Journal of Leukocyte Biology Myeloid cells, immune suppression, tumor immunology
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
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
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fogel, M.
Right arrow Articles by Upham, J. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fogel, M.
Right arrow Articles by Upham, J. W.
(Journal of Leukocyte Biology. 2002;72:932-938.)
© 2002 by Society for Leukocyte Biology

Dendritic cell maturation and IL-12 synthesis induced by the synthetic immune-response modifier S-28463

Mirjana Fogel, Julie A. Long, Philip J. Thompson and John W. Upham

Asthma & Allergy Research Institute and Department of Medicine, University of Western Australia, Sir Charles Gairdner Hospital, Nedlands

Correspondence: John Upham, Asthma & Allergy Research Institute, Ground Floor, E Block, Sir Charles Gairdner Hospital, Nedlands WA 6009, Australia. E-mail: jupham{at}cyllene.uwa.edu.au


   ABSTRACT
TOP
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Dendritic cells (DC) play a prominent role in the development of T cell-immune responses to antigens and have a key influence over the differentiation of naive T cells into T helper cell type 1 (Th1) or Th2 effector cells. Consequently, there is considerable interest in pharmacological agents that might alter DC function and thereby modulate allergic inflammation. We examined the effects of the imidazoquinoline S-28463 on human monocyte-derived DC (Mo-DC) cultured in granuloctye macrophage-colony stimulating factor and interleukin (IL)-4 to determine whether this agent might be useful in augmenting Th1 immunity. We determined that S-28463 acts directly on Mo-DC, inducing their maturation and enhancing their capacity to present antigen. Importantly, S-28463 strongly induces synthesis of bioactive IL-12 p70, a key Th1-polarizing cytokine. We also examined the ability of S-28463 to modulate DC function in the context of transforming growth factor-ß (TGF-ß), a negative, immunoregulatory cytokine released from the epithelium of nonlymphoid organs. S-28463 was able to induce IL-12 synthesis even in the presence of TGF-ß, whereas lipopolysaccharide (LPS) + interferon-{gamma}-stimulated DC did not produce IL-12 in the presence of TGF-ß. Taken together, our findings suggest that S-28463 and LPS are exerting their effects via distinctly different pathways and indicate that S-28463 may be beneficial in polarizing immune responses toward a Th1 response.

Key Words: IL-10 • TGF-ß • imidazoquinoline S-28463


   INTRODUCTION
TOP
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 
Dendritic cells (DC) are potent antigen presenting cells (APC) that play a prominent role in the development of T cell-immune responses. Immature DC are ideally localized within the airway epithelium to perform a surveillance role for exogenous antigens. After antigen uptake and processing, DC mature and migrate to draining lymph nodes where they interact with naïve T cells. Here, they have the potential to induce a polarized T helper cell type 1 (Th1) or Th2 response [1 2 3 ]. The type of antigen and its concentration and the cytokine microenvironment in which immature DC take up antigen critically influence the phenotype of the DC. This phenotype then influences whether a Th1 or Th2 response occurs. Thus, it appears that the effect of DC to induce T cell polarization is strongly influenced by environmental signals [4 ].

Current approaches to immunotherapy for allergic diseases emphasize the inhibition of allergen-specific effector Th2 cells and the induction of immunoglobulin (Ig)E-suppressive cytokines such as interleukin (IL)-10 or alternatively, the induction of IL-12 and interferon-{gamma} (IFN-{gamma}) synthesis and augmentation of counterbalancing Th1 cells [5 , 6 ]. Although a variety of biological agents have been shown experimentally to induce DC maturation and synthesis of the key Th1-trophic cytokine IL-12, there is also considerable interest in developing more "conventional", low molecular weight pharmacological compounds to achieve this same purpose. These would achieve the same results but be more easily directed to specific tissue sites.

It has been demonstrated previously that the imidazoquinoline imiquimod and its analogue S-28463 (R-848) are immune-response modifiers (IRMs) that have potent antiviral and antitumor properties [7 , 8 ]. Their effects are mediated through stimulation of innate immunity, in particular, via release of monocyte-macrophage-derived cytokines such as IFN-{alpha} and tumor necrosis factor {alpha} (TNF-{alpha}) [9 , 10 ]. In addition, recent studies have suggested that the imidazoquinolines also induce release of cytokines such as IL-12 p40 by monocyte-derived DC (Mo-DC) [10 ] and by epidermal Langerhans cells (LC) [11 ]. However, these studies examined only IL-12 p40 synthesis, which does not necessarily lead to synthesis of biologically active IL-12 p70, a cytokine whose role in the development of protective Th1-type immune response has been well-documented [12 ].

