Search

【Objective】Tembusu virus (TMUV) disease is an important infectious disease in waterfowl. In previous studies, we found that in the early stages of TMUV infection in ducks, the viral copy number of group 2 TMUV in organs such as the liver, kidney, and brain were significantly higher than those of group 3 TMUV. The study aimed to explore whether group 2 TMUV NS proteins had different effects on the innate immune response of ducks compared with group 3 TMUV.【Method】Taking the group 2 TMUV-JM strain and the group 3 TMUV-GX strain as research subjects, we constructed the eukaryotic expression plasmids of NS proteins of the two strains and compared the effects of the NS proteins on the RIG-Ⅰ-induced activity of the IFN-β (Type Ⅰ) promoter by a dual-Luciferase reporter system. With the eukaryotic expression plasmids of the constructed recombinant chimeric NS1 proteins, we investigated the interaction region between NS1 and the key molecules of RIG-Ⅰ signaling pathway by confocal laser scanning microscopy, co-IP and Western Blotting. By using the reverse genetic system, we constructed NS1 recombinant chimeric TMUV to clarify the inhibitory effect of NS1 on the IFN-β in DEF cells with TMUV infection.【Result】The study results showed that TMUV-JM NS1 could inhibit RIG-Ⅰ-induced activation of the IFN-β promoter, while TMUV-GX NS1 did not exhibit the inhibitory activity. Further studies revealed that the TMUV-JM NS1 inhibited the expression of type Ⅰ IFN via targeting TBK1, and the NS1 255-352 aa was the functional region of the inhibitory effect. It was found that TMUV-JM NS1 did not interact with TBK1 directly, but reduced the phosphorylation level of TBK1 indirectly, thereby suppressed the expression of type Ⅰ IFN.【Conclusion】Based on the study results, we found that the group 2 TMUV NS1 has activity in inhibiting the RIG-Ⅰ signaling pathway, identified the key activity region and targeted molecule of its inhibitory pathway, and clarified that group 2 TMUV NS1 affected duck type Ⅰ IFN production by indirectly inhibiting the phosphorylation of TBK1.

Goose astrovirus (GAstV) is a small, non-encapsulated virus, whose genome consists of a single-stranded, positive-stranded RNA molecule with a genome length of 7.1-7.3 kb. GAstV is a new member of the genus avian astrovirus in the family Astroviridae, which can be classified into two genetic subgroups (GAstV-1, GAstV-2) based on genetic homology and genetic distance, which are not yet involved in official classification. GAstV infection can lead to diarrhea, growth inhibition, and clinical signs dominated by joint urate deposition and visceral urate deposition in geese, and it is considered to be the main etiological agent causing gout in geese. There is a lack of commercialized vaccines or therapeutic drugs against GAstV, relying mainly on biosecurity measures for prevention and control. China's researchers first detected and isolated the GAstV strain in gouty geese flocks in Shandong Province in 2017. GAstV spreads quickly and radiates widely, with related cases reported in Guangdong, Fujian, and Anhui in the same year, resulting in up to 1.2 billion yuan to 1.5 billion yuan in economic losses. The incidence of GAstV can be up to 80%, and the mortality rate can be up to 50%. GAstV can lead to immunosuppression in geese, and they are susceptible to infection with other pathogens in the course of feeding, resulting in more severe clinical symptoms and increasing the difficulty of pathogen prevention and control. GAstV not only infects its natural host, geese, but also has the ability to cross the species barrier, causing diarrhea, growth inhibition, and triggering urate deposition in internal organs or joints in chickens and ducks. This suggests that GAstV may have the potential for human-animal transmission, and subsequent studies should strengthen the epidemiological monitoring of GAstV and pay close attention to the changes in its transmission characteristics. At present, scholars have made certain research progress in the pathogen detection of GAstV, and have established various technical methods that can efficiently and accurately detect GAstV. However, the research on the pathogenic mechanism of GAstV has not yet been in-depth, the research on vaccine preparation is relatively weak, and there is no uniform and effective in vitro culture method for GAstV, which has seriously hindered the pace of basic research on the pathogen. In order to better understand the impact of GAstV on goose farming industry in China, this paper reviews four aspects of GAstV, namely, pathogenesis, epidemiology, host immune response, and the association between GAstV and gout, which will provide a reference for the follow-up research and scientific control of GAstV.

