Effects of IL-31 inhibition on Th2 clonality in prurigo nodularis

Summary: Previous studies have indicated the increased expression of Th2-released <i>IL-31</i> in Prurigo Nodularis (PN), with associated increase in keratinocyte proliferation and fibrosis. We utilized data from a cohort of n=16 patients with PN treated with the IL-31R inhibitor nemolizumab (total of 81 bulk RNAseq datasets from lesional and non-lesional PN) to identify T cell clonotypes. We further integrated the results with three independent PN scRNA-seq cohorts, totaling 246k cells from 34 samples. TCR sequences from the bulk and scRNA-seq data were identified by mapping reads to the TCR regions by TRUST4 using the IMGT reference. We identified 409 and 103 unique clonotypes from the scRNA-seq and bulk RNA-seq cohorts, respectively, with 68 of the TCRs overlapping between the two sample types. Notably, 45.8% of the overlapping sequences were from Th2 cells (<i>IL4RA+</i>, <i>IL13+</i>, and <i>IL10+</i>). Five TCR clones from the PN lesions at baseline became absent in the nemolizumab treated cohort by week 12, while remaining stable in the placebo group at the same time point. Notably, from the bulk lesional skin, nearly twice as many TCR clones were detected in the placebo group when compared to the nemolizumab treated group after 12 weeks of treatment (25 vs. 14 unique clonotypes; compared to lesional baseline with 46 and 33). We found expression of the TCRs TRBV9*01_TRBJ2-1*01 and TRGV10*02_TRGJ1*02 in bulk RNA-seq data and lesional scRNAseq data from PN lesions at baseline. From the bulk RNAseq, we found that TRGV10*02_TRGJ1*02 positively correlated with <i>IL-13/IL-4 </i>signaling (p= 1.28x10^-9, R > 0.7; including <i>IL13RA2 </i>and <i>IL4R</i>), keratinocytes differentiation (including <i>DEFB4B</i> R=0.85, p=1.43x10^-18 and <i>KLF7</i> R=0.66, p=7.97x10-9), and IL-31 signaling (including <i>OSMR </i>R=0.34, P=7.47x10^-3), providing evidence for clonal specific Th2-keratinocyte interactions. Our findings demonstrate that IL-31 inhibition with nemolizumab suppresses Th2 clonality and associated type 2 signaling, providing evidence for the role of IL-31 in driving Th2-keratinocyte cross-talk in PN skin. Rachael Bogle¹, Yuntian Wu¹, Haihan Zhang¹, Tingting Qin¹, Matthew Patrick¹, Valérie Julia², Johann E. Gudjonsson¹, Lam C. Tsoi¹ 1. Dermatology, University of Michigan, Ann Arbor, MI, United States. 2. Galderma SA, Zug, ZG, Switzerland. Bioinformatics, Computational Biology, and Imaging