DC maturation can be promoted by a variety of stimuli, including bacterial components [lipopolysaccharides (LPS)], inflammatory cytokines (TNF-{alpha}, IL-1{alpha}), and activation of CD40 ligand. Mature DC express high levels of costimulatory molecules, CD80, CD83, and CD86, produce IL-12, and can prime naïve T cells [13 ]. Therefore, we evaluated the effect of S-28463 on DC activation, maturation, and ability to synthesize IL-12 p70. As transforming growth factor-ß (TGF-ß) readily inhibits DC maturation and IL-12 synthesis in response to TNF-{alpha}, IL-1, or LPS but has little effect on DC maturation and IL-12 synthesis in response to cognate signals such as those mediated via CD40 ligand [14 ], we also investigated whether TGF-ß modulates the effects of S-28463 on DC function.

Our studies have shown that S-28463 is able to induce production of bioactive IL-12 (IL-12 p70) via a mechanism that is distinct from that of LPS. Furthermore, we have shown that TGF-ß has inhibited IL-12 synthesis by DC stimulated with LPS but not when stimulated by S-28463, again suggesting that both stimuli exert their effects via distinct, intracellular pathways.


   MATERIALS AND METHODS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS
 DISCUSSION
 REFERENCES
 
Culture medium and reagents
Culture medium, RPMI 1640 (Gibco-BRL, Life Technologies, Paisley, UK), was supplemented with 2 mmol/L glutamine, gentamicin (60 ng/ml), penicillin (63 ng/ml), 50 µmol/L 2-ß-mercaptoethanol (Sigma Chemical Co., St. Louis, MO), 10% heat-inactivated fetal calf serum (FCS; Gibco-BRL, Life Technologies), and polymyxin B (10 µg/ml; Sigma Chemical Co.). The latter was used to avoid the possible confounding effects of trace amounts of endotoxin. For the mixed leukocyte reactions (MLRs), the serum-free medium AIM-V (Gibco-BRL, Life Technologies) was used instead of RPMI/FCS to reduce nonspecific stimulation by foreign protein in FCS. Recombinant IL-4 and granulocyte macrophage-colony stimulating factor (GM-CSF) were purchased from R&D Systems (Minneapolis, MN) and Schering-Plough Pty. Ltd. (Baulkman Hills, NSW, Australia), respectively. LPS isolated from Escherichia coli (serotype 055: B5), IFN-{gamma}, and TGF-ß were purchased from Sigma Chemical Co. The IRM S-28463 (4-amino-2-ethoxymethyl-{alpha}, {alpha}-dimethyl-1H-imidazo [4 5 ]quinoline-1-ethanol) was a gift from 3M Pharmaceuticals (St. Paul, MN). Radioactive [3H]thymidine was purchased from Amersham (Arlington Heights, IL).

Generation of Mo-DC
The ability of monocytes to differentiate in vitro into DC under physiological conditions has now been confirmed in vivo [15 ]. Mo-DC were prepared from adherent peripheral blood mononuclear cells (PBMC) using established methods [16 , 17 ]. Briefly, buffy coats from healthy volunteer donors were obtained from the Red Cross transfusion service, and PBMC were isolated by density centrifugation on Ficoll-Paque gradient (Pharmacia, Biotech, Uppsala, Sweden), resuspended in culture media, and allowed to adhere onto 150-mm flasks (108 cells/flask). After 2 h at 37°C, nonadherent cells were removed, and adherent cells were cultured in 20 ml culture medium containing GM-CSF (50 ng/ml) and IL-4 (10 ng/ml). Every 2–3 days, 10 ml fresh media was added containing GM-CSF and IL-4. After 7 days of culture, nonadherent cells corresponding to the DC-enriched fraction were washed, counted, and transferred into fresh medium that did not contain polymyxin B. The purity of Mo-DC (typically 85–98%) was assessed by analyzing cell-surface expression of CD1a by flow cytometry. Mo-DC were stimulated for 24 h with varying concentrations of S-28463 or with LPS (1 µg/ml) after priming with IFN-{gamma} (20 ng/ml) for 3 h. Supernatant was collected for IL-12 p70 analysis by enzyme-linked immunosorbent assay (ELISA). To assess the effects of TGF-ß on DC function, TGF-ß (2 ng/ml) was added for the final 48 h of DC culture, and then DC were stimulated for varying time intervals (indicated in experiments) with LPS or S-28463.

