Method of training examples in solving inverse ill-posed problems of spectroscopy

Further development of the method of computational experiments for solving ill-posed problems is given. The effective (unoverstated) estimate for solution error of the first-kind equation is obtained using the truncating singular numbers spectrum of an operator. It is proposed to estimate the magnitude of the truncation by results of solving model (training, learning) examples close to the initial example (problem). This method takes into account an additional information about the solution and gives a new principle for choosing the regularization parameter and error estimate for equation solution by the Tikhonov regularization method. The method is illustrated by a numerical example from the inverse problem of spectroscopy.Comment: 9 pages, 3 figure

TNF, SOLUBLE RECEPTORS AND AUTOANTIBODIES TO TNF OF PATIENTS WITH RHEUMATOID ARTHRITIS AND HEALTHY DONORS

The content of autoantibodies to TNF in the sera of patients with rheumatoid arthritis (RA) in conjunction with the definition of soluble receptors and TNF was investigated. A significant increase in the content of TNF and I and II types soluble receptors to TNF in sera of RA patients in the acute stage and of responding to therapy RA patients compared with relatively healthy donors was demonstrated. In determining autoantibodies subclasses a significant increase in the relative content of subclasses IgG2, IgG3 and IgG4 autoantibodies in sera of RA patients in the acute stage compared with relatively healthy donors, as well as a significant increase in the relative content of subclasses IgG2 and IgG4 autoantibodies in RA patients in the acute stage compared with RA patients, responding to therapy were shown. Thus we have shown the presence of antibodies, soluble receptors to TNF and cytokine in the serum of relatively healthy donors and RA patients, herewith taking into account significant changes in the relative content of the subclasses of autoantibodies and in the content of TNF and soluble receptors we can talk about the functional role of the autoantibodies and soluble receptors to TNF in the pathology

Myeloid-derived suppressor cells as biomarkers of the effectiveness of therapy with new biological agents in axial spondyloarthritis

Innate immune cells, including myeloid cells — myeloid derived suppressor cells (MDSCs) — are supposed to play an important role in the pathogenesis of axial spondyloarthritis (AxSp). Myeloid derived suppressor cells represent a heterogeneous population of immature cells capable of suppressing innate and adaptive immune responses with the most pronounced suppressor activity against T cells. Biological disease-modifying antirheumatic drugs (bDMARDs) can reduce the clinical and laboratory disease activity, but their effectiveness varies widely in different patients with AxSp. The present study is aimed at studying MDSCs subpopulations and their suppressive function depending on the response to bDMARD therapy in AxSp. The study included AxSp patients with a disease duration of 16.5 years (median); HLA-B27 (+) status was detected in 79% of cases. All patients received bDMARDs at least the past 12 weeks, including TNF inhibitors (etanercept, certolizumab pegol, adalimumab, or golimumab) or IL-17 inhibitors (secukinumab, ixekizumab, or netakimab). Percentage of granulocytic MDSCs (G-MDSCs, Lin-HLA-DR-CD33+CD66b+), monocytic MDSCs (M-MDSCs, HLA-DRlow/-CD14+), MDSCs of early stage differentiation (E-MDSCs, Lin-HLA-DR- CD33+CD66b-), as well as intracellular expression of arginase-1 was assessed by flow cytometry. Frequency of circulating MDSC subpopulations of patients with a stable response to bDMARDs (responders) did not differ significantly compared to healthy donors. Patients not responding to bDMARDs therapy showed increased relative and absolute number of E-MDSCs compared to healthy donors (pU = 0.01 and pU = 0.02, respectively) and the responders (pU = 0.03 and pU = 0.07, respectively). Increased percentage of E-MDSCs was positively correlated to disease activity — ESR (Rs = 0.821; p = 0.023), CRP (Rs = 0.714; p = 0.07) and ASDASCRP (Rs = 0.829; p = 0.042) in the non-responder group. Responder patients exhibited no correlation between disease activity and circulating MDSCs. The suppressor potential of MDSCs was analyzed by the intracellular expression of arginase-1 molecule which is involved in the inhibition of T cell response. Patients with the stable response were characterized by increased expression of arginase-1 in E-MDSCs compared to donors (pU = 0.02). Non-responders did not demonstrate significant changes in Arg-1 expression, however, the percentage of arginase-1-expressing G-MDSCs was positively correlated to indexes ASDASESR (Rs = 0.857; p = 0.014) and BASDAI (Rs = 0.785; p = 0.036). Thus, E-MDSCs as well as arginase-1 expression in MDSCs may serve as biomarkers of effectiveness bDMARD therapy, and act as potential candidate predictors of response to therapy in AxSp

