猫冠状 feline coronavirus - PubMed 文献(第 3 页)
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猫冠状 的 PubMed 搜索结果(第 3 页)
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B-cell activation in cats with feline infectious peritonitis (FIP) by FIP-virus-induced B-cell differentiation/survival factors. 猫传染性腹膜炎（FIP）猫中由FIP病毒诱导的B细胞分化/存活因子引起的B细胞活化
It has been suggested that antibody overproduction plays a role in the pathogenesis of feline infectious peritonitis (FIP). However, only a few studies on the B-cell activation mechanism after FIP virus (FIPV) infection have been reported. The present study shows that: (1) the ratio of peripheral blood sIg(+) CD21(-) B-cells was higher in cats with FIP than in SPF cats, (2) the albumin-to-globulin ratio has negative correlation with the ratio of peripheral blood sIg(+) CD21(-) B-cell, (3) cells strongly expressing mRNA of the plasma cell master gene, B-lymphocyte-induced maturation protein 1 (Blimp-1), were increased in peripheral blood in cats with FIP, (4) mRNA expression of B-cell differentiation/survival factors, IL-6, CD40 ligand, and B-cell-activating factor belonging to the tumor necrosis factor family (BAFF), was enhanced in macrophages in cats with FIP, and (5) mRNAs of these B-cell differentiation/survival factors were overexpressed in antibody-dependent enhancement (ADE)-induced macrophages. These data suggest that virus-infected macrophages overproduce B-cell differentiation/survival factors, and these factors act on B-cells and promote B-cell differentiation into plasma cells in FIPV-infected cats.
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Clathrin- and caveolae-independent entry of feline infectious peritonitis virus in monocytes depends on dynamin. 猫传染性腹膜炎病毒进入单核细胞不依赖网格蛋白和小窝，而依赖动力蛋白
Feline infectious peritonitis virus (FIPV), a coronavirus that causes a lethal chronic disease in cats, enters feline monocytes via endocytosis. In this study, the pathway of internalization is characterized by evaluating the effect of chemical inhibitors and/or expression of dominant-negative (DN) proteins on the percentage of internalized virions per cell and infection. Further, co-localization studies were performed to determine the involvement of certain cellular internalization proteins. FIPV is not internalized through a clathrin-mediated pathway, as chlorpromazine, amantadine and DN eps15 did not influence virus uptake and FIPV did not co-localize with clathrin. The caveolae-mediated pathway could be excluded based on the inability of genistein and DN caveolin-1 to inhibit virus uptake and lack of co-localization between FIPV and caveolin-1. Dynamin inhibitory peptide and DN dynamin effectively inhibited virus internalization. The inhibitor strongly reduced uptake to 20.3+/-1.1% of uptake in untreated cells. In the presence of DN dynamin, uptake was 58.7+/-3.9% relative to uptake in untransduced cells. Internalization of FIPV was slightly reduced to 85.0+/-1.4 and 87.4+/-6.1% of internalization in control cells by the sterol-binding drugs nystatin and methyl-beta-cyclodextrin, respectively. Rho GTPases were inhibited by Clostridium difficile toxin B, but no effect was observed. These results were confirmed with infection studies showing that infection was not influenced by chlorpromazine, amantadine and genistein, but was significantly reduced by dynamin inhibition and nystatin. In conclusion, these results indicate that FIPV enters monocytes through a clathrin- and caveolae-independent pathway that strongly depends on dynamin and is slightly sensitive to cholesterol depletion.
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Survey of feline leukemia virus and feline coronaviruses in captive neotropical wild felids from Southern Brazil. 巴西南部圈养新热带野生猫科动物中猫白血病病毒和猫冠状病毒的调查
A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refúgio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase-PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil.