Analysis of surface-marker expression by flow cytometry
For immunophenotyping, cells were washed in phosphate-buffered saline supplemented with 10 mmol/L NaN3 and resuspended in the same buffer containing 5% murine serum. Cells (105) from each sample were incubated for 30 min at 4°C with one of the following murine monoclonal antibodies (mAb): fluorescein isothiocyanate-conjugated anti-CD1a, phycoerythrin-conjugated anti-CD80 and anti-CD86, Peridin chlorophyll protein–conjugated anti-human leukocyte antigen (HLA)-DR, all obtained from Becton-Dickinson (San Diego, CA). As controls, cells were stained with corresponding isotype-matched control mAb (Becton-Dickinson, Mountain View, CA). Cells were washed and analyzed using a FACScan flow cytometer (Becton-Dickinson) after gating on CD1a-positive cells.

Cytokine determination
Concentrations of IL-12 p70 and IL-10 were measured in culture supernatant of unstimulated and stimulated Mo-DC by specific ELISA (PharMingen, San Diego, CA). Sensitivity of ELISA assays for IL-12 p70 and IL-10 detection was 7.8 pg/ml.

Antigen presentation (MLR assay)
Responder cells were obtained as a nonadherent fraction of PBMC of healthy donors. Accessory cells were depleted from PBMC by 2-h plastic adherence at 37°C. Stimulator cells, allogeneic Mo-DC, were pulsed for 24 h with medium alone (control sample), LPS (1 µg/ml), LPS + IFN-{gamma} (1 µg/ml + 20 ng/ml), or S-28463 (5 µg/ml). Mo-DC were subsequently washed and resuspended in AIM-V medium and added at various concentrations (2–200x102 cells per well) to responder cells (2x105 cells per well) in a total volume of 200 µl. Triplicate cocultures were maintained at 37°C for 6 days. T cell proliferation was assessed by incorporation of [3H]thymidine (1 µCi/well) during the final 18 h of culture.

Statistical analysis
Significance of differences between various stimuli was assessed with paired t test. All data were expressed as mean ± SE.


   RESULTS
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
DISCUSSION
 REFERENCES
 
Our initial experiments focused on the ability of S-28463 to induce maturation of Mo-DC, as shown by IL-12 synthesis and up-regulation of costimulatory and major histocompatibility complex (MHC) class II molecules.

S-28463 stimulates DC to synthesize the bioactive form of IL-12 p70
As shown in Figure 1a , Mo-DC stimulated with S-28463 (0.5–10 µg/ml) secreted bioactive IL-12 p70 in a dose- and time-dependent manner. IL-12 production reached a peak between 12 and 24 h following stimulation with 5 µg/ml S-28463 (Fig. 1b) . When the ability of S-28463 and LPS to induce IL-12 p70 by DC was compared, it was clear that LPS was only able to induce IL-12 p70 if DC were first primed with IFN-{gamma}, whereas S-28463 did not require priming with IFN-{gamma} to induce IL-12p70 synthesis. This finding suggested that the mechanism of action of S-28463 on DC differed from that of LPS. It is interesting that although LPS alone was not able to induce IL-12 p70, simultaneous exposure to S-28463 and LPS had a synergistic effect on IL-12 p70 production (Fig. 2a ) and further increased the expression of CD80 (Fig. 2b) and CD86 (data not shown), compared with either stimulus alone.



View larger version (15K):
[in this window]
[in a new window]
  		Figure 1. Effects of S-28463 on IL-12 p70 synthesis by DC. (a) Mo-DC were exposed to different concentrations (1, 2, 4, 6, 8, and 10 µg/ml) of S-28463 for 24 h. (b) Maximum IL-12 p70 secretion induced by S-28463 (4–6 µg/ml; between 12 and 48 h of stimulation). (a and b) Values represent the mean of three and four experiments, respectively. As a positive control, cells were primed for 3–4 h with IFN-{gamma} (20 ng/ml) and then stimulated with LPS (1 µg/ml) for 24 h.

 


View larger version (14K):
[in this window]
[in a new window]
  		Figure 2. Combined effects of S-28463 and LPS on DC maturation. (a) Mo-DC were stimulated with S-28463 (5 µg/ml) or LPS (1 µg/ml) or with both stimuli [LPS+S-28463 (S-28+LPS)] for 24 h. (b) Mo-DC were exposed to LPS (1 µg/ml) or S-28463 (5 µg/ml) or to both stimuli for 24 h. Histogram shows up-regulation of CD80 expression in response to each stimulus (dark line), relative to unstimulated DC (light line). Numbers, above each histogram, refer to absolute mean fluorescence intensity (MFI).Figure shows a representative of four independent experiments.

