Peptide ligands targeting the vesicular stomatitis virus G (VSV-G) protein for the affinity purification of lentivirus particles.

The recent uptick in the approval of ex vivo cell therapies highlights the relevance of lentivirus (LV) as an enabling viral vector of modern medicine. As labile biologics, however, LVs pose critical challenges to industrial biomanufacturing. In particular, LV purification-currently reliant on filtration and anion-exchange or size-exclusion chromatography-suffers from long process times and low yield of transducing particles, which translate into high waiting time and cost to patients. Seeking to improve LV downstream processing, this study introduces peptides targeting the enveloped protein Vesicular stomatitis virus G (VSV-G) to serve as affinity ligands for the chromatographic purification of LV particles. An ensemble of candidate ligands was initially discovered by implementing a dual-fluorescence screening technology and a targeted in silico approach designed to identify sequences with high selectivity and tunable affinity. The selected peptides were conjugated on Poros resin and their LV binding-and-release performance was optimized by adjusting the flow rate, composition, and pH of the chromatographic buffers. Ligands GKEAAFAA and SRAFVGDADRD were selected for their high product yield (50%-60% of viral genomes; 40%-50% of HT1080 cell-transducing particles) upon elution in PIPES buffer with 0.65 M NaCl at pH 7.4. The peptide-based adsorbents also presented remarkable values of binding capacity (up to 3·109 TU per mL of resin, or 5·1011 vp per mL of resin, at the residence time of 1 min) and clearance of host cell proteins (up to a 220-fold reduction of HEK293 HCPs). Additionally, GKEAAFAA demonstrated high resistance to caustic cleaning-in-place (0.5 M NaOH, 30 min) with no observable loss in product yield and quality.

[Health surveillance for subjects with past occupational exposure to asbestos: the experience of Local Health Unit Messina 5 (Sicily)]. / La sorveglianza sanitaria dei soggetti con pregressa esposizione professionale ad amianto: l'esperienza dell'AUSL Messina 5.

OBJECTIVE: In the framework of the World Health Organization (WHO)-Istituto superiore di sanità (ISS) joint research project «Cohort studies in areas of high environmental risk in Sicily¼, since 2007 a working group ISS-Local Health Unit Messina 5 (AUSL ME5) assessed the issue emerged during the course of a health monitoring program launched in 2003, dedicated to former employees of an asbestos-cement factory, and their relatives (378 subjects, 119 ex employees and 259 relatives). METHODS: Communication about the health risks linked to previous exposure to asbestos, diagnostic tools for asbestos-related diseases, available preventive measures (stopping smoking tobacco, avoiding further exposure to respiratory irritants, prophylaxis of any intercurrent respiratory diseases) were focused. The working group discussed the whole structure of the activity in progress, and identified the difficulties emerged in previous years. RESULTS AND CONCLUSIONS: The authors developed a health plan that could be useful in similar Sicilian contexts with public health problems due to past activities with asbestos.