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.