 
S-28463 stimulates DC to synthesize IL-10
Mo-DC stimulated with S-28463 also produced IL-10 in a dose- and time-dependent manner (Fig. 3a and b ). However, S-28463 induced three- to fivefold less IL-10 synthesis than LPS or LPS + IFN-{gamma}. Compared with its ability to induce IL-12 p70, it is clear that S-28463 induced much less IL-10 synthesis than IL-12 p70 (Figs. 1 and 3) . Simultaneous exposure to LPS + S-28463 did not enhance IL-10 production by DC (data not shown).



View larger version (18K):
[in this window]
[in a new window]
  		Figure 3. Effects of S-28463 on IL-10 synthesis. (a) Mo-DC were exposed to different concentrations of S-28463 (1, 2, 4, 6, 8, and 10 µg/ml) for 24 h. As a positive control, cells were stimulated with LPS (1 µg/ml) for 24 h or first primed for 3–4 h with IFN-{gamma} (20 ng/ml) and then stimulated with LPS (1 µg/ml) for 24 h. (b) Maximum IL-10 secretion induced by S-28463 (4–6 µg/ml; between 12 and 48 h of stimulation). Values for IL-10 production represent the mean values of three independent experiments.

 
Expression of costimulatory molecules
The stimulation of Mo-DC with S-28463 for 24 h also led to enhanced expression of costimulatory (CD80, CD86) and MHC class II (HLA-DR) molecules (Fig. 4a ). S-28463 exhibited stronger enhancement of costimulatory molecule expression compared with the same concentration of LPS or LPS + IFN-{gamma} stimulation (data not shown). In addition, S-28463 led to a very rapid up-regulation of DC maturation markers, and enhanced expression was detectable by 1–3 h post-stimulation (Fig. 4b) .



View larger version (18K):
[in this window]
[in a new window]
  		Figure 4. Effects of S-28463 on expression of CD80, CD86, and HLA-DR. The S-28463 stimulated and nonstimulated DC were labeled with CD80, CD86, or HLA-DR antibodies and analyzed by flow cytometry. (a) Histogram shows CD86 and CD80 expression in response to 1 and 5 µg/ml S-28463 stimulus (dark line), relative to unstimulated DC (light line).Figure shows representative of three independent experiments. (b) Time-dependent expression (for 3, 6, 12, 24, and 48 h) of CD80, CD86, and HLA-DR by DC stimulated with S-28463 (5 µg/ml). Results are expressed as the relative MFI of four independent experiments.

 
S-28463 enhances the antigen-presenting activity of DC
S-28463 also enhanced the antigen-presenting function of DC, as measured by increased T cell proliferation in an allogeneic MLR (Fig. 5 ). It was noticeable that S-28463 had a more pronounced effect on antigen-presenting activity compared with the positive control (LPS+IFN-{gamma} stimulation). As it has previously been shown that the ability of S-28463 to activate T cells is dependent on APC and that S-28463 has no direct effect on T cells [9 ], it is unlikely that the data shown in Figure 5 can be attributed to carryover of trace amounts of S-28463 into the MLR cultures.



View larger version (15K):
[in this window]
[in a new window]
  		Figure 5. Effects of S-28463 on APC activity of DC. Mo-DC were stimulated with S-28463 (5 µg/ml) or LPS + IFN-{gamma} (1 µg/ml+20 ng/ml) for 24 h and cocultured (at different ratios) with nonadherent fraction of PBMC from healthy donors in an allogeneic MLR. T cell proliferation was assessed by incorporation of [3H]thymidine (1 µCi/well) during the final 18 h of culture. Results are expressed as the mean of five independent experiments.

 
Effects of TGF-ß on DC maturation and IL-12/IL-10 production
As TGF-ß has previously been shown to differentially regulate cytokine production by DC exposed to different stimuli, we next examined the effects of TGF-ß on DC stimulated with S-28463. TGF-ß (2 ng/ml) was therefore added for the final 48 h of DC culture, prior to the addition of various stimuli. This exposure to TGF-ß did not alter DC morphology or expression of CD1a (data not shown). When DC were stimulated by LPS + IFN-{gamma} in the presence of TGF-ß, IL-12 p70 production was completely abrogated (Fig. 6a ). In sharp contrast, TGF-ß did not affect IL-12 p70 release by S-28463-stimulated DC (Fig. 6a) . Production of IL-10 by S-28463 did not appear to be affected by the presence of TGF-ß for the final 48 h of culture (Fig. 6b) , regardless of the nature of the stimulus applied (LPS, LPS+IFN-{gamma}, or S-28463). Similarly, TGF-ß did not significantly alter the up-regulation of CD80, CD86, or HLA-DR expression, when DC were stimulated by LPS or S-28463 (Fig. 6c) . Thus, TGF-ß had a selective, suppressive effect only on IL-12 p70 production by DC when they were stimulated to mature by LPS + IFN-{gamma} but not by S-28463, whereas IL-10 release and expression of costimulatory molecules were resistant to the inhibitory effect of TGF-ß.



