Haluk Barbaros Oral

Regulation of T cells and cytokines by the interleukin-10 (IL-10)-family cytokines IL-19, IL-20, IL-22, IL-24 and IL-26

The family of IL‐10‐related cytokines includes several human members, IL‐19, IL‐20, IL‐22, IL‐24 and IL‐26, and a series of herpesviral and poxviral paralogs. Some of these cytokines share common receptor subunits. In this study, we investigated the effects of these cytokines on naive T cell differentiation, antigen‐specific T cell suppression, survival ad expression of surface markers in comparison to IL‐10 and cytomegalovirus (CMV)‐IL‐10. Human CD45RA+ T cells were stimulated in the presence of IL‐10‐family cytokines in sequential 12‐day cycles. After three to four cycles of stimulation, IL‐10 and CMV‐IL‐10 led to increased IFN‐γ and IL‐10 but decreased IL‐4 and IL‐13. Interestingly, long‐term exposure of T cells to IL‐19, IL‐20 and IL‐22 down‐regulated IFN‐γ but up‐regulated IL‐4 and IL‐13 in T cells and supported the polarization of naive T cells to Th2‐like cells. In contrast, neutralization of endogenous IL‐22 activity by IL‐22‐binding protein decreased IL‐4, IL‐13 and IFN‐γ synthesis. The antigen‐specific suppressor activity of IL‐10 and CMV‐IL‐10 was not observed for any of the other IL‐10‐family cytokines. These data demonstrate that IL‐19, IL‐20 and IL‐22 may participate in T cell‐mediated diseases by distinct regulation of T cell cytokine profiles.

Circulating ICAM-1 and VCAM-1 Levels in Patients with Obstructive Sleep Apnea Syndrome

Background: Obstructive sleep apnea syndrome (OSAS)-induced hypoxic stress modulates circulating inflammatory mediators causing accelerated atherogenesis. Objectives: We hypothesized that OSAS-induced hypoxia might result in cardiovascular disease due to increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) on the endothelial surface. Methods: Thirty-nine subjects with moderate-to-severe OSAS and 34 non-apneic controls matched for age, gender, body mass index (BMI), smoking history, and cardiovascular disease were included in this prospective study. Overnight polysomnography was performed. Circulating ICAM-1 and VCAM-1 levels in the serum were measured by enzyme-linked immunosorbent assay. Results: Circulating levels of both ICAM-1 (480.1 ± 216.7 vs. 303.4 ± 98.6 ng/ml, p < 0.0001) and VCAM-1 (1,156.6 ± 79.8 vs. 878.8 ± 71.1 ng/ml, p = 0.002) were significantly increased in the OSAS group compared to the control group. For an ICAM-1 cutoff level of 375 ng/ml, predictive sensitivity and specificity for OSAS were 69.2% (95% confidence interval, CI: 52.4–83.0%) and 82.4% (95% CI: 65.5–93.2%), respectively. For a VCAM-1 cutoff level of 859 ng/ml, predictive sensitivity and specificity for OSAS were 74.4% (95% CI: 57.9–86.9%) and 64.7% (95% CI: 46.5–80.2%), respectively. There was a significant positive correlation between circulating levels of ICAM-1 and ln of AHI (r = 0.276, p = 0.018). Multiple logistic regression analyses showed that OSAS was associated with high ICAM-1 and high VCAM-1 levels independent of age, gender, BMI, smoking status and cardiovascular disease. Conclusion: We conclude that OSAS can independently increase circulating levels of adhesion molecules.

Minimum information about tolerogenic antigen-presenting cells (MITAP) : a first step towards reproducibility and standardisation of cellular therapies

Cellular therapies with tolerogenic antigen-presenting cells (tolAPC) show great promise for the treatment of autoimmune diseases and for the prevention of destructive immune responses after transplantation. The methodologies for generating tolAPC vary greatly between different laboratories, making it difficult to compare data from different studies; thus constituting a major hurdle for the development of standardised tolAPC therapeutic products. Here we describe an initiative by members of the tolAPC field to generate a minimum information model for tolAPC (MITAP), providing a reporting framework that will make differences and similarities between tolAPC products transparent. In this way, MITAP constitutes a first but important step towards the production of standardised and reproducible tolAPC for clinical application.

