Lifestyle Changes and Industrialization in the Development of Allergic Diseases.

PURPOSE OF REVIEW: Modernization and Westernization in industrialized and developing nations is associated with a substantial increase in chronic noncommunicable diseases. This transformation has far-reaching effects on lifestyles, impacting areas such as economics, politics, social life, and culture, all of which, in turn, have diverse influences on public health. Loss of contact with nature, alternations in the microbiota, processed food consumption, exposure to environmental pollutants including chemicals, increased stress and decreased physical activity jointly result in increases in the frequency of inflammatory disorders including allergies and many autoimmune and neuropsychiatric diseases. This review aims to investigate the relationship between Western lifestyle and inflammatory disorders. RECENT FINDINGS: Several hypotheses have been put forth trying to explain the observed increases in these diseases, such as 'Hygiene Hypothesis', 'Old Friends', and 'Biodiversity and Dysbiosis'. The recently introduced 'Epithelial Barrier Theory' incorporates these former hypotheses and suggests that toxic substances in cleaning agents, laundry and dishwasher detergents, shampoos, toothpastes, as well as microplastic, packaged food and air pollution damage the epithelium of our skin, lungs and gastrointestinal system. Epithelial barrier disruption leads to decreased biodiversity of the microbiome and the development of opportunistic pathogen colonization, which upon interaction with the immune system, initiates local and systemic inflammation. Gaining a deeper comprehension of the interplay between the environment, microbiome and the immune system provides the data to assist with legally regulating the usage of toxic substances, to enable nontoxic alternatives and to mitigate these environmental challenges essential for fostering a harmonious and healthy global environment.

The effects of enoxaparin treatment in a xenograft mouse model of oral squamous cell carcinoma: A pilot study.

BACKGROUND: Recent studies suggest that enoxaparin may have therapeutic effects on oral squamous cell carcinoma. We aimed to assess this effect utilizing xenograft mouse model through evaluations of proliferation and angiogenesis markers at the RNA and protein levels. METHODS: Mice were divided into enoxaparin treatment (n = 4), positive control (n = 4) and negative control (n = 3) groups. Immunohistochemical analyses were performed utilizing Bcl-2, Bax and Ki-67 antibodies. Expression levels of proliferation and apoptosis related genes were calculated utilizing qRT-PCR. Time-dependent proliferation assays were performed in OSC-19 and HEK293 cell-lines. RESULTS: Bax antibody showed positive staining in the cytoplasm and nuclei of tumor cells, while Bcl-2 antibody displayed staining only in the cytoplasm. A proliferation index of 15%-20% was found in all groups with the Ki-67 marker indicating no metastasis. Enoxaparin treatment caused decrease in BCL2, BAX and CCNB1 genes' expressions. Compared to HEK293, proliferation assays demonstrated higher division rates in OSC-19 with a significant decrease in viability after 96 h. CONCLUSION: Reduced BCL-2 expression indicates a regression of tumor growth, but reduced BAX expression is not correlated with increased apoptosis. Despite the aggressive nature of OSC-19, our results showed a low cell viability with a high division rate when compared with the control HEK293. This paralleled our in vivo findings that showed absence of lymph node metastasis across all mice groups. This discrepancy with the literature suggests that further investigations of the underlying mechanisms and protein-level analyses are needed to draw definitive conclusions about the effect of enoxaparin on OSC-19 behavior.

How does global warming contribute to disorders originating from an impaired epithelial barrier?

