethacin treatment suppressed MDC production by anti-CD40 Ab stimulation. However, the addition of PGE2 reversed the suppressed production of MDC by indomethacin. PGE2 only slightly enhanced MDC production by anti-CD40 Ab stimulation in the absence of indomethacin. We also assessed the amount of PGE2 in the supernatants after stimulation. Macrophages/dendritic cells produced PGE2 about 4000 pg/2 x 106 (about 1 nM), and indomethacin treatment completely inhibited PGE2 production (Fig. 7Go). These results indicate that endogenously produced PGE2 plays a role to enhance MDC production by macrophages/dendritic cells.



View larger version (38K):
[in this window]
[in a new window]
  		FIGURE 7. Effect of endogenous PGE2 on MDC production. Macrophages/dendritic cells were pretreated with or without PGE2 in the presence or absence of indomethacin (indo) for 12 h and then stimulated with anti-CD40 Ab for additional 48 h. Culture supernatants were collected, and the amount of MDC or PGE2 was assessed by competitive ELISA inhibition assay or enzyme immunoassay kit, respectively. *, Significantly different.

 

   Discussion
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
References
 
There are many reports showing that PGE2 plays an important role for Th2 activation and that PGE2 primarily affects the induction phase of Th differentiation, such as suppression of IL-12 production and Th1 development, and polarization to Th2 (25, 26, 27, 28). PGE2 also suppresses several chemokine production by various types of cells (39, 40, 41, 42, 43). To our knowledge, there has been no report on the up-regulation of chemokine production by PGE2. In this study, we found a novel function of PGE2 in the activation of Th2, that is, PGE2 selectively up-regulates Th2-related chemokine, MDC, production.

MDC and TARC are known as specific Th2 chemoattractants (11, 12, 13). Several reports have shown that the preferential chemoattractant properties of these chemokines are found not only in vitro but also in vivo using model mice with several Th2-related diseases. In the mouse model of airway inflammation, macrophages in lungs (resident and infiltrating macrophages) produced MDC, and the neutralization of MDC by the administration of specific Ab in vivo reduced Th2 recruitment to the inflammatory sites and inhibited airway hyperreactivity (17, 18). In NC/Nga mice, model mice of atopic dermatitis, MDC was highly produced by dermal dendritic cells in the lesional skin (19). In the mouse model of endotoxin liver injury, MDC and TARC were produced by cells in the granuloma, which was mainly composed of macrophages/dendritic cells, and neutralization of TARC protected the mice from acute lethal liver damage caused by Th2 (20). These reports suggest that not only Th2 and eosinophils, but also APCs recruited to the inflamed sites, and Th2 attractant chemokines, MDC or TARC, were mainly produced by APCs. Many reports have indicated that Th2 cytokines, IL-4 and IL-13, are strong inducers of MDC and TARC from APCs (12, 13, 23). However, we found that cell to cell interaction between T cells and APCs was more important for the chemokine production. Furthermore, MDC productions are regulated not only by cytokines, but also by PGE2. PGE2 up-regulated MDC production by CD40-stimulated macrophages/dendritic cells, but the enhancing effect of PGE2 on LPS-stimulated ones was weak (Fig. 5Go). On the other hand, IL-4 up-regulated MDC production by both LPS- and CD40-stimulated macrophages/dendritic cells. These differential effects probably depend on different signal transduction pathways. LPS is a representative APC stimulator. However, CD40 stimulation is a more appropriate model for an activation of APCs in vivo than LPS stimulation, because chemokine productions in vivo are not limited to endotoxin stimulation, and higher amounts of MDC were produced by CD40 stimulation than by LPS stimulation. We consider that, in the induction of chemokines by APCs, T-APC interaction is more important than the stimulation with LPS or cytokines alone, and propose that T-APC interaction, especially CD40-CD40L interaction, is a more effective signal for the induction of chemokine production by APCs. Kornbluth et al. also proposed the importance of CD40-CD40L interaction in chemokine production in an HIV infection model (44).

