Cell cycle independent role of cyclin D3 in host restriction of influenza virus infection

Abstract

Edited by Charles E. SamuelTo identify new host factors that modulate the replication of influenza A virus, we performed a yeast two-hybrid screen using the cytoplasmic tail of matrix protein 2 from the highly pathogenic H5N1 strain. The screen revealed a high-score interaction with cyclin D3, a key regulator of cell cycle early G 1 phase. M2-cyclin D3 interaction was validated through GST pull-down and recapitulated in influenza A/WSN/33-infected cells. Knockdown of Ccnd3 by small interfering RNA significantly enhanced virus progeny titers in cell culture supernatants. Interestingly, the increase in virus production was due to cyclin D3 deficiency per se and not merely a consequence of cell cycle deregulation. A combined knockdown of Ccnd3 and Rb1, which rescued cell cycle progression into S phase, failed to normalize virus production. Infection by influenza A virus triggered redistribution of cyclin D3 from the nucleus to the cytoplasm, followed by its proteasomal degradation. When overexpressed in HEK 293T cells, cyclin D3 impaired binding of M2 with M1, which is essential for proper assembly of progeny virions, lending further support to its role as a putative restriction factor. Our study describes the identification and characterization of cyclin D3 as a novel interactor of influenza A virus M2 protein. We hypothesize that competitive inhibition of M1-M2 interaction by cyclin D3 impairs infectious virion formation and results in attenuated virus production. In addition, we provide mechanistic insights into the dynamic interplay of influenza virus with the host cell cycle machinery during infection.

Cyclin D3 restricts SARS‐CoV‐2 envelope incorporation into virions and interferes with viral spread

“…This effect is reminiscent of the role of cyclin D3 in influenza infection, where cyclin D3 depletion resulted in increased viral production. This study also showed that cyclin D3 binds M2 protein and interferes with the M1–M2 interaction leading to defective viral assembly (Fan et al , 2017).…”

“…Cyclin D3 has been previously implicated in the restriction of influenza A virus through impairment of virus assembly (Fan et al , 2017). Cyclin D3 has been shown to interact with IAV protein M2, an ion channel that promotes viral replication (Pinto & Lamb, 2006; Fan et al , 2017). Interestingly, SARS‐CoV‐2 envelope (E) protein has been suggested to be an ion channel (Singh Tomar & Arkin, 2020; Xia et al , 2021).…”

Identification of key candidate biomarkers for severe influenza infection by integrated bioinformatical analysis and initial clinical validation

“…It has been reported that ‘cell cycle’ plays a pivotal role in host‐virus interaction. Influenza viruses could escape the host restriction and facilitate their own replication through changing the cell cycle transition points 30‐32 . Therefore, these findings provide a possible clinically relevant to better understand the relationship between immune cell proliferation and viral load change.…”

Destabilization of the human RED–SMU1 splicing complex as a basis for host-directed antiinfluenza strategy

“…The dual function of RED-SMU1 raises the question whether our observed antiviral effect of compounds LSP461 and LSP61 could be related not only to inhibition of viral mRNA splicing (as indicated by a reduced NS2-to-NS1 mRNA ratio upon treatment) but also to cell cycle arrest. Although this possibility cannot be formally excluded, it seems unlikely, as IAV infection per se has been shown to induce G0/G1 cell cycle arrest through inhibition of the RhoA/pRb signaling pathway (47) and down-regulation of cyclin D3 levels (48) in cultured cells. Besides, the tissue naturally targeted by IAVs (i.e., the airway epithelium) is essentially quiescent in healthy hosts (49).…”