The epithelial barrier represents the point of contact between the host and the external environment. It is the first line of defense against external insults in the skin and in the gastrointestinal and upper and lower respiratory tracts. The steep increase in chronic disorders in recent decades, including allergies and autoimmune disorders, has prompted studies to investigate the immune mechanisms of their underlying pathogeneses, all of which point to a thought-provoking shared finding: disrupted epithelial barriers. Climate change with global warming has increased the frequency of unpredictable extreme weather events, such as wildfires, droughts, floods, and aberrant and longer pollination seasons, among many others. These increasingly frequent natural disasters can synergistically damage the epithelial barrier integrity in the presence of environmental pollution. A disrupted epithelial barrier induces proinflammatory activation of epithelial cells and alarmin production, namely, epithelitis. The "opened" epithelial barrier facilitates the entry of the external exposome into and underneath the epithelium, triggering an expulsion response driven by inflammatory cells in the area and chronic inflammation. These changes are associated with microbial dysbiosis with colonizing opportunistic pathogens and decreased commensals. These cellular and molecular events are key mechanisms in the pathogenesis of numerous chronic inflammatory disorders. This review summarizes the impact of global warming on epithelial barrier functions in the context of allergic diseases. Further studies in the impact of climate change on the dysfunction of the epithelial barriers are warranted to improve our understanding of epithelial barrier-related diseases and raise awareness of the environmental insults that pose a threat to our health.

Natural killer cells dominate a Th-1 polarized response in Behçet's disease patients with uveitis.

OBJECTIVES: Behçet's disease (BD) is a systemic inflammatory disorder of unknown etiology, characterised by recurring relapses and remissions. BD manifestations have been thought to be associated with the immunological abnormalities triggered by environmental factors in genetically susceptible individuals. Natural killer (NK) cells are important members of innate immunity with their cytotoxic activity and also cytokine secretions. They have the capacity to induce or dampen immune responses. Different study groups have reported conflicting results about NK cell activity in the BD pathogenesis, however, contribution of NK cells to BD is still unclear. METHODS: NK cells from BD patients with uveitis (n=11) as well as age- and gender-matched healthy controls (n=9) were purified and intracytoplasmic cytokine levels of TNF-α, IFN-γ, IL-2, IL-4, IL-10, IL-12 and IL-13 were determined. RESULTS: Increased TNF-α, IFN-γ and IL-2 in relapse period and increased IL-4 as well as a slight increase of IL-10 in remission period were observed. CONCLUSIONS: Our results show that NK cells are the contributors of BD pathogenesis with their NK1 profile in relapse periods, and also with their NK2 profile in remission periods, in BD patients with uveitis. An increase in IL-10 observed in remission periods may be linked to the regulatory potential of NK cells in the recurrent nature of BD manifestations.

A stimulatory role of ozone exposure on human natural killer cells.

Ozone is claimed to have beneficial effects. While studies revealed the safe therapeutic use of ozone, there are conflicting results for the link between immune system and ozone encounter. Natural killer (NK) cells are important sentinels of immunity with their cytotoxic activity and immune-regulatory potentials. This study aimed to investigate the effects of direct ozone encountering on human immune system, at cellular level. Survival, proliferative capacity and subset content of peripheral blood mononuclear cells (PBMC) were analysed. PBMC of healthy donors (n=5, mean age: 27±6 years) were exposed to 1, 5, 10 and 50 µg/mL doses of medical ozone, directly injected into culture wells, once, initially. 1 and 5 µg/mL doses didn't show toxic effects while 10 and 50 µg/mL doses were toxic. PBMC were cultured for 5 days following 1 and 5 µg/mL ozone encountering. 1 µg/mL dose increased numbers of CD3-CD16+/56+ NK cells among PBMC. Following stimulation with ozone, no difference was observed in basal and phytohemaglutinin-stimulated proliferative capacity. 1 and 5 µg/mL doses of ozone were found to increase NK cytotoxicity. These data indicates influential effects of transient ozone exposure on NK cells, which in turn may have a role in control of immune responses.

Triggering of specific Toll-like receptors and proinflammatory cytokines breaks allergen-specific T-cell tolerance in human tonsils and peripheral blood.