【Objective】A disease model of fowl adenovirus serotype 2 (FAdV-2) was established to provide a refference for evaluating the immunogenicity and vaccine effectiveness of FAdV-2.【Method】The samples suspected to be infected with avian adenovirus were isolated and identified. The genetic evolution of the Fiber and Hexon gene sequences of the isolates was analyzed. The nucleotide and amino acid sequences of the isolated strain and other FAdV representative strains were analyzed using DNAStar and MEGA7.0. After determining that the isolated virus was FAdV-2, the pathogenicity of the isolated strain was analyzed in 6-week-old SPF chickens under different infection routes and different infection doses in animal experiment. The best infection model and infection dose were selected to establish the FAdV-2 pathogenesis model.【Result】One FAdV-2 strain was successfully isolated from the infected chicken tissue samples, named KM strain. Genetic evolution analysis shows that KM strain and GX01 strain belong to the FAdV-2 of avian adenovirus species D of group Ⅰ. The homology analysis shows that the nucleotide similarity of Fiber gene and Hexon gene between KM strain and GX01 strain is 98.9% and 99.3%, and the amino acid similarity is 98.9% and 98.8%, respectively. The pathogenicity of intravenous injection was higher than that of intramuscular injection, and the chickens showed obvious hepatitis hydropericardium syndrome (HHS). The infection route of the KM strain model was intravenous injection, and the infection dose was 108.0TCID50. The chickens died after infection, with a mortality rate of 50%. Obvious pathological changes were found in the dead chickens at necropsy, and the chickens were positive for cloaca virus shedding at 1 d post infection. The established KM strain disease model provides a certain reference for vaccine development and vaccine evaluation, which will effectively prevent and reduce the transmission of FAdV-2.【Conclusion】It is verified that FAdV-2 can cause hepatitis hydropericardium syndrome, and a pathogenesis model of FAdV-2 infection in SPF chickens is established for the first time.

【Objection】This study aimed to monitor the genetic variation and molecular evolutionary trends of H9N2 avian influenza virus (AIV) in Guangdong, and provide reference data for the evolutionary analysis and prevention and control of H9N2 AIV in China.【Method】The HA and NA genes of three H9N2 AIV strains isolated from Guangdong in 2022 were amplified, cloned, and sequenced. The DNAStar and PhyloSuite software were used for sequence assembly and alignment. The MEGA, Megalign, NetNGlyc 1.0 Server, and other software were used for genetic evolution, percent identity, receptor binding, protein activity, drug resistance, and glycosylation site analysis of their nucleotide and amino acid sequences.【Result】The phylogenetic tree showed that the HA gene of the three isolates belonged to the clade h9.4.2.5 and the NA gene belonged to the clade 1. However, the nucleotide homology with the early strain was only 81.6%~91.7% and 88.2%~91.2%, formed new clade named clade h9.4.2.5c and clade 1.2, respectively. The nucleotide and amino acid sequence analysis revealed that the HA cleavage site was PSRSSR ↓ GLF. The receptor binding site underwent I155T, H183N, A190T/V, T212I, Q226L, and Q227M mutations. The glycosylation site underwent 218N non-glycosylation and acquired new glycosylation site at 313N. The NA stalk showed nine nucleotides deletion at positions 187-195 (ACAGAGATA), leading to the loss of three amino acids at positions 63-65 (TEI). The absorbtion site of NA on red blood cells showed K/E/S368N and D369N mutations. No related mutations to neuraminidase activity and drug resistance were found at the E119, D151, R152, R224, E276, R292, and R371.【Conclusion】The HA and NA genes of the three H9N2 AIV isolated from Guangdong in 2022 had evolved into a new subgroup. Some mutaitons suggest that prevalent H9N2 in Guangdong may enhanc adaptability of mammals and its antigenicity has changed. Moreover, it has not yet acquired resistance to durgs oseltamivir and zanamivir.

Background Community-based intervention is an important part of palliative care for advanced cancer patients. However, its role in the health management of advanced cancer patients remains to be supported by medical evidence. Objective To evaluate the efficacy of community-involved hospice care for patients with advanced cancer. Methods Wanfang Data Knowledge Service Platform, CNKI, VIP were searched by using Chinese keywords such as "community" "medical model" and "advanced cancer", Cochrane Library, PubMed and Web of Science were searched by using English keywords such as "Community-based" "Model of Palliative Care" "Advanced Cancer" "Quality of Life", to obtain randomized controlled trials (RCTs) related to the efficacy of community-involved hospice care from 2007-01-01 to 2022-05-10 by using Cochrane system evaluation method on 2022-05-22. The quality of RCTs meeting the inclusion criteria was evaluated, and the valid information was extracted for meta-analysis. Results A total of 11 RCTs in English and 9 RCTs in Chinese were included in the study, involving 2 356 and 1 238 patients, respectively. Meta-analysis showed that compared with routine cancer care, community-involved hospice care could improve quality of life and symptom severity in patients with advanced cancer, demonstrated by increasing Functional Assessment of Chronic Illness Therapy-Palliative Care scale socre〔MD (95%CI) =3.77 (0.83, 6.71) , P=0.01〕and Quality of Life Instruments for Cancer Patients scale total score〔MD (95%CI) =12.53 (2.36, 22.69) , P=0.02〕, reducing Functional Assessment of Cancer Therapy scale total score〔MD (95%CI) =-2.61 (-3.53, -1.70) , P