Fig. 4: Further emerging mammalian adaptations in the cattle H5N1 PB2 enhance its replication in human and bovine, but not avian culture systems. | Nature Communications

Fig. 4: Further emerging mammalian adaptations in the cattle H5N1 PB2 enhance its replication in human and bovine, but not avian culture systems.

From: Polymerase mutations underlie early adaptation of H5N1 influenza virus to dairy cattle and other mammals

Fig. 4: Further emerging mammalian adaptations in the cattle H5N1 PB2 enhance its replication in human and bovine, but not avian culture systems.The alternative text for this image may have been generated using AI.

Reverse-genetics derived viruses, containing the HA and NA genes of the attenuated laboratory strain A/Puerto Rico/8/34, and the remaining genes from Cattle Texas (2:6 viruses; panels, (A–E, J, K)) or reverse genetics derived full H5N1 viruses (whole virus, panels (F–I) were used to infect) A bovine ex vivo mammary explants, B bovine mammary cells (MAC-T), C bovine respiratory cells (BAT II) cells, D human lung cells (MRC5), E human lung adenocarcinoma cells (A549), F human lung cells (Calu-3), G–I primary differentiated human nasal epithelial cultures (hNECs) maintained at air liquid interface (hNECs), J chicken lung cells, or K duck fibroblasts (CCL-141). Cells were infected with an MOI of 0.01, and explants were infected with 5000 PFU/explant. Infectious virus titres were determined by plaque assay on MDCKs. A Data from bovine explants represents total N = 34 repeats from 3 donor cattle from 3 different independent experiments. Data from cell lines plotted as (B), 2 x N = 4, (C–E, J, F) 2 x N = 3 technical repeats, F N = 3 repeats, from a representative repeat of N = 3 independent repeats and G–I 3 independent donors with virus replication tested in triplicate. WT and minimal avian precursor data through the figure are the same shown through Fig. 2. Data throughout are plotted as mean ± SD. Statistics throughout performed by two-way ANOVA on log-transformed data with multiple comparisons against WT cattle/Texas. Significance shown by asterisks indicating: *, 0.05  ≥  P  >  0.01; **, 0.01  ≥  P  >  0.001; ***, 0.001  ≥  P  >  0.0001; ****, P  ≤  0.0001. (Where P ≥ 0.0001, exact P-values A: WT vs WT + PB2 D740N 24 h P = 0.0096. B: WT vs WT + PB2 D740N 16 h P = 0.0095, 24 h P = 0.0194; WT vs WT + PB2 E627K 24 h P = 0.0002. C: WT vs WT + PB2 D740N 24 h P = 0.0052, 48 h P = 0.0035. F: WT vs mAP 48 h P = 0.0029. G: WT vs mAP 72 h P = 0.0017. H: WT vs mAP 48 h P = 0.0040, 72 h P = 0.0017. I: WT vs mAP 72 h P = 0.0011).

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