RESUMEN
Seneca Valley virus (SVV), a member of the Picornaviridae family, may cause serious water blister diseases in pregnant sows and acute death in newborn piglets, which have resulted in economic losses in pig production. The 3C protease is a vital enzyme for SVV maturation and is capable of regulating protein cleavage and RNA replication of the virus. Additionally, this protease can impede the host's innate immune response by targeting the interferon pathway's principal factor and enhance virus replication by modulating the host's RNA metabolism while simultaneously triggering programmed cell death. This article reviews recent studies on SVV 3C functions, which include viral replication promotion, cell apoptosis modulation and host immune response evasion, and provides a theoretical basis for research on preventing and controlling SVV infection.
RESUMEN
Swine acute diarrhoea syndrome coronavirus (SADS-CoV), which is a recently discovered enteric coronavirus, is the major aetiological agent that causes severe clinical diarrhoea and intestinal pathological damage in pigs, and it has caused significant economic losses to the swine industry. Nonstructural protein 5, also called 3C-like protease, cleaves viral polypeptides and host immune-related molecules to facilitate viral replication and immune evasion. Here, we demonstrated that SADS-CoV nsp5 significantly inhibits the Sendai virus (SEV)-induced production of IFN-ß and inflammatory cytokines. SADS-CoV nsp5 targets and cleaves mRNA-decapping enzyme 1a (DCP1A) via its protease activity to inhibit the IRF3 and NF-κB signaling pathways in order to decrease IFN-ß and inflammatory cytokine production. We found that the histidine 41 and cystine 144 residues of SADS-CoV nsp5 are critical for its cleavage activity. Additionally, a form of DCP1A with a mutation in the glutamine 343 residue is resistant to nsp5-mediated cleavage and has a stronger ability to inhibit SADS-CoV infection than wild-type DCP1A. In conclusion, our findings reveal that SADS-CoV nsp5 is an important interferon antagonist and enhance the understanding of immune evasion by alpha coronaviruses.
Asunto(s)
Alphacoronavirus , Coronavirus , Interferón Tipo I , Animales , Porcinos , Alphacoronavirus/genética , Alphacoronavirus/metabolismo , Coronavirus/metabolismo , Endopeptidasas , Interferón Tipo I/metabolismoRESUMEN
OBJECTIVES: The aim of this study was to evaluate the clinical outcomes of diode laser as an adjunct to nonsurgical periodontal therapy (NSPT) for residual periodontal pockets in mandibular second molars. MATERIALS AND METHODS: Sixty-seven mandibular second molars (154 residual periodontal pockets) were recruited into the study and randomly assigned to the Laser + NSPT group and the NSPT group. The Laser + NSPT group underwent NSPT adjunct with diode laser radiation (wavelength: 810 nm, power: 1.5 W, 40 s maximum), while the NSPT group underwent nonsurgical periodontal therapy alone. Clinical parameters were measured at baseline (T0) and 4(T1), 12(T2), and 24(T3), weeks after treatment. RESULTS: Periodontal pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP) in both groups showed significant improvements at the end of study compared to baseline. The reductions of PPD, CAL, and BOP in the Laser + NSPT group were significantly greater than NSPT group. At T3, the Laser + NSPT group had a mean PPD of 3.06 ± 0.86 mm, CAL of 2.58 ± 0.94 mm and BOP of 15.49%, while the NSPT group had a mean PPD of 4.46 ± 1.57 mm, CAL of 3.03 ± 1.25 mm and BOP of 64.29%. CONCLUSIONS: The diode laser as an adjunct to nonsurgical periodontal therapy may contribute to clinical outcomes for residual periodontal pockets. However, the approach may cause reduction of keratinized tissue width. TRIAL REGISTRATION NUMBER: This study was registered in the Chinese Clinical Trial Registry ChiCTR2200061194. CLINICAL RELEVANCE: Diode laser as an adjunct to nonsurgical periodontal therapy may contribute to the clinical outcomes for residual periodontal pockets in mandibular second molars.