RT Journal Article
SR Electronic
T1 Interleukin 12 and interleukin 23 play key pathogenic roles in inflammatory and proliferative pathways in giant cell arteritis
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 1815
OP 1824
DO 10.1136/annrheumdis-2018-213488
VO 77
IS 12
A1 Richard Conway
A1 Lorraine O’Neill
A1 Geraldine M McCarthy
A1 Conor C Murphy
A1 Aurelie Fabre
A1 Susan Kennedy
A1 Douglas J Veale
A1 Sarah M Wade
A1 Ursula Fearon
A1 Eamonn S Molloy
YR 2018
UL http://ard.bmj.com/content/77/12/1815.abstract
AB Objectives The pathogenesis of giant cell arteritis (GCA) remains unclear. TH1 and TH17 pathways are implicated, but the proximal initiators and effector cytokines are unknown. Our aim was to assess the role of interleukin 12 (IL-12) and interleukin 23 (IL-23) in GCA pathogenesis.Methods IL-12 and IL-23 expression were quantified by immunohistochemistry in temporal artery biopsies (TABs). Temporal artery (TA) explant, peripheral blood mononuclear cell (PBMC) and myofibroblast outgrowth culture models were established. PBMCs and TA explants were cultured for 24 hours in the presence or absence of IL-12 (50 ng/mL) or IL-23 (10 ng/mL). Gene expression in TA was quantified by real-time PCR and cytokine secretion by ELISA. Myofibroblast outgrowths were quantified following 28-day culture.Results Immunohistochemistry demonstrated increased expression of interleukin 12p35 (IL-12p35) and interleukin 23p19 (IL-23p19) in biopsy-positive TAs, localised to inflammatory cells. IL-12p35 TA expression was significantly increased in those with cranial ischaemic complications (p=0.026) and large vessel vasculitis (p=0.006). IL-23p19 TA expression was increased in those with two or more relapses (p=0.007). In PBMC cultures, exogenous IL-12 significantly increased interleukin 6 (IL-6) (p=0.009), interleukin 22 (IL-22) (p=0.003) and interferon γ (IFN-γ) (p=0.0001) and decreased interleukin 8 (IL-8) (p=0.0006) secretion, while exogenous IL-23 significantly increased IL-6 (p=0.029), IL-22 (p=0.001), interleukin 17A (IL-17A) (p=0.0003) and interleukin 17F (IL-17F) (p=0.012) secretion. In ex vivo TA explants, IL-23 significantly increased gene expression of IL-8 (p=0.0001) and CCL-20 (p=0.027) and protein expression of IL-6 (p=0.002) and IL-8 (p=0.004). IL-12 (p=0.0005) and IL-23 (p<0.0001) stimulation increased the quantity of myofibroblast outgrowths from TABs.Conclusion IL-12 and IL-23 play central and distinct roles in stimulating inflammatory and proliferative pathways relevant to GCA pathogenesis.