Porcine parvovirus(PPV)is a causative agent of porcine parvovirus infection(PPI),which significantly impacts the pig industry due to its association with reproductive dysfunction.The condition is characterized by stillbirth,mummified fetuses,fetal weakness,and abortion in pregnant sows.The pathogenic mechanism remains incompletely understood,with no effective therapeutic drugs available currently.Despite extensive research on the host's response to PPV in-fection and identification of various signaling pathway transduction mechanisms,a comprehensive understanding is still lacking.This review aims to summarize the current knowledge regarding al-terations in related signaling pathways following PPV infection,provide novel insights into the pathogenesis of PPV and facilitate the drug development.

This study aims to investigate the effects of Japanese encephalitis virus(JEV)on TLRs signaling pathway and its regulation of the secretion of inflammatory factors during the infection of testicular interstitial cells,In this study,the mRNA levels of TLR3,TLR7,TLR8,TRIF and MyD88 genes were detected by qPCR after 1 MOI dose of JEV was inoculated into testicular stro-mal cells at different time periods.Western blot assay was used to detect the expression levels of TLR3,TLR7,TRIF and MyD88 protein at 6 h after JEV infection,and ELISA was used to detect the expression levels of IL-1β,IL-6 and TNF-α at different time periods(6,12 and 24 h).The re-sults showed as follows:After 6 h of JEV infection,the mRNA levels of TLR3,TLR7,TRIF and MyD88 genes were significantly up-regulated(P＜0.05),and the mRNA levels of TLR8 genes were down-regulated(P＜0.05).Western blot results showed that the protein expressions of TLR3,TLR7,TRIF and MyD88 were significantly up-regulated when JEV infected testicular stromal cells for 6 h(P＜0.05),which was consistent with the corresponding mRNA transcription levels.There was no significant change in TLR8 protein expression.ELISA results showed that 6 h after JEV infection of testicular stromal cells,IL-6 was significantly increased(P＜0.01),and the expressions of IL-1β and TNF-α were not changed.TLR3,TLR7,TLR8,TRIF and MyD88 were si-lenced by siRNA,and the silenced cells were inoculated with JEV for 6 h,and IL-6 expression lev-els were detected by ELISA.The results showed that silenced TLR3,TLR7,TLR8,TRIF and MyD88 could significantly reduce the increase of IL-6 secretion induced by JEV infection(P＜0.05).These results indicated that JEV could induce the expression of inflammatory factor IL-6 by activating TLR3,TLR7 and TLR8 signaling pathway after infection of testicular stromal cells.This study provides a reference for further elucidating the mechanism of reproductive disorders caused by JEV infection.

Porcine circovirus type 2(PCV2)is the main pathogen causing porcine circovirus related diseases.PCV2 infection in pigs may lead to porcine dermatitis and nephrotic syndrome(PDNS)and weaned piglets multiple system failure syndrome(PMWS),etc.At present,the pathogenic mechanism is not fully understood.PCV2 is a single strand of negative link DNA,which can cause immune suppression in the body and lead to increased secondary susceptibility,which has a syner-gistic effect with various pig diseases and brings major economic losses to the pig industry.Al-though there are commercial vaccines,the prevention of vaccines has certain limitations and there is no effective drug treatment so far,an outbreak will threaten people's life and health and public safety,resulting in significant economic losses.In order to understand the latest progress of PCV2 escape mechanism and prevention and control,this paper summarizes the inhibition of interferon production,regulation of apoptosis,regulation of autophagy,regulation of pyroptosis and inflam-matory response,evasion of adaptive immune response,and prevention and control of PCV2,in or-der to provide new theoretical ideas for the research and prevention and control of PCV2.