View larger version (21K):
[in this window]
[in a new window]
  		Figure 6. Differential effects of TGF-ß on cytokine production and DC activation. DC were grown in culture medium supplemented with IL-4 and GM-CSF for 7 days and compared with cells exposed to TGF-ß (2 ng/ml) for the final 48 h. For the last 24 h, DC were stimulated with LPS (1 µg/ml), LPS + IFN-{gamma} (1 µg+20 ng/ml), or S-28463 (5 µg/ml), and synthesis of IL-12 p70 (a) and IL-10 (b) production and expression of CD80, CD86, and HLA-DR (c) were analyzed by ELISA and fluorescein-activated cell sorter, respectively. Note that TGF-ß completely prevented induction of IL-12 p70 by LPS + IFN-{gamma} stimulation (P<0.0001). The data for IL-12 and IL-10 production represent the mean values of four experiments. Expression of CD80, CD86, and HLA-DR is expressed as the MFI and represents the mean values of three experiments.

 

   DISCUSSION
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
REFERENCES
 
There is considerable interest in the development of low molecular weight compounds that can alter DC function and that can be used to modulate immunoinflammatory processes associated with human disease. We have shown that the imidazoquinoline S-28463 induces rapid activation and maturation of human Mo-DC. In particular, it significantly induces the synthesis of bioactive IL-12 p70, a key Th1-polarizing cytokine that is central in providing protection against intracellular infections, cancer, and allergic airway inflammation [18 19 20 ].

Previous studies of imiquimod and S-28463 (R-848) have indicated that these agents induce monocytes and DC to synthesize a variety of cytokines, including IL-12p40 [10 , 11 , 21 ]. Importantly, our investigations extend these findings to show that S-28463-stimulated DC also synthesize bioactive IL-12 p70. IL-12 is a 70-kDa heterodimeric protein composed of covalently linked p35 and p40 subunits, encoded by separate genes that must be expressed in the same cell to generate bioactive IL-12 [12 ]. Although S-28463 has previously been shown to induce IL-12 p40 production by Mo-DC [10 ], the consequences of this observation have not been clear, given that excess secretion of p40 may actually lead to the formation of (p40)2 homodimer and inhibition of IL-12 signaling [22 , 23 ]. Importantly, our results demonstrate for the first time that S-28463 induces DC to produce bioactive IL-12 in a dose- and time-dependent manner.

Production of IL-12 is highly dependent on the nature of the stimulus and the cytokine milieu during DC stimulation. In particular, IFN-{gamma}, GM-CSF, and IL-4 are enhancers of IL-12 production, whereas IL-10, prostaglandins, and TGF-ß are thought to inhibit IL-12 production [12 , 24 , 25 ]. In DC, the maximal production of IL-12 p70 heterodimer involves independent regulation of the p35 and p40 genes by microbial and T cell-derived stimuli such as CD40 ligation [24 , 26 ]. As S-28463 induces IL-12 synthesis by DC, we compared its effect with LPS, a known inducer of IL-12 p40 [26 ].

Our data suggest that the mechanisms of action of the two stimuli, LPS and S-28463, are distinct and that in contrast to LPS, S-28463 does not require IFN-{gamma} priming to induce IL-12 synthesis. LPS is known to increase IL-12 p40 mRNA and protein accumulation but fails to induce IL-12p70 production by DCs, except at high concentrations [27 , 28 ]. However, priming with IFN-{gamma}, a critical cofactor for IL-12 production, up-regulates IL-12 p35 mRNA and protein and provides the necessary conditions for optimal synthesis of bioactive IL-12 in response to LPS [27 , 29 ]. Furthermore, although LPS alone was not able to induce IL-12 p70, we demonstrated that S-28463 and LPS synergize to increase IL-12 p70 synthesis, suggesting that S-28463 may up-regulate the rate-limiting production of IL-12 p35 and thereby contribute to the generation of bioactive IL-12 p70.

