Development of benzodioxane-benzamides inhibitors of FtsZ as potent broad-spectrum antimicrobial agents

1 p.-1 graph. abst.Antimicrobial resistance is a serious worldwide health threat. The identification of novel potential antibiotic targets is one of the ways to slow down its worsening. FtsZ, one of the bacterial cell division machinery proteins, emerged in the last decade for its crucial role in bacterial replication and viability [1]. Benzamide compounds are the most studied and promising FtsZ inhibitors developed so far, due to their high anti-staphylococcal activity, their low cytotoxicity and the interesting results obtained in association with other antibiotic classes [2]. Along these lines, here we report our recent findings on a class of FtsZ inhibitors, containing a 2,6-difluoro-benzamide scaffold linked to a hydrophobically substituted 1,4-benzodioxane ring [3-6]. We firstly validated a robust computational model, which drove us to identify the structural features the 1,4-benzodioxane moiety and the alkoxy linker should possess, in order to perfectly fit the FtsZ binding pocket. We thus developed several interesting compounds, having submicromolar antibacterial activities and showing comparable inhibitory activities towards both Gram-positive (Staphylococcus aureus and Bacillus subtilis) [3,5] and Gram-negative (Escherichia coli) FtsZ. Nevertheless, these derivatives proved to be substrates of E. coli efflux pump AcrAB, thus affecting their potencies [4]. These surprising and novel results confirmed how a single molecule can target both species while maintaining potent antimicrobial activity. We set-up and performed different assays, to firstly validate FtsZ as the target of our class of compounds. Morphometric analysis and fluorescence microscopy let us evaluate the typical alterations of cell division and FtsZ inhibition, as well as the effects on FtsZ localization [6].Moreover, we took advantages of fluorescence anisotropy to investigate and assess the impact of our derivatives on the kinetics of disassembly of the GTP triggered FtsZ polymers. Furthermore, we used confocal microscopy, to evaluate the shape and the dimension of FtsZ polymers, when in presence or in absence of our compounds in solutions containing crowding agents mimicking the crowded environment in the cytoplasm.Peer reviewe

Fowlpox virus recombinants expressing HPV-16 E6 and E7 oncogenes for the therapy of cervical carcinoma elicit humoral and cell-mediated responses in rabbits

Background: Around half million new cases of cervical cancer arise each year, making the development of an effective therapeutic vaccine against HPV a high priority. As the E6 and E7 oncoproteins are expressed in all HPV-16 tumour cells, vaccines expressing these proteins might clear an already established tumour and support the treatment of HPV-related precancerous lesions. Methods: Three different immunisation regimens were tested in a pre-clinical trial in rabbits to evaluate the humoral and cell-mediated responses of a putative HPV-16 vaccine. Fowlpoxvirus (FP) recombinants separately expressing the HPV-16 E6 (FPE6) and E7 (FPE7) transgenes were used for priming, followed by E7 protein boosting. Results: All of the protocols were effective in eliciting a high antibody response. This was also confirmed by interleukin-4 production, which increased after simultaneous priming with both FPE6 and FPE7 and after E7 protein boost. A cell-mediated immune response was also detected in most of the animals. Conclusion: These results establish a preliminary profile for the therapy with the combined use of avipox recombinants, which may represent safer immunogens than vaccinia-based vectors in immuno-compromised individuals, as they express the transgenes in most mammalian cells in the absence of a productive replication

Effectiveness of cardiac resynchronization therapy in heart failure patients with valvular heart disease: comparison with patients affected by ischaemic heart disease or dilated cardiomyopathy. The InSync/InSync ICD Italian Registry

AimsTo analyse the effectiveness of cardiac resynchronization therapy (CRT) in patients with valvular heart disease (a subset not specifically investigated in randomized controlled trials) in comparison with ischaemic heart disease or dilated cardiomyopathy patients.Methods and resultsPatients enrolled in a national registry were evaluated during a median follow-up of 16 months after CRT implant. Patients with valvular heart disease treated with CRT (n = 108) in comparison with ischaemic heart disease (n = 737) and dilated cardiomyopathy (n = 635) patients presented: (i) a higher prevalence of chronic atrial fibrillation, with atrioventricular node ablation performed in around half of the cases; (ii) a similar clinical and echocardiographic profile at baseline; (iii) a similar improvement of LVEF and a similar reduction in ventricular volumes at 6-12 months; (iv) a favourable clinical response at 12 months with an improvement of the clinical composite score similar to that occurring in patients with dilated cardiomyopathy and more pronounced than that observed in patients with ischaemic heart disease; (v) a long-term outcome, in term of freedom from death or heart transplantation, similar to patients affected by ischaemic heart disease and basically more severe than that of patients affected by dilated cardiomyopathy.ConclusionIn 'real world' clinical practice, CRT appears to be effective also in patients with valvular heart disease. However, in this group of patients the outcome after CRT does not precisely overlap any of the two other groups of patients, for which much more data are currently available

