This review presents our own and literature data dedicated to predisposing and pathogenetic factors involved in development of a common comorbidity, diabetes-associated osteoarthritis (DAOA). So far, there is no wide-accepted clinical or scientific viewing of DAOA as a distinct clinical phenotype of osteoarthritis (OA). To our knowledge, the role of genetic factors in DAOA development was not discussed in details. Therefore, we have drawn attention to the cross-acting genes involved in both OA and diabetes, i.e., PPARγ, FTO, ADIPOQ, and AGE. These genes encode proteins which can contribute to the pathogenesis of both OA and diabetes. However, some controversies exist about genetic predisposal for OA and diabetes. We review the studies which concern various clinical characteristics of DAOA. We describe a role of chronic hyperglycemia, insulin resistance, advanced glycation end-products (AGE) in development of OA and micro- and macrovascular complications of diabetes. The mechanisms of low-grade inflammation, humoral and cellular immune responses to cartilage antigens, and their role in OA progression are discussed. We underline a similarity of low-grade inflammation in OA and microvascular complications in diabetes. In conclusion, OA and diabetes comorbidity is not a mere coincidence of these diseases. They share some common genetic and pathogenetic factors, a distinct phenotype, and may change thinking of physicians and scientists towards a holistic (personalized) approach to prevention, diagnosis, treatment and prognosis of this comorbidity. We discuss opportunities of DAOA pharmacotherapy based on the key comorbidity feature, i.e., emergence of a new disease property by coexistence of several diseases. One may hypothesize that studying genetic, molecular, and cellular networks in comorbidities may lead to new treatment strategies (‘network pharmacology”) based on targeting the network hubs. We provide examples of such approach in some polypathies (e.g., phenofibrate, a PPARα agonist; simvastatin, a GMGCoA reductase in OA, rheumatoid arthritis and psoriasis), and its potential discuss usefulness is discussed for DAOA. In particular, we provide an example of a pilot study of ademethionine, a methyl group donator.

B regulatory cells (Bregs) are shown to downregulate autoimmune and inflammation processes. Their modifying effects depend on IL-10 secretion. A role of Bregs in development of humoral immune response was not investigated. Influence of Bregs and IL-10 upon in vitro response of murine B1 and B2 cells to T-dependent and T-independent antigens was studied in a model system. A water-soluble sheep erythrocyte antigen was used as a T-dependent antigen, whereas LPS was applied as a type 1 T-independent antigen, and polyvinylpirrolidone and alpha(1→3)dextran were added as type 2 T-independent antigens. В1and B2 lymphocytes were isolated from, respectively, peritoneal cavity and spleen of CBA mice. The cells were cultured in RPMI1640 medium with 10% of FCS supplemented with appropriate antigens and IL-10. The numbers of antibody- and total Ig-forming cells were determined by ELISPOT method.

The erythrocyte antigen induced an increase of antibody- and total Ig-forming cell numbers in cultured B1 and B2 cell populations. IL-10 addition caused reduction of antibody- and total Ig-forming cells by 27%. Similarly, IL-10 caused a drop in antibody- and total Ig-forming cells in LPS-stimulated B2 cell cultures by 75%, as well as 50 per cent decrease in numbers of antibody-forming cells in B-1 cell cultures when induced by the type 2 T-independent antigens.

To assess functional activity of Bregs, the cells were isolated from peritoneal cavity and spleen of CBA mice. Total yields of Bregs were 20-fold increased upon activation of B cells with LPS, ionomycin and phorbol ester (from 4% to 96%). IgM was the main immunoglobulin isotype secreted by the Bregs. 96% of activated Bregs produced IL-10. About 12% of the cells were shown to produce immunoglobulins. This finding suggests that some of Bregs synthesize both IL-10 and immunoglobulins.

To study distant effect of Bregs upon immune response, the splenocyte culture of xid CBA/N mice were tested in Transwells with enriched Bregs. It was revealed that the Bregs caused inhibition of both specific and polyclonal immune response to the water-soluble sheep erythrocyte antigen. Hence, Bregs are shown to participate in humoral immune response, probably, by suppressing functional activity of splenocytes from CBA/N mice to T-dependent antigen. IL-10 secreted by Bregs may play a sufficient role in these regulatory effects.