Increased Pleural Soluble Fas Ligand (sFasL) Levels in Tuberculosis Pleurisy and Its Relation with T-helper Type 1 Cytokines

Tuberculosis (TB) pleurisy is accepted to be the best model for evaluating the local protective cellular immune response to Mycobacterium tuberculosis (MTB) since it can be spontaneously self-cured. Therefore, we aimed to evaluate the involvement of cytokines and the soluble apoptosis-modulating factors sFas and sFasL in local protective cellular immunity to MTB. Pleural fluid samples were collected from 35 patients with TB pleurisy, 39 patients with malignant pleurisy, and 14 patients with non-TB nonmalignant (n-TB n-M) pleurisy and were evaluated for the levels of several cytokines, soluble Fas (sFas), and sFas ligand (sFasL) by using ELISA. The levels of IFN-γ, IL-12p40, IL-18, IL-8, and sFasL in TB pleurisy were significantly higher in comparison to those in the malignant pleurisy and n-TB n-M pleurisy groups. In addition, pleural sFasL levels were increased and positively correlated with IFN-γ and IL-18 levels in TB patients. In conclusion, this study demonstrates that Th1-type-specific cellular immunity is responsible for protective immunity in TB and suggests that Fas-mediated apoptosis may be at least a part of protective immunity to tuberculosis and could be regulated by type 1 T-cell response. IFN-γ and sFasL levels can be used as diagnostic markers for differing TB pleurisy from other pleurisies.

Association between serum neopterin, obesity and daytime sleepiness in patients with obstructive sleep apnea

OBJECTIVE Obesity and obstructive sleep apnea (OSA) and systemic inflammation may interact through biochemical pathways. Neopterin (NP) is a monocyte/macrophage activation marker produced by macrophages in response to interferon-gamma secreted by activated T-lymphocytes. This study examines the association between NP, obesity and OSA. PATIENTS AND METHODS The study included 22 newly diagnosed OSA (+) patients and 18 OSA (-) patients. Subjects with history of coronary artery disease, transplant patients, history of alcohol and drug abuse, history of HIV and any other significant medical illnesses such as active infections, autoimmune disease, malignancy, liver disease, pulmonary disease (COPD, asthma,...), neuromuscular disease, patients on immunomodulating therapy or HMG-CoA reductase inhibitors were excluded. RESULTS There were no significant differences in age, body mass index (BMI), and smoking habits of the OSA (+) patients and OSA (-) patients. Serum NP levels did not show any significant difference between the OSA (+) patients and OSA (-) patients, however, NP levels were positively correlated with BMI (r=0.320, p=0.044). There was no significant correlation between NP and any of the polysomnographic parameters. The result of stepwise regression analyses (r(2)=0.320, p<0.001) showed that high serum NP levels (p=0.004) and apnea-hypopnea index (AHI) were a risk factor for elevated Epworth sleepiness score, independent of BMI. CONCLUSION We suggest that serum NP levels correlate with BMI. There was a significant relationship between serum NP levels and excessive daytime sleepiness in OSA patients.

Altered Expressions of miR-1238-3p, miR-494, miR-6069, and miR-139-3p in the Formation of Chronic Brucellosis

Brucellosis is a zoonotic disease that is still endemic in developing countries. Despite early diagnosis and treatment of patients, chronic infections are seen in 10–30% of patients. In this study, we aimed to investigate the immunological factors that play roles in the transition of brucellosis from acute infection into chronic infection. Here, more than 2000 miRNAs were screened in peripheral blood mononuclear cells (PBMCs) of patients with acute or chronic brucellosis and healthy controls by using miRNA array, and the results of the miRNA array were validated through qRT-PCR. Findings were evaluated using GeneSpring GX (Agilent) 13.0 software and KEGG pathway analysis. Four miRNAs were expressed in the chronic group but were not expressed in acute and control groups. Among these miRNAs, the expression level of miR-1238-3p was increased while miR-494, miR-6069, and miR-139-3p were decreased (p < 0.05, fold change > 2). These miRNAs have the potential to be markers for chronic cases. The differentially expressed miRNAs and their predicted target genes involved in endocytosis, regulation of actin cytoskeleton, MAPK signaling pathway, and cytokine-cytokine receptor interaction and its chemokine signaling pathway indicate their potential roles in chronic brucellosis and its progression. It is the first study of miRNA expression analysis of human PBMC to clarify the mechanism of inveteracy in brucellosis.

