Ragweed pollen extract intensifies lipopolysaccharide-induced priming of NLRP3 inflammasome in human macrophages

Ragweed pollen extract (RWE) possesses intrinsic NADPH oxidase activity that induces oxidative stress by initiating the production of intracellular reactive oxygen species (ROS). The ROS are important contributors to the manifestation of allergic inflammation; furthermore, concomitant exposure to an allergen and an endotoxin trigger a stronger inflammatory response. One of the main pro-inflammatory cytokines produced in inflammatory responses is interleukin-1β (IL-1β), and its production is associated with caspase-1-containing inflammasome complexes. Intracellular ROS have been implicated in NLRP3 inflammasome-mediated IL-1β production, therefore, we aimed to study whether RWE influences the function of NLRP3 inflammasome. Here we describe that, in the presence of NADPH, RWE significantly elevates lipopolysaccharide-induced IL-1β production of THP-1 cells as well as human primary macrophages and dendritic cells. We also demonstrate that increased IL-1β production is mediated through NLRP3 inflammasome in THP-1 macrophages. We provide evidence that RWE elevates cytosolic ROS level in these cells, and ROS inhibitors abolish IL-1β production. Furthermore, we show that RWE enhances lipopolysaccharide-induced gene transcription/expression of pro-IL-1β and key components of the inflammasome via a ROS-dependent mechanism

Individual positioning: a comparative study of adjuvant breast radiotherapy in the prone versus supine position

PURPOSE: To study breast radiotherapy in the prone vs. supine positions through dosimetry and clinical implementation. METHODS AND MATERIALS: Conformal radiotherapy plans in 61 patients requiring only breast irradiation were developed for both the prone and supine positions. After evaluation of the of the first 20 plan pairs, the patients were irradiated in the prone or supine position in a randomized fashion. These cases were analyzed for repositioning accuracy and skin reactions related to treatment position and patient characteristics. RESULTS: The planning target volume covered with 47.5-53.5 Gy in the prone vs. the supine position was 85.1% +/- 4.2% vs. 89.2 +/- 2.2%, respectively (p < 0.0001). Radiation exposure of the ipsilateral lung, expressed in terms of the mean lung dose and the V(20Gy), was dramatically lower in the prone vs. supine position (p < 0.0001), but the doses to the heart did not differ. There was no difference in the need to correct positioning during radiotherapy, but the extent of displacement was significantly higher in the prone vs. supine position (p = 0.021). The repositioning accuracy in the prone position exhibited an improvement over time and did not depend on any patient-related parameters. Significantly more radiodermatitis of Grade 1-2 developed following prone vs. supine irradiation (p = 0.025). CONCLUSIONS: Conformal breast radiotherapy is feasible in the prone position. Its primary advantage is the substantially lower radiation dose to the ipsilateral lung. The higher dose inhomogeneity and increased rate of Grade 1-2 skin toxicity, however, may be of concern

Dendritikus sejt altípusok együttműködése fiziológiás és kóros állapotban = The interplay of dendritic cell subtypes in health and disease

A dendritikus sejtek (DC) az immunfolyamatok fontos irányítói, melyek alapvető szerepet játszanak a központi és perifériás tolerancia és a gyulladásos folyamatok kiváltásában, fenntartásában és szabályozásában. Kis számuk ellenére számos, fenotípus és funkció alapján eltérő alcsoportot képviselnek. Kutatási koncepciónk szerint a DC altípusok a DC készlet védelmét, a hatékony feladatmegosztást és a celluláris együttműködési lehetőségek kihasználását szolgálja. Ennek alapján a plazmacitoid DC-ek és a monocita eredetű DC-ek altípusainak aktivációban betöltött szerepét vizsgáltuk és a DC stimulációban elsődleges szerepet játszó membránhoz kötött, valamint citoplazmatikus mintázatfelismerő receptorok ligand általi aktivációját követő jelátviteli pályák együttműködésére összpontosítottunk. Eredményeink a konvencionális és plazmacitoid DC-ekben is igazolták, hogy a mintázatfelismerő receptorok (PRR) kifejeződése még a ligandum jelenlétében sem elegendő feltétele funkcionális aktivitásuknak, hanem azt a jelpályák egymást erősítő vagy gátló hatása határozza meg. Ennek megfelelően az általunk vizsgált, lokalizációjukban eltérő, de működésük alapján átfedő aktivitással rendelkező PRR-ok által kiváltott jelek egymásra hatása alapvetően meghatározza a DC-ek válaszát és így a természetes és adaptív immunválasz irányultságát, mértékét és kimenetelét. | Dendritic cells (DC) are important regulators of immune responses, which play a pivotal role in the induction, maintenance and regulation of both peripheral tolerance and inflammation. Despite their low numbers, DC involve phenotypically and functionally distinct subtypes and subsets. Based on our concept of research, DC subtypes and subsets serve the maintenance of the DC pool, support appropriate labour distribution and promotes cell-to-cell collaborations. Thus we investigated the role of plasmacytoid DC and monocyte-derived DC subsets in the activation process of these cells and focused to the cross-talk of signaling pathways triggered by the ligation of membrane integrated and cytosolic pattern recognition receptors (PRR). Our results performed with both conventional and plasmacytoid DC revealed that the expression of PRR and their ligation by specific ligand by itself is not sufficient to induce functionality, but is highly dependent on the synergistic or inhibitory interplay of the signaling cascades actually triggered. In accordance with these findings we suggest that the collaboration of signaling cascades induced by PRR with distinct cellular localizations but overlapping functions determine the cellular response of DC and subsequently the polarization, extent and outcome of the immune response

Introduction of a pharmacological neurovascular uncoupling model in rats based on results of mice

Our aim was to establish a pharmacologically induced neurovascular uncoupling (NVU) method in rats as a model of human cognitive decline. Pharmacologically induced NVU with subsequent neurological and cognitive defects was described in mice, but not in rats so far. We used 32 male Hannover Wistar rats. NVU was induced by intraperitoneal administration of a pharmacological “cocktail” consisting of N-(methylsulfonyl)-2-(2-propynyloxy)-benzenehexanamide (MSPPOH, a specific inhibitor of epoxyeicosatrienoic acid-producing epoxidases, 5 mg kg−1), L-NG-nitroarginine methyl ester (L-NAME, a nitric oxide synthase inhibitor, 10 mg kg−1) and indomethacin (a nonselective inhibitor of cyclooxygenases, 1 mg kg−1) and injected twice daily for 8 consecutive days. Cognitive performance was tested in the Morris water-maze and fear-conditioning assays. We also monitored blood pressure. In a terminal operation a laser Doppler probe was used to detect changes in blood-flow (CBF) in the barrel cortex while the contralateral whisker pad was stimulated. Brain and small intestine tissue samples were collected post mortem and examined for prostaglandin E2 (PGE2) level. Animals treated with the “cocktail” showed no impairment in their performance in any of the cognitive tasks. They had higher blood pressure and showed cca. 50 decrease in CBF. Intestinal bleeding and ulcers were found in some animals with significantly decreased levels of PGE2 in the brain and small intestine. Although we could evoke NVU by the applied mixture of pharmacons, it also induced adverse side effects such as hypertension and intestinal malformations while the treatment did not cause cognitive impairment. Thus, further refinements are still required for the development of an applicable model