With the help of molecular genetic method we have investigated the level of mRNA gene expressions Glut1, mTOR and AMPK1α in PLN in pancreatic lymph nodes (PLN) of rats with streptozotocininduced diabetes mellitus (SIDM) and after administration of metformin. The levels of Glut1, mTOR and AMPK1α mRNA were determined by means of RT-PCR using CFX96™ thermocycler (Real-Time PCR Detection Systems, Bio-Rad, USA). Relative gene expression levels were calculated as ratios to GAPDH reference gene using ΔΔCt method. Statistical analysis was performed with available “Bio-Rad СFX Manager 3.1” software (Bio-Rad, USA). The mTOR+ positive lymphocytes were identified by means of monoclonal antibodies, using an indirect immunofluorescence method. Hyperglycemia was accompanied by transcriptional induction of glucose transporter Glut1 gene (9.9 to 28.9-fold, p < 0.05), and mTOR protein kinase gene (5.3 to 3.3-fold, p < 0.05) in PLN. Development of diabetes was also associated with increase by 24-34% in total mTOR+ cell numbers in PLN at the 5th week of developing diabetes (p <  0.05) and increased concentrations of rapamycin target in the immunopositive cells. Metformin administration to diabetic rats was followed by increased AMPK1α mRNA level of by 87% (p < 0,05) at the 3rd week, and 38-fold (p < 0,05), at the 5th week of SIDM development and inhibition of mTOR expression in PLN (3 to 14.7-fold, p < 0.05) accompanied by a 40 per cent decrease (p < 0.05) in total density of mTOR+ cells in PLN lymph cords of the rats following 5 weeks of SIDM.

Type I Interferons are potent inducers of monocyte’s differentiation into dendritic cells (DCs). However, sensitivity of these DCs to tolerogenic effect of glucocorticoids has not been previously investigated. The aim of this study was to investigate the effect of dexamethasone upon maturation and functions of interferonalpha-induced DCs (IFN-DC) derived from healthy donors. DCs were generated from blood monocytes cultured for 5 days with GM-CSF and IFNα, in absence or with addition of dexamethasone (10-6 M), applied on the 3rd day. Addition of dexamethasone inhibited IFN-DC maturation, which manifested with increasing numbers of CD14+ cells and decreased percentage of CD83+ DCs. Dexamethasone did not significantly influence HLA-DR, CD86 and B7H1 expression. However, it caused a 2-fold increase of tolerogenic TLR-2 molecule expression. Along with suppression of IFN-DC maturation, dexamethasone inhibited production of proinflammatory/Th1 cytokines (TNFα, IL-1, IL-2, IFNγ, IL-12), and some chemokines (MIP-1α, RANTES). Dexamethasone-treated IFN-DCs exhibited a 2-fold lower allostimulatory activity in mixed lymphocyte culture (MLC). Worth of note, the capacity of IFN-DCs to stimulate T cell proliferative response in allo-MLC showed direct correlation with CD83 expression on DCs, and an inverse correlation with CD14 and TLR-2. Evaluation of Th1/Th2-polarizing activity of IFN-DCs showed that dexamethasone exerted a pronounced inhibitory effect upon ability of DCs to stimulate T cells for IFNγ production, along with lowgrade suppressive effect upon ability of DCs to induce IL-6 production, thus being indicative for a dominance of Th2-polarizing activity of IFN-DCs under the influence of dexamethasone. In general, the data obtained show that IFN-DCs are sensitive to tolerogenic action of dexamethasone, and, hence, the IFN-DCs may mediate the immunomodulatory effect of glucocorticosteroids and represent novel candidate cells for the development of therapeutic tolerogenic DC-based vaccines applicable for management of autoimmune disorders.

VEGF-A contents was studied in blood serum, lacrimal fluid, and vitreous body of patients with different clinical forms of complicated proliferative diabetic retinopathy (PDR). The study included 50 patients with diabetes mellitus (type I, II), twelve patients with rhegmatogenous retinal detachment and fifteen healthy individuals. Complicated PDR was shown to be associated with higher levels of VEGF-A in blood serum and lacrimal fluid of these patients as compared to the cases of stable PDR and healthy individuals, as well as increased VEGF-A concentrations in vitreous humor. Concentrations of this cytokine in vitreous body proved to be significantly exceeded those in rhegmatogenous retinal detachment. Most severe clinical manifestations in complicated PDR and intraoperative hemorrhagic complications were associated with sharp VEGF-A increase in blood serum and vitreous humor, thus reflecting certain disturbances at local and systemic levels.

The authors propose a new methodological approach to rapid intensity assessment of specific sensitization in acute brucellosis. This technique shows high sensitivity (98%), and specificity (97%). We revealed a direct relation between the intensity of specific IgE-dependent sensitization accompanied by development of immunosuppressive state in patients with brucellosis, i.e., a mean reduction of total CD3+ cell counts by 17.9%; CD3+CD4+ cells, by 13.3%; CD16+CD56+, by 4.4%. Phagocytic ability of blood neutrophils was decreased by 25.8%. The study has shown that an increased reagin-dependent sensitization in brucellosis is closely associated with emergence of severe immunosuppression.

Forty-two patients with allergic bronchial asthma (ABA) forty persons with non-allergic bronchial asthma (NABA), and 47 healthy controls were involved into the study. Expression of FoxP3 mRNA was analyzed by RT-PCR. In patients with bronchial asthma (ABA and NABA) we have revealed a significant decrease in FoxP3 mRNA expression levels, in comparison with control group. The patients with severe BA exhibited lowest levels of the FoxP3 mRNA expression as compared with other groups.

We revealed a decreased FoxP3 mRNA expression in mononuclear cells from peripheral blood, and an increased IL-17 level in blood serum of patients with bronchial asthma. These results may be considered a manifestation of serious inflammatory process. Probably, the data may reflect a disregulated expression of FoxP3 transcription factor. Therefore, we may assume a key role of FoxP3 for regulation of inflammatory activity in bronchial asthma.

