title: Characterizing the thymic lesions in piglets infected with attenuated strains of highly pathogenic porcine reproductive and respiratory syndrome virus.
abstract: Piglets infected with the highly pathogenic PRRSV (HP-PRRSV) HuN4 strain develop severe thymus atrophy. However, the attenuated strain HuN4-F112 does not lead to lesions in organs. Here, we have characterized the thymic lesions in piglets infected with attenuated strains of HP-PRRSV HuN4 isolated at different passages in the attenuation process to produce HuN4-F112 from the parent HuN4 strain (HuN4-F5, HuN4-F15, HuN4-F23, HuN4-F30, and HuN4-F112). The thymic effects of infection were evaluated in terms of the thymus/body weight ratio, pathological changes, and thymocytes apoptosis. The ability of HP-PRRSV to induce thymus atrophy was reduced following attenuation after 23 passages; the HuN4-F23, but not HuN4-F30, caused thymus atrophy. The ability of the virus to induce thymocyte apoptosis decreased as it became attenuated. In addition, the viral load in the thymus was reduced as the virus was attenuated. The HuN4-F23 and HuN4-F30 strains might provide insight into the molecular mechanisms of HP-PRRSV pathogenesis. Taken together, our results indicate that the ability of HP-PRRSV to induce thymic atrophy is related to its pathogenicity.
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Yabin
authors.initials: Y
authors.lastname: Tu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Yuming
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Tong
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China; Jilin Agricultural University, Changchun 130118, PR China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Yonggang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Aidong
authors.initials: A
authors.lastname: Li
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Chenggang
authors.initials: C
authors.lastname: Jiang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Shujie
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tao
authors.affiliation: State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150001, PR China. Electronic address: cai139@hvri.ac.cn.
authors.forename: Xuehui
authors.initials: X
authors.lastname: Cai
mesh_terms: D000818:Animals; D019318:Porcine Reproductive and Respiratory Syndrome / Q000473:pathology* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000472:pathogenicity*; D013552:Swine; D013950:Thymus Gland / Q000473:pathology* / Q000821:virology; D019562:Viral Load; D014774:Virulence
keywords: HP-PRRSV; HP-PRRSV attenuated strains; Thymus atrophy