Molecular Mechanism Of Apoptosis Induced By Feline Calicivirus 2280

Feline calicivirus(FCV)is one of the main pathogens causing upper respiratory diseases in feline animals.After infection,symptoms such as fever,conjunctivitis,rhinitis,oral ulcers,or chronic stomatitis can occur,and it can infect all feline animals,including lions,tigers,and cheetahs.FCV is often coinfected with Feline herpesvirus(FHV),Feline parvovirus(FPV),and other viruses,and has serious harmful effects.FCV is an RNA virus with high genetic variability that cannot be fully protected by vaccination.FCV 2280 is a classic and highly virulent strain that can cause pangenetic infection.Apoptosis is a way of programmed cell death that is closely related to the invasion of pathogens invasion of the body.During the process of pathogen infection of the host,apoptosis can have a direct or indirect effect on viral replication as well as the immune system of the body through the regulation of apoptosis.Apoptosis has important biological significance in maintaining the body’s homeostasis,and its molecular mechanisms are also relatively complex.Research has shown that the pathogenicity of FCV is closely related to apoptosis,which may affect the process of FCV release from cells.The study of cell apoptosis caused by FCV infection can lay the foundation for exploring its pathogenic mechanism and provide new ideas and directions for its prevention and control.Firstly,it wasdemonstrated by flow cytometry that FCV infection caused apoptosis in cells.The cytopathic lesions caused by FCV 2280 after the addition of apoptosis or scorch death inhibitors were detected by CCK-8 assay and PI staining assay,and the results showed that the main mode of cytopathic lesions caused by FCV 2280 was apoptosis.Subsequently,by measuring the viral growth curve of FCV 2280 after the addition of apoptosis inhibitor treatment,it was found that the replication ability of FCV weaker after the addition of apoptosis inhibitor treatment,which proved that the pathogenicity of FCV was correlated with apoptosis.By comparing the levels of apoptosis and the levels of activated apoptosis-related molecules between the virulent strain 2280 and the avirulent strain F9 of FCV through flow cytometry and Western Blot experiments,it was found that the virulent strain 2280 caused stronger cell apoptosis than the F9,and the levels of Caspase-3,Caspase--6,-Caspase-8,and Caspase-9 activated by FCV2280 were higher than those of the F9.By comparing the apoptotic levels and activation levels of apoptotic enzymes between the severely ill group virus and the parent virus,the recombinant virus that replaced the main virus albumin between the rescued FCV 2280 and the F9 was rescued.The results showed that there was a significant difference in the level of apoptosis caused by the recombinant virus that replaced P30 compared to the parent virus,indicating that the non structural protein P30 played an important role in FCV induced cell apoptosis.In order to further explore the mechanism of P30 effects on FCV 2280 induced apoptosis,proteomics sequencing and immuno coprecipitation experiments proved that 2280-P30 interacted with Caspase-10,the key enzyme of the external pathway of apoptosis,or the heterogeneous ribonucleoprotein K(hnRNPK)in the nucleus,an important regulatory protein of apoptosis,thus affecting the level of apoptosis induced by FCV 2280.This study demonstrates that infection with FCV 2280 can promote cell apoptosis,while cell apoptosis can promote its replication.Non structural protein P30 that affects cell apoptosis caused by FCV 2280 was screened,and apoptosis related host proteins Caspase-10 and hnRNPK that interact with P30 were identified,providing new ideas and directions for the prevention and control of FCV infection.