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. 2014 Nov 13:5:5444.
doi: 10.1038/ncomms6444.

Fc gamma receptor-TLR cross-talk elicits pro-inflammatory cytokine production by human M2 macrophages

Lisa T C Vogelpoel  1 , Ivo S Hansen  1 , Theo Rispens  2 , Femke J M Muller  1 , Toni M M van Capel  1 , Maureen C Turina  3 , Joost B Vos  4 , Dominique L P Baeten  3 , Martien L Kapsenberg  1 , Esther C de Jong  1 , Jeroen den Dunnen  1
Affiliations

Fc gamma receptor-TLR cross-talk elicits pro-inflammatory cytokine production by human M2 macrophages

Lisa T C Vogelpoel et al. Nat Commun. .

Abstract

M2 macrophages suppress inflammation in numerous disorders, including tumour formation, infection and obesity. However, the exact role of M2 macrophages in the context of several other diseases is still largely undefined. We here show that human M2 macrophages promote inflammation instead of suppressing inflammation on simultaneous exposure to complexed IgG (c-IgG) and TLR ligands, as occurs in the context of diseases such as rheumatoid arthritis (RA). c-IgG-TLR ligand co-stimulation of M2 macrophages selectively amplifies production of pro-inflammatory cytokines TNF-α, IL-1β and IL-6 and promotes Th17 responses, which all play a critical role in RA pathology. Induction of pro-inflammatory cytokines on c-IgG co-stimulation mainly depends on Fc gamma receptor IIa (FcγRIIa), which selectively amplifies cytokine gene transcription and induces caspase-1 activation. These data indicate that FcγR-TLR cross-talk may be targeted for treatment to attenuate inflammation in RA, by restoring the anti-inflammatory function of M2 macrophages.

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Figures

Figure 1
Figure 1. c-IgG-TLR ligand co-stimulation of M2 macrophages induces pro-inflammatory cytokines.
(a) M1 or M2 macrophages were stimulated with Pam3CSK4 (Pam3) or LPS. (b) M2 macrophages were stimulated with TLR ligands, c-IgG or a combination. (c) M2 macrophages were stimulated with dead synovial fibroblasts either combined with c-IgG or not. (a–c) After 24 h, cytokine levels were determined by ELISA, mean+s.e.m. Data are representative of at least (a,b) twenty or (c) three experiments, performed in triplicate, with different donors. (d) CD163+ cells were isolated from synovial fluid of active RA patients (n=6) and stimulated with Pam3CSK4 or Pam3CSK4 combined with c-IgG. After 24 h, cytokine levels were determined by ELISA. Each pair of dots represents one patient. *P≪0.05; NS, not significant, two-tailed Wilcoxon matched-pair test.
Figure 2
Figure 2. Synergistic upregulation of pro-inflammatory cytokines on c-IgG-TLR ligand co-stimulation does not differ between HD and RA patients.
(a) M2 macrophages derived from monocytes of HD (n=20) or RA patients (n=9) were stimulated with Pam3CSK4 or Pam3CSK4 combined with c-IgG. Each pair of dots represents one donor. *P≪0.05, **P≪0.01, ***P≪0.001; NS, not significant, Kruskal Wallis test. (b) HD M2 macrophages were stimulated with Pam3CSK4 combined with HD c-IgG or c-IgG from RA patients. Data (mean+s.e.m.) are representative of four experiments with different donors. (a,b) After 24 h, cytokine levels were determined by ELISA. Experiments were performed in triplicate.
Figure 3
Figure 3. c-IgG-TLR ligand co-stimulation of M2 macrophages enhances pro-inflammatory cytokine transcription and caspase-1 activity.
M2 macrophages were stimulated with Pam3CSK4, c-IgG or a combination and analysed for (a,b) mRNA expression of indicated genes (normalized to GAPDH expression, fold increase compared with unstimulated control) that was determined by quantitative RT–PCR or (c) caspase-1 activity, using caspase-1-binding compound FAM-YVAD-FMK at indicated time points. (a–c) Data are representative of three experiments with different donors.
Figure 4
Figure 4. c-IgG-TLR ligand co-stimulation of M2 macrophages promotes Th17 responses.
M2 macrophages were stimulated with Pam3CSK4, c-IgG or a combination and co-cultured with allogeneic CD4+ T cells. After T cell outgrowth, resting T cells were restimulated. (a) After 24 h, cytokine levels were determined by ELISA, mean+s.e.m. Experiments were performed in triplicate. (b) T cells were analysed for intracellular IL-17 and IFN-γ by flow cytometry. (a,b) Data are representative of three experiments with different donors.
Figure 5
Figure 5. Synergistic upregulation of pro-inflammatory cytokines on c-IgG-TLR ligand co-stimulation is dependent on FcγRs and Syk.
(a) FcγR expression (10log fluorescence intensity) on unstimulated M2 macrophages was analysed by flow cytometry. (b) Before stimulation, M2 macrophages were incubated with blocking antibodies against indicated FcγRs or (c) 1 μM of Syk inhibitor R406. (a–c) Data are representative of at least three experiments with different donors. (b,c) After 24 h, cytokine levels were determined by ELISA, mean+s.e.m. Experiments were performed in triplicate.
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References

    1. Sica A. & Mantovani A. Macrophage plasticity and polarization: in vivo veritas. J. Clin. Invest. 122, 787–795 (2012). - PMC - PubMed
    1. Biswas S. K. & Mantovani A. Macrophage plasticity and interaction with lymphocyte subsets: cancer as a paradigm. Nat. Immunol. 11, 889–896 (2010). - PubMed
    1. Murray P. J. & Wynn T. A. Protective and pathogenic functions of macrophage subsets. Nat. Rev. Immunol. 11, 723–737 (2011). - PMC - PubMed
    1. Li J., Hsu H. C. & Mountz J. D. Managing macrophages in rheumatoid arthritis by reform or removal. Curr. Rheumatol. Rep. 14, 445–454 (2012). - PMC - PubMed
    1. Brennan F. M. & McInnes I. B. Evidence that cytokines play a role in rheumatoid arthritis. J. Clin. Invest. 118, 3537–3545 (2008). - PMC - PubMed

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