title: Analyzing the H19- and T65-epitopes in 38 kd phosphorylated protein of Marek's disease viruses and comparing chicken immunological reactions to viruses point-mutated in the epitopes.
abstract: DNA sequencing analysis in 38 kd phosphorylated protein (pp38) ORF of Marek's disease viruses (MDV) indicated that all tested 10 virulent strains with different pathotypes had 'A' at base #320 and glutamine at aa#107 while reacted with monoclonal antibody (Mab) H19 in indirect fluorescence antibody test (IFA). However, vaccine strain CVI988 had 'G' at base#320 and arginine at aa#107 instead, when it was negative in IFA with Mab H19. Some strains were also reactive with Mab T65 in IFA while there was 'G' at base #326 and glycine at aa#109, but the other strains, which had 'A' at base #326 and glutamic acid at aa#109, did not react with Mab T65. By comparison of CVI988 to its point mutants CVI/rpp38(AG) and CVI/rpp38(AA) with 1 or 2 base(s) changes at bases #320 and /or #326 of pp38 gene for their reactivity with Mab H19 and T65, it was confirmed that the glutamine at aa#107 and glycine at aa#109 were critical to epitopes H19 and T65 respectively. Immuno-reactions to MDV were compared in SPF chickens inoculated with cloned CVI988 and its mutant CVI/rpp38(AG). It was found that antibody responses to MDV in chickens inoculated with CVI/rpp38(AG) were delayed and significantly lower than that in chickens inoculated with the native CVI988. By differential comparison of antibody titers to different antigens, a third epitope specific to CVI988 and dependent on arginine at aa#107 was suggested to be responsible for the big difference in antibody responses induced by native CVI988 and its mutant.
authors.affiliation: Department of Preventive Veterinary Medicine, Shandong Agriculture University, Taian 271018, China. zzcui@sdau.edu.cn
authors.forename: Cui
authors.initials: C
authors.lastname: Zhizhong
authors.forename: Zhang
authors.initials: Z
authors.lastname: Zhi
authors.forename: Qin
authors.initials: Q
authors.lastname: Aijian
authors.forename: Lee F
authors.initials: LF
authors.lastname: Lucy
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000096:biosynthesis; D000956:Antigens, Viral / Q000737:chemistry* / Q000235:genetics* / Q000276:immunology; D001483:Base Sequence; D002478:Cells, Cultured; D002645:Chickens; D004279:DNA, Viral / Q000235:genetics; D000939:Epitopes / Q000737:chemistry / Q000235:genetics; D008381:Herpesvirus 2, Gallid / Q000235:genetics* / Q000276:immunology* / Q000472:pathogenicity; D008970:Molecular Weight; D010766:Phosphorylation; D017354:Point Mutation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D014779:Virus Replication
chemical_list: D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D000956:Antigens, Viral; D004279:DNA, Viral; D000939:Epitopes; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; D014764:Viral Proteins; C072811:glycoprotein B, Marek's disease virus