Molecular characterization of a novel mitochondrial NOD-like receptor X1 in chicken that negatively regulates IFN-β expression via STING

Genome-wide association study and transcriptomic analysis reveal the crucial role of sting1 in resistance to visceral white-nodules disease in Larimichthys polyactis

Introduction

Larimichthys polyactis is a promising marine fishery species, but visceral white-nodules disease (VWND) caused by Pseudomonas plecoglossicida causes significant losses. However, genetic resistance mechanisms to VWND remain elusive in this species.

Methods

This study combined genome-wide association study (GWAS) and transcriptome analysis to unravel resistance loci and transcriptional regulation in L. polyactis.

Results

As a result, GWAS on 946 infected fish genotyped by 100 K lipid chips identified 22 suggestive significantly associated single-nucleotide polymorphisms (SNPs), annotated 60 candidate genes, where DNA-sensing pathway were enriched. RNA-seq on liver tissues of resistant, sensitive, and control groups found immune-related pathways enriched in the comparisons of RL vs CL and RL vs SL, and autophagy-related pathways enriched in the comparisons of SL vs CL and RL vs SL. Then, the integration of GWAS and transcriptome analysis identified seven key genes associated with resistance to VWND. Among the genes, the expression levels of mRNA for genes related to the cyclic GMP-AMP synthase-stimulator of interferon genes (STING) signaling pathway, as well as the protein levels of STING1, were significantly upregulated in RL. Collectively, integrating KEGG pathway analysis, gene and protein expression analysis revealed that the importance of STING1 for VWND resistance.

Discussion

These findings deepen the available knowledge on molecular mechanisms of host genetic resistance to VWND and provide an important foundation for the selection and breeding of VWND-resistant L. polyactis.

The cGAS-STING pathway in HIV-1 and Mycobacterium tuberculosis coinfection

Mycobacterium tuberculosis (M. tuberculosis) infection is the most common opportunistic infection in human immunodeficiency virus-1 (HIV-1)-infected individuals, and the mutual reinforcement of these two pathogens may accelerate disease progression and lead to rapid mortality. Therefore, HIV-1/M. tuberculosis coinfection is one of the major global public health concerns. HIV-1 infection is the greatest risk factor for M. tuberculosis infection and increases the likelihood of endogenous relapse and exogenous reinfection with M. tuberculosis. Moreover, M. tuberculosis further increases HIV-1 replication and the occurrence of chronic immune activation, accelerating the progression of HIV-1 disease. Exploring the pathogenesis of HIV-1/M. tuberculosis coinfections is essential for the development of novel treatments to reduce the global burden of tuberculosis. Innate immunity, which is the first line of host immune defense, plays a critical role in resisting HIV-1 and M. tuberculosis infections. The role of the cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway, which is a major DNA-sensing innate immune signaling pathway, in HIV-1 infection and M. tuberculosis infection has been intensively studied. This paper reviews the role of the cGAS-STING signaling pathway in HIV-1 infection and M. tuberculosis infection and discusses the possible role of this pathway in HIV-1/M. tuberculosis coinfection to provide new insight into the pathogenesis of HIV-1/M. tuberculosis coinfection and the development of novel therapeutic strategies.

IFI16 plays a critical role in avian reovirus induced cellular immunosuppression and suppresses virus replication

Avian reovirus (ARV), which commonly induces viral arthritis or tenosynovitis and immunosuppression in chickens, is associated with the nonstructural protein p17 that plays a crucial role in viral replication and regulates cellular signaling pathways through its interaction with cellular proteins. In our previous study, we identified the host protein IFN-γ-inducible protein-16 (IFI16) as an interacting partner of ARV p17 through yeast two-hybrid screening. In the current study, we further confirmed the interaction between IFI16 and p17 protein using coimmunoprecipitation, glutathione S-transferase (GST)-pulldown assay, and laser confocal microscopy techniques. Additionally, we found that the amino acid of p1761-119 is responsible for mediating the interaction with the HINa and HINb domains of IFI16. Interestingly, we observed a significant increase in IFI16 expression upon ARV infection or p17 protein exposure. Moreover, the replication of ARV was found to be largely influenced by the quantity of IFI16 protein. Overexpression of IFI16 led to a significant decrease in ARV replication, while knockdown of the IFI16 expression led to the contrary result. Additionally, our findings demonstrate that IFI16 plays a crucial role in the induction of inflammatory cytokines IFN-β and IL-1β during ARV infection as confirmed by qRT-PCR and ELISA analyses. In conclusion, our study provides novel insights into the functional role of p17 protein and the pathogenic mechanism underlying ARV infection, particularly its association with inflammatory response. Furthermore, it offers new perspectives for identifying potential therapeutic targets against ARV infection.