OVX836 Heptameric Nucleoprotein Vaccine Generates Lung Tissue-Resident Memory CD8+ T-Cells for Cross-Protection Against Influenza

International audience; Tissue-resident memory (TRM) CD8+ T-cells play a crucial role in the protection against influenza infection but remain difficult to elicit using recombinant protein vaccines.

OVX836 is a recombinant protein vaccine, obtained by the fusion of the DNA sequence of the influenza A nucleoprotein (NP) to the DNA sequence of the OVX313 heptamerization domain.

We previously demonstrated that OVX836 provides broad-spectrum protection against influenza viruses.

Here, we show that OVX836 intramuscular (IM) immunization induces higher numbers of NP-specific IFNg-producing CD8+ T-cells in the lung, compared to mutant NP (NPm) and wild-type NP (NPwt), which form monomeric and trimeric structures, respectively.

OVX836 induces cytotoxic CD8+ T-cells and high frequencies of lung TRM CD8+ T-cells, while inducing solid protection against lethal influenza virus challenges for at least 90 days.

Adoptive transfer experiments demonstrated that protection against diverse influenza subtypes is mediated by NPspecific CD8+ T-cells isolated from the lung and spleen following OVX836 vaccination.

OVX836 induces a high number of NP-specific lung CD8+ TRM-cells for long-term protection against influenza viruses.