Updated mutational spectrum and genotype-phenotype correlations in ichthyosis patients with ABCA12 pathogenic variants.

Autosomal recessive congenital ichthyoses (ARCI) is a genetically heterogeneous condition that can be caused by pathogenic variants in at least 12 genes, including ABCA12. ARCI mainly consists of congenital ichthyosiform erythroderma (CIE), lamellar ichthyosis (LI) and harlequin ichthyosis (HI). The objective was to determine previously unreported pathogenic variants in ABCA12 and to update genotype-phenotype correlations for patients with pathogenic ABCA12 variants. Pathogenic variants in ABCA12 were detected using Sanger sequencing or a combination of Sanger sequencing and whole-exome sequencing. To verify the pathogenicity of a previously unreported large deletion and intron variant, cDNA analysis was performed using total RNA extracted from hair roots. Genetic analyses were performed on the patients with CIE, LI, HI and non-congenital ichthyosis with unusual phenotypes (NIUP), and 11 previously unreported ABCA12 variants were identified. Sequencing of cDNA confirmed the aberrant splicing of the variant ABCA12 in the patients with the previously unreported large deletion and intron variant. Our findings expand the phenotype spectrum of ichthyosis patients with ABCA12 pathogenic variants. The present missense variants in ABCA12 are considered to be heterogenous in pathogenicity, and they lead to varying disease severities in patients with ARCI and non-congenital ichthyosis with unusual phenotypes (NIUP).

Gene-Modified Blister Fluid-Derived Mesenchymal Stromal Cells for Treating Recessive Dystrophic Epidermolysis Bullosa.

Recessive dystrophic epidermolysis bullosa (RDEB) is a genodermatosis caused by variants in COL7A1-encoded type VII collagen, a major component of anchoring fibrils. In this study, we developed an ex vivo gene therapy for RDEB using autologous mesenchymal stromal cells (MSCs). On the basis of our previous studies, we first attempted to isolate MSCs from the blister fluid of patients with RDEB and succeeded in obtaining cells with a set of MSC characteristics from all 10 patients. We termed these cells blister fluid-derived MSCs. Blister fluid-derived MSCs were genetically modified and injected into skins of type VII collagen-deficient neonatal mice transplanted onto immunodeficient mice, resulting in continuous and widespread expression of type VII collagen at the dermal-epidermal junction, particularly when administered into blisters. When injected intradermally, the efforts were not successful. The gene-modified blister fluid-derived MSCs could be cultured as cell sheets and applied to the dermis with an efficacy equivalent to that of intrablister administration. In conclusion, we successfully developed a minimally invasive and highly efficient ex vivo gene therapy for RDEB. This study shows the successful application of gene therapy in the RDEB mouse model for both early blistering skin and advanced ulcerative lesions.

Fusion with type 2 macrophages induces melanoma cell heterogeneity that potentiates immunological escape from cytotoxic T lymphocytes.

Evasion from immunity is a major obstacle to the achievement of successful cancer immunotherapy. Hybrids derived from cell-cell fusion are theoretically associated with tumor heterogeneity and progression by conferring novel properties on tumor cells, including drug resistance and metastatic capacity; however, their impact on immune evasion remains unknown. Here, we investigated the potency of tumor-macrophage hybrids in immune evasion. Hybrids were established by co-culture of a melanoma cell line (A375 cells) and type 2 macrophages. The hybrids showed greater migration ability and greater tumorigenicity than the parental melanoma cells. The hybrids showed heterogeneous sensitivity to New York esophageal squamous cell carcinoma-1 (NY-ESO-1)-specific T-cell receptor-transduced T (TCR-T) cells and two out of four hybrid clones showed less sensitivity to TCR-T compared with the parental cells. An in vitro tumor heterogeneity model revealed that the TCR-T cells preferentially killed the parental cells compared with the hybrids and the survival rate of the hybrids was higher than that of the parental cells, indicating that the hybrids evade killing by TCR-T cells efficiently. Analysis of a single-cell RNA sequencing dataset of patients with melanoma revealed that a few macrophages expressed RNA encoding melanoma differentiation antigens including melan A, tyrosinase, and premelanosome protein, which indicated the presence of hybrids in primary melanoma. In addition, the number of potential hybrids was correlated with a poorer response to immune checkpoint blockade. These results provide evidence that melanoma-macrophage fusion has a role in tumor heterogeneity and immune evasion. © 2023 The Pathological Society of Great Britain and Ireland.