BACKGROUND: The generation and maintenance of allergen-specific T-cell tolerance is a key step in healthy immune responses to allergens and successful allergen-specific immunotherapy. Breaking of peripheral T-cell tolerance to allergens can lead to the development of allergies, but the mechanisms are not completely understood. OBJECTIVE: We sought to identify molecular mechanisms that break allergen-specific T-cell tolerance in human subjects. METHODS: Proliferative responses of allergen-specific T cells from tonsils and peripheral blood were measured by using tritiated thymidine incorporation and carboxyfluorescein succinimidyl ester (CFSE) dilution experiments. Cytokine levels in cell-free supernatants were quantified by using the cytometric bead array, and mRNA expression of transcription factors and cytokines was determined by using quantitative PCR. Myeloid dendritic cells (DCs) were characterized by using flow cytometry. RESULTS: In allergic patients the immune profile of the tonsils represents the atopic status of patients, with low expression of the TH1 cell-specific transcription factor T-bet and the cytokine IFN-γ, as well as IL-10. Human tonsils show very low levels of allergen-induced T-cell proliferation, thus representing a very suitable in vivo model to assess mechanisms of breaking allergen-specific T-cell tolerance. Triggering of Toll-like receptor (TLR) 4 or TLR8 and the proinflammatory cytokines IL-1ß or IL-6 break allergen-specific T-cell tolerance in human tonsils and peripheral blood through a mechanism dependent on the adaptor molecule myeloid differentiation primary response gene (88) (MyD88). In particular, myeloid DCs and stimulations that activate them broke the tolerance of allergen-specific CD4(+) T cells, whereas plasmacytoid DCs and stimulations that activate them, such as TLR7 and TLR9, did not have any effect. Tolerance-breaking conditions induced by different molecular mechanisms were associated with a mixed cytokine profile with a tendency toward increased levels of IL-13 and IL-17, which are TH2 and TH17 cytokines, respectively. CONCLUSION: Certain innate immune response signals and proinflammatory cytokines break allergen-specific CD4(+) T-cell tolerance in normally unresponsive subjects, which might lead to the development or exacerbation of allergic diseases after encountering microbes or inflammatory conditions.

Behçet's disease: immunological relevance with arthritis of ankylosing spondylitis.

Behçet's disease (BD) is a multi-system inflammatory disorder, in which cytokine balance is polarized to Th1. In this study, the cell surface molecule expression, Th1/Th2, inflammatory cytokine levels in blood, and synovial fluid of CD3(+) T lymphocytes in BD were investigated. The study group consisted of 10 BD, 10 ankylosing spondylitis (AS) patients with peripheral arthritis, and 10 healthy subjects. Expression of cell surface molecules, intracellular IL-2, IL-5, IL-8, IL-10, IL-12, IFN-γ, and TNF-α levels in CD3(+) T lymphocytes were determined by flow cytometry in synovial and peripheral blood mononuclear cells (PBMCs). Synovial and plasma cytokine levels were measured by ELISA and CBA. In PBMCs, CD4, CD25, HLA-DR expression and intracellular IL-12, and TNF-α levels of CD3(+) T lymphocytes were statistically increased in BD patients compared to healthy subjects. Compare to AS patients, CD25 and HLA-DR surface expression and intracellular IFN-γ and TNF-α levels in T cells were significantly elevated in BD patients. In BD patients, there was an increase in IL-8 secretion; however, in AS patients, both Th1- and Th2-type cytokines were increased compare to healthy subjects. Intracellular cytokine expression did not show any difference in BD patients; however, IL-12 content of synovial fluid was significantly increased compared to AS patients. Our findings revealed that Th1 polarization occurred in both peripheral blood and synovial fluid of BD patients with arthritis. It is found no difference between synovial fluid analysis of BD and AS patients, showing the similarities in the pathogenesis of both diseases.

Induction and maintenance of allergen-specific FOXP3+ Treg cells in human tonsils as potential first-line organs of oral tolerance.

