Cellular CARD11 Inhibits the Fusogenic Activity of Newcastle Disease Virus via CBM Signalosome-Mediated Furin Reduction in Chicken Fibroblasts.

Wenbin Wang,Sa Xiao,Youkun Bi,Zhongyuan Jin,Yongshan Li,Qiaolin Wei,Qiqi Hao,Haijin Liu,Zengqi Yang,Xuelan Liu,Yajie Zhang

doi:10.3389/fmicb.2021.607451

Abstract

Newcastle disease virus (NDV) causes an infectious disease that poses a major threat to poultry health. Our previous study identified a chicken brain-specific caspase recruitment domain-containing protein 11 (CARD11) that was upregulated in chicken neurons and inhibited NDV replication. This raises the question of whether CARD11 plays a role in inhibiting viruses in non-neural cells. Here, chicken fibroblasts were used as a non-neural cell model to investigate the role. CARD11 expression was not significantly upregulated by either velogenic or lentogenic NDV infection in chicken fibroblasts. Viral replication was decreased in DF-1 cells stably overexpressing CARD11, while viral growth was significantly increased in the CARD11-knockdown DF-1 cell line. Moreover, CARD11 colocalized with the viral P protein and aggregated around the fibroblast nucleus, suggesting that an interaction existed between CARD11 and the viral P protein; this interaction was further examined by suppressing viral RNA polymerase activity by using a minigenome assay. Viral replication was inhibited by CARD11 in fibroblasts, and this result was consistent with our previous report in chicken neurons. Importantly, CARD11 was observed to reduce the syncytia induced by either velogenic virus infection or viral haemagglutinin-neuraminidase (HN) and F cotransfection in fibroblasts. We found that CARD11 inhibited the expression of the host protease furin, which is essential for cleavage of the viral F protein to trigger fusogenic activity. Furthermore, the CARD11-Bcl10-MALT1 (CBM) signalosome was found to suppress furin expression, which resulted in a reduction in the cleavage efficiency of the viral F protein to further inhibit viral syncytia. Taken together, our findings mainly demonstrated a novel CARD11 inhibitory mechanism for viral fusogenic activity in chicken fibroblasts, and this mechanism explains the antiviral roles of this molecule in NDV pathogenesis.

Highlights

Newcastle disease is caused by Newcastle disease virus (NDV) and is one of the most fatal diseases in poultry worldwide
CARD11 is brain- upregulated by NDV infection in chickens, which reduces viral replication and the cytopathic effects (CPEs) in infected chicken neuronal cells as previously described (Wang et al, 2019)
To determine the roles of CARD11 in chicken non-neural cells, we used chicken chicken primary embryo fibroblasts (CEFs) and DF-1 fibroblasts as cell models

Summary

Introduction

Newcastle disease is caused by Newcastle disease virus (NDV) and is one of the most fatal diseases in poultry worldwide. CARD11, called CARMA1, is a multidomain scaffold protein that controls antigen-induced lymphocyte activation during the immune response (Bertin et al, 2001; Ramadas et al, 2011; Steinhardt et al, 2014). It interacts directly with B-cell lymphoma/leukemia 10 (Bcl10), and mucosaassociated lymphoid tissue lymphoma translocation protein 1 (MALT1) interacts with CARD11 only indirectly through Bcl to form the CARD11-Bcl10-MALT1 (CBM) complex (Wegener et al, 2006; Wegener and Krappmann, 2007; Roche et al, 2013; Juilland and Thome, 2016; Lork et al, 2019). The mutation and dysregulation of CARD11 in lymphocytes causes diseases, such as various lymphomas and primary immunodeficiency (MorenoGarcia et al, 2010; Scudiero et al, 2014; Turvey et al, 2014; Brohl et al, 2015)

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