Heterogeneous pathological outcomes after experimental pH1N1 influenza infection in ferrets correlate with viral replication and host immune responses in the lung

Vidaña, Beatriz; Martínez, Jorge; Martínez-Orellana, Pamela; García Migura, Lourdes; Montoya, María; Martorell, Jaime; Majó, Natàlia

To determine the relationships between the observed immunophenotypes, the different pathological outcomes and the cytokine, chemokine and TLR gene expressions, RT-qPCR was performed. Both infected groups exhibited elevated gene expression of pro-inflammatory markers and TLR3 compared to the control group at both 4 and 7 dpi (data not shown). The gene expression profiles of the lungs of the animals that presented with severe lung lesions exhibited increased expressions of CXCL8, CCL3, IFNγ, CXCL10, IL-1α, CCL5, IL-6 and TLR3 compared to those of the animals that presented with mild lung lesions at both 4 dpi ( Figure 5 ) and 7 dpi (data not shown). Interestingly, at 4 dpi, a statistically significant elevation in the induction of IFNα was observed in the lungs of the animals that presented with mild lung lesions ( Figure 5B ). No differences in CCL2 expression were observed between the pathological groups ( Figure 5C ). The expressions of all cytokines decreased in both pathological groups at 7 dpi with the exceptions of CCL2 and TLR3 in the animals with severe lung lesions (data not shown).