BACKGROUND: Tonsils are strategically located in the gateway of both alimentary and respiratory tracts representing the first contact point of food and aeroallergens with the immune system. Tonsillectomy removes only the palatine tonsils and sometimes adenoids. Lingual tonsil is anatomically big and remains lifelong intact. OBJECTIVE: The aim of this study was to demonstrate cellular and molecular mechanisms of oral tolerance induction to food and aeroallergens in human tonsils. METHODS: Tonsil allergen-specific FOXP3(+) regulatory T (Treg) cells, plasmacytoid dendritic cells (pDCs), and myeloid dendritic cells were characterized by flow cytometry and suppressive assays. Intracellular staining, [(3)H]-thymidine incorporation, and carboxy-fluorescein succinimidyl ester dilution experiments were performed. Tonsil biopsies were analyzed by confocal microscopy. RESULTS: CD4(+)FOXP3(+) Treg cells and pDCs constitute important T- and dendritic cell-compartments in palatine and lingual tonsils. Tonsil pDCs have the ability to generate functional CD4(+)CD25(+)CD127(-)FOXP3(+) Treg cells with suppressive property from naive T cells. CD4(+)FOXP3(+) Treg cells proliferate and colocalize with pDCs in vivo in T-cell areas of lingual and palatine tonsils. Tonsil T cells did not proliferate to common food and aeroallergens. Depletion of FOXP3(+) Treg cells enables the allergen-induced proliferation of tonsil T cells, indicating an active role of Treg cells in allergen-specific T-cell unresponsiveness. High numbers of major birch pollen allergen, Bet v 1-specific CD4(+)FOXP3(+) Treg cells, are identified in human tonsils compared with peripheral blood. A positive correlation between the percentages of FOXP3(+) Treg cells and pDCs is observed in tonsils from nonatopic individuals. CONCLUSION: Functional allergen-specific Treg cells are identified both in lingual and in palatine tonsils.

Comparison of mitogen-induced proliferation in child and adult healthy groups by flow cytometry revealed similarities.

The proliferation of antigen-specific lymphocyte clones, the initial step in acquired immunity, is vital for effector functions. Proliferation tests both in immunology research and diagnosis are gaining attendance gradually, while the use of adult healthy individuals as controls of pediatric patients is a question. This study aimed to investigate and compare mitogen-stimulated proliferation responses of total lymphocytes and T- and B-lymphocyte subsets in adult and children healthy donors. Nineteen children and 20 adult healthy donors were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) purified from peripheral blood samples of the donors, by Ficoll gradient centrifugation, were stained with CFSE and were cultured in a 37 â„ƒ CO2 incubator for 120 h with the absence or existence of polyclonal activators: PHA and CD-Mix. After cell culture, PBMCs were stained with monoclonal antibodies against CD4 and CD19, and proliferation percentages of CD4+ T and CD19+ B cells, together with total lymphocytes were determined by flow cytometry. This study revealed similarities between children and adult age groups, concerning mitogenic stimulation of the lymphocytes. The only difference was a significantly high proliferation of pediatric CD4+ T cells in response to PHA. CD4+ T cell responses against PHA were inversely correlated with altering age. When pediatric individuals were distributed into age groups of 0-2 years, 3-5 years, and 6-18 years, PHA responses of CD4+ cells were found to be diminished with advancing age. These findings propose the possibility of enrollment of adult healthy individuals as controls for pediatric patients.

The epithelial barrier theory: Development and exacerbation of allergic and other chronic inflammatory diseases.

It is now longer than half a century, humans, animals, and nature of the world are under the influence of exposure to many newly introduced noxious substances. These exposures are nowadays pushing the borders to be considered as the causative or exacerbating factors for many chronic disorders including allergic, autoimmune/inflammatory, and metabolic diseases. The epithelial linings serve as the outermost body's primary physical, chemical, and immunological barriers against external stimuli. The "epithelial barrier theory" hypothesizes that these diseases are aggravated by an ongoing periepithelial inflammation triggered by exposure to a wide range of epithelial barrier-damaging insults that lead to "epithelitis" and the release of alarmins. A leaky epithelial barrier enables the microbiome's translocation from the periphery to interepithelial and even deeper subepithelial areas together with allergens, toxins, and pollutants. Thereafter, microbial dysbiosis, characterized by colonization of opportunistic pathogen bacteria and loss of the number and biodiversity of commensal bacteria take place. Local inflammation, impaired tissue regeneration, and remodeling characterize the disease. The infiltration of inflammatory cells to affected tissues shows an effort to expulse the tissue invading bacteria, allergens, toxins, and pollutants away from the deep tissues to the surface, representing the "expulsion response." Cells that migrate to other organs from the inflammatory foci may play roles in the exacerbation of various inflammatory diseases in distant organs. The purpose of this review is to highlight and appraise recent opinions and findings on epithelial physiology and its role in the pathogenesis of chronic diseases in view of the epithelial barrier theory.

