Vol 66, No 2 (2024)

The amniotic variant of glycodelin (Gd) has pronounced immunomodulatory properties and is involved in the formation of immune tolerance during pregnancy. The role of recombinant Gd at physiological (0.2 and 2 μg/ml) and superphysiological (10 μg/ml) concentrations in regulating the differentiation and functional activity of human myeloid-derived suppressor cells (MDSCs) was investigated in vitro. MDSCs were generated from CD11b⁺ peripheral blood cells of healthy donors by two-step induction (IL-1β + GM-CSF and then lipopolysaccharide (LPS). The effect of Gd on the content of polymorphonuclear MDSC (PMN-MDSC) and monocytic MDSC (M-MDSC), intracellular expression of indoleamine 2.3-dioxygenase (IDO), arginase-1 (Arg1, and cytokine profile in cell cultures was investigated. In general, the transformation of CD11b⁺ cells into MDSCs exhibits the following characteristics: as a result of cytokine induction, predominantly M-MDSCs but no PMN-MDSCs are formed and Arg1 expression is virtually undetected. Gd was found to increase the number of M-MDSCs at concentrations of 2 and 10 μg/ml. Gd was found not to affect Arg1 expression but increased the percentage of MDSCs expressing IDO (10 μg/ml). Gd also modulated the cytokine profile of CD11b⁺ cells by suppressing the production of IL-19, IL-26 and TWEAK/TNFsF12 at a physiological concentration of 2 μg/ml and the production of IFN-α2 and IL-26 at a supraphysiological concentration. Thus, the role of Gd in the conversion of CD11b⁺ cells to MDSCs was examined under conditions of cytokine induction in vitro.

The occurrence of severe side effects in patients undergoing chemotherapy remains a significant clinical challenge. Therefore, the urgent task is to search for tumor-specific therapies that target opposing responses in non-transformed and tumorigenic cells. HSF1 is known to be an important marker of cancer progression and its transcriptional activity products allow tumor cells to escape the adverse effects of anticancer therapies. Thus, drugs inhibiting HSF1 activity hold promise as a therapeutic strategy. Our study shows that using the cardenolide group’s HSF1 activity inhibitor, CL-43, provides cytoprotective effects on primary, untransformed dermal fibroblast (DF-2) cells, making them less sensitive to etoposide, whereas we observed an increase in sensitivity in the DLD1 tumor cell line. Furthermore, our results show that CL-43 interferes with the intranuclear transport of the active form of HSF1, increasing its activity and consequently the synthesis of HSP70 in human fibroblasts, while suppressing this activity in tumor cells in a dose-dependent manner. Our findings demonstrate the unique potential of CL-43 as a tumor-specific compound with high therapeutic value.

Amitriptyline is a tricyclic antidepressant widely used in clinical practice for the treatment of anxiety, depression and chronic pain. These drugs have a multifaceted effect on cellular processes. One of their targets is sigma-1 receptors. Sigma-1 receptors are molecular chaperones located in endoplasmic reticulum membrane; they are characterized by a unique structure and pharmacological profile. Sigma-1 receptors regulate many cellular processes in health and disease, including Ca²⁺ signaling. Using Fura-2AM microfluorimetry, it was shown for the first time that sigma-1 receptor agonist, antidepressant amitriptyline, significantly suppresses both Ca²⁺ mobilization from intracellular Ca²⁺-stores and subsequent store-dependent Ca²⁺ entry into cells, induced by endoplasmic Ca²⁺-ATPase inhibitors thapsigargin and cyclopiazonic acid, as well as disulfide-containing immunomodulators glutoxim and molixan, in rat peritoneal macrophages. The results suggest the involvement of sigma-1 receptors in a complex signaling cascade induced by glutoxim or molixan, leading to an increase of intracellular Ca²⁺ concentration in macrophages. The results also indicate the participation of sigma-1 receptors in the regulation of store-dependent Ca²⁺ entry in macrophages.

In the сlinical practice, allogeneiс bone marrow transplantation (BMT) is often cause of the graft-versus-host disease (GvHD). GvHD is explained by the fact that T-lymphocytes, which are administered simultaneously with hematopoietic cells during transplantation and after then formed and matured in the timus of the recipient from donor progenitor cells, recognize and attack the cells of the host. However, a complete explanation of the phenomenon of the GvHD does not exists, and the chimerization of the recipient’s organism as a possible cause of damage of its organs is not taken into account. Therefore, the aim of this work was the modeling of allogeneic transplantation of the whole bone marrow (BM, experiment) and comparing its results with syngeneic transplantation (control) basing on the investigation of engraftment of cells of donor origin in the main GvHD target organs. Bone marrow (BM) donors were Tg(ACTB-EGFP)1Osb/J mice carrying a green fluorescent protein gene (EGFP), recipients were the animal of CBA and C57BL/6 inbred strains with age 2–10 months. 1 day before BMT (1.5×10⁷ cells per mouse) all recipients were irradiated at a dose of 6.5 Gy (LD 50/30). After 1, 3, 5, 7, 11, 14, 21, 28, 35 and 55 days the development of chimerism in the liver, skin and colon of animals was examined using a fluorescent microscope. Already in 1 day, single fibroblast-like donor cells were found in the colon, in 7 days – in the skin and liver. 14–28 days after BMT, with donor cells mainly stroma in the liver, in the skin fibroblasts and keratinocytes were formed, in the colon villous cells and also stromal and parenchymal cells of Peyer’s patches which were died off after irradiation were substituted. Unlike control, in the experimental groups GFP⁺ giant fibroblasts about 30 mkm in length were found in the stroma of the liver, in the skin and in the colon; in the liver there was a lot of GFP⁺-bulkheads and fibroblast-like Ito’s cells of a very intricate configuration. To 35–55 days after allogeneic BMT cells of the donor origin in the liver and in the villi of the colon began to destroy, the villi became overgrown with GFP⁺-connective tissue cells and warped, wall of the colon became thin and the skin was fully substituted with a new one (all these things were never observed in the conrol groups). We propose a hypothesis that beside with GvHD traits like thinning of the colon wall and plenty of roundish GFP⁺-cells on inner surface of the skin, other signs of the studied after allogeneic BMT organs suggest that the cells of the organs which are formed from mesenchymal stem cells of the whole bone marrow become target for the recipient’s T-cells, i.e. suggest existence of host-versus-graft (HVG) reaction. Obvious manifestation of immune reactions after BMT directly coincides with the term of massive engraftment of the studied organs with cells of donor origin and restoration of the host’s own immune system, i.e. the development of chimerism determines the development of organ damage. This explains the events of GvHD from medical practice – atrophy of the mucous membranes, excess production of collagen, sclerosis of the bile ducts, skin damage, colitis – and the timing of its manifestation.