This study is a successor of our previous work concerning changes in the chemokine profile in infection that are associated with different SARS-CoV-2 genetic variants. The goal of our study was to take into account both the virus and the host immune system by assessing concentrations of cytokines in patients infected with different SARS-CoV-2 variants (ancestral Wuhan strain, Alpha, Delta and Omicron). Our study was performed on 340 biological samples taken from COVID-19 patients and healthy donors in the timespan between May 2020 and April 2022. We performed genotyping of the virus in nasopharyngeal swabs, which was followed by assessment of cytokines’ concentration in blood plasma. We noted that out of nearly 30 cytokines, only four showed stable elevation independently of the variant (IL-6, IL-10, IL-18 and IL-27), and we believe them to be ‘constant’ markers for COVID-19 infection. Cytokines that were studied as potential biomarkers lose their diagnostic value as the virus evolves, and the specter of potential targets for predictive models is narrowing. So far, only four cytokines (IL-6, IL-10, IL-18, and IL-27) showed a consistent rise in concentrations independently of the genetic variant of the virus. Although we believe our findings to be of scientific interest, we still consider them inconclusive; further investigation and comparison of immune responses to different variants of SARS-CoV-2 is required.

Mesenchymal stem cells (MSCs) are multilineage differentiating stromal cells with extensive immunomodulatory and anti-inflammatory properties. MSC-based therapy is widely used in the treatment of various pathologies, including bone and cartilage diseases, cardiac ischemia, diabetes, and neurological disorders. Along with MSCs, it is promising to study the therapeutic properties of exosomes derived from MSCs (MSC-Exo). A number of studies report that the therapeutic properties of MSC-Exo are superior to those of MSCs. In particular, MSC-Exo are used for tissue regeneration in various diseases, such as healing of skin wounds, cancer, coronary heart disease, lung injury, liver fibrosis, and neurological, autoimmune, and inflammatory diseases. In this regard, it is not surprising that the scientific community is interested in studying the therapeutic properties of MSCs and MSC-Exo in the treatment of psoriasis. This review summarizes the recent advancements from preclinical and clinical studies of MSCs and MSC-Exo in the treatment of psoriasis, and it also discusses their mechanisms of therapeutic action involved in the treatment of this disease.

Background and Aim: Bovine interleukin 15 (bIL15) is a potential immunotherapy that can block the spread of bovine leukemia virus (BLV). However, immune checkpoints that maintain body homeostasis may reduce their effectiveness. Thus, an analysis of the effectiveness of bIL15 while blocking negative immune regulators is necessary. We aimed to obtain recombinant bIL15 (rbIL15) and determine its percentage using monoclonal antibodies against bovine cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed cell death ligand 1 (PD-L1). To achieve this goal, peripheral blood mononuclear cells (PBMCs) from healthy and BLV+ cattle were treated with bIL15 using a CTLA-4– and PD-L1–blocking algorithm. Materials and Methods: The codon-optimized bIL15 gene was synthesized under de novo conditions using polymerase chain reaction (PCR). The synthesized gene was cloned into pET28 and transformed into electrocompetent Escherichia coli BL21 cells; rbIL15 was purified using metal affinity chromatography and analyzed using sodium dodecyl-sulfate– polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The expression of the Bcl2, STAT3, and STAT5 genes was studied using qualitative PCR. An enzyme-linked immunosorbent assay (ELISA) was used to analyze interferon (IFN)-γ production by rbIL15-treated mononuclear cells. Results: Analysis of rbIL15 using SDS-PAGE and western blotting revealed a specific product weighing 24 kDa. The optimal conditions for rbIL15 induction were 0.2 mM isopropyl-β-D-1-galactopyranoside and 37°C. When rbIL15 was added to PBMCs from healthy cattle, the Bcl2, STAT3, and STAT5 genes were expressed. ELISA of the culture medium of rbIL15-treated PBMCs revealed IFN-γ production. When PBMCs from healthy cows were treated with rbIL15, CTLA-4, and PD-L1 blockade together, they did not produce more IFN-γ than the rbIL15 group. Using PBMCs from BLV+ cattle, combination treatment increased IFN-γ production. Conclusion: The biological activity of rbIL15 is characterized by the induction of transcription factors and the production of IFN-γ. Using rbIL15 with CTLA-4 and PD-L1 blockade in PBMCs from healthy and BLV+ cows led to the production of a transcription factor and cytokine. The results demonstrate the possibility of using this method to improve immunity and immunological memory in patients with chronic viral infections. Keywords: bovine interleukin-15, bovine leukemia virus, cytotoxic T-lymphocyte antigen 4, monoclonal antibody, programmed cell death ligand 1.