Further differences between the effects of S-28463 and LPS on DC emerged when we examined DC stimulated in the context of TGF-ß. This cytokine has been reported to inhibit LC maturation in response to nonspecific signals such as LPS, TNF-{alpha}, and IL-1 but not to the cognate signal CD40 ligand [14 ]. As shown in Figure 6a , TGF-ß selectively inhibited expression of IL-12 p70 when DC were stimulated with LPS + IFN-{gamma}, whereas synthesis of this cytokine by S-28463-stimulated DC was unaffected. S-28463 thus appears to resemble CD40 ligand in its resistance to the suppressive effects of TGF-ß on IL-12 expression [14 ].

DC express IL-10 mRNA and protein, which then regulates IL-12 synthesis [24 ]. However, IL-10 production was not influenced by TGF-ß, regardless of the type of stimulus (Fig. 6b) . S-28463-stimulated DC produced significantly less IL-10 compared with IL-12, whereas LPS or LPS + IFN-{gamma}-stimulated DC produced relatively more IL-10 (Fig. 3) .

The exact mechanism(s) by which S-28463 activates human DC has not been established to our knowledge. Recent reports have suggested that the imidazoquinolines activate murine immune cells via Toll-like receptor 7 (TLR7) [30 ], in contrast to LPS, which exerts it actions via TLR4 [31 ]. However, TLR7 is not thought to be expressed by human Mo-DC [32 ], so the mechanism(s) by which S-28463 activates these cells remains unclear at present.

The key finding to emerge from this study is that the IRM, S-28463 (in contrast to LPS+IFN-{gamma}) has the ability to retain its capacity to induce IL-12p70 even in a tissue environment characterized by high concentrations of TGF-ß. This suggests that S-28463 may be useful as a stimulator of DC function at epithelial surfaces. This compound also has immunomodulatory properties in vivo, augmenting Th1 cytokine and IgG2 production by murine splenocytes and at the same time inhibiting Th2 cytokine and IgE production [33 ].

Future studies will need to assess the mechanisms of action of S-28463 and address the important issue of whether the release of IL-12 p70 from S-28463-treated DC is able to alter the cytokine release pattern of allergen-specific T cells from atopic individuals.


   ACKNOWLEDGEMENTS
 
This work was supported in part by funding from 3M Pharmaceuticals (St. Paul, MN) and the Raine Foundation.

Received June 17, 2002; revised August 15, 2002; accepted August 20, 2002.


