Anti-IL17C monoclonal antibody, clone 288225

Background: NIPAL4, encoding the NIPA-like domain containing 4 protein (NIPAL4), is one of the causative genes of autosomal recessive congenital ichthyosis (ARCI). The physiological role of NIPAL4 and the pathogenetic mechanisms of ARCI caused by NIPAL4 mutations remain unclear. Objective: To clarify the changes of ceramide components in the lesional stratum corneum (SC) and the gene expression profile in the lesional skin of an ARCI patient with a novel frameshift mutation in NIPAL4. Methods: We performed ultrastructural and immunohistochemical analyses of the skin. We used RNA sequencing to determine the mRNA expression in the skin of the patient and healthy individuals. We investigated ceramide components using tape stripped SC samples from the patient. Results: mRNA expression profiling in the patient's skin showed significant upregulation of IL-17/TNF alpha-related genes (IL17C, IL36A, IL36G, S100A7A, S100A9) and psoriasis hallmark genes (VNN3, LCE3D, PLA2G4D), and significant downregulation of lipid-associated genes (GAL, HAO2, FABP7). Ceramide analysis in the patient's SC revealed amounts of CER[NS] with carbon chain-length (C) 32-52 were increased, while amounts of most acylceramide with C66:2- C72:2 were reduced relatively to those in healthy individuals. After the retinoid treatment, CER[NS] with carbon chains C46-54, CER[E01-1] and CER [EOP] increased. Conclusion: IL-17C and IL-36 family cytokines might be involved in the pathogenetic process of ARCI with NIPAL4 mutations. Reduced amounts of the acylceramides in the SC are associated with the skin phenotype due to NIPAL4 mutations. Efficacy of the oral retinoid treatment might be due to restored amounts of CERIEOHI and CER[EOP] in the SC. (C) 2019 Japanese Society for Investigative Dermatology. Published by Elsevier B.V. All rights reserved.

Human beta-defensin 2 (hBD2), encoded by the DEFB4 gene, is an antimicrobial peptide playing an essential role in inflammatory processes in the skin. hBD2 expression is regulated synergistically by tumor necrosis factor-alpha (TNF-alpha) and IL-17A; however, the underlying regulatory mechanisms are unknown. The purpose of this study was to characterize the molecular mechanism by which TNF-alpha and IL-17A synergistically induce hBD2 expression. In cultured human keratinocytes we show that a constitutive noninducible binding of the transcription factor organic cation transporter 1 (OCT1) to the DEFB4 promoter is crucial for IL-17A/TNF-alpha-mediated synergistic induction of hBD2 but not the synergistic induction of CCL20, IL8, IL17C and LCN2. Interestingly, stimulation with IL-17A results in a p38 mitogen-activated protein kinase-dependent accumulation of inhibitor of nuclear factor kappa B zeta (I kappa B zeta), which is a necessity for synergistic induction of hBD2. Finally, co-stimulation with TNF-alpha induces DNA binding of NF-kappa B and activator protein 1 (AP-1) to two specific sites in the DEFB4 promoter region. Hence, our study shows how two inflammatory stimuli are integrated by three different signaling pathways into the regulation of one specific target gene involving the three specific transcription factors OCT1, NF-kappa B, and AP-1 as well as the transcriptional cofactor I kappa B zeta. These findings may be important in psoriasis, where TNF-alpha and IL-17A have been identified as key pathogenic cytokines.