Background: The use of chimeric proteins that selectively interact with various immune cell receptors to treat oncology patients has increased. One effective way to obtain recombinant proteins is to use the E. coli expression system. However, in eukaryotic protein production in E. coli, several difficulties arise that can be solved by fusing ...

Background and Aim: In chronic viral infections, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death ligand 1 (PD-L1) significantly suppress immune responses. The CTLA-4 receptor abundance in regulatory T cells showed a positive association with viral load and a negative association with interferon-gamma (IFN-γ) production in bovine leukemia virus (BLV)-infected cattle. Blocking this receptor boosted IFN-γ production, recovering immune response against this illness. In human cancer patients, not everyone responded positively to non-immunotherapy using CTLA-4 receptor antibodies. The present study analyzed the synergistic effects of CTLA-4 and PD-L1 receptor blockade on IFN-γ production in BLV+ cattle in vitro. Materials and Methods: The genes for bovine CTLA-4 and PD-L1 were artificially produced. The amino acid sequences of the extracellular receptor domains were sourced from the National Center for Biotechnology Information PubMed database. The western blotting and liquid chromatography with tandem mass spectrometry (LC-MS/MS) techniques were employed for the characterization of recombinant CTLA-4 (rCTLA-4) and recombinant PD-L1 (rPD-L1) proteins. The immunoinhibitory effects of recombinant proteins in Staphylococcus enterotoxin B (SEB)-stimulated cattle peripheral blood mononuclear cells (PBMCs) were investigated. Enzyme-linked immunosorbent assay (ELISA) was used to analyze monoclonal antibodies against rCTLA-4 and rPD-L1. Antibodies generated from peripheral blood mononuclear cells of healthy and BLV-seropositive cows were employed to evaluate their blocking capabilities. Results: The resulting recombinant proteins specifically reacted with commercial homogeneous monoclonal antibodies (mAbs) using ELISA and anti-His-tag mAbs using western blotting. Analysis of the proteins using LC-MS/MS revealed correspondence with the sequences of rCTLA-4 and rPD-L1 located in the Mascot database. rCTLA-4 and rPD-L1 proteins inhibited IFN-γ production in bovine PBMCs of activated SEB. When PBMCs from cows were cultured with activated SEB containing rCTLA-4 and rPD-L1, the mAbs increased IFN-γ production in PBMCs. The combined cultivation of mAbs and PBMCs from BLV+ cattle enhanced IFN-γ production in the cells. Conclusion: These findings suggest that the combined blockade of bovine CTLA-4 and PD-L1 receptors can be used as a therapy for bovine leukemia. However, it was shown that a single PBMC sample from a BLV-positive donor did not amplify the synergistic effect. Therefore, it is necessary to perform further studies on a larger population and assessing a wider range of cytokines. Keywords: bovine, bovine leukemia virus, cytotoxic T-lymphocyte-associated antigen 4, interferon-gamma, programmed death ligand 1.

Background and Aim: Toxoplasma gondii is an intracellular protozoan and a major foodborne pathogen worldwide. Nearly, all warm-blooded animals are susceptible to toxoplasmosis, with raw and undercooked meat and animal products serving as the primary transmission routes. To date, the distribution of T. gondii among farm animals in Kazakhstan has been inadequately studied. This study aimed to determine the occurrence of antibodies against T. gondii in cattle and sheep in the Akmola and Kostanay regions. Materials and Methods: Blood samples were randomly collected from 437 cattle and 397 sheep from two regions of Kazakhstan: Akmola and Kostanay. A commercial enzyme-linked immunosorbent assay based on the native protein Toxoplasma surface antigen 1 was used for serological analysis. Results: The occurrences of T. gondii were 8.0% and 3.8% among cattle and 42.1% and 19.0% among sheep in the Akmola and Kostanay regions, respectively. Antibodies against T. gondii were detected in all study areas. The greatest frequency of seropositive reactions in cattle was observed in the Arshaly region (9.0%), whereas the least frequent was observed in Arkalyk (3.3%). The highest occurrence of seropositive reactions among sheep was found in the Zerenda region (54.5%), whereas the lowest was found in the Auliekol region (15.6%). Conclusion: The obtained results confirmed the circulation of the T. gondii pathogen among cattle and sheep in the investigated regions. These findings provide insight into the current distribution of this zoonotic parasite among farm animals in Kazakhstan. Keywords: antibodies, cattle, enzyme-linked immunosorbent assay, sheep, surface antigen 1, Toxoplasma gondii.