Regulatory CD4+ T cells are important for the homeostasis of the immune system and their absence correlates with autoimmune disorders. Here, we investigate the capacity of IL-27, a cytokine with pro- and anti-inflammatory properties, to regulate the generation of transforming growth factor beta (TGFbeta)-inducible forkhead box P3 (Foxp3)-positive regulatory T (Treg) cells. Our results demonstrate that IL-27 inhibits the acquisition of the Treg phenotype at the level of Foxp3, CD25 and CTLA-4 (CD152) expression as well as the suppressive function. In contrast to TGFbeta-induced Treg cells, the cells generated after differentiation in the presence of TGFbeta and IL-27 maintained the ability for IL-2 and tumour necrosis factor alpha (TNFalpha) production. The inhibitory effect of IL-27 on Treg generation was at least partially signal transducer and activator of transcription 3 (STAT3) dependent as examined by targeted STAT3 protein inhibition using small interfering RNA (siRNA), while STAT1-dependent signals seemed to oppose the STAT3 signals. In turn, TGFbeta blocked IL-27-induced T(h)1 differentiation. Thus, IL-27 and TGFbeta mutually control their effects on CD4+ T-cell differentiation, whereby IL-27 favours inflammatory conditions through a STAT3-dependent inhibition of Treg generation.
The endogenous anti-microbial peptide LL-37/hCAP-18 is an effector molecule of the innate host defense system at surfaces of the body. Besides its direct anti-microbial activity, the peptide interacts with different cell types. Dendritic cells (DCs) play a central role in mucosal host defense. It was the aim of the study to determine whether LL-37 modulates the response of DCs to pathogen-associated molecular patterns. Monocyte-derived DCs were stimulated with the Toll-like receptors (TLRs) ligands LPS, lipoteichoic acid and flagellin. We measured classical markers of DC maturation and assayed the ability of the DCs to activate T cell responses. Co-incubation with LL-37 resulted in suppressed activation of DCs. Levels of released IL-6, IL-12p70 and TNF-alpha and surface expression of HLA-DR, CD80, CD83, CD86 and the chemokine receptor CCR7 were decreased. Exposure of DCs to LL-37 during LPS exposure induced co-cultured naive T cells to produce less IL-2 and IFN-gamma and decreased their proliferation. The response of memory T cells to a recall antigen was also decreased. In conclusion, we demonstrate that the anti-microbial peptide LL-37 inhibits the activation of DCs by TLR ligands. We propose that LL-37 is a regulator of host defense responses at the intersection of innate and adaptive immune systems.
We report what is to the best of our knowledge the first case of persistent human listeriosis. A housewife underwent excision of a leiomyosarcoma and implantation of a prosthetic knee device. Infection of the device with Listeria monocytogenes occurred and persisted for 2 years. Despite having an allergy to ampicillin, the patient was cured solely by antibiotics and without surgery.
In order to assess if a mixture of phenylephrine/lignocaine is as effective as cocaine for local analgesia and vasoconstriction during nasal fibreoptic intubation, 99 patients receiving topical nasal analgesia either with cocaine 10% or a mixture of phenylephrine 1% and lignocaine 4% were studied in a randomized double-blind investigation. After topical analgesia a flexible fibreoptic endoscope was advanced through a nostril. Larynx, glottis and trachea were endoscopically sprayed with lignocaine. Following induction of anaesthesia a nasotracheal tube was inserted fibreoptically. Pain intensity and amount of epistaxis during endoscopy were assessed. Blood pressure, heart rate and ECG-ST segment were determined before and after topical nasal analgesia, after induction of anaesthesia and after nasotracheal intubation. There were no significant differences in pain intensity of epistaxis between groups during endoscopy, nor significant alterations in haemodynamic parameters or ST-segment. It is concluded that the mixture of phenylephrine and lignocaine is a useful alternative to cocaine for local analgesia and vasoconstriction during nasal fibreoptic intubation.
(1964) Muscle pain following suxamethonium: prevention by 13. MAYRHOPER, 0. (1959) Die Wirksarnkeit von d-Tubocurarin zur Verhiitung der Muskelschmerzen 14. WHITE, D.C. (1962) Observations on the prevention of muscle pains after suxarnethonium. British Journal, ii, 24. operative muscle pain. British Medical Journal, i, 383. the use of suxamethoniurn and suxethoniurn compounds.
Respiratory infection is a major cause of morbidity after general anaesthesia. Impairment of respiratory ciliary beat frequency (CBF) by different stress factors causes a decrease in mucus transport rate (MTR). We have tested the effect of different concentrations of oxygen on CBF of human respiratory epithelium in a prospective, randomized, in vitro study. Samples of superficial mucosa of the inferior nasal turbinates of 20 non-smoking healthy volunteers were harvested and exposed to three different oxygen environments (group I = 21% oxygen, group II = 60% oxygen and group III = 95% oxygen) for 2 h. In 50% of the samples, exposure time was prolonged. At 30, 60, 90, 120 and 240 min, light microscopic images of cilia activity were videotaped and CBF was later assessed in slow motion. Compared with baseline, group I showed no difference in CBF throughout the study. CBF was increased in group II from mean 9.7 (SD 0.4) to 11.2 (0.4) Hz (16%, P < 0.001) and in group III from 9.5 (0.6) to 12.1 (0.5) Hz (28%, P < 0.001) at 120 min. After 240 min of exposure to 95% oxygen, the CBF trend in group III was reduced to 11.8 (0.6) Hz but still remained above baseline. We conclude that oxygen appeared to have a dose- and time-dependent accelerating effect on CBF. Prolonged exposure to high oxygen concentrations reversed this trend. Direct oxygen toxicity ("oxygen stress") is a possible explanation for this effect. These changes may result in impaired MTR.
Helicobacter pylori is a Gram-negative bacterium that causes a variety of gastrointestinal diseases, such as duodenal ulcer and gastric carcinoma. The T cell response against H. pylori is thought to contribute to the pathogenesis of these diseases. Here, we show that mouse-adapted H. pylori is able to polyclonally activate murine CD4 + T lymphocytes, irrespective of their antigen specificity. Murine T helper cell clones as well as short-term cultured, polyclonal Th1 and Th2 cell lines and a human T cell clone, but not naive CD4 + T cells, could be activated in this manner. The effect was independent of antigenpresenting cells and required direct contact between H. pylori and T cells. Only whole cells of H. pylori, but not lysates or sonicates were able to activate T cells. The activity was lost after long-term culture of H. pylori on agar-plates. Degradation of H. pylori proteins with specific peptidases dramatically reduced the stimulating ability, implicating that the responsible molecule is likely to be a protein. This unexpected polyclonal T cell stimulatory mechanism may contribute to the T cell-mediated pathogenicity characteristic for H. pylori-mediated diseases.
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