Endogenous Retrovirus ev21 Dose Not Recombine with ALV-J and Induces the Expression of ISGs in the Host.
Avian leukosis virus subgroup J (ALV-J) infection can cause tumors and immunosuppression. Endogenous viruses integrate into host genomes and can recombine with exogenous avian leukosis virus (ALV). In this study, we analyzed the interaction of endogenous retrovirus 21 (ev21) with the ALV-J in late-feathering Chinese yellow chicken. Two ALV-J strains M180 and K243 were isolated from late-feathering and fast-feathering Chinese yellow chicken flocks, respectively. Theenvgene of the two strains showed 94.2-94.8% nucleotide identity with reference ALV-J strains. Compared with theenvgene and the LTR ofev21and M180, the nucleotide identity of LTR was 69.7% andenvgene was 58.4%, respectively, especially the amino acid identity ofenvgene as low as 14.2%. Phylogenetic analysis of the nucleotide sequence of the env gene and the 3'LTR showed that M180 was closely related to ALV-J, and was located in a distinct group withev21in the phylogenetic tree. Using co-immunoprecipitation (co-IP), we next demonstrate that the envelope protein ofev21does not interact with the M180 envelope protein. We further show that the envelope protein ofev21cannot activate ALV-J LTR promoter activity using luciferase-reporter assays. qPCR and western blot analysis revealed that envelope protein of endogenousev21can facilitate the expression ofPKRat 6h post ALV-J infection (hpi) and facilitate the expression ofISG12andCH25Hat 24 hpi. However, the expression of theenvgene of M180 strain was not significantly at 6 and 24 hpi. We conclude that there is no evidence of recombination between endogenous retrovirus ev21 and ALV-J strain M180 in late-feathering Chinese yellow chicken, and envelope protein of ev21 can affect the expression of host ISGs, but appears not to influence the replication of ALV-J strain M180. This is the first report of interaction among the endogenous retrovirus ev21, ALV-J and the late-feathering chicken.
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural UniversityGuangzhou, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of AgricultureGuangzhou, China.
Min
M
Feng
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural UniversityGuangzhou, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of AgricultureGuangzhou, China.
Yan
Y
Tan
Department of Preventive Veterinary, College of Veterinary Medicine, South China Agricultural University Guangzhou, China.
Manman
M
Dai
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural UniversityGuangzhou, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of AgricultureGuangzhou, China.
Yuanfang
Y
Li
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural UniversityGuangzhou, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of AgricultureGuangzhou, China.
Tingting
T
Xie
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural UniversityGuangzhou, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of AgricultureGuangzhou, China.
Hongmei
H
Li
Division of Immunology, Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland College Park, MD, USA.
Meiqing
M
Shi
Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural UniversityGuangzhou, China; Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of AgricultureGuangzhou, China.
Xiquan
X
Zhang
D000818:Animals; D001353:Avian Leukosis / Q000821:virology*; D001354:Avian Leukosis Virus / Q000235:genetics* / Q000302:isolation & purification; D001483:Base Sequence; D002460:Cell Line; D002645:Chickens / Q000235:genetics / Q000821:virology; D004279:DNA, Viral; D020077:Endogenous Retroviruses / Q000235:genetics*; D005241:Feathers / Q000821:virology; D015967:Gene Expression Regulation, Viral; D015752:Genes, env; D047468:Immunoprecipitation; D010802:Phylogeny; D011201:Poultry Diseases / Q000235:genetics* / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D017421:Sequence Analysis; D014759:Viral Envelope Proteins / Q000235:genetics; D014777:Virus Diseases / Q000235:genetics* / Q000662:veterinary*
D004279:DNA, Viral; D012367:RNA, Viral; D014759:Viral Envelope Proteins
ALV-J; ISGs; envelope protein; ev21; late feathering chicken