Genome-scale CRISPR screen identifies TRIM2 and SLC35A1 associated with porcine epidemic diarrhoea virus infection.

Porcine epidemic diarrhoea (PED) caused by the porcine epidemic diarrhoea virus (PEDV) is the most devastating disease in the global pig industry due to its high mortality rate in piglets. The host factors critical for PEDV replication are poorly understood. Here, we designed a pooled African green monkey genome-scale CRISPR/Cas9 knockout (VeroCKO) library containing 75,608 single guide RNAs targeting 18,993 protein-coding genes. Subsequently, we use the VeroCKO library to identify key host factors facilitating PEDV infection in Vero E6 cells. Several previously unreported genes associated with PEDV infection are highly enriched post-PEDV selection. We discovered that knocking out the tripartite motif 2 (TRIM2) and the solute carrier family 35 member A1 (SLC35A1) inhibited PEDV replication. Virtual screening and molecular docking approaches showed that chem-80,048,685 (M2) s ignificantly inhibited PEDV attachment and late replication by impeding SLC35A1. Furthermore, we found that knocking out SLC35A1 in Vero E6 cells upregulated a disintegrin and metalloprotease protein-17 (ADAM17) by splicing porcine aminopeptidase N (pAPN) and angiotensin-converting enzyme 2 (ACE2) ectodomains to reduce PEDV-infection in a CMP-Sialic Acid (CMP-SA) cell entry-independent manner. These findings provide a new perspective for a better understanding of host-pathogen interactions and new therapeutic targets for PEDV infection.

Rapid and Easy-Read Porcine Circovirus Type 4 Detection with CRISPR-Cas13a-Based Lateral Flow Strip.

First identified as a new circovirus in Hunan Province in China in 2019, porcine circovirus (PCV4) is now widely detected in other Chinese provinces and South Korea. In recent years, the virus has threatened pig health and operations in the pig industry. Hence, early PCV4 detection and regular surveillance are required to control the spread of infection and prevent collateral damage to the industry. Due to PCV4 being difficult to isolate in vitro, molecular detection methods, such as conventional PCR and real-time PCR, and serological assays are currently the main methods used for the detection of PCV4 infection. However, they are time-consuming, labor-intensive, and complex and require professional personnel. To facilitate rapid pen-side PCV4 diagnoses, we used clustered regularly interspaced short palindromic repeats (CRISPR) and Cas13a technology to develop a quick testing kit. Five recombinase-aided amplification (RPA) primer sets were designed based on the conserved PCV4-Cap gene nucleotide region, which were used to determine several key lateral flow strip (LFD) characteristics (sensitivity, specificity, and accuracy). The results showed that the RPA-Cas13a-LFD reaction could detect PCV4 within 1.5 h in genomic DNA harboring a minimum of a single copy. Furthermore, the assay showed good specificity and absence of cross-reactivity with PCV2, PCV3, or other porcine viruses. When we tested 15 clinical samples, a high accuracy was also recorded. Therefore, we successfully developed a detection assay that was simple, fast, accurate, and suitable for on-site PCV4 testing.

CCR4-NOT Complex 2-A Cofactor in Host Cell for Porcine Epidemic Diarrhea Virus Infection.

The porcine epidemic diarrhea virus (PEDV) has catastrophic impacts on the global pig industry. However, there is no consensus on the primary receptor associated with the PEDV invasion of host cells. An increasing number of studies have reported that PEDV invading host cells may require collaboration between multiple receptors and to better understand the virus-host interaction during PEDV entry, surface plasmon resonance (SPR) assays are performed to investigate relevant host factors interacting with PEDV spike-1 protein (S1) in Vero and IPEC-J2 cell membranes. Subsequently, the rabbit anti-PEDV S1 polyclonal antibody is used as bait to recognize the complexes of IPEC-J2 membrane proteins with or without PEDV infection, followed by detection using liquid chromatography with tandem mass spectrometry (LC-MS-MS). Our results show that 13 and 10 proteins interacting between the S1 protein and plasma membrane protein of Vero or IPEC-J2 can be identified. More specifically, a total of 11 differentially expressed interacting proteins were identified in IPEC-J2 membrane proteins after PEDV infection, compared to the uninfected group. Furthermore, we found that the differentially interacting protein CCR4-NOT complex 2 (CNOT2), identified in PEDV S1 with plasma membrane proteins of Vero cells, is involved in viral infection. The results show that the knockout of CNOT2 significantly inhibits PEDV replication in vitro. These data provide novel insights into the entry mechanism of PEDV.