There are several reports indicating that PGE2 suppresses chemokine mRNA expression and chemokine production in various types of cells, and this suppressive effect depends on the accumulation of intracellular cAMP. For example, PGE2 or intracellular accumulation of cAMP suppresses RANTES production by murine mesangial cells (39), MIP-1{alpha} production by RAW264.7 macrophage cell line (40), IL-8 release from human neutrophils (41), MIP-1{alpha} production by PBMC (42), and IP-10 mRNA expression by cultured keratinocytes (43). Our results also indicate that the IP-10 production of spleen cells is reduced by PGE2 (Fig. 1Go), which is consistent with the report on IP-10 production by keratinocytes (43), and that the enhanced production of MDC by PGE2 also depends on the accumulation of intracellular cAMP (Fig. 2Go). It has also been reported that PGE2 alters the cytokine profile in several cells, for example, PGE2 suppresses IL-12, but enhances IL-10 production via accumulation of intracellular cAMP (27). However, neutralization of IFN-{gamma} or IL-12 and the addition of IL-10 had only a little effect on MDC production (Fig. 2Go). Furthermore, cAMP-enhancing agents such as dbcAMP and IBMX also enhanced MDC production (Fig. 4Go). These results suggest that PGE2-induced elevation of cAMP is an important signal for MDC production. The accumulation of intracellular cAMP is not restricted to the regulation of cytokine and chemokine productions. Several reports have indicated that the elevation of cAMP enhanced the expression of costimulatory molecules, B7-2, on macrophages, and these macrophages preferentially activated Th2 (45, 46). Another report showed that the cAMP accumulation in naive T cells inhibited Th1 development in vitro (25). These reports and our findings indicate that cAMP regulates Th1/Th2 balance at a number of different stages. Interestingly, a representative Th2 activator, IL-4, does not participate in the elevation of cAMP (47). This finding indicates that PGE2 engages Th2 activation in a quite different way from IL-4.

We determined cell types of MDC production and found that all cell types, such as T cells, B cells, macrophages, and dendritic cells, produced MDC following appropriate stimuli and were up-regulated by PGE2 (Fig. 5Go). Several reports have indicated that MDC is produced by T cells and is regulated by Th1/Th2 cytokines such as IL-4 and IFN-{gamma}, and that T cell-derived MDC is very important in several diseases (37, 38). We also found that T cells, especially CD4+ T cells, produced MDC after CD3 ligation in the presence of PGE2 the same as the MDC production by APCs (Fig. 5Go). However, the amount of MDC produced by CD4+ T cells was much lower than that of APCs (B cells, macrophages, and dendritic cells). Therefore, we consider that the main cell types of MDC production are APCs. MDC production by B cells is also an interesting finding, and ABCD-1, a mouse homologue of human MDC, was found to be expressed in B cells and dendritic cells (33, 34). It is well known that B cells participate in the development of Th2 subset, and it has been reported that CD40 stimulation is necessary for the induction of Th2 by B cells (6, 48). However, we suggest that T-B interaction also induces T cell recruitment via B cell-derived chemokines, and PGE2 up-regulate chemokine production by B cells.

We also found an interesting phenomenon regarding IL-5. IL-5 is a well-known cytokine generally detected in allergic diseases and produced by Th2, mast cells, and eosinophils (1). Our results indicate that IL-5 is also an enhancing factor for MDC production by APCs (Figs. 4Go and 6Go). Surprisingly, IL-5 in cooperation with PGE2 induced a much higher amount of MDC from APCs, which was stronger than the combination of IL-4 and PGE2 (Fig. 6Go). These results suggest that IL-5, PGE2, or the combination of both factors are more important than IL-4 in the recruitment of Th2. LTB4, another arachidonic acid derivative that is one of the chemical mediators detected in allergic response, alone and in combination with PGE2, had only a little effect on MDC production (Fig. 6Go).

