Identification of Ochrobactrum as a bacteria with transstadial transmission and potential for application in paratransgenic control of leishmaniasis.

Leishmaniasis is a zoonotic vector-borne disease with worldwide distribution. All current approaches in leishmaniasis control or development of vaccines/cures showed only limited success. Recently, paratransgenesis has been marked as a promising strategy for leishmaniasis control. Thus, the investigations of the gut microbial content of sand flies have gained popularity. Gut microbial composition of the laboratory colony of Phlebotomus papatasi was investigated via microbial culturomics approach which refers to the combination of multiple culture conditions and different selective and/or enriched culture mediums, followed by 16S rDNA sequencing. Investigations were conducted on three offspring generations, with six samplings of immature stages (four larval samplings, one pre-pupa, one pupa) and samplings of adults before and after blood feeding. The aim was to determine if microbiome changes during the sand fly development and to identify bacteria with transstadial potential. The presence of 8 bacterial taxa (Bacillus sp., Terribacillus sp., Staphylococcus sp., Alcaligenes sp., Microbacterium sp., Leucobacter sp., Ochrobactrum sp. and Enterobacter sp.), 2 fungi (Fusarium sp. and Acremonium sp.) and 1 yeast (Candida sp.) were recorded. Gram-positive bacteria were more diverse, but gram-negative bacteria were more abundant. All taxa were recorded among immature stage samples, while only one bacterium was detected in adults. Microbial diversity among larval samples was stable, with a steady decrease in pre-pupa and pupa, resulting in the survival of only Ochrobactrum sp. in adults. Abundance of microbes was higher when larvae were actively feeding, with a gradual decrease after larvae stopped feeding and commenced pupation. Ochrobactrum sp. is the bacteria with transstadial potential, worthy of future in-depth analysis for the application in paratransgenic approach for the control of Leishmania sp.

Cytokine Profiles of Chronic Urticaria Patients and The Effect of Omalizumab Treatment.

INTRODUCTION: Cytokines are key mediators in immunological and inflammatory conditions, including chronic spontaneous urticaria (CSU). OBJECTIVES: To investigate Th1, Th2, and Th17 cytokine profiles in CSU and to evaluate the possible effect of omalizumab treatment. METHODS: Patients who were followed up for CSU, as well as healthy volunteers, were included in the study. To assess urticaria activity, the 7-day-Urticaria Activity Score (UAS-7), the Urticaria Control Test (UCT), and the Chronic Urticaria Quality of Life Questionnaire (CU-QoL) were filled. Serum levels of IL-6, IL-17, IL-31, eotaxin, RANTES, TNF-α, and TSLP were analyzed by ELISA and compared in CSU and control groups. The patients were analyzed in two groups as the omalizumab group and the non-omalizumab group based on their treatment status. RESULTS: Total IgE, ESR, CRP, RANTES, and TNF-a were significantly different in the overall comparison of the three groups: CSU-receiving omalizumab, CSU-not receiving omalizumab, and control groups (P <0.01, 0.015, <0.01, <0.01 and <0.01 respectively). Total IgE, CRP, RANTES, and TNF-α values were similar in those who received and did not receive omalizumab, yet these biomarkers were significantly higher in both groups than in the control group (P < 0.05). Statistical significance in ESR was observed only between the CSU-receiving omalizumab group and the control group (P = 0.01). Within the CSU patients, there was a slight but significant correlation between UCT and TNF-α (P = 0.008, r = 0.32) and IL-17 (P = 0.06, r = 0.33) levels. CONCLUSIONS: The investigated cytokine profile in CSU patients may differ from healthy controls, particularly with the higher levels of RANTES and TNF-α, and omalizumab treatment does not seem to affect that profile in CSU patients.

Oxidative stress stimulation leads to cell-specific oxidant and antioxidant responses in airway resident and inflammatory cells.

