Mertins, B. | bioRxiv Science

bioRxiv2024

Controlling reactogenicity while preserving immunogenicity from a self-amplifying RNA vaccine by modulating nucleocytoplasmic transport

Self-amplifying RNA (saRNA)-based vaccines have emerged as a potent and durable RNA vaccine platform. However, RNA vaccine platforms trigger undesirable side effects at protective doses, underscoring the need for improved tolerability. To address this, we leveraged the Cardiovirus leader protein, which is well-characterized to dampen host innate signaling by modulating nucleocytoplasmic transport (NCT). Co-administration of a leader-protein-encoding mRNA (which we have named "RNAx") delivered alongside vaccine cargo saRNA reduced interferon production while enhancing Influenza hemagglutinin (HA) expression in human primary cells and murine models. RNAx potently decreased serum biomarkers of reactogenicity after immunizations with an HA-expressing saRNA-LNP vaccine while maintaining the magnitude of the antibody and cellular response. RNAx also consistently enhanced binding antibody titers after a single injection and in some conditions enhanced binding antibody and neutralization titers post-boost. These findings support RNAx as a promising platform approach for improving tolerability of saRNA-LNP vaccines while preserving or enhancing immunogenicity.

immunology↗

bioRxiv2021

Interaction between BID and VDAC1 is required for mitochondrial demise and cell death in neurons

Mitochondrial damage is a key feature of regulated cell death in neurons. In particular, mitochondrial outer membrane permeabilization (MOMP) has been proposed as a starting point for mitochondrial demise upon cellular stress. Potential mechanisms for MOMP presented in the literature include membrane pore formation by Bcl2-family proteins such as BID and BAX, oligomerization of voltage-dependent anion channels (VDACs) and hetero-oligomer formation of these proteins. In our study, we demonstrate a direct interaction between the voltage-dependent anion channel VDAC1 and the pro-apoptotic protein BID in dying neurons both in vitro and in vivo. Binding of BID to VDAC1 affects anion conductance through VDAC1 and is associated with glutamate-induced cell death in cultured neurons and ischemic brain injury. In cultured neurons, reducing VDAC1 expression significantly attenuates BID-induced hallmarks of mitochondrial damage such as mitochondrial fission, declined mitochondrial respiration, increased ROS production, and mitochondrial membrane potential breakdown. Our data highlight a critical role for VDAC1 as a mitochondrial receptor for activated BID, thereby serving as a key decision point between life and death in neurons. One Sentence SummaryVDAC1 interacts with BID to mediate mitochondrial membrane permeabilization and neuronal cell death.

molecular biology↗