Fibrinogen-like protein 2 fibroleukin expression and its correlation with disease progression in murine hepatitis virus type 3-induced fulminant hepatitis and in patients with severe viral hepatitis B

AIM： To evaluate the expression of fibrinogenlike protein 2 （fgl2） and its correlation with disease progression in both mice and patients with severe viral hepatitis. METHODS： Balb/cJ or A/J mice were infected intraperitoneally （ip） with 100 PFU of murine hepatitis virus type 3 （MHV-3）, liver and serum were harvested at 24, 48, and 72 h post infection for further use. Liver tissues were obtained from 23 patients with severe acute chronic （AOC） hepatitis B and 13 patients with mild chronic hepatitis B. Fourteen patients with mild chronic hepatitis B with cirrhosis and 4 liver donors served as normal controls. In addition, peripheral blood mononuciear cells （PBMC） were isolated from 30 patients （unpaired） with severe AOC hepatitis B and 10 healthy volunteers as controls. Procoagulant activity representing functional prothrombinase activity in PBMC and white blood cells was also assayed. A polyclonal antibody against fgl2 was used to detect the expression of both mouse and human fgl2 protein in liver samples as well as in PBMC by immunohistochemistry staining in a separate set of studies. Alanine aminotransferase （ALT） and total bilirubin （TBil） in serum were measured to assess the severity of liver injury.RESULTS： Histological changes were found in liver sections 12-24 h post MHV-3 infection in Balb/cJ mice. In association with changes in liver histology, marked elevations in serum ALT and TBil were observed. House fgl2 （mfgl2） protein was detected in the endothelium of intrahepatic veins and hepatic sinusoids within the liver 24 h after MHV-3 infection. Liver tissues from the patients with severe AOC hepatitis B had classical pathological features of acute necroinflammation. Human fgl2 （hfgl2） was detected in 21 of 23 patients （91.30%） with severe AOC hepatitis B, while only 1 of 13 patients （7.69%） with mild chronic hepatitis B and cirrhosis had hfgl2 mRNA or protein expression. Twenty-eight of thirty patients （93.33%） with severe AOC hepatitis B and 1 of 10 with mild chronic hepatitis B had detectable hfgl2 expression in PBMC. No hfgl2 expression was found either in the liver tissue or in the PBMC from normal donors. There was a positive correlation between hfgl2 expression and the severity of the liver disease as indicated by the levels of TBil. PCA significantly increased in PBMC in patients with severe AOC hepatitis B. CONCLUSION： The molecular and cellular results reported here in both mice and patients with severe viral hepatitis suggest that virus-induced hfgl2 prothrombinase/fibroleukin expression and the coagulation activity associated with the encoded fgl2 protein play a pivotal role in initiating severe hepatitis. The measurement of hfgl2/fibroleukin expression in PBMC may serve as a useful marker to monitor the severity of AOC hepatitis B and a target for therapeutic intervention.

Inactivated Sendai Virus Induces Apoptosis in Murine Melanoma Cells by IGF-1R Down-regulation

The mortality of cancer patients has considerably improved due to progress in surgery, chemotherapy and radiotherapy. However, some types of cancers, such as melanoma, remain refractory to conventional strategies. Although melanoma accounts for only 4% of all dermatological malignancies, it is responsible for 80% of mortalities from skin tumors[11. The reported survival rate of melanoma over 5 years is not yet encouraging due to its chemo-resistance and rapid metastasis. Therefore, it is necessary to develop new drugs with potent activity and weak side-effect against melanoma.

CD69+NK Cells Contribute to the Murine Hepatitis Virus Strain 3-Induced Murine Hepatitis

Summary： The role of hepatic CD69＋ natural killer （NK） cells in virus-induced severe liver injury and subsequent hepatic failure is not well defined. In this study, a mouse model of fulminant liver failure （FHF） induced by murine hepatitis virus strain 3 （MHV-3） was used to study the role of hepatic CD69＋NK cells in the development of FHF. The CD69 expression in NK cells in the liver, spleen, bone marrow and peripheral blood was detected by using flow cytometry. The correlation between the CD69 level in hepatic NK cells and liver injury was studied. The functional marker （CD107a）, and activating and inhibitory receptor （NKG2D and NKG2A） expressed on CD69＋NK cells and CD69-NK cells were detected by using flow cytometry. Pro-inflammatory cytokines （IL-9, IFN-y and TNF-a） were also examined by using intracellular staining. After MHV-3 infection, the number of CD69＋NK cells in the liver of BALB/cJ mice was increased markedly and peaked at 72 h post-infection. Similar changes were also observed in the spleen, bone marrow and peripheral blood. Meanwhile, the CD69 expression in hepatic NK cells was highly correlated with the serum level of ALT and AST. The expression of CD107a and NKG2D, as well as the production of TNF-a, IFN-7 and IL-9 in hepatic CD69＋NK cells was all significantly up-regulated during 48-72 h post-infection. In contrast, the NKG2A expression was increased in hepatic CD69-NK cells but not in CD69＋NK cells. These results suggested that hepatic CD69＋NK cells play a pivotal role in the pathogenesis of FHF by enhancing degranulation and cytotoxic ability of NK cells and increasing the production of pro-inflammatory cytokines.