The decreased CD4+CD25+ FoxP3+ T cells in nonstimulated allergic rhinitis patients sensitized to house dust mites.

OBJECTIVE: Regulatory (CD4(+)CD25(+)) T cells have been shown to play an important role in the development of allergic diseases. This study aims to investigate CD4(+)CD25(+) T cells, Forkhead box P3 (FoxP3(+) cells), and T-helper 1/T-helper 2 (Th1/Th2) cytokines in newly diagnosed allergic rhinitis (AR) patients. METHODS: Altogether, 10 subjects with AR and 12 age-matched nonallergic healthy subjects were included in this study. CD4(+)CD25(+) T cells, FoxP3(+) T cells in peripheral blood mononuclear cells (PBMCs) were evaluated by flow cytometry, and the Th1/Th2 cytokine levels were determined by cytometric bead array immunoassay in both PBMC supernatants and nasal lavage fluids. RESULTS: The percentage of CD4(+)CD25(+) T cells were significantly higher, whereas the percentage of FoxP3(+) cells were lower in AR patients compared with healthy subjects. In PBMC culture supernatants, interleukin-10 (IL-10) levels were significantly lower (p = .012), whereas IL-4, IL-5, and tumor necrosis factor-α (TNF-α) levels in nasal lavage fluids were higher in AR patients compared with healthy subjects (p = .026, p = .015, p = .03, respectively). CONCLUSIONS: Our findings indicate that decrease in CD4(+)CD25(+)FoxP3(+) T cell fraction and diminished levels of IL-10 are noteworthy without allergen stimulation in house dust mite AR patients.

Effect of different cytokines in combination with IL-15 on the expression of activating receptors in NK cells of patients with Behçet's disease.

Behçet's disease (BD) is a systemic, autoinflammatory, chronic disorder which affects various parts of the body in genetically susceptible individuals. BD has a multi-factorial etiopathogenesis which encompasses both innate and adaptive arms of immunity. NK cells, which kill virus-infected or malign cells and provide interaction between adaptive and innate immune system, are also known to involve in the pathogenesis of autoimmune/autoinflammatory diseases including BD. NK cells function in immune responses via the signals obtained from surface-expressed activating and inhibitory receptors. In this study, we aimed to explore NK cell activation status by measuring the levels of activation marker CD69 and activating receptors NKG2D, NKp30, and NKp46 as well as proliferative and cytotoxic capacities in response to stimulation with interleukin (IL)-15-combined cytokines in BD patients. CD4+ and CD8+ T cell responses were also evaluated to compare with those of NK cells. As a result, the expression of activating receptors on NK cells was demonstrated to be varied among patients with active and inactive BD and healthy controls. The proliferation levels of NK cells were elevated in BD patients, especially in inactive phase of disease compared to healthy controls. Additionally, CD107a levels of inactive BD patients were detected to be lower in comparison with healthy controls and active BD patients. These findings suggest that BD patients in active and inactive phases display different activation status of NK cells which indicate NK cells might be associated with immune attacks and remissions during the course of BD.

Immune modulation as a consequence of SARS-CoV-2 infection.

Erroneous immune responses in COVID-19 could have detrimental effects, which makes investigation of immune network underlying COVID-19 pathogenesis a requisite. This study aimed to investigate COVID-19 related alterations within the frame of innate and adaptive immunity. Thirty-four patients clinically diagnosed with mild, moderate and severe COVID-19 disease were enrolled in this study. Decreased ILC1 and increased ILC2 subsets were detected in mild and moderate patients compared to healthy controls. NK cell subsets and cytotoxic capacity of NK cells were decreased in severe patients. Moreover, CD3+ T cells were reduced in severe patients and a negative correlation was found between CD3+ T cells and D-dimer levels. Likewise, moderate and severe patients showed diminished CD3+CD8+ T cells. Unlike T and NK cells, plasmablast and plasma cells were elevated in patients and IgG and IgA levels were particularly increased in severe patients. Severe patients also showed elevated serum levels of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-8, reduced intracellular IFN-γ and increased intracellular IL-10 levels. Our findings emphasize that SARS-CoV-2 infection significantly alters immune responses and innate and acquired immunity are differentially modulated in line with the clinical severity of the disease. Elevation of IL-10 levels in NK cells and reduction of CD3+ and CD8+ T cells in severe patients might be considered as a protective response against the harmful effect of cytokine storm seen in COVID-19.

