Thrombospondin 1 is an autocrine negative regulator of human dendritic cell activation - PubMed (original) (raw)

Thrombospondin 1 is an autocrine negative regulator of human dendritic cell activation

Virginie Doyen et al. J Exp Med. 2003.

Abstract

Thrombospondin 1 (TSP) elicits potent antiinflammatory activities in vivo, as evidenced by persistent, multiorgan inflammation in TSP null mice. Herein, we report that DCs represent an abundant source of TSP at steady state and during activation. Human monocyte-derived immature dendritic cells (iDCs) spontaneously produce TSP, which is strongly enhanced by PGE2 and to a lesser extent by transforming growth factor (TGF) beta, two soluble mediators secreted by macrophages after engulfment of damaged tissues. Shortly after activation via danger signals, DCs transiently produce interleukin (IL) 12 and tumor necrosis factor (TNF) alpha, thereby eliciting protective and inflammatory immune responses. Microbial stimuli increase TSP production, which is further enhanced by IL-10 or TGF-beta. The endogenous TSP produced during early DC activation negatively regulates IL-12, TNF-alpha, and IL-10 release through its interactions with CD47 and CD36. After prolonged activation, DCs extinguish their cytokine synthesis and become refractory to subsequent stimulation, thereby favoring the return to steady state. Such "exhausted" DCs continue to release TSP but not IL-10. Disrupting TSP-CD47 interactions during their restimulation restores their cytokine production. We conclude that DC-derived TSP serves as a previously unappreciated negative regulator contributing to arrest of cytokine production, further supporting its fundamental role in vivo in the active resolution of inflammation and maintenance of steady state.

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Figures

Figure 1.

Figure 1.

Immature and mature DCs express TSP. 0.5 × 106/ml monocyte-derived iDCs were cultured for 48 h (A) or the indicated time (B) in the absence or presence of 1 μg/ml LPS or 0.0025% SAC. Cells were permeabilized, fixed, and stained for intracellular TSP as described in Materials and Methods. (A) TSP staining is depicted as follows: iDCs (left, thick line); iDCs (middle, thin line) versus iDCs + LPS (thick line); and iDCs (right, thin line) versus iDCs + SAC (thick line). (dotted lines) Isotype control mAb. Data are from one representative experiment out of three (A) and out of five (B).

Figure 2.

Figure 2.

TSP secretion by activated DCs. (A) Monocyte-derived iDCs were cultured for 24 h in the absence or presence of LPS, SAC, or L-CD40L + IFN-γ. TSP production was determined in the culture supernatants by ELISA (sensitivity, 10 ng/ml). Data are from one representative experiment out of three. (B and C) Kinetics of cytokine production by SAC-activated DCs. Monocyte-derived iDCs were cultured for the indicated periods of time in the absence or presence of SAC. IL-12, TNF-α, IL-10, and TSP production was determined by ELISA. Data are from one representative experiment out of three.

Figure 3.

Figure 3.

IL-10, TGF-β, and PGE2 enhance TSP secretion by DCs. (A and B) Monocyte-derived iDCs were cultured for 24 h in the absence or presence of SAC with or without IL-10 or TGF-β. TSP production was determined by ELISA and TSP levels expressed in fold increase compared with iDCs. Mean ± SEM of five experiments (paired Student's t test; *, P < 0.05). (C and D) Monocyte-derived iDCs were cultured for 24 h in the absence or presence of SAC with or without 100 nM PGE2. TSP and IL-12, TNF-α production was determined by ELISA. (C) TSP levels expressed in fold increase as in A and B. (D) IL-12 and TNF-α levels expressed as percentage of control response (100%, cytokine production by activated DCs). Mean ± SEM of five experiments (paired Student's t test; **, P < 0.01). (E) Dose–response curve of PGE2 effect on TSP secretion by iDCs. (F) Effect of 100 nM PGE2 on intracytoplasmic TSP expression by iDCs. (thin line) TSP staining of iDCs. (thick line) iDCs + PGE2. (dotted line) Control mAb. Data are from one representative experiment out of three for E and F.

Figure 4.

Figure 4.

Endogenous TSP negatively regulates cytokine release and mediates DC exhaustion. (A) Monocyte-derived iDCs were activated with SAC for 48 h in the presence of neutralizing anti-TSP mAbs or respective control mAbs (10 μg/ml). Anti-TSP mAb III selectively interferes with TSP–CD47 interactions and anti-TSP mAb I with TSP–CD36 interactions. Data are from one representative experiment out of six. (B) Monocyte-derived iDCs were cultured for 48 h with SAC, washed, and restimulated for 24 h with L-CD40L transfectants and IFN-γ (to mimic T cell interactions) in the presence or absence of the two different neutralizing anti-TSP mAbs. Data are from one representative experiment out of four. IL-12, TNF-α, and IL-10 production were determined by ELISA.

References

    1. Steinman, R.M., D. Hawiger, and M.C. Nussenzweig. 2003. Tolerogenic dendritic cells. Annu. Rev. Immunol. 21:685–711. - PubMed
    1. Langenkamp, A., M. Messi, A. Lanzavecchia, and F. Sallusto. 2000. Kinetics of dendritic cell activation: impact on priming of TH1, TH2 and nonpolarized T cells. Nat. Immunol. 1:311–316. - PubMed
    1. Harizi, H., M. Juzan, V. Pitard, J.F. Moreau, and N. Gualde. 2002. Cyclooxygenase-2-issued prostaglandin e(2) enhances the production of endogenous IL-10, which down-regulates dendritic cell functions. J. Immunol. 168:2255–2563. - PubMed
    1. Morelli, A.E., and A.W. Thomson. 2003. Dendritic cells under the spell of prostaglandins. Trends Immunol. 24:108–111. - PubMed
    1. Aliberti, J., S. Hieny, C. Reis e Sousa, C.N. Serhan, and A. Sher. 2002. Lipoxin-mediated inhibition of IL-12 production by DCs: a mechanism for regulation of microbial immunity. Nat. Immunol. 3:76–82. - PubMed

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