   REFERENCES
TOP
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. Steinman, R. M. (1991) The dendritic cell system and its role in immunogenicity Annu. Rev. Immunol. 9,271-296[Medline]
  2. Bellinghausen, I., Brand, U., Enk, A. H., Knop, J., Saloga, J. (1999) Signals involved in the early TH1/TH2 polarization of an immune response depending on the type of antigen J. Allergy Clin. Immunol. 103,298-306[Medline]
  3. Moser, M., Murphy, K. M. (2000) Dendritic cell regulation of TH1-TH2 development Nat. Immunol. 1,199-205[Medline]
  4. Vieira, P. L., de Jong, D. C., Wierenga, E. A., Kapsenberg, M. L., Kalinski, P. (2000) Development of Th1-inducing capacity in myeloid dendritic cells requires environmental instruction J. Immunol. 164,4507-4512[Abstract/Free Full Text]
  5. Akdis, C. A., Blesken, T., Akdis, M., Wuthrich, B., Blaser, K. (1998) Role of interleukin 10 in specific immunotherapy J. Clin. Investig. 102,98-106[Medline]
  6. Kranzer, K., Bauer, M., Lipford, G. B., Heeg, K., Wagner, H., Lang, R. (2000) CpG-oligodeoxynucleotides enhance T-cell receptor-triggered interferon-gamma production and up-regulation of CD69 via induction of antigen-presenting cell-derived interferon type I and interleukin-12 Immunology 99,170-178[Medline]
  7. Megyeri, K., Au, W. C., Rosztoczy, I., Raj, N. B., Miller, R. L., Tomai, M. A., Pitha, P. M. (1995) Stimulation of interferon and cytokine gene expression by imiquimod and stimulation by Sendai virus utilize similar signal transduction pathways Mol. Cell. Biol. 15,2207-2218[Abstract]
  8. Sidky, Y. A., Borden, E. C., Weeks, C. E., Reiter, M. J., Hatcher, J. F., Bryan, G. T. (1992) Inhibition of murine tumor growth by an interferon-inducing imidazoquinolinamine Cancer Res 52,3528-3533[Abstract/Free Full Text]
  9. Wagner, T. L., Ahonen, C. L., Couture, A. M., Gibson, S. J., Miller, R. L., Smith, R. M., Reiter, M. J., Vasilakos, J. P., Tomai, M. A. (1999) Modulation of TH1 and TH2 cytokine production with the immune response modifiers, R-848 and imiquimod Cell. Immunol. 191,10-19[Medline]
  10. Ahonen, C. L., Gibson, S. J., Smith, R. M., Pederson, L. K., Lindh, J. M., Tomai, M. A., Vasilakos, J. P. (1999) Dendritic cell maturation and subsequent enhanced T-cell stimulation induced with the novel synthetic immune response modifier R-848 Cell. Immunol. 197,62-72[Medline]
  11. Burns, R. P., Jr, Ferbel, B., Tomai, M., Miller, R., Gaspari, A. A. (2000) The imidazoquinolines, imiquimod and R-848, induce functional, but not phenotypic, maturation of human epidermal Langerhans’cells Clin. Immunol. 94,13-23[Medline]
  12. Trinchieri, G. (1994) Interleukin-12: a cytokine produced by antigen-presenting cells with immunoregulatory functions in the generation of T-helper cells type 1 and cytotoxic lymphocytes Blood 84,4008-4027[Free Full Text]
  13. Banchereau, J., Steinman, R. (1998) Dendritic cells and the control of immunity Nature 392,245-252[Medline]
  14. Geissmann, F., Revy, P., Regnault, A., Lepelletier, Y., Dy, M., Brousse, N., Amigorena, S., Hermine, O., Durandy, A. (1999) TGF-beta 1 prevents the noncognate maturation of human dendritic Langerhans cells J. Immunol. 162,4567-4575[Abstract/Free Full Text]
  15. Randolph, G. J., Inaba, K., Robbiani, D. F., Steinman, R. M., Muller, W. A. (1999) Differentiation of phagocytic monocytes into lymph node dendritic cells in vivo Immunity 11,753-761[Medline]
  16. Romani, N., Reider, D., Heuer, M., Ebner, S., Kampgen, E., Eibl, B., Niederwieser, D., Schuler, G. (1996) Generation of mature dendritic cells from human blood. An improved method with special regard to clinical applicability J. Immunol. Methods 196,137-151[Medline]
  17. Anton, D., Dabadghao, S., Palucka, K., Holm, G., Yi, Q. (1998) Generation of dendritic cells from peripheral blood adherent cells in medium with human serum Scand. J. Immunol. 47,116-121[Medline]
  18. Hsieh, C. S., Macatonia, S. E., Tripp, C. S., Wolf, S. F., O’Garra, A., Murphy, K. M. (1993) Development of TH1 CD4+ T cells through IL-12 produced by Listeria-induced macrophages Science 260,547-549[Abstract/Free Full Text]
  19. Trinchieri, G., Scott, P. (1994) The role of interleukin 12 in the immune response, disease and therapy Immunol. Today 15,460-463[Medline]
  20. Gavett, S. H., O’Hearn, D. J., Li, X., Huang, S. K., Finkelman, F. D., Wills-Karp, M. (1995) Interleukin 12 inhibits antigen-induced airway hyperresponsiveness, inflammation, and Th2 cytokine expression in mice J. Exp. Med. 182,1527-1536[Abstract/Free Full Text]
  21. Testerman, T. L., Gerster, J. F., Imbertson, L. M., Reiter, M. J., Miller, R. L., Gibson, S. J., Wagner, T. L., Tomai, M. A. (1995) Cytokine induction by the immunomodulators imiquimod and S-27609 J. Leukoc. Biol. 58,365-372[Abstract]
  22. Kalinski, P., Vieira, P. L., Schuitemaker, J. H., de Jong, E. C., Kapsenberg, M. L. (2001) Prostaglandin E(2) is a selective inducer of interleukin-12 p40 (IL-12p40) production and an inhibitor of bioactive IL-12p70 heterodimer Blood 97,3466-3469[Abstract/Free Full Text]
  23. Ling, P., Gately, M. K., Gubler, U., Stern, A. S., Lin, P., Hollfelder, K., Su, C., Pan, Y. C., Hakimi, J. (1995) Human IL-12 p40 homodimer binds to the IL-12 receptor but does not mediate biologic activity J. Immunol. 154,116-127[Abstract]
  24. Koch, F., Stanzl, U., Jennewein, P., Janke, K., Heufler, C., Kampgen, E., Romani, N., Schuler, G. (1996) High level IL-12 production by murine dendritic cells: upregulation via MHC class II and CD40 molecules and downregulation by IL-4 and IL-10 J. Exp. Med. 184,741-746[Abstract/Free Full Text]
  25. Kalinski, P., Hilkens, C., Snijders, A., Snijdewint, F., Kapsenberg, M. (1997) IL-12 deficient dendritic cells, generated in the presence of prostaglandin E2, promote type 2 cytokine production in maturing human naive T helper cells J. Immunol. 159,28-35[Abstract]
  26. Schulz, O., Edwards, D. A., Schito, M., Aliberti, J., Manickasingham, S., Sher, A., Reis e Sousa, C. (2000) CD40 triggering of heterodimeric IL-12 p70 production by dendritic cells in vivo requires a microbial priming signal Immunity 13,453-462[Medline]
  27. Snijders, A., Hilkens, C. M., van der Pouw Kraan, T. C., Engel, M., Aarden, L. A., Kapsenberg, M. L. (1996) Regulation of bioactive IL-12 production in lipopolysaccharide-stimulated human monocytes is determined by the expression of the p35 subunit J. Immunol. 156,1207-1212[Abstract]
  28. Reis e Sousa, C., Sher, A., Kaye, P. (1999) The role of dendritic cells in the induction and regulation of immunity to microbial infection Curr. Opin. Immunol. 11,392-399[Medline]
  29. Snijders, A., Kalinski, P., Hilkens, C. M., Kapsenberg, M. L. (1998) High-level IL-12 production by human dendritic cells requires two signals Int. Immunol. 10,1593-1598[Abstract/Free Full Text]
  30. Hemmi, H., Kaisho, T., Takeuchi, O., Sato, S., Sanjo, H., Hoshino, K., Horiuchi, T., Tomizawa, H., Takeda, K., Akira, S. (2002) Small anti-viral compounds activate immune cells via the TLR7 MyD88-dependent signaling pathway Nat. Immunol. 3,196-200[Medline]
  31. Poltorak, A., He, X., Smirnova, I., Liu, M. Y., Huffel, C. V., Du, X., Birdwell, D., Alejos, E., Silva, M., Galanos, C., Freudenberg, M., Ricciardi-Castagnoli, P., Layton, B., Beutler, B. (1998) Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene Science 282,2085-2088[Abstract/Free Full Text]
  32. Kadowaki, N., Ho, S., Antonenko, S., de Waal Malefyt, R., Kastelein, R. A., Bazan, F., Liu, Y-J. (2001) Subsets of human dendritic cell precursors express different Toll-like receptors and respond to different microbial antigens J. Exp. Med. 194,863-870[Abstract/Free Full Text]
  33. Vasilakos, J. P., Smith, R. M., Gibson, S. J., Lindh, J. M., Pederson, L. K., Reiter, M. J., Smith, M. H., Tomai, M. A. (2000) Adjuvant activities of immune response modifier R-848: comparison with CpG ODN Cell. Immunol. 204,64-74[Medline]