In conclusion, we found a novel function of PGE2 in Th2 activation. PGE2 preferentially enhanced MDC, but suppressed IP-10 production. These effects depended on the accumulation of intracellular cAMP, but not on the suppression of Th1 cytokines, IFN-{gamma} and IL-12, and the induction of suppressive cytokines, IL-10 and TGF-{beta}. APCs produced especially higher amounts of MDC via CD40 stimulation and PGE2, suggesting that T-APC interaction is very important signal for the induction of MDC. PGE2 has been known as one of the immunosuppressive factors. PGE2 mainly inhibited Th1 development at the induction phase of Th subset differentiation. There are also several reports that PGE2 production is enhanced in Th2-related diseases (49, 50, 51). From our findings, we propose that PGE2 also affects Th2 activation at an effector phase, that is, PGE2 up-regulates Th2-related chemokine production and enhances Th2 recruitment to the inflammatory sites. Large amounts of PGE2 are produced by suppressor macrophages and endothelial cells in chronic inflammation (52). Therefore, we consider that PGE2 plays an important role for the progression of Th2-type inflammation and Th2-related diseases. Further clarification of the regulation mechanism of not only cytokine, but also chemokine and PGE2 productions will be required to understand the precise mechanism of immunological diseases such as autoimmune or allergic diseases.


   Footnotes
 
1 This work was supported in part by a Grant-in-Aid for Scientific Research from the Japanese Government (Grants 12670311). Back

2 Address correspondence and reprint requests to Dr. Uki Yamashita, Department of Immunology, University of Occupational and Environmental Health, School of Medicine, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan. Back

3 Abbreviations used in this paper: CXCR, CXC chemokine receptor; CD40L, CD40 ligand; dbcAMP, dibutyryl cAMP; IBMX, 3-isobutyl-1-methylxanthine; IP-10, IFN-inducible protein-10; LTB4, leukotriene B4; MDC, macrophage-derived chemokine; MIP, macrophage-inflammatory protein; TARC, thymus and activation-regulated chemokine. Back

Received for publication August 7, 2000. Accepted for publication November 10, 2000.


   References
Top
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 References
 

  1. Mosmann, T. R., R. L. Coffman. 1989. Th1 and Th2 cells: different patterns of lymphokine secretion lead to different functional properties. Annu. Rev. Immunol. 7:145.[Medline]
  2. Constant, S. L., K. Bottomly. 1997. Induction of Th1 and Th2 CD4+ T cell responses: the alternative approaches. Annu. Rev. Immunol. 15:297.[Medline]
  3. DeKruyff, R. H., Y. Fang, D. T. Umetsu. 1992. IL-4 synthesis by in vitro primed keyhole limpet hemocyanin-specific CD4+ T cells. I. Influence of antigen concentration and antigen-presenting cell type. J. Exp. Med. 149:3468.
  4. Guéry, J. C., F. Galbiati, S. Smiroldo, L. Adorini. 1996. Selective development of T helper (Th) 2 cells induced by continuous administration of low dose soluble proteins to normal and {beta}2-microglobulin-deficient BALB/c mice. J. Exp. Med. 183:485.[Abstract/Free Full Text]
  5. Kuchroo, V. K., M. P. Das, J. A. Brown, A. M. Ranger, S. S. Zamvil, R. A. Sobel, H. L. Weiner, N. Nabavi, L. H. Glimcher. 1995. B7-1 and B7-2 costimulatory molecules activate differentially the Th1/Th2 developmental pathways: application to autoimmune disease therapy. Cell 80:707.[Medline]
  6. Macaulay, A. E., R. H. DeKruyff, C. C. Goodnow, D. T. Umetsu. 1997. Antigen-specific B cells preferentially induce CD4+ T cells to produce IL-4. J. Immunol. 158:4171.[Abstract]
  7. Zlotnik, A., O. Yoshie. 2000. Chemokines: a new classification system and their role in immunity. Immunity 12:121.[Medline]
  8. Loetscher, P., B. Moser, M. Bassiolini. 2000. Chemokines and their receptors in lymphocyte traffic and HIV infection. Adv. Immunol. 74:127.[Medline]
  9. Sallust, F., A. Lanzavecchia, C. R. Mackay. 1998. Chemokines and chemokine receptors in T-cell priming and Th1/Th2-mediated responses. Immunol. Today 19:568.[Medline]
  10. Mantovani, A.. 1999. The chemokine system: redundancy for robust outputs. Immunol. Today 20:254.[Medline]
  11. Bonecchi, R., G. Bianchi, P. P. Bordignon, D. D’Ambrosio, R. Lang, A. Borsatti, S. Sozzani, P. Allavena, P. A. Gray, A. Mantovani, F. Sinigaglis. 1998. Differential expression of chemokine receptors and chemotactic responsiveness of type 1 T helper cells (Th1s) and Th2s. J. Exp. Med. 187:129.[Abstract/Free Full Text]
  12. Andrew, D. P., M. Chang, J. McNinch, S. T. Wathen, M. Rihanek, J. Tseng, J. P. Spellberg, III C. G. Elias. 1998. STCP-1 (MDC) CC chemokine acts specifically on chronically activated Th2 lymphocytes and is produced by monocytes on stimulation with Th2 cytokines IL-4 and IL-13. J. Immunol. 161:5027.[Abstract/Free Full Text]
  13. Imai, T., M. Nagira, S. Takagi, M. Kakizaki, M. Nishimura, J. Wang, P. W. Gray, K. Matsushima, O. Yoshie. 1999. Selective recruitment of CCR4-bearing Th2 cells toward antigen-presenting cells by the CC chemokines thymus and activation-regulated chemokine and macrophage-derived chemokine. Int. Immunol. 11:81.[Abstract/Free Full Text]
  14. Balashov, K. E., J. B. Rottman, H. L. Weiner, W. W. Hancock. 1999. CCR5+ and CXCR3+ T cells are increased in multiple sclerosis and their ligands MIP-1{alpha} and IP-10 are expressed in demyelinating brain lesions. Proc. Natl. Acad. Sci. USA 96:6873.[Abstract/Free Full Text]
  15. Shixin, Q., J. B. Rottman, P. Myers, N. Kassam, M. Weinblatt, M. Loetscher, A. E. Koch, B. Moser, C. R. Mackay. 1998. The chemokine receptors CXCR3 and CCR5 mark subsets of T cells associated with certain inflammatory reactions. J. Clin. Invest. 101:746.[Medline]
  16. Van den Berg, A., L. Visser, S. Poppema. 1999. High expression of the CC chemokine TARC in Reed-Sternberg cells: a possible explanation for the characteristic T-cell infiltrate in Hodgkin’s lymphoma. Am. J. Pathol. 154:1685.[Abstract/Free Full Text]
  17. Lloyd, C. M., T. Delaney, T. Nguyen, J. Tian, C. Martinez-A., A. J. Coyle, J. C. Gutierrez-Ramos. 2000. CC chemokine receptor (CCR)3/eotaxin is followed by CCR4/monocyte-derived chemokine in mediating pulmonary T helper lymphocyte type 2 recruitment after serial antigen challenge in vivo. J. Exp. Med. 191:265.[Abstract/Free Full Text]
  18. Gonzalo, J. A., Y. Pan, C. M. Lloyd, G. Q. Jia, G. Yu, B. Dussault, C. A. Powers, A. E. I. Proudfoot, A. J. Coyle, D. Gearing, J. C. Gutierrez-Ramos. 1999. Mouse monocyte-derived chemokine is involved in airway hyperreactivity and lung inflammation. J. Immunol. 163:403.[Abstract/Free Full Text]
  19. Vestergaard, C., H. Yoneyama, M. Murai, K. Nakamura, K. Tamaki, Y. Terashima, T. Imai, O. Yoshie, T. Irimura, H. Mizutani, K. Matsushima. 1999. Overproduction of Th2-specific chemokines in NC/Nga mice exhibiting atopic dermatitis-like lesions. J. Clin. Invest. 104:1097.[Medline]
  20. Yoneyama, H., A. Harada, T. Imai, M. Baba, O. Yoshie, Y. Zhang, H. Higashi, M. Murai, H. Asakura, K. Matsushima. 1998. Pivotal role of TARC, a CC chemokine, in bacteria-induced fulminant hepatic failure in mice. J. Clin. Invest. 102:1933.[Medline]
  21. Luster, A. D., J. V. Ravetch. 1987. Biochemical characterization of a {gamma} interferon-inducible cytokine (IP-10). J. Exp. Med. 166:1084.[Abstract/Free Full Text]
  22. Deng, W., Y. Ohmori, T. A. Hamilton. 1994. Mechanisms of IL-4-mediated suppression of IL-10 gene expression in murine macrophages. J. Immunol. 153:2130.[Abstract]
  23. Bonecchi, R., S. Sozzani, J. T. Stine, W. Luini, G. D’Amico, P. Allavena, D. Chantry, A. Mantovani. 1998. Divergent effects of interleukin-4 and interferon-{gamma} on macrophage-derived chemokine production: an amplification circuit of polarized T helper 2 responses. Blood 92:2668.[Abstract/Free Full Text]
  24. Phipps, R. P., S. H. Stein, R. L. Roper. 1991. A new view of prostaglandin E regulation of the immune response. Immunol. Today 12:349.[Medline]
  25. Katamura, K., N. Shintaku, Y. Yamauchi, T. Fukui, Y. Ohshima, M. Mayumi, K. Furusho. 1995. Prostaglandin E2 at priming of naive CD4+ T cells inhibits acquisition of ability to produce IFN-{gamma} and IL-2, but not IL-4 and IL-5. J. Immunol. 155:4604.[Abstract]
  26. Wu, C. Y., K. Wang, J. F. McDyer, R. A. Seder. 1998. Prostaglandin E2 and dexamethasone inhibit IL-12 receptor expression and IL-12 responsiveness. J. Immunol. 161:2723.[Abstract/Free Full Text]
  27. Van der Pouw Kraan, T. C. T. M., L. C. M. Boeije, R. J. T. Smeenk, J. Wijdenes, L. A. Aarden. 1995. Prostaglandin-E2 is a potent inhibitor of human interleukin 12 production. J. Exp. Med. 181:775.[Abstract/Free Full Text]
