Haviernik, J. | bioRxiv Science

bioRxiv2025

Viral Infection Induces Alzheimer's Disease-Related Pathways and Senescence in iPSC-Derived Neuronal Models

Structured AbstractO_ST_ABSINTRODUCTIONC_ST_ABSThe Pathogen Infection Hypothesis proposes that {beta}-Amyloid (A{beta}) functions as an antimicrobial peptide, with pathogen-induced aggregation potentially contributing to Alzheimers disease (AD) pathology. METHODSWe used human iPSC-derived 2D neurons and 3D cerebral organoids from wild-type and familial AD (PSEN1/2 mutant) lines to model acute infections with HSV-1 and TBEV and A{beta} aggregation. Transcriptomic and proteomic analyses were conducted to assess molecular responses. RESULTSHSV-1, but not TBEV, induced robust A{beta} clustering, which was, however, dependent on extracellular amyloid peptides. Transcriptomic profiling revealed widespread HSV-1-induced changes, including activation of neurodegeneration-related pathways. Proteomic profiling confirmed enrichment of neurodegeneration- and senescence-associated secretome signatures. PSEN1/2 mutations did not alter the acute infection response. Reanalysis of independent datasets confirmed our findings and revealed a limited protective effect of acyclovir. DISCUSSIONResults directly support the Pathogen Infection Hypothesis and suggest that preventing viral infections via vaccinations may represent a feasible approach to reducing AD risk.

neuroscience↗

bioRxiv2021

Bispecific antibody prevents SARS-CoV-2 escape and protects mice from disease

Neutralizing antibodies targeting the receptor binding domain (RBD) of the SARS-CoV-2 Spike (S) are among the most promising approaches against coronavirus disease 2019 (COVID-19)1,2. We developed a bispecific, IgG1-like molecule (CoV-X2) based on two antibodies derived from COVID-19 convalescent donors, C121 and C1353. CoV-X2 simultaneously binds two independent sites on the RBD and, unlike its parental antibodies, prevents detectable S binding to Angiotensin-Converting Enzyme 2 (ACE2), the virus cellular receptor. Furthermore, CoV-X2 neutralizes SARS-CoV-2 and its variants of concern, as well as the escape mutants generated by the parental monoclonals. In a novel animal model of SARS-CoV-2 infection with lung inflammation, CoV-X2 protects mice from disease and suppresses viral escape. Thus, simultaneous targeting of non-overlapping RBD epitopes by IgG-like bispecific antibodies is feasible and effective, combining into a single molecule the advantages of antibody cocktails.

immunology↗

bioRxiv2019

An E460D substitution in the NS5 protein of tick-borne encephalitis virus confers resistance to the inhibitor Galidesivir (BCX4430) and also attenuates the virus for mice

The adenosine analogue Galidesivir (BCX4430), a broad-spectrum RNA virus inhibitor, has entered a Phase 1 clinical safety and pharmacokinetics study in healthy subjects and is under clinical development for treatment of Ebola virus infection. Moreover, Galidesivir also inhibits the reproduction of tick-borne encephalitis virus (TBEV) and numerous other medically important flaviviruses. Until now, studies of this antiviral agent have not yielded resistant viruses. Here, we demonstrate that an E460D substitution, in the active site of TBEV RNA-dependent-RNA-polymerase (RdRp), confers resistance to Galidesivir in cell culture. Stochastic molecular simulations indicate that the steric freedom caused by the E460D substitution increases close electrostatic interactions between the inhibitor and the interrogation residue of the TBEV RdRp motif F, resulting in rejection of the analogue as an incorrect/modified nucleotide. Galidesivir-resistant TBEV exhibited no cross-resistance to structurally different antiviral nucleoside analogues, such as 7-deaza-2-C-methyladenosine, 2-C-methyladenosine and 4-azido-aracytidine. Although, the E460D substitution led only to a subtle decrease in viral fitness in cell culture, Galidesivir-resistant TBEV was highly attenuated in vivo, with 100% survival rate and no clinical signs observed in infected mice. Our results contribute to understanding the molecular basis of Galidesivir antiviral activity, flavivirus resistance to nucleoside inhibitors and the potential contribution of viral RdRp to flavivirus neurovirulence. ImportanceTick-borne encephalitis virus (TBEV) is a pathogen that causes severe human neuroinfections in large areas of Europe and Asia and for which there is currently no specific therapy. We have previously found that Galidesivir (BCX4430), a broad-spectrum RNA virus inhibitor, which is under clinical development for treatment of Ebola virus infection, has a strong antiviral effect against TBEV. For any antiviral drug, it is important to generate drug-resistant mutants to understand how the drug works. Here, we produced TBEV mutants resistant to Galidesivir and found that the resistance is caused by a single amino acid substitution in an active site of the viral RNA-dependent RNA polymerase, an enzyme which is crucial for replication of viral RNA genome. Although, this substitution led only to a subtle decrease in viral fitness in cell culture, Galidesivir-resistant TBEV was highly attenuated in a mouse model. Our results contribute to understanding the molecular basis of Galidesivir antiviral activity.

microbiology↗