This article has been cited by other articles:


Home page
 J. Leukoc. Biol.Home page
E. Assier, V. Marin-Esteban, A. Haziot, E. Maggi, D. Charron, and N. Mooney
TLR7/8 agonists impair monocyte-derived dendritic cell differentiation and maturation
J. Leukoc. Biol., January 1, 2007; 81(1): 221 - 228.
[Abstract] [Full Text] [PDF]

Home page
 JEMHome page
G. Gautier, M. Humbert, F. Deauvieau, M. Scuiller, J. Hiscott, E. E.M. Bates, G. Trinchieri, C. Caux, and P. Garrone
A type I interferon autocrine-paracrine loop is involved in Toll-like receptor-induced interleukin-12p70 secretion by dendritic cells
J. Exp. Med., May 2, 2005; 201(9): 1435 - 1446.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Respir. Crit. Care Med.Home page
J. A. Long, M. Fogel-Petrovic, D. A. Knight, P. J. Thompson, and J. W. Upham
Higher Prostaglandin E2 Production by Dendritic Cells from Subjects with Asthma Compared with Normal Subjects
Am. J. Respir. Crit. Care Med., September 1, 2004; 170(5): 485 - 491.
[Abstract] [Full Text] [PDF]

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
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
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Fogel, M.
Right arrow Articles by Upham, J. W.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Fogel, M.
Right arrow Articles by Upham, J. W.

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS