4.2 - Protectins and viral infections
Although there is limited data available, the existing studies suggest a
promising role for protectins in viral infections. For instance, during
HSV-1 infection, treatment with protectin D1 (PD1) reduced inflammation
in stromal keratitis lesions by decreasing pro-inflammatory cytokine
levels and increasing IL-10 levels (Rajasagi et al, 2013). In murine
models, intranasal therapeutical administration of PD1 or protein
conjugates in tissue regeneration 1 (PCTR1), which is also derived from
docosahexaenoic acid (DHA), decreased viral load, tissue lesions, and
prevented the decrease of IFN-λ caused by RSV in the lungs. Moreover,
these lipids increased IFN-λ levels in human bronchial epithelial cells
infected with RSV (Walker et al, 2021). PD1 also demonstrated antiviral
effects against H1N1 and H5N1 in vitro in A549 cells and improved
survival in mice infected with the PR8 strain of H1N1 (Morita et al,
2013). Notably, the levels of PD1 were downregulated in the lungs of
mice infected with the pathogenic H5N1 strain of influenza (Morita et
al, 2013). These findings collectively indicate that PD1 may modulate a
common host antiviral pathway, making it an intriguing molecule for
further investigation in the context of viral infections.