AIMS: The imbalance between reactive oxygen species (ROS) and the antioxidant response has been linked to various airway diseases, including asthma. However, knowledge on cell-specific responses of the airway resident and inflammatory cells against increased oxidant stress is very limited. We aim to better understand the cell-specific antioxidant response that contributes to the pathophysiology of lung disease in response to oxidative stress. MATERIALS AND METHODS: The human cell lines of epithelial, fibroblast, endothelial, monocyte, eosinophil and neutrophil were incubated with tert-butyl hydroperoxide (tBHP) or cigarette smoke condensate (CSC). Following stimulation, cell viability, total oxidant and antioxidant activity were assessed in both residential and inflammatory cells. Human Oxidative Stress Plus RT2 Profiler PCR array was used to determine 84 gene expression differences in oxidant and antioxidant pathways following oxidant stimulus in all cells. KEY FINDINGS: We showed that various cell types respond differently to oxidative stress inducers, with distinct gene expression and oxidant-antioxidant generation. Most importantly, eosinophils increased the activity of all main antioxidant enzymes in response to both oxidants. Monocytes, on the other hand, showed no change in response to each stimulation, whereas neutrophils only increased their CAT activity in response to both stimuli. The increase in NRF2-regulated genes HSPA1A, HMOX1 and DUSP1 after both tBHP and CSC in epithelial cells and fibroblasts indicates Nfr2 pathway activation. SIGNIFICANCE: This study advances our knowledge of the molecular and cellular mechanisms of cell-specific antioxidant response upon exposure to oxidative stress. Additionally, our observations imply that the eosinophils' distinct biological response may be utilized for endotype-based cell-targeted antioxidant therapy.

Omics technologies in allergy and asthma research: An EAACI position paper.

Allergic diseases and asthma are heterogenous chronic inflammatory conditions with several distinct complex endotypes. Both environmental and genetic factors can influence the development and progression of allergy. Complex pathogenetic pathways observed in allergic disorders present a challenge in patient management and successful targeted treatment strategies. The increasing availability of high-throughput omics technologies, such as genomics, epigenomics, transcriptomics, proteomics, and metabolomics allows studying biochemical systems and pathophysiological processes underlying allergic responses. Additionally, omics techniques present clinical applicability by functional identification and validation of biomarkers. Therefore, finding molecules or patterns characteristic for distinct immune-inflammatory endotypes, can subsequently influence its development, progression, and treatment. There is a great potential to further increase the effectiveness of single omics approaches by integrating them with other omics, and nonomics data. Systems biology aims to simultaneously and longitudinally understand multiple layers of a complex and multifactorial disease, such as allergy, or asthma by integrating several, separated data sets and generating a complete molecular profile of the condition. With the use of sophisticated biostatistics and machine learning techniques, these approaches provide in-depth insight into individual biological systems and will allow efficient and customized healthcare approaches, called precision medicine. In this EAACI Position Paper, the Task Force "Omics technologies in allergic research" broadly reviewed current advances and applicability of omics techniques in allergic diseases and asthma research, with a focus on methodology and data analysis, aiming to provide researchers (basic and clinical) with a desk reference in the field. The potential of omics strategies in understanding disease pathophysiology and key tools to reach unmet needs in allergy precision medicine, such as successful patients' stratification, accurate disease prognosis, and prediction of treatment efficacy and successful prevention measures are highlighted.

The Expression Profile of Protease Inhibitors in the Airway Epithelial Cells after Allergen (Der p 1) Stimulation.