Comparative analysis of the expression of the soluble IL-7 receptor in patients with arthropathy

Arthropathy is one of the most prevalent diseases, which are based on the destruction and remodeling of cartilage and bone tissue. The inflammation that precedes destruction can be caused by mechanical stress on the joints, or by autoimmune reactions. Recently, IL-7 is considered as one of the key cytokines that promote the production of matrix metalloproteinases, catabolic enzymes, T cell-mediated activation of monocytes, and maturation of osteoclasts. The soluble form of the IL-7 receptor can help prolong the lifespan of IL-7 and thereby it ensures the bioavailability of the cytokine and mediates effect of IL-7 on cells. The aim of this study was to determine the soluble form of the IL-7 receptor (sIL-7R) in the blood plasma of patients with rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA) and psoriasis vulgaris (PS), as well as healthy individuals. The RA patients included in the study had moderate to high disease activity according to the DAS28 index. Patients with PsA predominantly had moderate and low disease activity (DAS28) and were characterized by mild to moderate disease severity (PASI). In accordance with the PASI index, patients with PS with mild and severe severity of the disease were included in the study. All patients with OA had a metabolic phenotype that is accompanied by an elevated body mass index.sIL-7R was determined in blood plasma by enzyme-linked immunosorbent assay. It was found that in patients with arthropathy, the level of soluble form of IL-7 was increased relative to healthy individuals, with the exception of the group of patients with PsA. Also, a high concentration of sIL-7R was observed in patients with PS. Analyzing the clinical characteristics of the patients, we found that sIL-7R levels were elevated in RA and PsA patients with high disease activity by DAS28. In addition, positive correlations were found between the concentration of sIL-7R and DAS28 in RA and PsA. In patients with PsA with moderate severity of the disease (PASI), the concentration of sIL-7R was also increased relative to donor's values. On the contrary, in patients with PS, a high level of sIL-7R was noted regardless of the severity of the disease. In patients with OA, no relationship was found between sIL-7R levels and clinical parameters.Thus, an elevated level of sIL-7R in patients with arthropathy may indicate the involvement of IL-7 and its receptor system in the pathogenesis of joint diseases. The IL-7 receptor may become a promising target both in the treatment of joint diseases and other autoimmune diseases, including psoriasis

Studies of non-autonomous effects of apoptosis in the course of in vitro apoptotic cell death initiation in healthy persons and patients with rheumatoid arthritis

The process of apoptosis is known that play an important role in cellular homeostasis, and the altered cell death may lead to development of pathological disorders. Evolving autoimmune conditions, in particular, rheumatoid arthritis, are associated with decreased rates of apoptosis as a form of programmed cell death. The aim of this study was to evaluate expression of activation and proliferation markers on T lymphocytes during initiation of apoptotic cell death under the conditions of “cell neighborhood” in healthy individuals and patients with rheumatoid arthritis. Patients and methods. The study was performed with blood samples of the patients with rheumatoid arthritis (RA) and healthy women of comparable age. During the study, we conducted experiments aimed to identify the in vitro influence of non-stimulated apoptosis-induced cells, as well as aCD3- and dexamethasone (Dexa)-stimulated apoptosis-induced cells upon autologous T lymphocytes cultured under physiological conditions. Development of a “cell neighborhood” model, i.e., co-cultures of CFSE- T cells subjected to incubation under crowding condition and depletion of the culture medium which is the most physiological variant of apoptosis activation, and CFSE+ autologous cells placed in the complete culture medium, has revealed some relationships. We have revealed an opportunity of secondary induction of early and late apoptosis by means of humoral and cellular components of autologous cell culture subjected to activation apoptosis. We determined the features of apoptosis in unstimulated, as well as aCD3- and dexamethasone-stimulated cultures, compared with controls. There were no differences in these parameters of apoptosis between RA patients and healthy people for all variants of cultures. An increased proportion of viale cells was found in the CFSE- culture of patients with RA when compared to donors. The donor group had more lymphocytes with activation parameters CD25+, CD69+ and low level of proliferation marker Ki-67 than patients. In contrast to healthy, the RA patients demonstrated a significantly increased expression of Ki 67 in T lymphocytes when co-culturing CFSE- and CFSE+ cells. An increased number of living cells in apoptotic cultures of patients with RA relative to healthy people, in absence of significant differences in the parameters of apoptosis and activation markers in dynamics, as well as pattern of changes in the Ki-67+ cell contents suggested a contribution of the non-autonomous effects of apoptosis to cellular homeostasis in RA patients

Studies of effector molecules exerting autonomous and nonautonomous influence of T lymphocyte apoptosis under the conditions of in vitro “cell neighborhood” in healthy people and patients with rheumatoid arthritis