Protective effects of pharmacological therapies in animal models of multiple sclerosis: a review of studies 2014–2019

Multiple sclerosis(MS)is an inflammatory demyelinating disease of the central nervous system.The disability caused by inflammatory demyelination clinically dominates the early stages of relapsing-remitting MS and is reversible.Once there is considerable loss of axons,MS patients enter a secondary progressive stage.Disease-modifying drugs currently in use for MS suppress the immune system and reduce relapse rates but are not effective in the progressive stage.Various animal models of MS(mostly mouse and rat)have been established and proved useful in studying the disease process and response to therapy.The experimental autoimmune encephalomyelitis animal studies reviewed here showed that a chronic progressive disease can be induced by immunization with appropriate amounts of myelin oligodendrocyte glycoprotein together with mycobacterium tuberculosis and pertussis toxin in Freund's adjuvant.The clinical manifestations of autoimmune encephalomyelitis disease were prevented or reduced by treatment with certain pharmacological agents given prior to,at,or after peak disease,and the agents had protective effects as shown by inhibiting demyelination and damage to neurons,axons and oligodendrocytes.In the cuprizone-induced toxicity animal studies,the pharmacological agents tested were able to promote remyelination and increase the number of oligodendrocytes when administered therapeutically or prophylactically.A monoclonal IgM antibody protected axons in the spinal cord and preserved motor function in animals inoculated with Theiler's murine encephalomyelitis virus.In all these studies the pharmacological agents were administered singly.A combination therapy may be more effective,especially using agents that target neuroinflammation and neurodegeneration,as they may exert synergistic actions.

Structures of the N- and C-terminal domains of MHV-A59 nucleocapsid protein corroborate a conserved RNA-protein binding mechanism in coronavirus

Coronaviruses are the causative agent of respiratory and enteric diseases in animals and humans.One example is SARS,which caused a worldwide health threat in 2003.In coronaviruses,the structural protein N(nucleocapsid protein)associates with the viral RNA to form the filamentous nucleocapsid and plays a crucial role in genome replication and transcription.The structure of Nterminal domain of MHV N protein also implicated its specific affinity with transcriptional regulatory sequence(TRS)RNA.Here we report the crystal structures of the two proteolytically resistant N-(NTD)and C-terminal(CTD)domains of the N protein from murine hepatitis virus(MHV).The structure of NTD in two different crystal forms was solved to 1.5Å.The higher resolution provides more detailed structural information than previous reports,showing that the NTD structure from MHV shares a similar overall and topology structure with that of SARS-CoV and IBV,but varies in its potential surface,which indicates a possible difference in RNA-binding module.The structure of CTD was solved to 2.0-Åresolution and revealed a tightly intertwined dimer.This is consistent with analytical ultracentrifugation experiments,suggesting a dimeric assembly of the N protein.The similarity between the structures of these two domains from SARS-CoV,IBV and MHV corroborates a conserved mechanism of nucleocapsid formation for coronaviruses.

The role of picornavirus infection in epileptogenesis

Picornaviridae are a family of small positive-strand RNA viruses,and transmitted via the respiratory or fecal-oral route.The neurotropic picornaviruses can induce acute or late recurrent seizures following central nervous system infection,by infecting the peripheral nerve,crossing the blood-brain barrier and migrating in the Trojan-horse method.Theiler’s murine encephalomyelitis virus(TMEV),as a member of Picornaviridae family,can cause encephalitis,leading to chronic spontaneous seizures.TMEV-infected C57BL/6 mice have been used as an animal model for exploring the mechanism of epileptogenesis and assessing new antiepileptic drugs.Astrogliosis,neuronal death and microglial recruitment have been detected in the hippocampus following the picornaviruse-induced encephalitis.The macrophages,monocytes,neutrophils,as well as IL-6 and TNF-αreleased by them,play an important role in the epileptogenesis.In this review,we summarize the clinical characteristics of picornavirus infection,and the immunopathology involved in the TMEV-induced epilepsy.