Therapeutic effect of IL-12/23 and their signaling pathway blockade on brain ischemia model Fumie Konoeda a,b , Takashi Shichita a , Hideyuki Yoshida a , Yuki Sugiyama a , Go Muto a , Eiichi Hasegawa a , Rinpei Morita a , Norihiro Suzuki b , Akihiko Yoshimura a,c,⇑ a Department of Microbiology and Immunology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan b Department of Neurology, Keio University School of Medicine, Shinjuku-ku, Tokyo 160-8582, Japan c Japan Science and Technology Agency (JST), CREST, Chiyoda-ku, Tokyo 102-0075, Japan article info Article history: Received 4 October 2010 Available online 20 October 2010 Keywords: Brain ischemia JAK3 inhibitor Anti-IL12p40 antibody CP-690550 IL-17 abstract Recently, T cell cytokines such as IL-17 and IFN-c have been shown to play important roles in the progres- sion of brain injury induced by ischemia. We have shown that IL-23 from infiltrated macrophages acti- vates cdT cells, thereby inducing IL-17 from these cells. However, deletion of the IL-23 gene in mice showed a more dramatic protective effect against brain ischemia reperfusion (I/R) model than cdT cell depletion did, suggesting that IL-23 plays some other pivotal role in brain injury in addition to its role in IL-17 induction. To develop therapeutic methods based on these findings, we examined the effect of the JAK kinase inhibitor CP-690550 and an anti-IL12/23 monoclonal antibody on an I/R model. CP- 690550 efficiently inhibited IL-17 production from memory T cells in vitro and partly suppressed infarct volume increase after I/R. Anti-p40 antibody, which blocks both IL-12 and IL-23, efficiently suppressed I/R injury and improved recovery of neurological deficits. The number of IL-17-producing cells was decreased by anti-p40 antibody treatment. Thus the JAK inhibitor and anti-p40 antibody, both of which have already been under trial for the treatment of several human inflammatory diseases, appear to be promising therapeutic agents for the amelioration of stroke. Ó 2010 Elsevier Inc. All rights reserved. 1. Introduction Stroke is a leading cause of death and disability worldwide, but no successful therapy has been established that can be initiated at the subacute phase of brain infarction [1,2]. As thrombolysis is cur- rently the only approved therapy, there is a dramatic need for addi- tional therapeutic targets. Recombinant tissue-type plasminogen activator (rt-PA) may be used within a period which has recently been lengthened to 4.5 h after the onset of symptoms, but it is not indicated after that point because the risk of secondary intra- cranial hemorrhage after treatment begins to outweigh the poten- tial benefits [3], and many stroke patients are not eligible for rt-PA treatment at any time. Therefore a novel approach is needed, and must be effective even in late phase of ischemia. Previous studies have suggested that T lymphocytes appear to be localized to the infarction boundary zones 24 h after reperfusion [4,5], and that they play essential roles in brain ischemic injury [6,7]. Antibodies directed against lymphocyte adhesion receptors blocked T-cell transmigration and reduced stroke volumes at day 1 after transient middle cerebral artery occlusion (tMCAO) in rats. Recombination activating gene 1 (RAG1) – deficient mice, which lack functional T and B cells, are protected from cerebral ischemia after 24 h, and this protection is lost upon reconstitution of RAG1 À/ À mice with T cells from wild-type littermates. Detailed analysis of lymphocyte subsets has revealed that T cells, but not B cells, are detrimental during stroke, though the molecular mechanism underlying this phenomenon has not been clarified. We have shown that, among the effector T cell cytokines, IL-17 plays a more important role in I/R injury than IFN-c does [8], and that IL-17 and cdT cells are good therapeutic targets for I/R injury. The major producer of IL-17 in the ischemic brain is infiltrated cdT cells, while IFN-c is produced by Th1 and CTLs. IL-17 is strongly in- duced from cdT cells as well as from Th17 cells by IL-23 [9–11], which is mostly produced by infiltrated macrophages. IL-23-KO mice consistently exhibit no IL-17 production, and are resistant against I/R injury, much more so than IL-17-KO mice. This suggests that IL-23 has an additional target other than IL-17. The nature of this target and the action of IL-23 remain to be investigated. From a therapeutic point of view, IL-23 could be a good tar- get along with IL-17, given that anti-p40 antibody has been proven or suggested to be effective for the treatment of psoriasis, psoriasis arthritis, IBD and MS [12–15]. Anti-p40 antibody blocks both IL-12 and IL-23 and may thereby effect the suppression of Th1 and Th17 0006-291X/$ - see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.bbrc.2010.10.058 ⇑ Corresponding author at: Department of Microbiology and Immunology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. Fax: +81 3 5360 1508. E-mail address: yoshimura@a6.keio.jp (A. Yoshimura). Biochemical and Biophysical Research Communications 402 (2010) 500–506 Contents lists available at ScienceDirect Biochemical and Biophysical Research Communications journal homepage: www.elsevier.com/locate/ybbrc