The aim of this study was to investigate phenotypic profile of B lymphocytes in peripheral blood of the patients with chronic endometritis and adnexitis. The study involved 89 women in their reproductive age (18 to 45 years) with chronic endometritis (48 cases) and adnexitis (41 cases). Ninety-eight healthy agematched women participated as a control group. Phenotypic B-cell subpopulations were analyzed by flow cytometry performed with direct immunofluorescent staining of peripheral cells from whole blood using the following antibody panel: CD5-FITC/CD23-PE/CD19-ECD/CD45-PC5/CD27-PC7. A significantly reduced B-lymphocyte content was revealed in peripheral blood of women with chronic endometritis and adnexitis. The reduced cell numbers occurred due to reduced B2 (main fraction of B-lymphocytes) and as B1 cells (minor fraction) which determines insufficient reactivity of specific humoral immune response, including immune reactions at the mucous membranes. However, percentage of B2-lymphocytes was decreased only in endometriosis, whereas patients with adnexitis showed decrease in both relative and absolute counts of this B cell subpopulation. A decreased content of naive B-cells in the peripheral blood is another feature of the B cell phenotypic profile in chronic endometritis and adnexitis. Moreover, the drop of the naive B-cell levels in patients with adnexitis proved to be more pronounced than in persons with endometritis. Expression of CD23- antigen (a low-affinity receptor for IgE) has been investigated as a functional marker of B cells. All the studied peripheral B cell subpopulations expressing CD23 were decreased in the patients with chronic endometritis. The numbers of different B cell fractions expressing CD23 antigen were also reduced in the women with chronic adnexitis as compared to the levels detected in patients with chronic endometritis. Alterations of the B-cell immunity were more pronounced in chronic adnexitis, due to more extensive infectious/inflammatory process which involved both endometrium, and appendages, and clinical manifestation of the disease. The results suggest a need for evaluation of the B cell phenotypic profiles as a marker of inadequate immune response in infectious and inflammatory diseases of pelvic organs, as well as planning rational immunotherapy, in order to enhance therapeutic efficiency in these disorders.

Chronic viral hepatitis C is the most common cause of liver damage and the global problem worldwide since is characterized by a high prevalence, high chronization rates, and significantly increases the risk of liver cirrhosis and hepatocellular carcinoma. Many studies have shown that antigen-specific СD4+ and CD8+T-cells play a key role in pathogenesis and outcome of the infection. While the strong sustained antigenspecific multi-epitopic T-cell response predicts successful viral elimination, a deficiency of adaptive immune response is associated with virus persistence. This review presents data about pathogenetic significance of T-cell response in viral elimination, viral persistence and hepatitis development. Possible mechanisms of T-cell response failure in chronic infection are discussed as well.

Detection of total free light chains (FLC) of immunoglobulins and their ratio (kappa/lambda quotient) are used in diagnostics and monitoring of multiple myeloma and other gammapathies, primary amyloidosis and multiple sclerosis. Previously described immunoassays with monoclonal antibodies (Mabs) against cryptic and constantly exposed epitopes of FLC failed to recognize rare variants of lambda Bence-Jones proteins and a significant proportion of lambda chains excreted with urine. Aiming to improve this approach, a novel murine Mab (IgG2b coded as 1C8) was employed, which specifically binds free lambda chains but doesn’t interact with native IgA, IgG, and IgM. The novel Mab recognized an epitope exposed at free lambda chains in peripheral blood of healthy donors and patients with multiple myeloma. It is not destroyed or masked upon renal filtration.

The aim of this study was to determine basic features of improved assay system, and to estimate its potential in diagnostics of monoclonal gammapathies. The mixtures of three Bence-Jones proteins of either kappa- or lambda- types purified from the urine of multiple myeloma patients were used as calibrator samples.

Improved immunometric assay is able to detect free kappa and lambda chains in serum and urine at a scale of 1 to 100 ng/ml, thus being three orders more sensitive than, e.g., detection levels of Freelite method based on polyclonal antibodies.

A novel assay allows to detect free kappa and lambda chains at comparable levels in serum or urine, and to deduce kappa/lambda ratio. The proposed assay is able to detect FLC in 10,000-fold excess of whole IgG molecules. The calibrating plots for both antigens are linear on log-log scales, with very similar slopes. Detection thresholds for kappa or lambda chains proved to be 5 and 3 ng/ml, respectively. Mean concentrations of free kappa chains in sera of healthy donors were 6.7±2.1, in urine, 4.2±3.8 mcg/ml. Mean concentrations of free lambda chains were 4.7±1.96, and 1.6±1.0 mcg/ml, respectively. This method, if applied to serum and urine samples from multiple myeloma patients, revealed free light chains were similar to the paraproteins detected by means of electrophoresis/immunofixation. The values of kappa/lambda ratios corresponded to the types of gammapathies revealed.