Bulletin of Experimental Biology and Medicine最新文献

Modified vaccinia virus Ankara (MVA) is a highly attenuated strain of vaccinia virus widely used as a recombinant vector in vaccine development. Several studies have shown that deletion of the C12L, A35R, A40R, and A41L genes from the MVA genome can enhance T-cell and/or humoral immune responses not only to MVA vector proteins, but also to incorporated recombinant antigens. Here, we generated recombinant MVA (rMVA) constructs expressing the SARS-CoV-2 Spike protein, each harboring a deletion of one of the C12L, A35R, A40R, or A41L genes, and compared the immune responses in mice vaccinated with these rMVAs. None of these deletions altered T-cell or humoral responses to the Spike protein. However, immunization of mice with rMVAs bearing deletions of the A40R or A41L genes resulted in increased titers of MVA-specific antibodies. Meanwhile, the examined deletions did not affect the T-cell response to MVA itself, with the exception of the C12L gene deletion, which reduced the number of interferon-producing cells in response to MVA-specific peptides.

Immunofluorescence analysis was used to study the expression pattern of macrophage colony-stimulating factor 1 (CSF-1) in spinal cord cells in a murine model of multiple sclerosis (experimental autoimmune encephalomyelitis). Marked upregulation of CSF-1⁺ signal was observed in spinal cord astrocytes in both acute and chronic stages of the disease. These findings suggest a potential role for CSF-1 in the pathogenesis and progression of experimental autoimmune encephalomyelitis/multiple sclerosis.

Lantibiotics warnerin and hominin isolated from growth media of Staphylococcus warneri DSMZ 16081 and S. hominis GISK 284, respectively, have pronounced immunomodulatory effects. Both peptides significantly modulated the microbicidal potential of leukocytes; the effect depended on the concentration and presence of the inducer. Warnerin inhibited ROS in high concentrations and stimulated ROS production in low concentrations in both spontaneous and stimulated samples. Hominin, on the contrary, enhanced spontaneous ROS production, but inhibited stimulated ROS production. Both peptides decreased the phagocytic activity of monocytes and neutrophils and activated the spontaneous production of both pro- (IL-1β, IL-6) and anti-inflammatory (IL-10) cytokines. Comparison of the two peptides revealed that hominin showed higher immunomodulatory activity.

Assessment of fractional anisotropy (FA) in diffusion tensor imaging (DTI) and measurement of transverse relaxation time T2* in T2*-weighted imaging (T2*WI) are the basic MRI methods used in the diagnosis of Parkinson's disease (PD). However, it remains unclear which of these methods is more effective. We compared the sensitivity and specificity of DTI and T2*WI methods to determine which one is more effective in the early diagnosis of PD. For PD modeling, male Sprague-Dawley rats (n = 20) were injected with 6-hydroxydopamine (6-OHDA) into the right substantia nigra (SN). MRI was performed and FA and T2* of each SN were measured and analyzed every week after surgery over 6 weeks. The ROC curves were used to evaluate sensitivity and specificity of these parameters in the early diagnosis of PD. Significant differences between the lesioned and control SN were revealed for FA and T2* values on weeks 1, 2, 5, and 6 and on weeks 5 and 6 after injection, respectively (p < 0.01). Six weeks after injection, the Youden's indices of FA and T2* were higher compared to the earlier terms of the experiment. The optimal cut-off values of FA and T2* were 0.395 (area under the ROC curve (AUC) = 0.9075, 100% sensitivity, and 70% specificity) and 9.48 msec (AUC = 0.9450, 90% sensitivity, and 95% specificity), respectively. In 6 weeks after 6-OHDA injection, the diagnostic effectiveness of FA and T2* was higher than that determined in previous weeks. The T2* was more effective than FA for early diagnosis of PD.

