Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression
Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and a variety of non-neoplastic syndromes in chickens. Furthermore, very virulent plus (vv+) MDVs induce a form of immunosuppression (late-MDV-IS) that might involve both neoplastic and non-neoplastic mechanisms. The objective o...
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| Format: | Article |
| Language: | English |
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Microbiology Society
2018
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| Online Access: | http://psasir.upm.edu.my/id/eprint/72299/ http://psasir.upm.edu.my/id/eprint/72299/1/Differential%20attenuation%20of%20Marek%E2%80%99s%20disease%20virus-induced%20tumours.pdf |
| _version_ | 1848857085209477120 |
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| author | Nik Mohd Azmi, Nik Mohd Faiz Cortes, Aneg L. Guy, James S. Reddy, Sanjay M. Gimeno, Isabel M. |
| author_facet | Nik Mohd Azmi, Nik Mohd Faiz Cortes, Aneg L. Guy, James S. Reddy, Sanjay M. Gimeno, Isabel M. |
| author_sort | Nik Mohd Azmi, Nik Mohd Faiz |
| building | UPM Institutional Repository |
| collection | Online Access |
| description | Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and a variety of non-neoplastic syndromes in chickens. Furthermore, very virulent plus (vv+) MDVs induce a form of immunosuppression (late-MDV-IS) that might involve both neoplastic and non-neoplastic mechanisms. The objective of this study was to evaluate whether the attenuation of MDV-induced tumours and late-MDV-IS occurs simultaneously or can be dissociated. The immunosuppressive ability of three viruses derived from vv+ MDV strain 686 (wild-type 686, the somewhat attenuated molecular clone 686-BAC, and the nononcogenic molecular clone lacking the two copies of the oncogene meq 686-BACΔMEQ) was evaluated. Late-MDV-IS was evaluated indirectly by assessing the negative effect of MDV strains on the protection conferred by infectious laryngotracheitis (ILT) vaccines. Our results showed that the ability to induce late-MDV-IS was attenuated before the ability to induce tumours. Strain 686 induced both tumours and late-MDV-IS, 686-BAC induced tumours but did not induce late-MDV-IS and 686-BACΔMEQ did not induce either tumours or late-MDV-IS. Further comparison of strains 686 and 686-BAC revealed that strain 686 reduced the humoral immune responses to ILTV (1132 vs 2167) more severely, showed higher levels of meq transcripts (2.1E+09 vs 4.98E+8) and higher expression of MDV microRNAs (mdv1-miR-M4-5p and mdv1-miR-M2-3p) in the spleen, and further reduced the percentage of CD45+-MHC-I+splenocytes (13 vs32 %) compared to molecular clone 686-BAC. This study suggests that the immunosuppressive ability of MDV might follow a continuous spectrum and only the most virulent MDVs can overcome a certain threshold level and induce clinical MDV-IS in the ILT model. |
| first_indexed | 2025-11-15T11:51:56Z |
| format | Article |
| id | upm-72299 |
| institution | Universiti Putra Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-15T11:51:56Z |
| publishDate | 2018 |
| publisher | Microbiology Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | upm-722992020-05-03T03:58:31Z http://psasir.upm.edu.my/id/eprint/72299/ Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression Nik Mohd Azmi, Nik Mohd Faiz Cortes, Aneg L. Guy, James S. Reddy, Sanjay M. Gimeno, Isabel M. Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and a variety of non-neoplastic syndromes in chickens. Furthermore, very virulent plus (vv+) MDVs induce a form of immunosuppression (late-MDV-IS) that might involve both neoplastic and non-neoplastic mechanisms. The objective of this study was to evaluate whether the attenuation of MDV-induced tumours and late-MDV-IS occurs simultaneously or can be dissociated. The immunosuppressive ability of three viruses derived from vv+ MDV strain 686 (wild-type 686, the somewhat attenuated molecular clone 686-BAC, and the nononcogenic molecular clone lacking the two copies of the oncogene meq 686-BACΔMEQ) was evaluated. Late-MDV-IS was evaluated indirectly by assessing the negative effect of MDV strains on the protection conferred by infectious laryngotracheitis (ILT) vaccines. Our results showed that the ability to induce late-MDV-IS was attenuated before the ability to induce tumours. Strain 686 induced both tumours and late-MDV-IS, 686-BAC induced tumours but did not induce late-MDV-IS and 686-BACΔMEQ did not induce either tumours or late-MDV-IS. Further comparison of strains 686 and 686-BAC revealed that strain 686 reduced the humoral immune responses to ILTV (1132 vs 2167) more severely, showed higher levels of meq transcripts (2.1E+09 vs 4.98E+8) and higher expression of MDV microRNAs (mdv1-miR-M4-5p and mdv1-miR-M2-3p) in the spleen, and further reduced the percentage of CD45+-MHC-I+splenocytes (13 vs32 %) compared to molecular clone 686-BAC. This study suggests that the immunosuppressive ability of MDV might follow a continuous spectrum and only the most virulent MDVs can overcome a certain threshold level and induce clinical MDV-IS in the ILT model. Microbiology Society 2018 Article PeerReviewed text en http://psasir.upm.edu.my/id/eprint/72299/1/Differential%20attenuation%20of%20Marek%E2%80%99s%20disease%20virus-induced%20tumours.pdf Nik Mohd Azmi, Nik Mohd Faiz and Cortes, Aneg L. and Guy, James S. and Reddy, Sanjay M. and Gimeno, Isabel M. (2018) Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression. Journal of General Virology, 99 (7). 927 - 936. ISSN 0022-1317; ESSN: 1465-2099 https://www.microbiologyresearch.org/content/journal/jgv/10.1099/jgv.0.001076 10.1099/jgv.0.001076 |
| spellingShingle | Nik Mohd Azmi, Nik Mohd Faiz Cortes, Aneg L. Guy, James S. Reddy, Sanjay M. Gimeno, Isabel M. Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression |
| title | Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression |
| title_full | Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression |
| title_fullStr | Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression |
| title_full_unstemmed | Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression |
| title_short | Differential attenuation of Marek's disease virus-induced tumours and late-Marek's disease virus-induced immunosuppression |
| title_sort | differential attenuation of marek's disease virus-induced tumours and late-marek's disease virus-induced immunosuppression |
| url | http://psasir.upm.edu.my/id/eprint/72299/ http://psasir.upm.edu.my/id/eprint/72299/ http://psasir.upm.edu.my/id/eprint/72299/ http://psasir.upm.edu.my/id/eprint/72299/1/Differential%20attenuation%20of%20Marek%E2%80%99s%20disease%20virus-induced%20tumours.pdf |