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. 2023 Jan;56(1):27-38.
doi: 10.1111/iej.13839. Epub 2022 Oct 13.

Immunomodulatory effect of IL-1RA in LPS-activated macrophage/dental pulp stem cells co-culture

Vellore Kannan Gopinath  1   2 , Mohammad G Mohammad  2   3 , Soumya Sheela  2
Affiliations

Immunomodulatory effect of IL-1RA in LPS-activated macrophage/dental pulp stem cells co-culture

Vellore Kannan Gopinath et al. Int Endod J. 2023 Jan.

Abstract

Aims: Lipopolysaccharides (LPS)-activated human dental pulp stem cells (hDPSCs) and macrophage co-cultures showed downregulated TNF-α secretion that is modulated by hDPSCs through IDO axis, whereas the secretory levels of IL-1β remained unchanged. Therefore, sustained production of IL-1β could contribute to progressive dental pulp inflammation. However, the role of interleukin-1 receptor antagonist (IL-1RA) in downregulating the secretion of IL-1β and TNF-α in LPS-activated M0/M1/M2 macrophage and hDPSCs co-culture has not been studied yet. Therefore, the aim of the present study was to determine the immunomodulatory role of blocking IL-1 receptors in DPSCs macrophage co-culture activated with LPS.

Methodology: Human monocytic cell line THP-1 was polarized to M0, M1 and M2 macrophages and co-cultured with hDPSCs. The viability of the co-cultured cells was assessed by apoptosis assay. Co-cultures were activated with LPS followed by the assessment of gene expression and protein levels of IL-1β and TNF-α with and without IL-1RA blocking via qRT-PCR and cytokine flex assay by flow cytometry. Data from three separate experiments were analysed using one-way anova followed by Tukey's post hoc test and a p-value of <.05 was considered statistically significant.

Results: THP-1-derived M0, M1 and M2 macrophages co-cultured with hDPSCs showed spindle and round-shaped cells, with >90% viability when assessed by apoptosis assay. Inflammatory TNF-α and IL-1β profiles in stimulated co-cultures showed upregulated IL-1β, whereas TNF-α was downregulated (p < .05). Anti-inflammatory gene expression levels of IL-10 and TGF-β were downregulated (p < .05). Blocking with IL-1RA resulted in a remarkable decrease in IL-1β at the gene expression and protein production levels whilst TNF-α levels remained low (p < .05). Levels of anti-inflammatory cytokine IL-10 showed no significant difference.

Conclusion: Blocking the IL-1 receptor in hDPSCs and macrophage (M0, M1, M2) co-cultures activated with LPS resulted in downregulation of inflammatory cytokines IL-1β and TNF-α. These findings highlight the immunomodulatory effect of IL-1RA in inflammatory conditions of dental pulp infections.

Keywords: IL-1 receptor antagonist; THP-1; cytokines; human dental pulp stem cells; macrophages.

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References

REFERENCES

    1. Arora, S., Cooper, P.R., Friedlander, L.T., Rizwan, S., Seo, B., Rich, A.M. et al. (2021) Potential application of immunotherapy for modulation of pulp inflammation: opportunities for vital pulp treatment. International Endodontic Journal, 54, 1263-1274.
    1. Chang, J., Zhang, C., Tani-Ishii, N., Shi, S. & Wang, C.Y. (2005) NF-kappaB activation in human dental pulp stem cells by TNF and LPS. Journal of Dental Research, 84, 994-998.
    1. Chanput, W., Mes, J.J., Savelkoul, H.F. & Wichers, H.J. (2013) Characterization of polarized THP-1 macrophages and polarizing ability of LPS and food compounds. Food & Function, 4, 266-276.
    1. Cooper, P.R., Holder, M.J. & Smith, A.J. (2014) Inflammation and regeneration in the dentin-pulp complex: a double-edged sword. Journal of Endodontics, 40, S46-S51.
    1. Evans, I., Dower, S.K., Francis, S.E., Crossman, D.C. & Wilson, H.L. (2006) Action of intracellular IL-1Ra (type 1) is independent of the IL-1 intracellular signalling pathway. Cytokine, 33, 274-280.

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