Mobilization of HIV Spread by Diaphanous 2 Dependent Filopodia in Infected Dendritic Cells

Paramount to the success of persistent viral infection is the ability of viruses to navigate hostile environments en route to future targets. In response to such obstacles, many viruses have developed the ability of establishing actin rich-membrane bridges to aid in future infections. Herein through dynamic imaging of HIV infected dendritic cells, we have observed how viral high-jacking of the actin/membrane network facilitates one of the most efficient forms of HIV spread. Within infected DC, viral egress is coupled to viral filopodia formation, with more than 90% of filopodia bearing immature HIV on their tips at extensions of 10 to 20 µm. Live imaging showed HIV filopodia routinely pivoting at their base, and projecting HIV virions at µm.sec−1 along repetitive arc trajectories. HIV filopodial dynamics lead to up to 800 DC to CD4 T cell contacts per hour, with selection of T cells culminating in multiple filopodia tethering and converging to envelope the CD4 T-cell membrane with budding HIV particles. Long viral filopodial formation was dependent on the formin diaphanous 2 (Diaph2), and not a dominant Arp2/3 filopodial pathway often associated with pathogenic actin polymerization. Manipulation of HIV Nef reduced HIV transfer 25-fold by reducing viral filopodia frequency, supporting the potency of DC HIV transfer was dependent on viral filopodia abundance. Thus our observations show HIV corrupts DC to CD4 T cell interactions by physically embedding at the leading edge contacts of long DC filopodial networks

Ineffectiveness and adverse events of nitrofurantoin in women with urinary tract infection and renal impairment in primary care

Item does not contain fulltextPURPOSE: To determine whether treatment with nitrofurantoin in women with urinary tract infection (UTI) and renal impairment in primary care is associated with a higher risk of ineffectiveness and/or serious adverse events than in women without renal impairment. METHODS: A cohort of 21,317 women treated with nitrofurantoin and a cohort of 7,926 women treated with trimethoprim, identified from the Pharmo Record Linkage System, were analysed. The primary outcome was ineffectiveness of treatment of nitrofurantoin defined as the start of a second antibacterial within 1 month after the start of nitrofurantoin. The secondary outcome was the occurrence of serious adverse events of nitrofurantoin leading to hospitalization within 90 days. A cohort of trimethoprim users was used to determine if the associations found for nitrofurantoin were mainly related to nitrofurantoin itself. The association between renal impairment and the risk of these outcomes was determined with Cox regression and expressed as hazard ratios (HRs). RESULTS: Overall, the incidence density for ineffectiveness was 5.4 per 1,000 person-days, and moderate renal impairment was not associated with ineffective treatment [HR 1.1, 95 % confidence interval (CI) 0.74-1.51]. The overall incidence density for adverse events was 0.02 per 1,000 person-days. In patients with renal impairment (<50 ml/min/1.73 m(2)) the risk of pulmonary adverse events leading to hospitalization was significantly increased (HR 4.1, 95 % CI 1.31-13.09) CONCLUSIONS: Nitrofurantoin treatment was not associated with a higher risk of ineffectiveness in women with UTI and moderate renal impairment (30-50 ml/min/1.73m(2)). However, we did find a significant association between renal impairment (<50 ml/min/1.73 m(2)) and pulmonary adverse events leading to hospitalization

A global view of the proteome perturbations by Hsp90 inhibitors

Heat shock protein 90 (Hsp90) is a highly efficient molecular chaperone and a major hub in the protein network that maintains cellular homeostasis and function. The qualitative and quantitative changes and rewiring of this protein network in tumor cells make them vastly dependent on Hsp90, which therefore becomes a key target to fight cancer. The inhibition of Hsp90 creates a profound transformation in the cell proteome. In this chapter, we review and analyze the most recent efforts that take advantage of the druggability of Hsp90 in order to understand the global changes at the proteome level that this inhibition produces. The considerable impact that the targeting of Hsp90 has on the structure of these protein networks is also discussed