Biology subjects

Rioux, M.

Publications and source records attributed to Rioux, M..

4 recordsLinked to original sources

bioRxiv2026

A minimally modified AAV9 variant (AAV9fyhr) for enhanced CNS gene delivery by intra-CSF administration.

Adeno-associated virus (AAV) mediated gene therapies continue to show promise for the treatment of genetic diseases. However, delivery and safety still represent significant prohibitive barriers restricting translation of these delivery modalities to humans. We describe a novel AAV9 variant, AAV9fyhr or FYHR, identified from screening a controlled randomization point mutation AAV9 library in mice and nonhuman primates followed by directed evolution of in vivo CNS-derived libraries screened in human iPSC differentiated cortical neurons. Capsid variants of interest were identified by coupling long read sequencing and computational structure modeling. Structure-function analysis of our lead candidate reveal that two targeted amino acid changes are sufficient to result in beneficial pleiotropic effects across viral stability, cell surface attachment, and gene delivery. We developed a novel multiplexed barcoding reporter system, enabling a time and cost-effective option to gather spatially resolved single cell capsid validation data in mice and nonhuman primates. When administered intrathecally, AAV9fyhr exhibits 2-to-6-fold higher gene delivery across several tissues in the CNS while minimally altering the tropism to peripheral tissues in comparison to AAV9. These findings demonstrate the potential of whole capsid engineering for the rational development of translational next generation AAV capsids.

bioengineering↗

bioRxiv2022

Pre-existing immunity to influenza viruses through infection and/or vaccination leads to viral mutational signatures associated with unique immune responses during a subsequent infection

Our biggest challenge to reducing the burden of seasonal influenza is the constant antigen drift of circulating influenza viruses which then evades the protection of pre-existing immunity. Continual viral infection and influenza vaccination creates a layered immune history in people, however, how host preimmunity interacts with an antigenically divergent virus exposure is poorly understood. Here we investigated the influence of host immune histories on influenza viral mutations. Immune backgrounds were devised in mice similar to what is experienced in people: naive; previously infected (A/FM/1/1947); previously vaccinated (Sanofi quadrivalent vaccine); and previously infected and then vaccinated. Mice were challenged with the heterologous H1N1 strain A/Mexico/4108/2009 to assess protection, viral mutation, and host responses in respect to each immune background by RNAseq. Viral sequences were analyzed for antigenic changes using DiscoTope 2.0 and Immune Epitope Database (IEDB) Analysis Resource NetMHCpan EL 4.1 servers. The mock infected-vaccinated group consistently had the greatest number of viral mutations seen across several viral proteins, HA, NA, NP, and PB1 which was associated with strong antiviral responses and moderate T cell and B cell responses. In contrast, the preimmune-vaccinated mice were not associated with variant emergence and the host profiles were characterized by minimal antiviral immunity but strong T cell, B cell, and NK cell responses. This work suggests that the infection and vaccination history of the host dictates the capacity for viral mutation at infection through immune pressure. These results are important for developing next generation vaccination strategies. ImportanceInfluenza is a continual public health problem. Due to constant virus circulation and vaccination efforts, people have complex influenza immune histories which may impact the outcome of future infections and vaccinations. How immune histories influence the emergence of new variants and the immune pressure stimulated at exposure is poorly understood. Our study addressed this knowledge gap by utilizing mice that are preimmune to influenza viruses and analyzing host responses as well as viral mutations associated with changes in antigenicity. Importantly, we found previous vaccination induced immune responses with moderate adaptive immunity and strong antiviral immunity which was associated with increased mutations in the influenza virus. Interestingly, animals that were previously infected with a heterologous virus and also vaccinated had robust adaptive responses with little to no antiviral induction which was associated with no emergence of viral variants. These results are important for the design of next generation influenza vaccines.

microbiology↗

bioRxiv2021

Computational assessment of the spike protein antigenicity reveals diversity in B cell epitopes but stability in T cell epitopes across SARS-CoV-2 variants

Since its emergence into the human population at the end of 2019, SARS-CoV-2 has caused significant morbidity and mortality worldwide. Efforts to develop a protective vaccine against COVID-19 have yielded several vaccine platforms currently in distribution targeting the original SARS-CoV-2 spike protein sequence from the first cases of infection. In recent months, variants of SARS-CoV-2 have raised concerns that viral mutation may undermine vaccination efforts through viral escape of host immune memory acquired from infection or vaccination. We therefore used a computational approach to predict changes in spike protein antigenicity with respect to host B cell and CD8+ T cell immunity across six SARS-CoV-2 variants (D614G, B.1.1.7, B.1.351, P.1, B.1.429, and mink-related). Our epitope analysis using DiscoTope suggests possible changes in B cell epitopes in the S1 region of the spike protein across variants, in particular the B.1.1.7 and B.1.351 lineages, which may influence immunodominance. Additionally, we show that high-affinity MHC-I-binding peptides and glycosylation sites on the spike protein appear consistent between variants with the exception of an extra glycosylation site in the P.1 variant. Together, these analyses suggests T cell vaccine strategies have the most longevity before reformulation.

microbiology↗

bioRxiv2021

Male sex and age biases viral burden, viral shedding, and type 1 and 2 interferon responses during SARS-CoV-2 infection in ferrets

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) hospitalizations and deaths disportionally affect males and the elderly. Here we investigated the impact of male sex and age by infecting adult male, aged male, and adult female ferrets with SARS-CoV-2. Aged male ferrets had a decrease in temperature which was accompanied by prolonged viral replication with increased pathology in the upper respiratory tract after infection. Transcriptome analysis of the nasal turbinates and lungs indicated that female ferrets had significant increases in interferon response genes (OASL, MX1, ISG15, etc.) on day 2 post infection which was delayed in aged males. In addition, genes associated with taste and smell such as RTP1, CHGA, and CHGA1 at later time points were upregulated in males but not in females. These results provide insight into COVID-19 and suggests that older males may play a role in viral transmission due to decreased antiviral responses.

microbiology↗