Expression of IL33 and IL35 in oral lichen planus
ARCHIVES OF DERMATOLOGICAL RESEARCH
Authors: Javvadi, L. R.; Parachuru, V. P. B.; Milne, T. J.; Seymour, G. J.; Rich, Alison M.
Abstract
Oral lichen planus (OLP) is a complex immunological disorder, mediated in part by the release of cytokines by activated T-cells. Recently, the role of novel cytokines including IL33 and IL35 has been described in various chronic inflammatory diseases. IL33, a member of the IL-1 superfamily of cytokines, functions as an 'alarmin' released after cell necrosis to alert the immune system to tissue damage or stress. IL35, a member of IL12 cytokine family, is produced by regulatory T-cells and suppresses the immune response. The expression of IL33 and IL35 is yet to be investigated in OLP. The aim of this study was to determine the presence and topographical distribution of IL33 and IL35 in OLP using immunohistochemistry and quantitative real-time reverse transcriptase polymerase chain reaction (qPCR). For IHC, formalin-fixed paraffin-embedded archival specimens of OLP (n = 10) and a non-specific inflammatory (NSI) control group (n = 9) were used. A double-labelling immunofluorescence technique was used to determine the expression of IL33 and IL35 on CD3(+) T-cells. In addition, 12 fresh tissue samples (OLP n = 6 and NSI controls n = 6) were used to determine the gene expression of IL33 and EBI3 (one chain of the dimeric IL35). Quantitative and qualitative analysis was performed with statistical significance set at p < 0.05. IHC showed positive immunostaining with IL33 and IL35 in both OLP and NSI. Comparison of the numbers of IL33(+) and IL35(+) cells in OLP and NSI did not show any significant difference. In OLP, there were significantly more IL33(+) cells in the deeper connective tissue region than at the epithelial-connective tissue interface. Interestingly, all IL35(+) cells observed in both OLP and NSI tissues showed ovoid/plasmacytoid morphology. Double-labelling immunofluorescence showed that IL33 and IL35 expression was not localized within CD3(+) T-cells. The gene expression experiments showed significantly higher expression of EBI3 (fold regulation 14.02) in OLP when compared to the inflammatory controls. IL33 gene expression was not different between the groups. However, within the OLP tissues, there was a significantly higher expression of IL33 than EBI3. Our data demonstrate the expression of IL33 and IL35 in OLP lesions. Further studies are needed to understand the functional role of these cytokines in OLP pathogenesis.
IL-33-mediated IL-13 secretion by ST2(+) Tregs controls inflammation after lung injury
JCI INSIGHT
Authors: Liu, Quan; Dwyer, Gaelen K.; Zhao, Yifei; Li, Huihua; Mathews, Lisa R.; Chakka, Anish Bhaswanth; Chandran, Uma R.; Demetris, Jake A.; Alcorn, John F.; Robinson, Keven M.; Ortiz, Luis A.; Pitt, Bruce R.; Thomson, Angus W.; Fan, Ming-Hui; Billiar, Timothy R.; Turnquist, Heth R.
Abstract
Acute respiratory distress syndrome is an often fatal disease that develops after acute lung injury and trauma. How released tissue damage signals, or alarmins, orchestrate early inflammatory events is poorly understood. Herein we reveal that IL-33, an alarmin sequestered in the lung epithelium, is required to limit inflammation after injury due to an unappreciated capacity to mediate Foxp3(+) Treg control of local cytokines and myeloid populations. Specifically, Il33 (-1-) mice are more susceptible to lung damage-associated morbidity and mortality that is typified by augmented levels of the proinflammatory cytokines and Ly6C(hi) monocytes in the bronchoalveolar lavage fluid. Local delivery of IL-33 at the time of injury is protective but requires the presence of Treg cells. IL-33 stimulates both mouse and human Tregs to secrete IL-13. Using Foxp3(cre) x Il4/Il13(fl/fl) mice, we show that Treg expression of IL-13 is required to prevent mortality after acute lung injury by controlling local levels of G-CSF,IL-6, and MCP-1 and inhibiting accumulation of Ly6C(hi) monocytes. Our study identifies a regulatory mechanism involving IL-33 and Treg secretion of IL-13 in response to tissue damage that is instrumental in limiting local inflammatory responses and may shape the myeloid compartment after lung injury.