Binding properties, cell delivery, and gene transfer of adenoviral penton base displaying bacteriophage.

The penton base of adenovirus mediates viral attachment to integrin receptors and particle internalisation, properties that can be exploited to reengineer prokaryotic viruses for the infection of mammalian cells. We report that filamentous phage displaying either the full-length penton base gene or a central region of 107 amino acids on their surface were able to bind, internalise, and transduce mammalian cells expressing integrin receptors. Both phage bound alphavbeta3, alphavbeta5, alpha3beta1, and alpha5beta1 integrin subtypes. Cell-binding was shown by electron microscopy; internalisation was investigated by immunofluorescence and confirmed by micropanning. As it has been described for adenovirus, pharmacologic disruption of phosphoinositide-30H kinase, but not of myosin light-chain kinase, inhibited phage internalisation. Recombinant phage encoding an eukaryotic expression cassette was able to mediate gene expression in mammalian cells. Taken together, these data open insights for the exploit of recombinant phage for integrin-targeted gene delivery.

The role of IL-6 in the inflammatory and humoral response to adenoviral vectors.

BACKGROUND: The major concern for the use of adenoviral vectors for gene therapy is the viral-induced immune response that has been shown to be responsible for short-term transgene expression and inefficient viral readministration. In vivo studies and clinical trials with recombinant adenovirus have suggested a role for interleukin 6 (IL-6) in the inflammatory reaction that follows Ad-infection. IL-6 plays an important role in the acute-phase innate response, in the differentiation of B-cells and in the activation of the Th2 cell subsets. METHODS: To clarify the role of IL-6 in the immune response to Ad-vectors, we used IL-6 knock-out mice (IL-6 -/- ). E1/E3 deleted recombinant adenoviruses encoding reporter genes were administered to wild type or IL-6-/- mice; transgene expression kinetics and immune response were analyzed. RESULTS: Acute phase protein production was significantly diminished in IL-6 -/- mice after adenoviral injection. No significant difference between wild type and knock-out animals in the level or the nature of leucocyte recruitment in the liver was detectable. A minor decrease in the IgG response to Ad-recombinants was observed in knock-out mice. Gene transfer efficiency, both in terms of levels and duration of transgene expression, were comparable in IL-6+/+ and IL-6-/- mice. An increase in IL-1beta and tumor necrosis factor-alpha (TNF-alpha) levels was observed in the sera of IL-6 -/- mice as compared to wild type animals: this phenomenon represents a possible compensatory mechanism for the establishment of the immune phenotype observed in mutant mice. CONCLUSIONS: IL-6 plays a role in the acute phase response to adenoviral vectors. Nevertheless, possibly due to a compensatory mechanism exerted by other cytokines, the antibody and cellular responses to adenoviruses are very similar in wild type and IL-6 -/- mice.

[The heart rate variability indices and the circadian rhythm of the hourly heart rate: 2 prognostic indicators of mortality and malignant ventricular arrhythmias in patients with a myocardial infarct]. / Indici di variabilità della frequenza cardiaca e ritmo circadiano della frequenza cardiaca oraria: due indicatori prognostici di mortalità e di aritmie ventricolari maligne nei pazienti con infarto miocardico.

The aim of this study was to investigate the circadian variability of heart rate in acute myocardial infarction (AMI) in identifying patients at high risk for malignant ventricular arrhythmias (MVA) and sudden death within 1 year of the acute event. The investigation was carried out in 43 patients, who underwent 24-hour Holter monitoring within 3 months of AMI. Besides the time domain indexes of heart rate variability (SDNN, SDNN index, pNN50, rMSSD), the circadian rhythm of hourly total beats (HTB) and hourly qualified beats (HQB) has been analyzed by the Cosinor method. The AMI patients with MVA and those with MVA who died within 1 year the acute event showed SDNN, SDNN index and pNN50 values lower than subjects without MVA and survived patients with MVA, respectively; the individuals with AMI at high risk for MVA and for sudden death had an SDNN value < 105 ms and 50 ms, respectively. The circadian rhythm of HTB and HQB was statistically validated only in the group without MVA; patients without the circadian rhythm of HTB and HQB showed a higher mortality rate within 1 year of AMI, and the majority was in the group with MVA. The contemporary evidence of an SDNN value < 105 ms and the lack of HTB and HQB circadian rhythm increased sensitivity for identifying patients with MVA to 75%. On the other hand, the contemporary evidence of an SDNN value < 50 ms and the lack of HTB and HQB circadian rhythm increased sensitivity for identifying patients who died within 1 year of AMI to 100%. In conclusion, the assayed methods seem to be both useful and complementary in identifying patients at high risk for MVA and sudden death within 1 year of AMI.