Limits...
Engulfment of activated apoptotic cells abolishes TGF-β-mediated immunoregulation via the induction of IL-6.

Notley CA, Brown MA, McGovern JL, Jordan CK, Ehrenstein MR - J. Immunol. (2015)

Bottom Line: However, ACs derived from LPS-activated DCs failed to restrain inflammation because of a short-lived but marked IL-6 response, which abolished the increase in TGF-β.These transferred DCs stimulated B cell TGF-β production and relied on an intact B cell compartment to limit inflammation.These results highlight how the activation state of AC governs their ability to control inflammation through reciprocal regulation of IL-6 and TGF-β.

View Article: PubMed Central - PubMed

Affiliation: Division of Medicine, Centre for Rheumatology, University College London, London WC1E 6JF, United Kingdom.

Show MeSH

Related in: MedlinePlus

Activation of ACs abolishes the ability of ACs to induce TGF-β. (A) Arthritis was monitored in mice left untreated (No AC) or injected with AC or aAC on the day of immunization and for a further 2 consecutive days before intra-articular injection of mBSA to induce inflammation in the knee. Lymph nodes and spleens were harvested on day 7 after knee injection. LN cells were analyzed for IL-17 production by (B) ELISA after no stimulation (Nil) or stimulation with anti-CD3 mAb (aCD3) and (C) flow cytometry. IFN-γ production in the LNs was also determined by flow cytometry after gating on lymphocytes (C). IL-10 production by the spleen was assessed by (B) ELISA and (D) flow cytometry, after gating on lymphocytes. TGF-β production by splenic B cells (E) and DCs (F) was analyzed by flow cytometry. Live lymphocytes were gated; then CD11c+ or CD19+ populations were gated and assessed for TGF-β production. n = 12 pooled from 4 independent experiments. (G) Mice were left untreated (No AC) or injected with AC or aAC, then immunized and spleens harvested 48 h later. The production of TGF-β by DCs and B cells was determined by flow cytometry, gated as mentioned earlier. Histograms show pooled data from 4 independent experiments; n = 12. FACS plots are representative data.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4319310&req=5

fig03: Activation of ACs abolishes the ability of ACs to induce TGF-β. (A) Arthritis was monitored in mice left untreated (No AC) or injected with AC or aAC on the day of immunization and for a further 2 consecutive days before intra-articular injection of mBSA to induce inflammation in the knee. Lymph nodes and spleens were harvested on day 7 after knee injection. LN cells were analyzed for IL-17 production by (B) ELISA after no stimulation (Nil) or stimulation with anti-CD3 mAb (aCD3) and (C) flow cytometry. IFN-γ production in the LNs was also determined by flow cytometry after gating on lymphocytes (C). IL-10 production by the spleen was assessed by (B) ELISA and (D) flow cytometry, after gating on lymphocytes. TGF-β production by splenic B cells (E) and DCs (F) was analyzed by flow cytometry. Live lymphocytes were gated; then CD11c+ or CD19+ populations were gated and assessed for TGF-β production. n = 12 pooled from 4 independent experiments. (G) Mice were left untreated (No AC) or injected with AC or aAC, then immunized and spleens harvested 48 h later. The production of TGF-β by DCs and B cells was determined by flow cytometry, gated as mentioned earlier. Histograms show pooled data from 4 independent experiments; n = 12. FACS plots are representative data.

Mentions: It has previously been shown that transfer of thymically derived ACs at the time of immunization can suppress the development and severity of inflammatory arthritis through the production of IL-10 (10, 18). Given the differences we found with respect to cytokine production between ACs and aACs, we next sought to investigate whether both are equally potent at suppressing inflammation in vivo. We used the Ag-induced arthritis (AIA) model, which is IL-17 dependent (22, 23). Although ACs derived from resting DCs suppressed the development of AIA, activation of the DCs with LPS before apoptosis induction resulted in an inability to modulate arthritis development (Fig. 3A). ELISA (Fig. 3B) and flow cytometry (Fig. 3C–F) data show that suppression of arthritis was determined by the balance of IL-17 and TGF-β production, where decreased production of IL-17 by draining lymph node cells and an increase in TGF-β production by the splenocytes were protective. aAC transfer was neither able to suppress IL-17 responses in the lymph node nor boost TGF-β production by splenic B cells and DCs. IL-10 production by splenocytes was upregulated by aACs to a similar level observed by resting ACs (Fig. 3B, 3D).