Diagnostic value of serum concentrations of high-mobility group-box protein 1 and soluble hemoglobin scavenger receptor in brucellosis

Both cluster of differentiation (CD)4+ and CD8+ T lymphocytes play key roles in immunity to Brucella, in part because they secrete interferon (IFN)‐γ and activate bactericidal functions in macrophages. Therefore, use of markers of macrophage activation may have diagnostic and prognostic significance. High‐mobility group‐box 1 protein (HMGB1), a late‐onset pro‐inflammatory cytokine, is secreted by activated macrophages. Soluble hemoglobin scavenger receptor (sCD163) is a specific marker of anti‐inflammatory macrophages. The aim of this study was to investigate the diagnostic value of HMGB1 and sCD163 concentrations in brucellosis and its various clinical forms. Serum HMGB1 and sCD163 concentrations in 49 brucellosis patients were compared with those in 52 healthy control subjects. Both serum HMGB1 and sCD163 concentrations were significantly higher in brucellosis patients than in healthy controls (P < 0.001). There were no statistically significant differences in serum concentrations of HMGB1 and sCD163 between cases of acute, subacute and chronic brucellosis. Additionally, serum HMGB1 concentrations were positively correlated with sCD163 concentrations, whereas neither HMGB1 nor sCD163 concentrations were correlated with C‐reactive protein concentrations, white cell counts or erythrocyte sedimentation rates. Therefore, serum concentrations of HMGB1 and sCD163 may be diagnostic markers for brucellosis, but neither can be used to differentiate the three different forms of this disease (acute, subacute and chronic).

Frontiers in Clinical Immunology 2008

In recent years, investigations in immunology have led to progress in clinical medicine, including understanding transplant rejection, autoimmune diseases, immune deficiencies, inflammation, transplantation, cancer and the development of new vaccines. At a meeting recently held on the Mediterranean shore, advances in several facets of clinical immunology were the focus of discussion. Here, we highlight some of the debates that reflected advances in a variety of human immune disorders.

Functional imaging in the immune system.

Developments in imaging technologies are revolutionizing our ability to probe more directly the behaviour of molecules and cells of the immune system. As discussed at a recently held meeting supported in part by European Federation of Immunological Societies (EFIS)/ European Journal of Immunology (EJI) monies, combining single molecule imaging and micropatterning allows molecular interactions in living lymphocytes to be analysed. Whole body imaging, on the other hand, enables immunologists to track changes in response to, for example, infectious agents and tumours or to gain insight into autoimmune pathology throughout different disease phases and over long time periods. Tackling the complexity of the immune system has relied essentially on investigating the interactions of soluble mediators and cells in vitro or ex vivo; however, immune responses progress dynamically and involve the rapid movement of cells to peripheral tissues. In higher vertebrates, environmental factors shape the complex and dynamic individual behaviour of cells that often interact interdependently. For example, in addition to their motility and migratory behaviour, innate and adaptive immune cells communicate continuously and guide the differentiation of each other, allowing optimal responses to foreign insults. Since cells of the immune system co-localize spatially and temporally, and often engage in direct contacts, techniques that allow real-time observation of single cells and molecules in situ have become the focus of much investigation. Currently, developments in imaging technology and advanced light microscopy are revolutionizing our ability to probe more directly the behaviour of the molecules and cells of the immune system in their natural environment. Insights into the application of imaging technologies to the field of immunology were recently discussed at the Second Mediterranean Clinical Immunology Meeting, which was held in Antalya, on the Mediterranean shore of Turkey from October 4 to 7, 2008. The meeting brought together established researchers and young scientists from Europe, America, Asia and Africa.

The microRNA expression signature of CD4+ T cells in the transition of brucellosis into chronicity

Brucellosis is a serious infectious disease that continues to be a significant cause of morbidity worldwide and across all ages. Despite early diagnosis and treatment, 10–30% of patients develop chronic brucellosis. Although there have been recent advances in our knowledge of Brucella virulence factors and hosts’ immune response to the infection, there is a lack of clear data regarding how the infection bypasses the immune system and becomes chronic. The present study investigated immunological factors and their roles in the transition of brucellosis from an acute to a chronic infection in CD4+ T cells. CD4+ T cells sorted from peripheral blood samples of patients with acute or chronic brucellosis and healthy controls using flow cytometry as well as more than 2000 miRNAs were screened using the GeneSpring GX (Agilent) 13.0 miRNA microarray software and were validated using reverse transcription polymerase chain reaction (RT-qPCR). Compared to acute cases, the expression levels of 28 miRNAs were significantly altered in chronic cases. Apart from one miRNA (miR-4649-3p), 27 miRNAs were not expressed in the acute cases (p <0.05, fold change> 2). According to KEGG pathway analysis, these miRNAs are involved in the regulation of target genes that were previously involved in the MAPK signalling pathway, regulation of the actin cytoskeleton, endocytosis, and protein processing in the endoplasmic reticulum. This indicates the potential role of these miRNAs in the development of chronic brucellosis. We suggest that these miRNAs can be used as markers to determine the transition of the disease into chronicity. This is the first study of miRNA expression that analyses human CD4+ T cells to clarify the mechanism of chronicity in brucellosis.