The E3 ubiquitin ligase Itch regulates expression of transcription factor Foxp3 and airway inflammation by enhancing the function of transcription factor TIEG1.

Transforming growth factor-beta (TGF-beta) signaling in naive T cells induces expression of the transcription factor Foxp3, a 'master' regulator of regulatory T cells (T(reg) cells). However, the molecular mechanisms leading to Foxp3 induction remain unclear. Here we show that Itch-/- T cells were resistant to TGF-beta treatment and had less Foxp3 expression. The E3 ubiquitin ligase Itch associated with and promoted conjugation of ubiquitin to the transcription factor TIEG1. Itch cooperated with TIEG1 to induce Foxp3 expression, which was reversed by TIEG1 deficiency. Functionally, 'TGF-beta-converted' T(reg) cells generated from TIEG1-deficient mice were unable to suppress airway inflammation in vivo. These results suggest TIEG and Itch contribute to a ubiquitin-dependent nonproteolytic pathway that regulates inducible Foxp3 expression and the control of allergic responses.

Clinical features of bacteremia caused by methicillin-resistant Staphylococcus aureus in a tertiary hospital.

Methicillin-resistant Staphylococcus aureus (MRSA) has become a leading cause of infections in both the community and in hospitals. MRSA bacteremia is a serious infection with a very high mortality rate. The aim of this study was to assess the clinical features of MRSA bacteremia and to evaluate predictors of mortality in patients with this infection. The medical records of 83 patients with MRSA bacteremia, who had been admitted to Nagasaki University Hospital between January 2003 and December 2007, were retrospectively reviewed. Underlying disease, presumed source, MRSA sensitivity, Staphylococcal cassette chromosome mec (SCCmec) types, virulence genes and prognosis were evaluated. Of the 83 patients (44 men and 39 women; mean age: 63.7 years) with MRSA bacteremia, 30 (36.1%) had malignancy and 25 (30.1%) had been treated with immunosuppressive drugs. Fifteen patients (18.1%) were intravascular catheter related. SCCmec typeII accounted for 80% of SCCmec types of MRSA isolates. The mortality rate was 39.8% (33/83), which is similar to that of previous reports. The ratio of males to females, the mean age or the body temperature did not differ between survivors and nonsurvivors. Independent predictors associated with mortality in the multivariate analyses are pneumonia (P = 0.016), treatment with VCM (P = 0.039), and transplantation (P = 0.021). We suggest that poor prognosis achieved with VCM is in part due to its low blood concentration and poor tissue penetration. VCM should not be selected when presumed source of MRSA bacteremia is pneumonia.

Do you know otitis media with ANCA-Associated Vasculitis (OMAAV)?

Hearing loss is often the only symptom of OMAAV at initial presentation, thus making early diagnosis difficult. We present OMAAV in a 70-year-old woman with hearing loss and dry cough. Otoscopy showed otitis media with effusion. Audiometry showed mixed hearing loss, especially in the right ear. Serum myeloperoxidase antineutrophil cytoplasmic antibody was positive. Image analyses showed lung lesion and interstitial pneumonia, while bronchoscopy showed possible microscopic polyangiitis. After starting and tapering prednisolone, respiratory and otologic symptoms improved. When examining patients with acute otologic symptoms and suspected lung and/or renal disease, OMAAV should be included in differential diagnosis.