The composition of mucosa-associated microbiota of the colon of experimental animals was studied under conditions of chronic restraint stress of varying duration (14 and 28 days). Identification and quantitative assessment of microorganisms was carried out by mass spectrometry of microbial markers. Stress has a pronounced inhibitory effect on most non-spore-forming anaerobes, facultative anaerobic and aerobic bacteria, and actinomycetes, promotes the growth and reproduction of Candida fungi and Clostridium difficile. Enterococci, staphylococci, and lactobacilli exhibit adaptive properties under stress for 28 days, bifidobacteria are most sensitive to restraint stress.

Pancreatic stellate cells (PSCs) are involved in the homeostasis maintenance in the pancreas, but upon activation, they are capable of excessive production of extracellular matrix proteins, which can aggravate the course of the pathological process, in particular diabetes. The changes in the functional activity of PSCs in the acinar and islet parts of the pancreas in rats with experimental type 2 diabetes mellitus were assessed by the expression of GFAP and α-SMA markers, as well as by the intensity of collagen proportion. During the development of experimental type 2 diabetes mellitus, PSCs are activated in the pancreas as evidenced by enhanced expression of α-SMA accompanied by increased collagen production. We revealed a direct correlation of the levels of glucose and HbA1c with relative collagen content in the islets and the number of α-SMA+ cells. The results obtained can further contribute to the development of therapeutic strategies for the treatment of type 2 diabetes mellitus.

A recombinant modified human transferrin (N413D and N611D) was produced by the Pichia pastoris strain pPIC9pGAPZalpha-short_hTFNG (Yst-TFNG2). A multi-step protocol for isolation and purification of recombinant transferrin was developed achieving the target protein yield of 70.29% and a purity of at least 95%. Structural correspondence of the recombinant transferrin to the natural protein was confirmed by mass spectrometry and circular dichroism analysis. Functional analysis demonstrated the protein's ability to bind and release iron ions, as well as support the proliferation of eukaryotic cells.

Male Wistar rats were subjected to mild, moderate, and heavy physical exercises (10 swimming sessions), after which they were euthanized (immediately or 30 days after the last session). Animals of the experimental groups received meldonium (100-120 mg/kg of body weight) with food for 10 days of swimming. Heavy exercise led to the development of degeneration, necrotic patches, and cellular infiltration in the liver and a decrease of the TGF-β1 level. In 30 days after the last swimming session, an increase in both the level of TGF-β1 in the cytoplasmic fraction and the expression of the tgfb1 gene were observed. The level of TGF-β1 increased by 1.8 times against the background of meldonium treatment and decreased by 1.6 times in 30 days; tgfbl expression also decreased by 1.3 times in comparison with that in rats exposed to a similar exercise without meldonium (p < 0.05). The use of meldonium against the background of heavy physical exercise contributed to the achievement of gene expression and cytokine levels approaching the target values observed in intact animals and prevent severe alterative changes in the liver.

We studied the effect of gaseous transmitter H₂S on the cytokine-producing activity of perivascular adipose tissue in rats with metabolic syndrome modeled by high-fat high-carbohydrate diet for 12 weeks. It was shown that the serum concentration of H₂S and the level of H₂S biosynthesis enzyme (CSE) were decreased in animals with metabolic syndrome. The secretory activity of perivascular adipose tissue cellular elements after high-fat high-carbohydrate diet is characterized by increased synthesis of proinflammatory cytokines (IL-6, TNFα, MCP-1) and decreased production of anti-inflammatory IL-10. It was found that exogenous H₂S donor (NaHS, 100 μM) shifted the balance of cytokines secreted by the perivascular adipose tissue by reducing the concentration of proinflammatory mediators, thereby exerting an anti-inflammatory effect on the perivascular adipose tissue.

An immunohistochemical study of connexin-43 (Cx43) was carried out in the myocardium of the left ventricle of 6-month-old rats born one day preterm. Using computer morphometry, the relative area of immunopositive staining was determined. The intensity of immunopositive staining was evaluated spectrophotometrically. It was shown that in preterm born 6-month-old rats, Cx43 is located in the region of intercalated discs. However, the relative area, as well as the intensity of Cx43-positive staining in this case was lower than in full-term animals. Thus, preterm birth affects the expression of Cx43 in the myocardium in the late postnatal period.