Biology subjects

Baalen, C. v.

Publications and source records attributed to Baalen, C. v..

2 recordsLinked to original sources

bioRxiv2021

Mechanism of Antiviral Activity of Nitazoxanide against the Influenza Virus: Effect of Tizoxanide on AdenosineTriphosphate in Influenza-virus Infected Madin Darby Canine Kidney Cells

BackgroundNitazoxanide (NTZ) is a broad-spectrum antiviral undergoing clinical development for treating influenza and other viral respiratory infections such as those caused by rhinovirus/enterovirus and coronavirus including the emerging SARS-CoV-2. MethodsNitazoxanide is a mild uncoupler of oxidative phosphorylation, which is modulating the ATP production in cells. ATP is an essential component of viral replication, and we have evaluated the effect of tizoxanide (TIZ), the active circulating metabolite of NTZ, on ATP in Madin-Darby canine kidney (MDCK) cells and in MDCK cells infected with influenza A and B viruses. ResultsTIZ decreased cellular ATP in a dose-dependent manner in MDCK cells and in MDCK cells infected with influenza A and B viruses. Maximum inhibition of ATP in influenza infected or uninfected MDCK cells reached up to 45% after 6 and 24 hours of exposure to 100{micro}M TIZ. The decrease in cellular ATP did not affect cell viability and was reversible after eliminating TIZ from the culture. ConclusionThe concentrations of TIZ required to decrease cellular ATP levels were similar to those reported to inhibit replication of influenza A and B viruses in our laboratory. A decrease in ATP triggers activation of AMP-activated protein kinase, which is known to suppress the secretion of pro-inflammatory cytokines. Additional studies are warranted to evaluate the effect of TIZ on mitochondrial function.

microbiology↗

bioRxiv2021

Therapeutic efficacy of CT-P59 against P.1 variant of SARS-CoV-2

P.1. or gamma variant also known as the Brazil variant, is one of the variants of concern (VOC) which appears to have high transmissibility and mortality. To explore the potency of the CT-P59 monoclonal antibody against P.1 variant, we tried to conduct binding affinity, in vitro neutralization, and in vivo animal tests. In in vitro assays revealed that CT-P59 is able to neutralize P.1 variant in spite of reduction in its binding affinity against a RBD (receptor binding domain) mutant protein including K417T/E484K/N501Y and neutralizing activity against P.1 pseudoviruses and live viruses. In contrast, in vivo hACE2 (human angiotensin-converting enzyme 2)-expressing TG (transgenic) mouse challenge experiment demonstrated that a clinically relevant or lower dosages of CT-P59 is capable of lowering viral loads in the respiratory tract and alleviates symptoms such as body weight losses and survival rates. Therefore, a clinical dosage of CT-P59 could compensate for reduced in vitro antiviral activity in P.1-infected mice, implying that CT-P59 has therapeutic potency for COVID-19 patients infected with P.1 variant. HighlightsO_LICT-P59 could bind to and neutralize P.1 variant, but CT-P59 showed reduced susceptibility in in vitro tests. C_LIO_LIThe clinical dosage of CT-P59 demonstrated in vivo therapeutic potency against P.1 variants in hACE2-expressing mice challenge study. C_LIO_LICT-P59 ameliorates their body weight loss and prevents the lethality in P.1 variant-infected mice. C_LI

microbiology↗