Cellular homeostasis in the body is known to be maintained by the processes of cell proliferation and death, whereas apoptosis is the most frequent and physiological, “silent” mechanism of cell elimination. It has been currently shown that the process of apoptosis traditionally considered an autonomous event, has a pronounced non-autonomous effect on migration, proliferation, and death of the neighboring cells. This work was based on the data on impaired programmed death of mononuclear cells from the patients with rheumatoid arthritis (RA) leading to the evolving autoimmune inflammation. The aim of this study was to evaluate effector molecules exerting autonomous and non-autonomous influence of T cell apoptosis under the conditions of “cell neighborhood” in cell cultures of healthy people and RA patients. The studies were performed with blood samples of RA patients and healthy women of comparable age. These experiments were performed in order to assess the levels of main molecules mediating the in vitro receptor and mitochondrial apoptosis of T lymphocytes. In previous studies, using the original “cell neighborhood” model, no differences were found in parameters of early and late activation apoptosis between the groups of donors and RA patients. At the same time, 1-week incubation in apoptotic cultures of the patients was followed by significantly increased number of viable cells carrying the proliferation marker Ki-67. Different results of in vitro apoptosis induction in cultures under similar conditions of “cell neighborhood” in healthy people and patients with RA have revealed the importance of main effector molecules of apoptosis in the studied groups. In this study, we have revealed low potential of the receptor pathway for apoptosis activation in healthy people, due to suppression of TNFα production during cell incubation under the conditions of “cell neighborhood”, and in RA patients due to initially low TNFα in supernatants which did not change over time and in various incubation variants, along with low content of initiating caspase 8 in both groups. Significant suppression of effector molecules of mitochondrial pathway of apoptosis activation, i.e., Bcl-2 anti-apoptotic factor and p53 transcription factor was detected in cultures of apoptotic cells, as well as mixtures of proliferating and apoptotic cells under the conditions of “cell neighborhood” in RA patients. The amounts of these molecules did not change in healthy persons. At the same time, no differences in these molecules were found between individual variants of cell cultures from the patients with RA and healthy people. The both studied groups were characterized by a significant activation of IL-4 and IL-6 production, i.e., the cytokines with autonomous and non-autonomous protective and reparative properties, Hence, one may conclude that high levels of these cytokines had different effects in cell cultures under the conditions of “cell neighborhood”. Incubation of cells from healthy people under suboptimal conditions was associated with maintaining the balance of proliferation and apoptosis, whereas, in cell cultures of RA patients, this balance caused activation of proliferation processes, being accompanied by an increase in the number of living cells in apoptotic cultures

Comparison of phenotypic properties of innate lymphoid cells at various stages of rheumatoid arthritis

Autoimmune diseases currently take a leading place in terms of frequency of occurrence in the population, among which 1 percent is occupied by rheumatoid arthritis (RA). Remission in this type of disease is extremely rare and requires constant use of pharmacotherapy. Studying the pathogenesis of RA is necessary to study to search for new drug targets. It is known that T helpers 1 (Th) and Th17 are involved in the development of RA. However, some researchers suggest that ILCs play a role in the development of RA. ILCs are “innate analogues” of Th, due to the fact that this subpopulation synthesizes the same cytokines. ILC1 is innate analogs of Th1, ILC2-Th2, ILC3-Th17. ILCs are tissue-resident innate lymphoid cells that have functional diversity and regulate the direction of the immune response through the production of cytokines.We used peripheral blood mononuclear cells (PBMCs) from patients (n = 19) and conditionally healthy donors (n = 10) as material. The group of patients was divided biologic disease-modifying anti-rheumatic drugs (bDMARDs) and Metotrexate (MTX) and of stage of RA (early and very early arthritis, advanced and late). PBMCs were stained with monoclonal antibodies. ILCs were identified as Lin-CD127+, CD294+ILCs (ILC2) were measured in the general population, CD117-CD294-ILCs were identified as ILC1, and CD117+CD294-ILCs were identified as ILC3.We obtained the following results: ILC1 was significantly reduced in patients treated with MTX comparison with patients on bDMARDs and healthy donors. However, patients on MTX with advanced RA had low levels of ILC2 and ILC3 compared to patients on bDMARDs. ILC2 significantly increased in patients with early stages of RA comparison with patients with advanced RA. However, ILC1 was significantly reduced in patients treated with MTX, and ILC3 increased significantly in patients treated with MTX comparison with bDMARDs. Expression of PD1 on ILC1 was increased compared to patients treated with bDMARDs. However, ILC3 patients with advanced stages on MTX had increased expression of PD1 comparison with patients taking bDMARDs. The ILC3 of donors was significantly increased comparison with patients on bDMARDs