Although the expression of thousands of host long noncoding RNAs (lncRNAs) can be regulated by viral infection, the number of lncRNAs with experimentally verified function is limited. In this study, the expression of host lncRNA TSPOAP1-AS1 was significantly induced by influenza A virus (IAV) infection in a dose-and time-dependent manner. Polyinosine-polycytidylic acid (poly (I:C)), a synthetic analog of doublestranded RNA, also increased TSPOAP1-AS1 expression. RNA fractionation revealed that TSPOAP1-AS1 was a nucleocytoplasmic lncRNA, and an increased nuclear/ cytoplasmic ratio was detected after IAV infection. The nuclear factor-κB signaling acting as a critical factor in the transcription of TSPOAP1-AS1 was determined through the use of pharmacological and genetic approaches. Functionally, overexpression of TSPOAP1-AS1 resulted in a significant increase in IAV replication. In contrast, the abolition of TSPOAP1-AS1 by RNA interference restricted viral replication. Furthermore, we demonstrated that TSPOAP1-AS1 negatively modulated the IAV-induced Ifnb1 transcription, interferon-sensitive response element (ISRE) activation, and downstream interferon-stimulated genes expression. Collectively, our data provides evidence for the host lncRNA utilized by viruses to support its replication.

In August 2019, a suspected outbreak of canine distemper was observed in a masked palm civet farm that also received stray civets and rescued wild civets in Henan Province of China. A virulent canine distemper virus (CDV) strain, named HN19, from vaccinated masked palm civets was the etiologic agent identified in this outbreak using RT-PCR and sequencing of the complete genome. Serological analysis indicated a lower positive rate of CDV-neutralizing antibody in wild civets than in captive civets. Phylogenetic analysis of viral hemagglutinin (H) and the complete genome showed high identities with Rockborn-like strains at the nucleotide (98.7~99.72%) and the closest nucleotide similarity with a strain that killed lesser pandas in China in 1997, but low identities with America-1 strains (vaccine strains). Most importantly, one distinct amino acid exchange in the H protein at position 540 Asp → Gly (D540G), which confers CDV with an improved ability to adapt and utilize the human receptor, was observed in HN19. This study represents the first reported outbreak of a Rockborn-like CDV strain infection in masked palm civets in China. Based on this report, the existence of Rockborn-like strains in Chinese wild animals may not only cause immune failure in captive animals, but may also confer increased zoonotic potential.