59 research outputs found

    Human neutrophils phagocytose and kill Acinetobacter baumanii and A. pittii

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    Acinetobacter baumannii is a common cause of health care associated infections worldwide. A. pittii is an opportunistic pathogen also frequently isolated from Acinetobacter infections other than those from A. baumannii. Knowledge of Acinetobacter virulence factors and their role in pathogenesis is scarce. Also, there are no detailed published reports on the interactions between A. pittii and human phagocytic cells. Using confocal laser and scanning electron microscopy, immunofluorescence, and live-cell imaging, our study shows that immediately after bacteria-cell contact, neutrophils rapidly and continuously engulf and kill bacteria during at least 4 hours of infection in vitro. After 3 h of infection, neutrophils start to release neutrophil extracellular traps (NETs) against Acinetobacter. DNA in NETs colocalizes well with human histone H3 and with the specific neutrophil elastase. We have observed that human neutrophils use large filopodia as cellular tentacles to sense local environment but also to detect and retain bacteria during phagocytosis. Furthermore, co-cultivation of neutrophils with human differentiated macrophages before infections shows that human neutrophils, but not macrophages, are key immune cells to control Acinetobacter. Although macrophages were largely activated by both bacterial species, they lack the phagocytic activity demonstrated by neutrophils

    Purinergic signalling and immune cells

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    This review article provides a historical perspective on the role of purinergic signalling in the regulation of various subsets of immune cells from early discoveries to current understanding. It is now recognised that adenosine 5'-triphosphate (ATP) and other nucleotides are released from cells following stress or injury. They can act on virtually all subsets of immune cells through a spectrum of P2X ligand-gated ion channels and G protein-coupled P2Y receptors. Furthermore, ATP is rapidly degraded into adenosine by ectonucleotidases such as CD39 and CD73, and adenosine exerts additional regulatory effects through its own receptors. The resulting effect ranges from stimulation to tolerance depending on the amount and time courses of nucleotides released, and the balance between ATP and adenosine. This review identifies the various receptors involved in the different subsets of immune cells and their effects on the function of these cells

    Gene therapy for primary immune deficiencies: a Canadian perspective

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    The use of gene therapy (GT) for the treatment of primary immune deficiencies (PID) including severe combined immune deficiency (SCID) has progressed significantly in the recent years. In particular, long-term studies have shown that adenosine deaminase (ADA) gene delivery into ADA-deficient hematopoietic stem cells that are then transplanted into the patients corrects the abnormal function of the ADA enzyme, which leads to immune reconstitution. In contrast, the outcome was disappointing for patients with X-linked SCID, Wiskott–Aldrich syndrome and chronic granulomatous disease who received GT followed by autologous gene corrected transplantations, as many developed hematological malignancies. The malignancies were attributed to the predilection of the viruses used for gene delivery to integrated at oncogenic areas. The availability of safer and more efficient self-inactivating lentiviruses for gene delivery has reignited the interest in GT for many PID that are now in various stages of pre-clinical studies and clinical trials. Moreover, advances in early diagnosis of PID and gene editing technology coupled with enhanced abilities to generate and manipulate stem cells ex vivo are expected to further contribute to the benefit of GT for PID. Here we review the past, the present and the future of GT for PID, with particular emphasis on the Canadian perspective

    Primjena i kompozicija individualiziranih zaštitnih elemenata linijske grafike u projektiranju novčanica

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    Proces stvaranja novčanica je dugotrajan i složen, što rezultira kompleksnim rješenjima koja predstavljaju pravo remek djelo grafike. Novčanice su prožete brojnim detaljima i prenose različite informacije koje se analiziraju u teorijskom dijelu rada. Prvotno se postavljaju kriteriji po kojima se izrađuje detaljna analiza velikog broja zaštitnih i konceptualnih elemenata na primjerima novčanica. Time je prikazan okvirni povijesni pregled razvoja novčanica i utjecaji kojima je bio izložen. Analizira se međuovisnost dizajna o sigurnosnim značajkama, te se ispituje razina informiranosti javnosti o zaštitama na novčanicama. Zaključuje se koje metode zaštite su najučinkovitije, te kako šira javnost najčešće provjerava autentičnost novčanica. U eksperimentalnom dijelu rada se na temelju donesenih zaključaka iz teorijskog dijela izrađuje prototip novčanice koja je u najvećoj mjeri prožeta individualiziranim PostScript programskim rješenjima elemenata linijske grafike (rozete, mikrotekst, zaštitne linije, brojevi apoena), a od ostalih zaštita modeliran je individualizirani raster transformacijom matematičkog izraza u PostScript programski kod. Sve ostale zaštite tipične za novčanice simulirane su alatima za rastersku i vektorsku grafiku. U radu se ispituje utjecaj kompozicije zaštitnih elemenata na prepoznavanje autentičnosti novčanica, te efikasnost samih individualiziranih programskih rješenja

    Genetic Risk for Inflammatory Bowel Disease Is a Determinant of Crohn\u27s Disease Development in Chronic Granulomatous Disease.

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    BACKGROUND: Approximately, one-third to one-half of children with chronic granulomatous disease (CGD) develop gastrointestinal inflammation characteristic of idiopathic inflammatory bowel disease (IBD), usually Crohn\u27s disease. We hypothesized that the overall IBD genetic risk, determined by IBD genetic risk score (GRS), might in part determine IBD development in CGD. METHODS: We reviewed medical records to establish IBD diagnoses in CGD subjects seen at NIAID. IBD risk single nucleotide polymorphism genotypes were determined using the Immunochip, and GRS were estimated by Mangrove. RESULTS: Among 157 white patients with CGD, 55 were confirmed, 78 excluded, and 24 were uncertain for IBD. Two hundred one established, independent European IBD risk single nucleotide polymorphisms passed QC. After sample QC and removing non-IBD CGD patients with perianal disease, mean GRS for 40 unrelated patients with CGD-IBD was higher than 53 CGD non-IBD patients (in log2-scale 0.08 ± 1.62 versus -0.67 ± 1.64, P = 0.026) but lower than 239 IBD Genetics Consortium (IBDGC) young-onset Crohn\u27s disease cases (0.76 ± 1.60, P = 0.025). GRS for non-IBD CGD was similar to 609 IBDGC controls (-0.69 ± 1.60, P = 0.95). Seven established IBD single nucleotide polymorphisms were nominally significant among CGD-IBD versus CGD non-IBD, including those near LACC1 (P = 0.005), CXCL14 (P = 0.007), and TNFSF15 (P = 0.016). CONCLUSIONS: The weight of the common IBD risk alleles are significant determinants of IBD in CGD. However, IBD risk gene burden among CGD children with IBD is significantly lower than that in nonsyndromic pediatric Crohn\u27s disease, congruent with the concept that defective superoxide production in CGD is also a major IBD risk factor. Individual IBD genes might interact with the CGD defect to cause IBD in CGD
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