BACKGROUND: Airway epithelial cells are constantly exposed to intracellular and extracellular proteases that play a pivotal role in several airway diseases. Dermatophagoides pteronyssinus (Der p) 1 derived from house dust mite has protease activity that causes epithelial barrier defect and inflammatory response. Protease inhibitors released against proteases are involved in the maintenance of homeostasis. A disruption of the balance between proteases and protease inhibitors can lead to distortion of the cellular structures and cellular activities and thus culminate in disease processes. Although the effects of Der p 1 allergen on epithelial barrier integrity and inflammatory response are well-established, its contribution to protease inhibitor production is highly limited. OBJECTIVE: This study aimed to determine the profile of the protease inhibitor response to Der p 1 allergen in human airway epithelial cells, A549 and BEAS-2B. METHODS: Differentiated cells by the air-liquid interface were exposed to Der p 1 with or without Th2 type cytokines (IL-4 and IL-13). Gene expression of protease inhibitors was determined by qPCR at 2 different time points. RESULTS: We found that the effect of allergen exposure on the protease inhibitor profile can vary depending on the antigen concentration, treatment duration, and the presence or absence of type 2 cytokines. Gene expressions of serine protease inhibitor (SERPIN)B3 and SERPINB4 were increased following Th2 cytokine stimulation in both cell types at both time points, whereas SERPINB2 and TFPI-2 expressions were induced by 24-h Der p 1 stimulation in both cells. CONCLUSIONS: Our study suggests that Der p 1 exposure of the airway epithelium may have consequences related to its protease activity in the presence as well as in the absence of Th2 cytokines in the microenvironment.

House dust mite-derived allergens effect on matrix metalloproteases in airway epithelial cells.

Aim of the Study: Many allergens have protease activities. Although the immunomodulatory effects of these antigens are well known, the effects attributed to their protease activities are not thoroughly investigated. We set out to determine the effects of house dust mite (HDM) allergens with varying protease activities on bronchial epithelial cell functions. Materials and methods: BEAS-2B cells were maintained in ALI-culture and stimulated with Der p1 (cysteine protease), Der p6 (serine protease), and Der p2 (non-protease) with and without specific protease inhibitors or heat denaturation. Cell viability and epithelial permeability were measured with MTT and paracellular flux assay, respectively. The effect of heat denaturation on allergen structure was examined using in silico models. Matrix metalloproteinases (MMPs) were investigated at the transcription (qPCR), protein (ELISA), and functional (zymography) levels. Results: Epithelial permeability increased only after Der p6 but not after Der p1 or Der p2 stimulation. Der p2 increased both MMP-2 and MMP-9 expression, while Der p1 increased only MMP-9 expression. The heat-denatured form of Der p1 unexpectedly increased MMP-9 gene expression, which, through the use of in silico models, was attributed to its ability to change receptor connections by the formation of new electrostatic and hydrogen bonds. IL-8 and GM-CSF production were increased after Der p1 and Der p2 but decreased after Der p6 stimulation. IL-6 decreased after Der p1 but increased following stimulation with Der p6 and heat-denatured Der p2. Conclusion: Allergens in house dust mites are capable of inducing various changes in the epithelial cell functions by virtue of their protease activities.

The Genetic Variants of Interferon Regulatory Factor-3 in Children with Asthma.

Interferon Regulatory Factor-3 (IRF-3) is one of the key players in the inflammatory response mediated by the innate immune system. Although many studies have implicated a role for IRF-3 in the pathogenesis of inflammatory airway diseases, information about the possible association of IRF-3 genetic variants with asthma is scarce. We aimed to investigate the potential effects of IRF-3 polymorphisms in childhood asthma and asthma-related phenotypes. IRF-3 polymorphisms were first determined by sequencing 25 asthmatic and 25 healthy children. For further analysis, 609 asthmatic children and 191 healthy controls were screened for the genetic variants, such as rs2304204, rs2304205, rs320440, rs34739574, and rs7251. In addition, the relationship between these polymorphisms and asthma-related phenotypic features, including forced expiratory volume in one second values, eosinophil counts, and IgE levels was determined. rs7251 was associated with asthma in the codominant (P = 0.049) and G dominant (P = 0.025) model, however this significance was lost after False Discovery Rate analysis. Other investigated single nucleotide polymorphisms (SNPs) showed no significant association with asthma or asthma-related phenotypes. In conclusion, the seven SNPs of IRF-3 gene are not associated with asthma or asthma-related phenotypes in Turkish asthmatic children.