title: Response of white leghorn chickens of various B haplotypes to infection at hatch with subgroup J avian leukosis virus.
abstract: White leghorn chickens from seven 15.B congenic lines (genetically similar except for genes linked to the major histocompatibility complex [MHC] B haplotype) and two Line 0.B semicongenic lines were infected at hatch with strain ADOL Hc-1 of subgroup J avian leukosis virus (ALV-J). At 5, 8, 16, and 36 wk of age, chickens were tested for viremia, serum-neutralizing antibody, and cloacal shedding. Chickens were also monitored for development of neoplasia. In the 15.B congenic lines (B*2, B*5, B*12, B*13, B*15, B*19, and B*21) there were no significant differences in the incidence of viremia between B haplotypes. In fact, infection at hatch in all of the 15.B congenic lines induced tolerance to ALV-J because 100% of these chickens were viremic and transient circulating serum-neutralizing antibody was detected in only a few chickens throughout the 36 wk experiment. However, at 16 wk of age more B*15 chickens had antibody and fewer B*15 chickens shed virus than did the 16-wk-old B*2, B*5, or B*13 chickens. Moreover, compared with B*15 chickens, a higher percentage of B*13 chickens consistently shed virus from 8 wk postinfection to termination at 36 wk postinfection. The B haplotype had a transient effect on viral clearance in Line 0.B semicongenics, as more B*13 than B*21 chickens remained viremic through 5 wk of age. Very few (0%-18%) of the Line 0.B semicongenic chickens shed virus. By 36 wk of age, all Line 0 B*13 and B*21 chickens produced serum-neutralizing antibodies and cleared the virus. These results show that following ALV-J infection at hatch the immune response is influenced transiently by the B haplotype and strongly by the line of chicken. Although this study was not designed to study the effect of endogenous virus on ALV-J infection, the data suggest that endogenous virus expression reduced immunity to ALV-J in Line 15I5, compared with Line 0, a line known to lack endogenous virus genes.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Avian Disease and Oncology Laboratory, 3606 East Mount Hope Road, East Lansing, MI 48823, USA.
authors.forename: Jody K
authors.initials: JK
authors.lastname: Mays
authors.forename: Larry D
authors.initials: LD
authors.lastname: Bacon
authors.forename: Arun R
authors.initials: AR
authors.lastname: Pandiri
authors.forename: Aly M
authors.initials: AM
authors.lastname: Fadly
mesh_terms: D000818:Animals; D001353:Avian Leukosis / Q000235:genetics* / Q000276:immunology; D001354:Avian Leukosis Virus / Q000302:isolation & purification*; D001788:Blood Grouping and Crossmatching / Q000662:veterinary; D002645:Chickens / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics; D006386:Hemagglutination Tests / Q000662:veterinary; D008285:Major Histocompatibility Complex / Q000235:genetics; D009500:Neutralization Tests / Q000662:veterinary; D011201:Poultry Diseases / Q000235:genetics / Q000276:immunology / Q000821:virology*; D014766:Viremia / Q000662:veterinary; D017201:Virus Shedding / Q000276:immunology