  28. Hilkens, G. M. U., A. Snijders, H. Vermeulen, P. H. V. D. Meide, E. A. Wierenga, M. L. Kapsenberg. 1996. Accessory cell-derived IL-12 and prostaglandin E2 determine the IFN-{gamma} level of activated human CD4+ T cells. J. Immunol. 156:1722.[Abstract]
  29. Fedyk, E. R., R. P. Phipps. 1996. Prostaglandin E2 receptors of the EP2 and EP4 subtypes regulate activation and differentiation of mouse B lymphocytes to IgE-secreting cells. Proc. Natl. Acad. Sci. USA 93:10978.[Abstract/Free Full Text]
  30. Sugiura, T., H. Nakamura. 1994. Metallothionein in platelets. Int. Arch. Allergy Immunol. 103:341.[Medline]
  31. Zar, J. H.. 1974. Biostatistical Analysis Prentice Hall, Eaglewood Cliffs.
  32. Maruo, S., M. Oh-hora, H. J. Ahn, S. Ono, M. Wyscoka, Y. Kaneko, H. Yagita, K. Okumura, H. Kikutani, T. Kishimoto, et al 1997. B cells regulate CD40 ligand-induced IL-12 production in antigen-presenting cells (APC) during T cell/APC interactions. J. Immunol. 158:120.[Abstract]
  33. Schaniel, C., E. Pardali, F. Sallusto, M. Speletas, C. Ruedl, T. Shimazu, T. Seidl, J. Andersson, F. Melchers, A. G. Rolink, P. Sideras. 1998. Activated murine B lymphocytes and dendritic cells produce a novel CC chemokine which acts selectively on activated T cells. J. Exp. Med. 188:451.[Abstract/Free Full Text]
  34. Schaniel, C., F. Sallusto, C. Ruedl, P. Sideras, F. Melchers, A. G. Rolink. 1999. Three chemokines with potential functions in T lymphocyte-independent and -dependent B lymphocyte stimulation. Eur. J. Immunol. 29:2934.[Medline]
  35. Rodenburg, R. J. T., R. F. B. Brinkhuis, R. Peek, J. R. Westphal, F. H. J. van den Hoogen, W. J. van Venrooji, L. B. A. van de Putte. 1998. Expression of macrophage-derived chemokine (MDC) mRNA in macrophages is enhanced by interleukin-1{beta}, tumor necrosis factor {alpha}, and lipopolysaccharide. J. Leukocyte Biol. 63:606.[Abstract]
  36. Sallusto, F., B. Palermo, D. Lenig, M. Miettinen, S. Matikainen, I. Julkunen, R. Forster, R. Burgstahler, M. Lipp, A. Lanzavecchia. 1999. Distinct patterns and kinetics of chemokine production regulate dendritic cell function. Eur. J. Immunol. 29:1617.[Medline]
  37. Iellem, A., L. Colantpnio, S. Bhakta, S. Sozzani, A. Mantovani, F. Sinigaglia, D. D’Ambrosio. 2000. Inhibition of IL-12 and IFN-{alpha} of I-309 and macrophage-derived chemokine production upon TCR triggering of human Th1 cells. Eur. J. Immunol. 30:1030.[Medline]
  38. Galli, G., D. Chantry, F. Annunziato, P. Romagnani, L. Cosmi, E. Lazzeri, R. Manetti, E. Maggi, P. W. Gray, S. Romagnani. 2000. Macrophage-derived chemokine production by activated human T cells in vitro and in vivo: preferential association with the production of type 2 cytokines. Eur. J. Immunol. 30:204.[Medline]
  39. Satriano, J. A., B. Banas, B. Luckow, P. Nelson, D. O. Schlomdorff. 1997. Regulation of RANTES and ICAM-1 expression in murine mesangial cells. J. Am. Soc. Nephrol. 8:596.[Abstract]
  40. Haskó, G., T. P. Shanley, G. Egnaczyk, Z. H. Németh, A. L. Salzman, E. S. Vizi, C. Szabó. 1998. Exogenous and endogenous catecholamines inhibit the production of macrophage inflammatory protein (MIP) 1{alpha} via a {beta} adrenoceptor mediated mechanism. Br. J. Pharmacol. 125:1297.[Medline]
