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Background: Mammalian orthoreovirus type 3 (MRV3), which is responsible for gastroenteritis in many mammalian species including pigs, has been isolated from piglets with severe diarrhea. However, the use of pig-derived cells as an infection model for swineMRV3 has rarely been studied. Objectives: This study aims to establish porcine intestinal organoids (PIOs) and examine their susceptibility as an in vitro model for intestinal MRV3 infection. Methods: PIOs were isolated and established from the jejunum of a miniature pig. Established PIOs were characterized using polymerase chain reaction (PCR) and immunofluorescence assays (IFAs) to confirm the expression of small intestine-specific genes and proteins, such as Lgr5, LYZI, Mucin-2, ChgA, and Villin. The monolayered PIOs and threedimensional (3D) PIOs, obtained through their distribution to expose the apical surface, were infected with MRV3 for 2 h, washed with Dulbecco’s phosphate-buffered saline, and observed. Viral infection was confirmed using PCR and IFA. We performed quantitative realtime reverse transcription-PCR to assess changes in viral copy numbers and gene expressions linked to intestinal epithelial genes and antiviral activity. Results: The established PIOs have molecular characteristics of intestinal organoids. Infected PIOs showed delayed proliferation with disruption of structures. In addition, infection with MRV3 altered the gene expression linked to intestinal epithelial cells and antiviral activity, and these effects were observed in both 2D and 3D models. Furthermore, viral copy numbers in the supernatant of both models increased in a time-dependent manner. Conclusions: We suggest that PIOs can be an in vitro model to study the infection mechanism of MRV3 in detail, facilitating pharmaceutical development. [ABSTRACT FROM AUTHOR]

Background: Mammalian orthoreovirus type 3 (MRV3), which is responsible for gastroenteritis in many mammalian species including pigs, has been isolated from piglets with severe diarrhea. However, the use of pig-derived cells as an infection model for swine-MRV3 has rarely been studied., Objectives: This study aims to establish porcine intestinal organoids (PIOs) and examine their susceptibility as an in vitro model for intestinal MRV3 infection., Methods: PIOs were isolated and established from the jejunum of a miniature pig. Established PIOs were characterized using polymerase chain reaction (PCR) and immunofluorescence assays (IFAs) to confirm the expression of small intestine-specific genes and proteins, such as Lgr5 , LYZI , Mucin-2 , ChgA , and Villin . The monolayered PIOs and three-dimensional (3D) PIOs, obtained through their distribution to expose the apical surface, were infected with MRV3 for 2 h, washed with Dulbecco's phosphate-buffered saline, and observed. Viral infection was confirmed using PCR and IFA. We performed quantitative real-time reverse transcription-PCR to assess changes in viral copy numbers and gene expressions linked to intestinal epithelial genes and antiviral activity., Results: The established PIOs have molecular characteristics of intestinal organoids. Infected PIOs showed delayed proliferation with disruption of structures. In addition, infection with MRV3 altered the gene expression linked to intestinal epithelial cells and antiviral activity, and these effects were observed in both 2D and 3D models. Furthermore, viral copy numbers in the supernatant of both models increased in a time-dependent manner., Conclusions: We suggest that PIOs can be an in vitro model to study the infection mechanism of MRV3 in detail, facilitating pharmaceutical development., Competing Interests: The authors declare no conflicts of interest., (© 2023 The Korean Society of Veterinary Science.)

During a surveillance study to monitor porcine epidemic diarrohoea virus and transmissible gastroenteritis virus in India, a total of 1043 swine samples including faeces (n = 264) and clotted blood (n = 779) were collected and tested. Five samples (four faecal and one serum) showed cytopathic effects in Vero cells. Transmission electron microscopy of infectious cell supernatant revealed the presence of two types of virions. Next-generation sequencing (de novo) allowed the complete genome sequence of mammalian orthorubulavirus 5 (MRuV5; 15246 bp) and that of all 10 gene segments of mammalian orthoreovirus to be determined. Genetic analysis of MRuV5 revealed grouping of the Indian MRuV5 with isolates from various mammalian species in South Korea and China, sharing more than 99% nucleotide sequence identity. The deduced amino acid sequences of the HN, NP, and F genes of MRuV5 isolates showed three (92L, 111R, 447H), two (86S, 121S), and two (139T, 246T) amino acid substitutions, respectively, compared to previously reported virus strains. Phylogenic analysis based on S1 gene sequences showed the Indian MRV isolates to be clustered in lineage IV of MRV type 3, with the highest nucleotide sequence identity (97.73%) to MRV3 strain ZJ2013, isolated from pigs in China. The protein encoded by the MRV3 S1 gene was found to contain the amino acid residues 198-204NLAIRLP, 249I, 340D, and 419E, which are known to be involved in sialic acid binding and neurotropism. This is the first report of co-isolation and whole-genomic characterisation of MRuV5 and MRV3 in domestic pigs in India. The present study lays a foundation for further surveillance studies and continuous monitoring of the emergence and spread of evolving viruses that might have pathogenic potential in animal and human hosts., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Treatment of castration-resistant prostate cancer remains a challenging clinical problem. Despite the promising effects of immunotherapy in other solid cancers, prostate cancer has remained largely unresponsive. Oncolytic viruses represent a promising therapeutic avenue, as oncolytic virus treatment combines tumour cell lysis with activation of the immune system and mounting of effective anti-tumour responses. Mammalian Orthoreoviruses are non-pathogenic human viruses with a preference of lytic replication in human tumour cells. In this study, we evaluated the oncolytic efficacy of the bioselected oncolytic reovirus mutant jin-3 in multiple human prostate cancer models. The jin-3 reovirus displayed efficient infection, replication, and anti-cancer responses in 2D and 3D prostate cancer models, as well as in ex vivo cultured human tumour slices. In addition, the jin-3 reovirus markedly reduced the viability and growth of human cancer cell lines and patient-derived xenografts. The infection induced the expression of mediators of immunogenic cell death, interferon-stimulated genes, and inflammatory cytokines. Taken together, our data demonstrate that the reovirus mutant jin-3 displays tumour tropism, and induces potent oncolytic and immunomodulatory responses in human prostate cancer models. Therefore, jin-3 reovirus represents an attractive candidate for further development as oncolytic agent for treatment of patients with aggressive localised or advanced prostate cancer., (© 2021. The Author(s).)