Cytosolic Gram-negative bacteria prevent apoptosis by inhibition of effector caspases through lipopolysaccharide.

The cytosolic appearance and propagation of bacteria cause overwhelming cellular stress responses that induce apoptosis under normal conditions. Therefore, successful bacterial colonization depends on the ability of intracellular pathogens to block apoptosis and to safeguard bacterial replicative niches. Here, we show that the cytosolic Gram-negative bacterium Shigella flexneri stalls apoptosis by inhibiting effector caspase activity. Our data identified lipopolysaccharide (LPS) as a bona fide effector caspase inhibitor that directly binds caspases by involving its O-antigen (O Ag) moiety. Bacterial strains that lacked the O Ag or failed to replicate within the cytosol were incapable of blocking apoptosis and exhibited reduced virulence in a murine model of bacterial infection. Our findings demonstrate how Shigella inhibits pro-apoptotic caspase activity, effectively delays coordinated host-cell demise and supports its intracellular propagation. Next to the recently discovered pro-inflammatory role of cytosolic LPS, our data reveal a distinct mode of LPS action that, through the disruption of the early coordinated non-lytic cell death response, ultimately supports the inflammatory breakdown of infected cells at later time points.

The transitioning from conventional therapy to biological treatment in psoriatic patients: STRATOS, a project of Marche Region.

BACKGROUND: STRATOS is the acronym of the "STRuctured Approach to the Treatment of psOriatic patientS". The optimization of the psoriasis's therapeutic management is one of the most important goals for dermatologists. According to Mrowietz's consensus report, the transitioning from conventional therapy to biological therapy is mainly due to the lack/loss of efficacy and/or for safety reasons. The aim of the manuscript was to describe the principal results obtained by the Dermatologic Clinic of Polytechnic University of Marche Region and the Units of Dermatology of the Marche Region applying, in our regional reality, Mrowietz's protocol for the daily management of patients with moderate-to-severe plaque. METHODS: Forty-seven patients with moderate to severe chronic plaque psoriasis have been monitored during the six-months study period. RESULTS: Psoriatic patients with diabetes showed further concomitant comorbidities compared to non-diabetics, as hypertension and hypercholesterolemia. Moreover, based on WHO classification, overweight was diagnosed in female patients, whereas obesity was prevalent in male patients. This aspect confirms the strict link between the multifaceted aspects of psoriatic patient which is primarily related to the persistent low-grade inflammation. In our psoriatic group, 10% of monitored patients were affected by Crohn disease or ulcerative colitis. CONCLUSIONS: The Mrowietz's transitioning protocol is a useful, reliable and feasible tool to manage the therapeutic iter of psoriatic patients in an Italian clinical setting also at regional level.