  41. Au, B. T., M. M. Teixeira, P. D. Collins, T. J. Williams. 1998. Effect of PDE4 inhibitor on zymosan-induced IL-8 release from human neutrophils: synergism with prostanoids and salbutamol. Br. J. Pharmacol. 123:1260.[Medline]
  42. Kimata, M., M. Shichijo, M. Daikoku, N. Inagaki, H. Mori, H. Nagai. 1998. Pharmacological modulation of LPS-induced MIP-1 {alpha} production by peripheral blood mononuclear cells. Pharmacology 56:230.[Medline]
  43. Boorsma, D. M., J. Flier, E. N. van den Brink, S. Sampat, H. L. Walg, R. Willemze, C. P. Tensen, T. J. Stoof. 1999. IP-10 mRNA expression in cultured keratinocytes is suppressed by inhibition of protein kinase C and tyrosine kinase and elevation of cAMP. Cytokine 11:469.[Medline]
  44. Kornbluth, R. S., K. Kee, D. D. Richman. 1998. CD40 ligand (CD154) stimulation of macrophages to produce HIV-1-suppressive {beta}-chemokines. Proc. Natl. Acad. Sci. USA 95:5205.[Abstract/Free Full Text]
  45. Delgado, M., J. Leceta, R. P. Gomariz, D. Ganea. 1999. Vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide stimulate the induction of Th2 responses by up-regulating B7.2 expression. J. Immunol. 163:3629.[Abstract/Free Full Text]
  46. Delgado, M., W. Sun, J. Leceta, D. Ganea. 1999. VIP and PACAP differentially regulate the costimulatory activity of resting and activated macrophages through the modulation of B7.1 and B7.2 expression. J. Immunol. 163:4213.[Abstract/Free Full Text]
  47. Abe, N., K. Katamura, N. Shintaku, T. Fukui, T. Kiyomasu, J. Iio, H. Ueno, G. Tai, M. Mayumi, K. Furusho. 1997. Prostaglandin E2 and IL-4 provide naive CD4+ T cells with distinct inhibitory signals for the priming of IFN-{gamma} production. Cell. Immunol. 181:86.[Medline]
  48. Skok, J., J. Poudrier, D. Gray. 1999. Dendritic cell-derived IL-12 promotes B cell induction of Th2 differentiation: a feedback regulation of Th1 development. J. Immunol. 163:4284.[Abstract/Free Full Text]
  49. Gonzalo, J. A., C. M. Lloyd, D. Wen, J. P. Albar, T. N. C. Well, A. Proudfoot, C. Martinez-A., M. Dorf, T. Bjerke, A. J. Coyle, J. C. Gutierrez-Ramos. 1998. The coordinated action of CC chemokine in the lung orchestrates allergic inflammation and airway hyperresponsiveness. J. Exp. Med. 188:157.[Abstract/Free Full Text]
  50. Chan, S. C., J. W. Kim, Jr W. R. Henderson, J. M. Hanifin. 1993. Altered prostaglandin E2 regulation of cytokine production in atopic dermatitis. J. Immunol. 151:3345.[Abstract]
  51. Snijders, A., T. C. T. M. van der Pouw Kraan, M. Engel, J. Wormmeester, P. Widjaja, I. M. Zonneveld, J. D. Bos, M. L. Kapsenberg. 1998. Enhanced prostaglandin E2 production by monocytes in atopic dermatitis (AD) is not accompanied by enhanced production of IL-6, IL-10 or IL-12. Clin. Exp. Immunol. 111:472.[Medline]
  52. Miralpeix, M., M. Camacho, J. Lopez-Belmonte, F. Canalis, J. Beleta, J. M. Palacios, L. Vila. 1997. Selective induction of cyclo-oxygenase-2 activity in the permanent human endothelial cell line HUV-EC-C: biochemical and pharmacological characterization. Br. J. Pharmacol. 121:171.[Medline]