Engulfment of activated apoptotic cells abolishes TGF-β-mediated immunoregulation via the induction of IL-6.

Notley CA, Brown MA, McGovern JL, Jordan CK, Ehrenstein MR - J. Immunol. (2015)

Activation of ACs abolishes the ability of ACs to induce TGF-β. (A) Arthritis was monitored in mice left untreated (No AC) or injected with AC or aAC on the day of immunization and for a further 2 consecutive days before intra-articular injection of mBSA to induce inflammation in the knee. Lymph nodes and spleens were harvested on day 7 after knee injection. LN cells were analyzed for IL-17 production by (B) ELISA after no stimulation (Nil) or stimulation with anti-CD3 mAb (aCD3) and (C) flow cytometry. IFN-γ production in the LNs was also determined by flow cytometry after gating on lymphocytes (C). IL-10 production by the spleen was assessed by (B) ELISA and (D) flow cytometry, after gating on lymphocytes. TGF-β production by splenic B cells (E) and DCs (F) was analyzed by flow cytometry. Live lymphocytes were gated; then CD11c+ or CD19+ populations were gated and assessed for TGF-β production. n = 12 pooled from 4 independent experiments. (G) Mice were left untreated (No AC) or injected with AC or aAC, then immunized and spleens harvested 48 h later. The production of TGF-β by DCs and B cells was determined by flow cytometry, gated as mentioned earlier. Histograms show pooled data from 4 independent experiments; n = 12. FACS plots are representative data.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4319310&req=5

fig03: Activation of ACs abolishes the ability of ACs to induce TGF-β. (A) Arthritis was monitored in mice left untreated (No AC) or injected with AC or aAC on the day of immunization and for a further 2 consecutive days before intra-articular injection of mBSA to induce inflammation in the knee. Lymph nodes and spleens were harvested on day 7 after knee injection. LN cells were analyzed for IL-17 production by (B) ELISA after no stimulation (Nil) or stimulation with anti-CD3 mAb (aCD3) and (C) flow cytometry. IFN-γ production in the LNs was also determined by flow cytometry after gating on lymphocytes (C). IL-10 production by the spleen was assessed by (B) ELISA and (D) flow cytometry, after gating on lymphocytes. TGF-β production by splenic B cells (E) and DCs (F) was analyzed by flow cytometry. Live lymphocytes were gated; then CD11c+ or CD19+ populations were gated and assessed for TGF-β production. n = 12 pooled from 4 independent experiments. (G) Mice were left untreated (No AC) or injected with AC or aAC, then immunized and spleens harvested 48 h later. The production of TGF-β by DCs and B cells was determined by flow cytometry, gated as mentioned earlier. Histograms show pooled data from 4 independent experiments; n = 12. FACS plots are representative data.
Mentions: It has previously been shown that transfer of thymically derived ACs at the time of immunization can suppress the development and severity of inflammatory arthritis through the production of IL-10 (10, 18). Given the differences we found with respect to cytokine production between ACs and aACs, we next sought to investigate whether both are equally potent at suppressing inflammation in vivo. We used the Ag-induced arthritis (AIA) model, which is IL-17 dependent (22, 23). Although ACs derived from resting DCs suppressed the development of AIA, activation of the DCs with LPS before apoptosis induction resulted in an inability to modulate arthritis development (Fig. 3A). ELISA (Fig. 3B) and flow cytometry (Fig. 3C–F) data show that suppression of arthritis was determined by the balance of IL-17 and TGF-β production, where decreased production of IL-17 by draining lymph node cells and an increase in TGF-β production by the splenocytes were protective. aAC transfer was neither able to suppress IL-17 responses in the lymph node nor boost TGF-β production by splenic B cells and DCs. IL-10 production by splenocytes was upregulated by aACs to a similar level observed by resting ACs (Fig. 3B, 3D).

Bottom Line: However, ACs derived from LPS-activated DCs failed to restrain inflammation because of a short-lived but marked IL-6 response, which abolished the increase in TGF-β.These transferred DCs stimulated B cell TGF-β production and relied on an intact B cell compartment to limit inflammation.These results highlight how the activation state of AC governs their ability to control inflammation through reciprocal regulation of IL-6 and TGF-β.

View Article: PubMed Central - PubMed

Affiliation: Division of Medicine, Centre for Rheumatology, University College London, London WC1E 6JF, United Kingdom.

Show MeSH
Related in: MedlinePlus