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Seroprevalence of SARS-CoV-2 (COVID-19) exposure in pet cats and dogs in Minnesota, USA. 美国明尼苏达州宠物猫和狗中SARS-CoV-2（COVID-19）暴露的血清流行率
The COVID-19 pandemic caused by the coronavirus SARS-CoV-2 is continuing to spread globally. SARS-CoV-2 infections of feline and canine species have also been reported. However, it is not entirely clear to what extent natural SARS-CoV-2 infection of pet dogs and cats is in households. We have developed enzyme-linked immunosorbent assays (ELISAs) using recombinant SARS-CoV-2 nucleocapsid (N) protein and the receptor-binding-domain (RBD) of the spike protein, and the SARS-CoV-2 spike-pseudotyped vesicular stomatitis virus (VSV)-based neutralization assay to screen serum samples of 239 pet cats and 510 pet dogs in Minnesota in the early phase of the COVID-19 pandemic from mid-April to early June 2020 for evidence of SARS-CoV-2 exposures. A cutoff value was used to identify the seropositive samples in each experiment. The average seroprevalence of N- and RBD-specific antibodies in pet cats were 8% and 3%, respectively. Among nineteen (19) N-seropositive cat sera, fifteen (15) exhibited neutralizing activity and seven (7) were also RBD-seropositive. The N-based ELISA is also specific and does not cross react with antigens of common feline coronaviruses. In contrast, SARS-CoV-2 antibodies were detected at a very low percentage in pet dogs (~ 1%) and were limited to IgG antibodies against SARS-CoV-2 N protein with no neutralizing activities. Our results demonstrate that SARS-CoV-2 seropositive rates are higher in pet cats than in pet dogs in MN early in the pandemic and that SARS-CoV-2 N-specific IgG antibodies can detect SARS-CoV-2 infections in companion animals with higher levels of specificity and sensitivity than RBD-specific IgG antibodies in ELISA-based assays.
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A novel glycoprotein of feline infectious peritonitis coronavirus contains a KDEL-like endoplasmic reticulum retention signal. 猫传染性腹膜炎冠状病毒的一种新型糖蛋白含有KDEL样内质网滞留信号
A new protein of feline infectious peritonitis coronavirus (FIPV) was discovered in lysates of [35S]cysteine-labeled infected cells. Expression of open reading frame (ORF) 6b of FIPV in recombinant vaccinia virus-infected cells was used to identify it as the 6b protein. Further characterization revealed that it is a novel type of viral glycoprotein whose function is not clear. It is a soluble protein contained in microsomes; its slow export from the cell is caused by the presence of an endoplasmic reticulum (ER) retention signal at the C terminus. This amino acid sequence, KTEL, closely resembles the consensus KDEL signal of soluble resident ER proteins. A mutant 6b protein with the C-terminal sequence KTEV became resistant to digestion by endo-beta-N-acetylglucosaminidase H with a half-time that was reduced threefold. In contrast, a mutant with the sequence KDEL was completely retained in the ER. The FIPV 6b protein is the first example of a viral protein with a functional KDEL-like ER retention signal.
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Nucleotide sequence of the inter-structural gene region of feline infectious peritonitis virus. 猫传染性腹膜炎病毒结构间基因区的核苷酸序列
The sequence of the region located between the S and M glycoprotein genes of the 79-1146 strain of feline infectious peritonitis virus (FIPV) is presented. The inter-structural gene region encodes 3 open reading frames (ORFs), termed ORFs 3a, 3b and 4, with nucleotide sequences conforming to the minimum conserved transcription signal upstream of each. An additional ORF, 3x, partially overlaps the 3' end of ORF 3a. The FIPV interstructural gene region is identical in length when compared to the Insavc-1 strain of canine coronavirus (CCV) but differs from various strains of transmissible gastroenteritis virus (TGEV) by the presence of deletions and insertions. The sizes of ORF 3a and 4 are conserved in FIPV, TGEV and CCV. However, as with CCV, the FIPV ORF 3b is truncated in comparison with TGEV.
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Establishment and characterization of a cell line from a feline histiocytic sarcoma. 猫组织细胞肉瘤细胞系的建立和鉴定
Feline histiocytic sarcoma (HS) is an aggressive and uncommon tumor originating from dendritic cells/macrophages. Here, a feline HS cell line, FHS-1, was established from a case of feline HS and characterized. Immunohistochemically, FHS-1 cells were positive for vimentin and Iba-1, and negative for MHC class II and CD163. FHS-1 cells were positive for α-naphthyl butyrate esterase staining, which was clearly inhibited by sodium fluoride. FHS-1 cells had phagocytic and antigen uptake/processing activities. Moreover, FHS-1 cells were tested for susceptibility to feline infectious peritonitis virus (FIPV) strain 79-1146; however, this cell line was not susceptible to this viral strain. Although FHS-1 cells lost the expression of MHC class II and CD163, our findings indicate that FHS-1 is a feline HS cell line that retains functional properties of dendritic cells/macrophages in terms of phagocytic and antigen uptake/processing activities. While FHS-1 cells are not suitable for in vitro study of FIP using strain 79-1146, they may be applicable for studies aimed at developing new diagnostic and therapeutic strategies for feline HS.