SOX10 Inhibits T Cell Recognition by Inducing Expression of the Immune Checkpoint Molecule PD-L1 in A375 Melanoma Cells.

BACKGROUND/AIM: Malignant melanoma is a fatal skin cancer and is among the most immunogenic malignancies expressing melanoma-differentiation antigens and neoantigens. SRY-related HMG-box 10 (SOX10) is a transcription factor and a neural-crest differentiation marker that is used as a diagnostic marker for melanoma whilst playing a role in melanoma initiation through activation of the SOX10-MITF axis. SOX10 was shown to play a role in melanoma initiation by inducing expression of immune checkpoint molecules (e.g., HVEM and CEACAM1). In this study, we aimed to investigate the relationship between SOX10 and the expression an immune checkpoint molecule, programmed death-1 ligand 1 (PD-L1). MATERIALS AND METHODS: SOX10 overexpression and knockdown was performed using SOX10 gene transfection and SOX10 siRNA transfection into A375 melanoma cells. PD-L1 expression was assessed by flow cytometry and western blotting. T cell response was evaluated using NY-ESO-1 specific TCR-transduced T (TCR-T) cells by IFNγ ELISPOT assay. RESULTS: SOX10 overexpression increased the expression of PD-L1, whereas SOX10 knockdown, using siRNA, decreased its expression. IFNγ ELISPOT assay revealed that overexpression of SOX10 decreased the susceptibility of cells to NY-ESO-1-specific TCR-T cells. CONCLUSION: SOX10 has a role in the intrinsic immune suppressive mechanisms of melanoma through expression of PD-L1.

Autoimmunity-related neutrophilic dermatosis after coronavirus disease 2019 vaccination: A case report and literature review.

Autoimmune diseases triggered by coronavirus disease 2019 (COVID-19) mRNA vaccination have been emerging. Here, we report the case of a 27-year-old Japanese man with autoimmunity-related neutrophilic dermatosis, occurring as an initial cutaneous manifestation of systemic lupus erythematosus with Sjögren syndrome after the second dose of the Pfizer/BioNTech COVID-19 vaccination. The patient presented with urticarial erythema and partially annular erythema on the trunk and extremities with severe pruritus. Histopathological analysis showed vacuolar degeneration at the dermo-epidermal junction and interstitial neutrophil infiltration. We reviewed eight patients, including the aforementioned patient, with exacerbation or new-onset of SLE after COVID-19 vaccination and found the patient had relatively mild symptoms, itchy annular erythema, and positive anti-SS-A/SS-B antibodies. COVID-19 mRNA vaccination can induce the production of type-I interferon, which plays a crucial role in the pathogenesis of SLE and may cause autoimmunity-related neutrophilic dermatosis in susceptible individuals. In the case that itchy annular erythema develops approximately 2 weeks after the vaccination, the possibility of systemic or cutaneous lupus erythematosus should be considered. For an accurate diagnosis, dermatologists should obtain a recent vaccination history and perform complete antibody profiling and skin biopsy for patients presenting with annular or erythema multiforme-like lesions.

Ninjurin1 Deletion in NG2-Positive Pericytes Prevents Microvessel Maturation and Delays Wound Healing.

The formation of mature vasculature through angiogenesis is essential for adequate wound healing, such that blood-borne cells, nutrients, and oxygen can be delivered to the remodeling skin area. Neovessel maturation is highly dependent on the coordinated functions of vascular endothelial cells and perivascular cells, namely pericytes (PCs). However, the underlying mechanism for vascular maturation has not been completely elucidated, and its role in wound healing remains unclear. In this study, we investigated the role of Ninjurin-1 (Ninj1), a new molecule mediating vascular maturation, in wound healing using an inducible PC-specific Ninj1 deletion mouse model. Ninj1 expression increased temporarily in NG2-positive PCs in response to skin injury. When tamoxifen treatment induced a decreased Ninj1 expression in PCs, the neovessels in the regenerating wound margins were structurally and functionally immature, but the total number of microvessels was unaltered. This phenotypic change is associated with a reduction in PC-associated microvessels. Wound healing was significantly delayed in the NG2-specific Ninj1 deletion mouse model. Finally, we showed that Ninj1 is a crucial molecule that mediates vascular maturation in injured skin tissue through the interaction of vascular endothelial cells and PCs, thereby inducing adequate and prompt wound healing.