o:2639 C-type lectin receptor expression is a hallmark of neutrophils infiltrating the skin in epidermolysis bullosa acquisita en Inflammatory epidermolysis bullosa acquisita (EBA) is characterized by a neutrophilic response to anti-type VII collagen (COL7) antibodies resulting in the development of skin inflammation and blistering. The antibody transfer model of EBA closely mirrors this EBA phenotype.To better understand the changes induced in neutrophils upon recruitment from peripheral blood into lesional skin in EBA, we performed single-cell RNA-sequencing of whole blood and skin dissociate to capture minimally perturbed neutrophils and characterize their transcriptome.Through this approach, we identified clear distinctions between circulating activated neutrophils and intradermal neutrophils. Most strikingly, the gene expression of multiple C-type lectin receptors, which have previously been reported to orchestrate host defense against fungi and select bacteria, were markedly dysregulated. After confirming the upregulation of Clec4n, Clec4d, and Clec4e in experimental EBA as well as in lesional skin from patients with inflammatory EBA, we performed functional studies in globally deficient Clec4e-/- and Clec4d-/- mice as well as in neutrophil-specific Clec4n-/- mice. Deficiency in these genes did not reduce disease in the EBA model.Collectively, our results suggest that while the upregulation of Clec4n, Clec4d, and Clec4e is a hallmark of activated dermal neutrophil populations, their individual contribution to the pathogenesis of EBA is dispensable. Inflammation; Dectin-2 1552099 10.3389/fimmu.2023.1266359 2024-02-27T10:25:44.197Z 44 yes 46 Christian F. Guerrero-Juarez University of Illinois / Rush University Medical Center Paul Schilf University of Lübeck person Jing Li Rush University Medical Center person Maria Paula Zappia University of Illinois person Lei Bao University of Lübeck person Payal M. Patel Rush University Medical Center / Massachusetts General Hospital person Jenny Gieseler-Tillmann University of Lübeck person Sripriya Murthy University of Lübeck person Connor Cole Rush University Medical Center person Maria Sverdlov University of Illinois person Maxim V. Frolov University of Illinois person Takashi Hashimoto Osaka Metropolitan University Graduate School of Medicine person Norito Ishii Kurume University person Thomas Rülicke University of Veterinary Medicine Vienna person 0000-0002-2121-9496 Katja Bieber University of Lübeck person Ralf J. Ludwig University of Lübeck person Christian D. Sadik University of Lübeck person Kyle T. Amber Rush University Medical Center person application/pdf 6562441 https://phaidra.vetmeduni.ac.at/o:2639 no yes 16 70 1552253 Frontiers in Immunology 12 14 Frontiers Media Sa 2023