Alexander Aimaletdinov

Autosomal recessive congenital ichthyosis (ARCI) is a heterogeneous group of inherited keratinization disorders with diffuse skin lesions. It includes lamellar ichthyosis, congenital ichthyosiform erythroderma, and fetal ichthyosis. The common pathognomonic feature is generalized neonatal erythroderma. Lamellar ichthyosis is caused by mutations in the TGM1 gene encoding transglutaminase 1 (TGM1), leading to a functional deficiency of the enzyme in the epidermis. TGM1 deficiency causes severe keratinization defects and skin barrier impairment (leading to metabolic disorders, growth delay, and bacterial infections), with severe cases risking potentially fatal sepsis. Current therapeutic approaches are only symptomatic. In this study, we analyzed the functionality and safety of an adeno-associated viral vector of serotype 2 encoding TGM1 (AAV2-TGM1) for gene therapy of lamellar ichthyosis. The functionality of AAV2-TGM1 was confirmed in vitro on HEK293, HaCaT, and SH-SY5Y cells and human primary fibroblasts. A significant increase in TGM1 mRNA, protein levels, and enzymatic activity was shown. The vector was characterized and applied in vivo in rats and pigs. Intradermal injection and topical application resulted in increased protein levels in the skin, as shown by PCR and immunofluorescence. Safety was confirmed by the absence of significant histological, biochemical, and cellular changes. The results demonstrate the promise of AAV2-TGM1 for dermal application in gene therapy of lamellar ichthyosis.

In order to improve the regeneration of full-layer skin defects, hydrogels were developed based on the combination of chitosan (Cs), Daba silk fibroin (DSF), and graphene oxide (GO): CS, DSF/Cs and DSF/Cs/GO. The biocompatibility of hydrogels with human dermis fibroblasts in vitro was evaluated using the MTS assay. To assess the regenerative potential of hydrogels, a model of a full-layer skin defect was reconstructed on the back of rats and closed the wound surface with CS, DSF/Cs and DSF/Cs/GO hydrogels. The morphological and morphometric characteristics of regenerate tissues were obtained by staining with hematoxylin-eosin, Heidengain azocarmine, and immunohistochemistry on days 7 and 14 of the experiment. It has been shown that the use of DSF/Cs and DSF/Cs/GO promotes enhanced healing and epithelization of a full-layer skin wound. The addition of GO to the hydrogel increased the synthetic activity of fibroblasts and improved the characteristics of the produced collagen fibers.

Interleukin 2 (IL2) was one of the first cytokines used for cancer treatment due to its ability to stimulate anti-cancer immunity. However, recombinant IL2-based therapy is associated with high systemic toxicity and activation of regulatory T-cells, which are associated with the pro-tumor immune response. One of the current trends for the delivery of anticancer agents is the use of extracellular vesicles (EVs), which can carry and transfer biologically active cargos into cells. The use of EVs can increase the efficacy of IL2-based anti-tumor therapy whilst reducing systemic toxicity. In this study, human adipose tissue-derived mesenchymal stem cells (hADSCs) were transduced with lentivirus encoding IL2 (hADSCs-IL2). Membrane vesicles were isolated from hADSCs-IL2 using cytochalasin B (CIMVs-IL2). The effect of hADSCs-IL2 and CIMVs-IL2 on the activation and proliferation of human peripheral blood mononuclear cells (PBMCs) as well as the cytotoxicity of activated PBMCs against human triple negative cancer MDA-MB-231 and MDA-MB-436 cells were evaluated. The effect of CIMVs-IL2 on murine PBMCs was also evaluated in vivo. CIMVs-IL2 failed to suppress the proliferation of human PBMCs as opposed to hADSCs-IL2. However, CIMVs-IL2 were able to activate human CD8⁺ T-killers, which in turn, killed MDA-MB-231 cells more effectively than hADSCs-IL2-activated CD8⁺ T-killers. This immunomodulating effect of CIMVs-IL2 appears specific to human CD8⁺ T-killer cells, as the same effect was not observed on murine CD8⁺ T-cells. In conclusion, the use of CIMVs-IL2 has the potential to provide a more effective anti-cancer therapy. This compelling evidence supports further studies to evaluate CIMVs-IL2 effectiveness, using cancer mouse models with a reconstituted human immune system.