Genes & Cells

The generation of induced pluripotent stem cells (iPSCs) from adult human somatic cells and their subsequent differentiation into various cell types for regenerative medicine is currently considered a basis for creating a new class of biomedical cell products and drugs. Cell therapy products derived from iPSCs have broad therapeutic potential and proven clinical efficacy. However, compared to traditional pharmaceuticals, cell-based drugs are more difficult to standardize, which requires the development of a separate regulatory framework for them. Furthermore, cell therapy products derived using iPSC technology can potentially cause unique adverse effects, including neoplasm formation; therefore, the risk–benefit assessment for their use is highly relevant.

This paper highlights the features of obtaining iPSC cultures; safety of using somatic cells differentiated from iPSCs for therapeutic purposes; and the regulatory framework for preclinical and clinical trials of cell products and drugs based on cells differentiated from iPSCs in the European Union, the United States, and Russia. The article also describes the state of clinical trials of cell products and drugs derived using iPSC technology worldwide and the state of preclinical trials of such products in Russia.

A hallmark of synucleinopathies, including Parkinson disease, is the aggregation of alpha-synuclein, a regulatory protein that modulates presynaptic vesicle dynamics. Mutations in the central fragment and several other factors increase the risk of alpha-synuclein oligomerization, leading to the formation of amorphous aggregates and cross-beta amyloid-type structures (fibrils) that exhibit pronounced neurotoxicity. Their structure is stabilized by intramolecular contacts of beta-strands from the N-terminal and central regions of alpha-synuclein. Peptides that exhibit affinity for these regions have been shown to block the intermolecular contacts characteristic of the pathogenic conformation of alpha-synuclein and thereby prevent its aggregation. Such peptides are potential neuroprotectors and may find application in the treatment of Parkinson disease and other synucleinopathies. In recent years, dozens of promising peptides that block alpha-synuclein aggregation have been identified. The protective effect of several leading peptides has been confirmed in animal models of Parkinson disease; however, due to intracellular delivery challenges, the search for alternative cell-penetrating peptides remains a pressing task.

This review examines key strategies for the rational design of peptide inhibitors of alpha synuclein aggregation and approaches to their testing, and summarizes data on the mechanism of action of the most fully characterized effective inhibitors.

BACKGROUND: To develop targeted immunotherapy against ovarian adenocarcinoma, direct identification of peptides presented by major histocompatibility complex class I (HLA class I) on the surface of tumor cells can be used. However, standard immunopeptidome analysis protocols may vary substantially in the efficiency of immunopeptidome isolation depending on lysis conditions. Optimizing detergents for immunoaffinity purification of HLA complexes enhances analytical sensitivity, expands the repertoire of identified ligands, and increases the likelihood of detecting clinically relevant peptides suitable for personalized immunotherapeutic approaches.

AIM: To evaluate the effect of various detergents on the efficiency of identifying peptide ligands of HLA class I complexes; to identify HLA class I ligands in ovarian adenocarcinoma tumors; and to characterize the surface antigens of ovarian adenocarcinoma tumors presented by HLA class I complexes that are potentially promising for immunotherapy.

METHODS: The immunopeptidome of cell lines and postoperative specimens from patients with ovarian adenocarcinoma was isolated using immunoaffinity chromatography followed by liquid chromatography–mass spectrometry analysis.

RESULTS: In this study, we tested an immunoaffinity isolation protocol for the immunopeptidome, comparing various detergents (CHAPS, NP-40, SOD, and Triton X-100) for cell lysis, and observed no statistically significant differences in the number of peptides identified. Using NP-40, we identified 5 peptides belonging to cancer/testis antigen proteins in the immunopeptidomes of postoperative specimens from patients with ovarian adenocarcinoma, 3 of which, according to the Human Protein Atlas, are indeed not expressed in normal ovarian tissues.

CONCLUSION: Each of the four tested detergents leads to the identification of unique sets of peptides. Immunopeptidome analysis enables the identification of peptides derived from cancer/testis antigen proteins; however, a larger sample of postoperative specimens from patients with ovarian adenocarcinoma and experimental validation of the immunogenicity of the identified peptides are necessary.

BACKGROUND: Antiseptic solutions and abrasive agents are widely used in dentistry for surface decontamination and may have a cytotoxic effect on progenitor cells. However, comparative studies evaluating the cytocompatible properties of such substances in cultures of multipotent human mesenchymal stromal cells (MSCs) are lacking.

AIM: To comprehensively evaluate the immediate and delayed cytotoxic effects of antiseptics and abrasives used in dentistry on MSCs derived from human adipose tissue (MSC-AT) in vitro.

METHODS: Human MSC-AT were incubated with antiseptic solutions—benzyldimethyl-myristoylamino-propylammonium 0.01%, chlorhexidine 0.05%, octenidine dihydrochloride 0.1% + 2-phenoxyethanol 2%—and with abrasive powders—sodium bicarbonate, glycine, and erythritol. The solutions were tested at their original concentrations and at 2-, 4-, and 10-fold dilutions. Cell viability was assessed immediately after exposure and after 24 hours using an MTT assay and fluorescence microscopy.

RESULTS: All substances demonstrated dose-dependent cytotoxicity. Among the antiseptics, benzyldimethyl-myristoylamino-propylammonium was found to be the least toxic. Chlorhexidine at its original concentration significantly reduced cell viability in both immediate and delayed assessments. Octenidine dihydrochloride 0.1% + 2-phenoxyethanol 2% caused pronounced cell death and led to cell fixation. Among the abrasives, glycine and sodium bicarbonate showed acceptable cytocompatibility, whereas erythritol exhibited high cytotoxicity.

CONCLUSION: From the perspective of preserving the regenerative potential of MSC-AT, diluted benzyldimethyl-myristoylamino-propylammonium and sodium bicarbonate are the most biocompatible agents for surface decontamination. The use of octenidine dihydrochloride 0.1% + 2-phenoxyethanol 2% and erythritol at clinically relevant concentrations is associated with irreversible damage to progenitor cells.