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Circulation and Genetic Characterizations of Coronaviruses From Companion Animals in Chengdu, Southwest China: One-Year Postpandemic. 中国西南成都伴侣动物冠状病毒的流行和遗传特征：大流行后一年
Coronaviruses (CoVs) can cross species barriers and endanger public health. Despite reports on their circulation and evolution in companion animals during the pandemic, postpandemic surveillance remains crucial. Therefore, during the first postpandemic year, 309 samples from 263 companion animals (cats and dogs) in Chengdu, China, were detected for CoVs using a universal assay based on Rdrp genes combined with one-generation sequencing. Four kinds of CoVs, including feline CoV (FCoV), canine CoV (CCoV), CRCoV, and SARS-CoV-2 (the first reported case of SARS-CoV-2 in a dog in mainland China, confirmed by viral nucleic acid detection and analysis), were detected with an overall positive rate of 21.7% (57/263); FCoV-I and CCoV-IIa were the dominant genotypes, and of these 57 positive cases, 71.9% (41/57) were in pets ≤12 months old. In CCoV-positive dogs, 72.2% (13/18) were coinfected with other viruses (primarily canine parvovirus [CPV], 76.9%; 10/13), while 13.9% (5/36) codetection with feline parvovirus (FPV). A 21-nt deletion in two genes and a 145-nt deletion in one gene were identified, and recombination events at positions 919 and 1639 nt in two genes were noticed. Notably, the amino acid variations in and genes revealed distinct regional adaptations: FCoV strains showed unique substitutions (e.g., Ala/Ser129Leu) and a shift from RSRR to RARR furin cleavage motifs; CCoV strains in China exhibited significant differences from those in other countries. Phylogenetic analysis demonstrated that the genes of FCoV and CCoV were closely related to those of the prevalent strains in China, whereas the genes of CRCoV were closely related to that of human CoV (HCoV) OC43. These findings highlight the need for continued surveillance of CoV infection in companion animals (especially ≤12 months old) in the postpandemic era.
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Immunization of cats against feline infectious peritonitis with anti-idiotypic antibodies. 用抗独特型抗体免疫猫抵抗猫传染性腹膜炎
Anti-idiotypic antibodies (Ab2s) generated against neutralizing antibodies (Ab1s) specific for feline infectious peritonitis virus (FIPV) were shown to be specific for paratope-associated idiotopes of the Ab1s and not against isotypic determinants. In a study to determine the efficacy of an anti-idiotypic vaccine against feline infectious peritonitis (FIP), cats that were immunized with a pool of monoclonal Ab2s developed Ab3s that recognized the variable regions of the Ab2s as well as the natural antigen. In cats challenged with a lethal dose of virus the control group followed a predictable course of infection ultimately succumbing to FIP. Two immunized cats survived virus challenge and a third cat lived twice as long as the controls. The fourth immunized cat showed no evidence of protection. The ability to induce levels of protection against FIP lends support to the concept of using anti-idiotypic antibodies as a prophylactic vaccine.
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Reversal of the Progression of Fatal Coronavirus Infection in Cats by a Broad-Spectrum Coronavirus Protease Inhibitor. 广谱冠状病毒蛋白酶抑制剂逆转猫致死性冠状病毒感染的进展
Coronaviruses infect animals and humans causing a wide range of diseases. The diversity of coronaviruses in many mammalian species is contributed by relatively high mutation and recombination rates during replication. This dynamic nature of coronaviruses may facilitate cross-species transmission and shifts in tissue or cell tropism in a host, resulting in substantial change in virulence. Feline enteric coronavirus (FECV) causes inapparent or mild enteritis in cats, but a highly fatal disease, called feline infectious peritonitis (FIP), can arise through mutation of FECV to FIP virus (FIPV). The pathogenesis of FIP is intimately associated with immune responses and involves depletion of T cells, features shared by some other coronaviruses like Severe Acute Respiratory Syndrome Coronavirus. The increasing risks of highly virulent coronavirus infections in humans or animals call for effective antiviral drugs, but no such measures are yet available. Previously, we have reported the inhibitors that target 3C-like protease (3CLpro) with broad-spectrum activity against important human and animal coronaviruses. Here, we evaluated the therapeutic efficacy of our 3CLpro inhibitor in laboratory cats with FIP. Experimental FIP is 100% fatal once certain clinical and laboratory signs become apparent. We found that antiviral treatment led to full recovery of cats when treatment was started at a stage of disease that would be otherwise fatal if left untreated. Antiviral treatment was associated with a rapid improvement in fever, ascites, lymphopenia and gross signs of illness and cats returned to normal health within 20 days or less of treatment. Significant reduction in viral titers was also observed in cats. These results indicate that continuous virus replication is required for progression of immune-mediated inflammatory disease of FIP. These findings may provide important insights into devising therapeutic strategies and selection of antiviral compounds for further development for important coronaviruses in animals and humans.