Fowlpox virus recombinants expressing HPV-16 E6 and E7 oncogenes for the therapy of cervical carcinoma elicit humoral and cell-mediated responses in rabbits

Abstract Background Around half million new cases of cervical cancer arise each year, making the development of an effective therapeutic vaccine against HPV a high priority. As the E6 and E7 oncoproteins are expressed in all HPV-16 tumour cells, vaccines expressing these proteins might clear an already established tumour and support the treatment of HPV-related precancerous lesions. Methods Three different immunisation regimens were tested in a pre-clinical trial in rabbits to evaluate the humoral and cell-mediated responses of a putative HPV-16 vaccine. Fowlpoxvirus (FP) recombinants separately expressing the HPV-16 E6 (FPE6) and E7 (FPE7) transgenes were used for priming, followed by E7 protein boosting. Results All of the protocols were effective in eliciting a high antibody response. This was also confirmed by interleukin-4 production, which increased after simultaneous priming with both FPE6 and FPE7 and after E7 protein boost. A cell-mediated immune response was also detected in most of the animals. Conclusion These results establish a preliminary profile for the therapy with the combined use of avipox recombinants, which may represent safer immunogens than vaccinia-based vectors in immuno-compromised individuals, as they express the transgenes in most mammalian cells in the absence of a productive replication.</p

Understanding and overcoming fundamental limits of asymmetric light-light switches

The interplay between interference and absorption leads to interesting phenomena like coherent perfect absorption and coherent perfect transparency (CPA and CPT), which can be exploited for fully optical modulation. While it is known that it is possible to harness CPA and CPT for switching a strong signal beam with a weak control beam, it is not immediate that this process su ers from a fundamental compromise between the device e ciency (quantified by device loss and modulation depth) and the asymmetry between signal and control intensity desired for operation. This article quantifies this compromise and outlines a possible way to overcome it by means of a combination of optical gain and loss in the same photonic component. A general formulation and a specific device realization are both discussed

Construction and characterisation of a recombinant fowlpox virus that expresses the human papilloma virus L1 protein

<p>Abstract</p> <p>Background</p> <p>Human papilloma virus (HPV)-16 is the most prevalent high-risk mucosal genotype. Virus-like-particle (VLP)-based immunogens developed recently have proven to be successful as prophylactic HPV vaccines, but are still too expensive for developing countries. Although vaccinia viruses expressing the HPV-16 L1 protein (HPV-L1) have been studied, fowlpox-based recombinants represent efficient and safer vectors for immunocompromised hosts due to their ability to elicit a complete immune response and their natural host-range restriction to avian species.</p> <p>Methods</p> <p>A new fowlpox virus recombinant encoding HPV-L1 (FP_L1) was engineered and evaluated for the correct expression of HPV-L1 <it>in vitro</it>, using RT-PCR, immunoprecipitation, Western blotting, electron microscopy, immunofluorescence, and real-time PCR assays.</p> <p>Results</p> <p>The FP_L1recombinant correctly expresses HPV-L1 in mammalian cells, which are non-permissive for the replication of this vector.</p> <p>Conclusion</p> <p>This FP_L1recombinant represents an appropriate immunogen for expression of HPV-L1 in human cells. The final aim is to develop a safe, immunogenic, and less expensive prophylactic vaccine against HPV.</p

Comparative analysis of immune responses and cytokine profiles elicited in rabbits by the combined use of recombinant fowlpox viruses, plasmids and virus-like particles in prime-boost vaccination protocols against SHIV

Three different prime-boost immunization protocols were tested in rabbits and their immune response was evaluated and compared with the final aim of identifying a vaccine strategy that might be able to protect non-human primates from infection with the pathogenic chimera simian/human immunodeficiency virus (SHIV)(89.6P). Protocols were based on priming with two fowlpox (FP) recombinant vectors and two expression plasmids, which express either the simian immunodeficiency virus (SIV)mac(239) gag/pol or the human immunodeficiency virus (HIV-1)env(89.6P) genes, followed by boosting with virus-like particles (VLP). All protocols were effective in eliciting homologous neutralizing Ab and highlighted the efficacy of VLP boosting. The FP vector was less efficient than plasmid DNA in inducing Ab against the gag core proteins. Analysis of cytokine expression 5 months after last immunization indicated that priming with pcDNA3gag/pol(SIV) and FPenv(89.6P) followed by VLP boosting generated a T helper (Th0) profile and a good Ab titer, suggesting a potential protocol to be tested in the SHIV-macaque model of HIV-1 infection