A Genome-Wide SNP Linkage Analysis Suggests a Susceptibility Locus on 6p21 for Ankylosing Spondylitis and Inflammatory Back Pain Trait.

OBJECTIVES: To screen susceptibility loci for ankylosing spondylitis (AS) using an affected-only linkage analysis based on high-density single nucleotide polymorphisms (SNPs) in a genome-wide manner. PATIENTS AND METHODS: AS patients from ten families with Cantonese origin of China were enrolled in the study. Blood samples were genotyped using genomic DNA derived from peripheral blood leukocytes by Illumina HumanHap 610-Quad SNP Chip. Genotype data were generated using the Illumina BeadStudio 3.2 software. PLINK package was used to remove non-autosomal SNPs and to further eliminate markers of typing errors. An affected-only linkage analysis was carried out using both non-parametric and parametric linkage analyses, as implemented in MERLIN. RESULT: Seventy-eight AS patients (48 males and 30 females, mean age: 39±16 years) were enrolled in the study. The mean age of onset was 23±10 years and mean duration of disease was 16.7±12.2 years. Iritis (2/76, 2.86%), dactylitis (5/78, 6.41%), hip joint involvement (9/78, 11.54%), peripheral arthritis (22/78, 28.21%), inflammatory back pain (IBP) (69/78, 88.46%) and HLA-B27 positivity (70/78, 89.74%) were observed in these patients. Using non-parameter linkage analysis, we found one susceptibility locus for AS, IBP and HLA-B27 in 6p21 respectively, spanning about 13.5Mb, 20.9Mb and 21.2Mb, respectively No significant results were found in the other clinical trait groups including dactylitis, hip involved and arthritis. The identical susceptibility locus region spanning above 9.44Mb was detected in AS IBP and HLA-B27 by the parametric linkage analysis. CONCLUSION: Our genome-wide SNP linkage analysis in ten families with ankylosing spondylitis suggests a susceptibility locus on 6p21 in AS, which is a risk locus for IBP in AS patients.

A genome-wide association study in Han Chinese identifies new susceptibility loci for ankylosing spondylitis.

To identify susceptibility loci for ankylosing spondylitis, we performed a two-stage genome-wide association study in Han Chinese. In the discovery stage, we analyzed 1,356,350 autosomal SNPs in 1,837 individuals with ankylosing spondylitis and 4,231 controls; in the validation stage, we analyzed 30 suggestive SNPs in an additional 2,100 affected individuals and 3,496 controls. We identified two new susceptibility loci between EDIL3 and HAPLN1 at 5q14.3 (rs4552569; P = 8.77 × 10(-10)) and within ANO6 at 12q12 (rs17095830; P = 1.63 × 10(-8)). We also confirmed previously reported associations in Europeans within the major histocompatibility complex (MHC) region (top SNP, rs13202464; P < 5 × 10(-324)) and at 2p15 (rs10865331; P = 1.98 × 10(-8)). We show that rs13202464 within the MHC region mainly represents the risk effect of HLA-B*27 variants (including HLA-B*2704, HLA-B*2705 and HLA-B*2715) in Chinese. The two newly discovered loci implicate genes related to bone formation and cartilage development, suggesting their potential involvement in the etiology of ankylosing spondylitis.

ERAP1 is associated with ankylosing spondylitis in Han Chinese.

OBJECTIVE: Genetic components play important roles in the incidence and development of ankylosing spondylitis (AS). Aminopeptidase regulator of tumor necrosis factor receptor shedding 1 (ERAP1) was recently found to be associated with AS in North American and British cohorts. We evaluated whether ERAP1 is associated with AS in a Chinese Han population. METHODS: A sample of 50 patients and 50 healthy controls was recruited for preliminary screening for informative single-nucleotide polymorphisms (SNP). Then 6 SNP of suggestive significance in the initial screening were followed up in a large sample of 471 patients with AS and 456 ethnically matched controls. Diagnosis of AS followed the 1984 modified New York criteria. Linkage disequilibrium coefficient (D' and r(2)) and haplotypes were estimated by Haploview. Result. Two SNP (rs27434, p = 0.00039, and rs27529, p = 0.0083) in ERAP1 other than that reported previously were found to be significantly associated with AS. Haplotype analysis using 5 SNP within 1 linkage disequilibrium block identified 2 risk haplotypes (GATGT and GACGT) and 1 protective haplotype (GGTGT) for AS. CONCLUSION: Our study demonstrated that 2 novel SNP in ERAP1 were associated with AS in the Han Chinese population, suggesting that ERAP1 might confer genetic risk for AS in Han Chinese through the common mechanism shared by different populations, although the AS-associated SNP in ERAP1 might be population-specific.