Specific immunotherapy and turning off the T cell: how does it work?

OBJECTIVE: To examine T-regulatory (Treg) cell functions in allergic immune responses and their roles during allergen specific immunotherapy based on recent developments and current understanding of immune regulation. DATA SOURCES: PubMed search of English-language articles regarding Treg cells and allergen specific immunotherapy. STUDY SELECTION: Articles on the subject matter were selected and reviewed. RESULTS: Allergen specific immunotherapy is the ultimate treatment modality targeting the immunopathogenic mechanisms of allergic disorders. A diminished allergen-specific T-cell proliferation and suppressed secretion of T(H)1- and T(H)2-type cytokines are the characteristic hallmarks. In addition, Treg cells inhibit the development of allergen-specific T(H)2 and T(H)1 cell responses and therefore exert key roles in healthy immune response to allergens. Treg cells potently suppress IgE production and directly or indirectly control the activity of effector cells of allergic inflammation, such as eosinophils, basophils, and mast cells. CONCLUSION: As advancements in the field of allergen specific immunotherapy ensue, they may provide novel progression of more rational and safer approaches for the prevention and treatment of allergic disorders. Currently, the Treg cell field is an open research area to increase our understanding in mechanisms of peripheral tolerance to allergens.

Combined evaluation of proliferation and apoptosis to calculate IC50 of VPA-induced PANC-1 cells and assessing its effect on the Wnt signaling pathway.

Pancreatic ductal adenocarcinoma (PDAC) is among the most deadly cancers. Since most patients develop resistance to conventional treatments, new approaches are in urgency. Valproic acid (VPA) was shown to induce apoptosis and reduce proliferation in PANC-1 cells. Wnt signaling pathway is known to be involved in apoptosis and PDAC onset. However, VPA-induced apoptosis and its impact on Wnt signaling in PDACs are not linked, yet. We aimed to calculate IC50 of VPA-induced PANC-1 cells by combined analyses of proliferation and apoptosis, while assessing its effect on Wnt signaling pathway. PANC-1 was induced with increased VPA doses and time points. Three independent proliferation and apoptosis assays were performed utilizing carboxyfluorescein succinimidyl ester and Annexin V/PI staining, respectively. Flow cytometry measurements were analyzed by CellQuest and NovoExpress. Taqman hydrolysis probes and SYBR Green PCR Mastermix were assessed in expression analyses of Wnt components utilizing 2-ΔΔCt method. Cell proliferation was inhibited by 50% at 2.5 mM VPA that evoked a significant apoptotic response. Among the screened Wnt components and target genes, only LEF1 exhibited significant four-fold upregulation at this concentration. In conclusion, cancer studies mostly utilize MTT or BrdU assays in estimating cell proliferation and calculating IC50 of drugs, which provided conflicting VPA dosages utilizing PANC-1 cells. Our novel combined approach enabled specific, accurate and reproducible IC50 calculation at single cell basis with no apparent effect on Wnt signaling components. Future studies are needed to clarify the role of LEF1 in this model.

The Role of Natural Killer Cells in Autoimmune Diseases.