This article has been cited by other articles:


Home page
 Cancer Res.Home page
R. Muthuswamy, J. Urban, J.-J. Lee, T. A. Reinhart, D. Bartlett, and P. Kalinski
Ability of Mature Dendritic Cells to Interact with Regulatory T Cells Is Imprinted during Maturation
Cancer Res., July 15, 2008; 68(14): 5972 - 5978.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
T. Khayrullina, J.-H. Yen, H. Jing, and D. Ganea
In Vitro Differentiation of Dendritic Cells in the Presence of Prostaglandin E2 Alters the IL-12/IL-23 Balance and Promotes Differentiation of Th17 Cells
J. Immunol., July 1, 2008; 181(1): 721 - 735.
[Abstract] [Full Text] [PDF]

Home page
 Ann Rheum DisHome page
C Ospelt, M Kurowska-Stolarska, M Neidhart, B A Michel, R E Gay, S Laufer, and S Gay
The dual inhibitor of lipoxygenase and cyclooxygenase ML3000 decreases the expression of CXCR3 ligands
Ann Rheum Dis, April 1, 2008; 67(4): 524 - 529.
[Abstract] [Full Text] [PDF]

Home page
 J. Leukoc. Biol.Home page
J. Lattin, D. A. Zidar, K. Schroder, S. Kellie, D. A. Hume, and M. J. Sweet
G-protein-coupled receptor expression, function, and signaling in macrophages
J. Leukoc. Biol., July 1, 2007; 82(1): 16 - 32.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
V. Mariani, S. Gilles, T. Jakob, M. Thiel, M. J. Mueller, J. Ring, H. Behrendt, and C. Traidl-Hoffmann
Immunomodulatory Mediators from Pollen Enhance the Migratory Capacity of Dendritic Cells and License Them for Th2 Attraction
J. Immunol., June 15, 2007; 178(12): 7623 - 7631.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
N. A. Siciliano, J. A. Skinner, and M. H. Yuk
Bordetella bronchiseptica Modulates Macrophage Phenotype Leading to the Inhibition of CD4+ T Cell Proliferation and the Initiation of a Th17 Immune Response
J. Immunol., November 15, 2006; 177(10): 7131 - 7138.
[Abstract] [Full Text] [PDF]

Home page
 BloodHome page
M. S. von Bergwelt-Baildon, A. Popov, T. Saric, J. Chemnitz, S. Classen, M. S. Stoffel, F. Fiore, U. Roth, M. Beyer, S. Debey, et al.
CD25 and indoleamine 2,3-dioxygenase are up-regulated by prostaglandin E2 and expressed by tumor-associated dendritic cells in vivo: additional mechanisms of T-cell inhibition
Blood, July 1, 2006; 108(1): 228 - 237.
[Abstract] [Full Text] [PDF]

Home page
 Int ImmunolHome page
Y.-N. Zhu, Y.-F. Yang, S. Ono, X.-G. Zhong, Y.-H. Feng, Y.-X. Ren, J. Ni, Y.-F. Fu, W. Tang, and J.-P. Zuo
Differential expression of inducible nitric oxide synthase and IL-12 between peritoneal and splenic macrophages stimulated with LPS plus IFN-{gamma} is associated with the activation of extracellular signal-related kinase
Int. Immunol., June 1, 2006; 18(6): 981 - 990.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Cell Mol. Bio.Home page
M. Arras, J. Louahed, V. Simoen, V. Barbarin, P. Misson, S. van den Brule, M. Delos, L. Knoops, J.-C. Renauld, D. Lison, et al.
B Lymphocytes Are Critical for Lung Fibrosis Control and Prostaglandin E2 Regulation in IL-9 Transgenic Mice
Am. J. Respir. Cell Mol. Biol., May 1, 2006; 34(5): 573 - 580.
[Abstract] [Full Text] [PDF]

Home page
 J. Leukoc. Biol.Home page
N. Guriec, C. Daniel, K. Le Ster, E. Hardy, and C. Berthou
Cytokine-regulated expression and inhibitory function of Fc{gamma}RIIB1 and -B2 receptors in human dendritic cells
J. Leukoc. Biol., January 1, 2006; 79(1): 59 - 70.
[Abstract] [Full Text] [PDF]

Home page
 J. Leukoc. Biol.Home page
J. Noguchi, E. Kuroda, and U. Yamashita
Strain difference of murine bone marrow-derived mast cell functions
J. Leukoc. Biol., September 1, 2005; 78(3): 605 - 611.
[Abstract] [Full Text] [PDF]

Home page
 J. Immunol.Home page
E. Vassiliou, V. Sharma, H. Jing, F. Sheibanie, and D. Ganea
Prostaglandin E2 Promotes the Survival of Bone Marrow-Derived Dendritic Cells
J. Immunol., December 1, 2004; 173(11): 6955 - 6964.