Biology subjects

Carzaniga, T.

Publications and source records attributed to Carzaniga, T..

3 recordsLinked to original sources

bioRxiv2026

Identification of ICAM-1-targeting DNA aptamers as a host-directed strategy to inhibit Human Rhinovirus infection

Exacerbations of respiratory viral infections significantly contribute to morbidity and healthcare burden. Among these viruses, Human Rhinoviruses (HRVs) are the most frequent causative agents of upper respiratory tract infections. To date, over 150 HRV serotypes have been identified, classified into three species: HRV-A, HRV-B, and HRV-C. No antiviral therapies are currently available against this viral family, largely due to the high serotype diversity and limited cross-protection. The major group of HRVs relies on the Intercellular Adhesion Molecule-1 (ICAM-1) receptor to infect airway epithelial cells, making ICAM-1 an attractive target for broad-spectrum therapeutic interventions. Here, we report the development of nucleic acid-based aptamers designed to disrupt ICAM-1-HRV binding and thereby prevent viral infection. Aptamers are single-stranded DNA molecules that fold into precise three-dimensional structures, enabling highly specific protein recognition. Using a Systematic Evolution of Ligands by EXponential Enrichment (SELEX) approach guided by a minimal peptide mimicking the ICAM-1 viral binding interface, a library of >1024 random single-stranded DNA sequences was screened. Through iterative rounds of selection, we identified eight candidate 77-nt DNA aptamers, which were subsequently evaluated for their potential using in silico and in vitro assays, as well as functional assays in human epithelial cells. From this strategy, two lead aptamers were selected that effectively inhibited HRV-A16 replication in a concentration-dependent manner, as measured by viral titers (TCID assay) and viral RNA quantification by RT-PCR. These findings demonstrate the potential of ICAM-1-targeting aptamers as antiviral agents capable of preventing HRV entry. By targeting a host receptor and creating a protective barrier at the cell surface, this approach may offer a broadly applicable strategy against multiple HRV serotypes, paving the way for the development of novel antiviral interventions. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=131 SRC="FIGDIR/small/717810v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@130d8org.highwire.dtl.DTLVardef@2dd09borg.highwire.dtl.DTLVardef@1da744eorg.highwire.dtl.DTLVardef@109ea5b_HPS_FORMAT_FIGEXP M_FIG C_FIG

pharmacology and toxicology↗

bioRxiv2020

Non-Langmuir kinetics of DNA surface hybridization

Hybridization of complementary single strands of DNA represents a very effective natural molecular recognition process widely exploited for diagnostic, biotechnology and nanotechnology applications. A common approach relies on the immobilization on a surface of single stranded DNA probes that bind complementary targets in solution. However, despite the deep knowledge on DNA interactions in bulk solution, the modelling of the same interactions on a surface are still challenging and perceived as strongly system-dependent. Here we show that a two dimensional analysis of the kinetics of hybridization, performed at different target concentration and probe surface density by a label-free optical biosensor, reveals peculiar features inconsistent with an ideal Langmuir-like behaviour. We propose a simple non-Langmuir kinetic model accounting for an enhanced electrostatic repulsion originating from the surface immobilization of nucleic acids and for steric hindrance close to full hybridization of the surface probes. The analysis of the kinetic data by the model enables to quantify the repulsive potential at the surface, as well as to retrieve the kinetic parameters of isolated probes. We show that the strength and the kinetics of hybridization at large probe density can be improved by a 3D immobilization strategy of probe strands with a double stranded linker. Statement of SignificanceHybridization of nucleic acids strands with complementary sequences is a fundamental biological process and is also widely exploited for diagnostic purposes. Despite the availability of effective models for the equilibrium strength of freely diffusing strands, a general predictive model for surface hybridization is still missing. Moreover, the kinetics of hybridization is not fully understood neither in solution nor on a surface. In this work we show that the analysis of the kinetics of hybridization on a surface reveals and enables to quantify two main additional contributions: electrostatic repulsion and steric hindrance. These are general effects expected to occur not only on a surface but in any condition with large density of nucleic acids, comparable to that of the cellular nucleus.

biophysics↗

bioRxiv2017

Antibacterial nucleoside-analog inhibitor of bacterial RNA polymerase: pseudouridimycin

There is an urgent need for new antibacterial drugs effective against bacterial pathogens resistant to current drugs1-2. Nucleoside-analog inhibitors (NAIs) of viral nucleotide polymerases have had transformative impact in treatment of HIV3 and HCV4. NAIs of bacterial RNA polymerase (RNAP) potentially could have major impact on treatment of bacterial infection, particularly because functional constraints on substitution of RNAP nucleoside triphosphate (NTP) binding sites4-5 could limit resistance emergence4-5. Here we report the discovery, from microbial extract screening, of an NAI that inhibits bacterial RNAP and exhibits antibacterial activity against a broad spectrum of drug-sensitive and drug-resistant bacterial pathogens: pseudouridimycin (PUM). PUM is a novel microbial natural product consisting of a formamidinylated, N-hydroxylated Gly-Gln dipeptide conjugated to 6'-amino-pseudouridine. PUM potently and selectively inhibits bacterial RNAP in vitro, potently and selectively inhibits bacterial growth in culture, and potently clears infection in a mouse model of Streptococcus pyogenes peritonitis. PUM inhibits RNAP through a binding site on RNAP (the \"i+1\" NTP binding site) and mechanism (competition with UTP for occupancy of the \"i+1\" NTP binding site) that differ from those of the RNAP inhibitor and current antibacterial drug rifampin (Rif). PUM exhibits additive antibacterial activity when co-administered with Rif, exhibits no cross-resistance with Rif, and exhibits a spontaneous resistance rate an order-of-magnitude lower than that of Rif. The results provide the first example of a selective NAI of bacterial RNAP, provide an advanced lead compound for antibacterial drug development, and provide structural information and synthetic routes that enable lead optimization for antibacterial drug development.

molecular biology↗