Antisense peptide
nucleic acids (PNAs) have yet to translate to
the clinic because of poor cellular uptake, limited solubility, and
rapid elimination. Cell-penetrating peptides (CPPs) covalently attached
to PNAs may facilitate clinical development by improving uptake into
cells. We report an efficient technology that utilizes a fully automated
fast-flow instrument to manufacture CPP-conjugated PNAs (PPNAs) in
a single shot. The machine is rapid, with each amide bond being formed
in 10 s. Anti-IVS2-654 PPNA synthesized with this instrument presented
threefold activity compared to transfected PNA in a splice-correction
assay. We demonstrated the utility of this approach by chemically
synthesizing eight anti-SARS-CoV-2 PPNAs in 1 day. A PPNA targeting
the 5′ untranslated region of SARS-CoV-2 genomic RNA reduced
the viral titer by over 95% in a live virus infection assay (IC
50
= 0.8 μM). Our technology can deliver PPNA candidates
to further investigate their potential as antiviral agents.
A novel betacoronavirus (SARS-CoV-2) that causes severe pneumonia emerged through zoonosis in late 2019. The disease, referred to as COVID-19, has an alarming mortality rate and it is having a devastating effect on the global economy and public health systems. A safe, effective vaccine is urgently needed to halt this pandemic. In this study, immunogenicity of the receptor binding domain (RBD) of spike (S) glycoprotein was examined in mice. Animals were immunized with recombinant RBD antigen intraperitoneally using three different adjuvants (Zn-chitosan, Alhydrogel, and Adju-Phos), and antibody responses were followed for over 5 months. Results showed that potent neutralizing antibodies (nAbs) can be induced with 70% neutralization titer (NT70) of ~14,580 against live, infectious viruses. Although antigen-binding antibody titers decreased gradually over time, sufficiently protective levels of nAbs persisted (NT80 >2,430) over the 5-month observation period. Results also showed that adjuvants have profound effects on kinetics of nAb induction, total antibody titers, antibody avidity, antibody longevity, and B-cell epitopes targeted by the immune system. In conclusion, a recombinant subunit protein immunogen based on the RBD is a highly promising vaccine candidate. Continued evaluation of RBD immunogenicity using different adjuvants and vaccine regimens could further improve vaccine efficacy.
Preventing nosocomial infection is a major unmet need of our times. Existing air decontamination technologies suffer from demerits such as toxicity of exposure, species specificity, noxious gas emission, environment-dependent performance and high power consumption. Here, we present a novel technology called ZeBox that transcends the conventional limitations and achieves high microbicidal efficiency. In ZeBox, a non-ionizing electric field extracts naturally charged microbes from flowing air and deposits them on engineered microbicidal surfaces. The surfaces three dimensional topography traps the microbes long enough for them to be inactivated. The electric field and chemical surfaces synergistically achieve rapid inactivation of a broad spectrum of microbes. ZeBox achieved near complete kill of airborne microbes in challenge tests (5-9 log reduction) and >90% efficiency in a fully functional stem cell research facility in the presence of humans. Thus, ZeBox fulfills the dire need for a real-time, continuous, safe, trap-and-kill air decontamination technology.
The Coronaviridae family hosts various coronaviruses responsible for many diseases, from the common cold, severe lung infections to pneumonia. SARS-CoV-2 was discovered to be the etiologic agent of the Coronavirus pandemic, and numerous basic and applied laboratory techniques were utilized in virus culture and examination of the disease. Understanding the replication kinetics and characterizing the effect of the virus on different cell lines is crucial for developingin vitrostudies. With the emergence of multiple variants of SARS-CoV-2, a comparison between their infectivity and replication in common cell lines will give us a clear understanding of the characteristic differences in pathogenicity. In this study, we compared the cytopathic effect (CPE) and replication of Wild Type (WT), Omicron (B.1.1.529), and Delta (B.1.617.2) variants on 5 different cell lines; VeroE6, VeroE6 expressing high endogenous ACE2, VeroE6 highly expressing human ACE2 (VeroE6/ACE2) and TMPRSS2 (VeroE6/hACE2/TMPRSS2), Calu3 cells highly expressing human ACE2 and A549 cells. All 3 VeroE6 cell lines were susceptible to WT strain, where CPE and replication were observed. Along with being susceptible to Wild type, VeroE6/hACE2/TMPRSS2 cells were susceptible to both omicron and delta strains, whereas VeroE6/ACE2 cells were only susceptible to omicron in a dose-dependent manner. No CPE was observed in both human lung cell lines, A549 and Calu3/hACE2, but Wild type and omicron replication was observed. As SAR-CoV-2 continues to evolve, this data will benefit researchers in experimental planning, viral pathogenicity analysis, and providing a baseline for testing future variants.
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