Natural killer (NK) cells, the large granular lymphocytes differentiated from the common lymphoid progenitors, were discovered in early 1970's. They are members of innate immunity and were initially defined by their strong cytotoxicity against virus-infected cells and by their important effector functions in anti-tumoral immune responses. Nowadays, NK cells are classified among the recently discovered innate lymphoid cell subsets and have capacity to influence both innate and adaptive immune responses. Therefore, they can be considered as innate immune cells that stands between the innate and adaptive arms of immunity. NK cells don't express T or B cell receptors and are recognized by absence of CD3. There are two major subgroups of NK cells according to their differential expression of CD16 and CD56. While CD16+CD56dim subset is best-known by their cytotoxic functions, CD16-CD56bright NK cell subset produces a bunch of cytokines comparable to CD4+ T helper cell subsets. Another subset of NK cells with production of interleukin (IL)-10 was named as NK regulatory cells, which has suppressive properties and could take part in immune-regulatory responses. Activation of NK cells is determined by a delicate balance of cell-surface receptors that have either activating or inhibitory properties. On the other hand, a variety of cytokines including IL-2, IL-12, IL-15, and IL-18 influence NK cell activity. NK-derived cytokines and their cytotoxic functions through induction of apoptosis take part in regulation of the immune responses and could contribute to the pathogenesis of many immune mediated diseases including ankylosing spondylitis, Behçet's disease, multiple sclerosis, rheumatoid arthritis, psoriasis, systemic lupus erythematosus and type-1 diabetes. Dysregulation of NK cells in autoimmune disorders may occur through multiple mechanisms. Thanks to the rapid developments in biotechnology, progressive research in immunology enables better characterization of cells and their delicate roles in the complex network of immunity. As NK cells stand in between innate and adaptive arms of immunity and "bridge" them, their contribution in inflammation and immune regulation deserves intense investigations. Better understanding of NK-cell biology and their contribution in both exacerbation and regulation of inflammatory disorders is a requisite for possible utilization of these multi-faceted cells in novel therapeutic interventions.

Pseudomonas aeruginosa colonization in cystic fibrosis: Impact on neutrophil functions and cytokine secretion capacity.

BACKGROUND: Chronic colonization with Pseudomonas (P.) aeruginosa worsens the prognosis of cystic fibrosis (CF) patients. This study aims to analyze the functional properties of neutrophils in CF patients with P. aeruginosa colonization. METHODS: Patients with CF (n = 16) were grouped by positivity of P. aeruginosa in sputum culture, as positive (P.+) or negative (P.-), then compared with age and sex matched healthy controls (n = 8). Adhesion molecules, apoptotic index, intracellular CAP-18, interleukin 8 (IL-8), and tumor necrosis factor α (TNF-α) levels of neutrophils, following P. aeruginosa and lipopolysaccharides (LPS) stimulation, were analyzed by flow cytometry. IL-1ß, IL-6, TNF-α, and IL-17 plasma levels were determined by Luminex. RESULTS: Patients with CF had increased phagocytosis of Escherichia coli and P. aeruginosa, upregulated oxidative burst and chemotaxis. Increased neutrophil apoptosis was noted in CF patients. In unstimulated conditions, higher levels of CD16+ TNF-α+ and CD16+ IL-8+ neutrophils were determined, whereas bacteria and LPS stimulation significantly decreased secretion of CAP-18 from CD16+ neutrophils of CF patients. Plasma levels of IL-1ß, TNF-α and IL-17 in P.+ patients were higher than in P.- group. CONCLUSION: Our findings confirm inadequate neutrophil defense towards pathogens in CF. A significant difference in migration, phagocytosis, oxidative burst, percentage of IL-8 producing neutrophils, IL-1ß, TNF-α, and IL-17 secretions were noted among CF patients according to their colonization status, which might induce a further destructive effect on airways, resulting in an unfavorable prognosis for children with CF who also have colonization.

Relationship between CD107a expression and cytotoxic activity.

NK cells play important roles in innate immunity against tumors and infections of the host. Studies show that CD107a (LAMP-1) may be a marker for degranulation of NK and activated CD8+ T cells. In our study, the relationship between the expression of CD107a, cytokine secretion and cytotoxic activity in CD56+ NK, CD8+ T cells and lymphocytes has been determined after various stimuli. Effector cells from PBMCs of healthy subjects were isolated and K562 cell line was used as target of cytotoxicity. IL-2 stimulation resulted in a significant increase of CD107a expression in CD56+ NK, CD8+ T cells and lymphocytes. Increased expression of CD107a after IL-2 stimulation of NK cells was parallel to the increase of cytotoxicity. Our results suggest that CD107a expression may be a sensitive marker for the cytotoxic activity determination.