title: MHC expression on spleen lymphocyte subsets in genetically resistant and susceptible chickens infected with Marek's disease virus.
abstract: Resistance and susceptibility to Marek's disease (MD) are strongly influenced by the chicken major histocompatibility complex (MHC). In this study, splenic lymphocytes from MD-resistant and MD-susceptible chickens of three MHC genotypes (B21/B21, B19/B21, and B19/B19) were analyzed by flow cytometry for MHC surface expression. In the spleen, constitutive MHC class I surface expression was found to be highest in homozygous B19, lowest in homozygous B21, and intermediate in heterozygous B19/B21 animals. This was observed on CD4(+), CD8(+), and Bu-1(+) splenic lymphocytes. Chickens of all three genotypes were subjected to infection with MD virus (GA strain) and spleen samples from infected as well as MHC-matched negative controls were analyzed at 1, 4, and 8 wk post-infection (p.i.). It was observed that MDV induced an increase in MHC class I expression late in the infection. Thus, MHC class I was increased on the surface of CD4(+) cells from infected chickens of all genotypes at 4 and 8 wk p.i. compared with negative controls. Also, MHC class I expression was increased on CD8(+) cells from infected chickens of all genotypes at 4 and 8 wk p.i., except for the homozygous B19 animals, that showed no increase at 8 wk p.i. MDV-induced differences in MHC class II surface levels were also found. Thus, MHC class II expression was increased on CD4(+) cells from infected B19/21 and B21/B21 chickens at 4 wk p.i., and also at 8 wk p.i. on CD4(+) cells from infected B19/B21 animals. MHC class II expression was increased on CD8(+) cells from infected chickens of all genotypes at 4 wk p.i. These findings suggest that MDV infection in vivo increases the level of MHC surface expression on splenic T cells, indicating a possible role in immunity against MDV.
authors.affiliation: Department of Animal Health, Welfare, and Nutrition, University of Aarhus, Tjele, Denmark. tina.dalgaard@agrsci.dk
authors.forename: Tina
authors.initials: T
authors.lastname: Dalgaard
authors.forename: Mette K
authors.initials: MK
authors.lastname: Boving
authors.forename: Kurt
authors.initials: K
authors.lastname: Handberg
authors.forename: Karin H
authors.initials: KH
authors.lastname: Jensen
authors.forename: Liselotte R
authors.initials: LR
authors.lastname: Norup
authors.forename: Helle R
authors.initials: HR
authors.lastname: Juul-Madsen
mesh_terms: D000818:Animals; D002645:Chickens; D020022:Genetic Predisposition to Disease; D014644:Genetic Variation / Q000276:immunology; D054884:Host-Pathogen Interactions / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology* / Q000378:metabolism; D008285:Major Histocompatibility Complex / Q000502:physiology*; D025922:Mardivirus / Q000276:immunology; D008380:Marek Disease / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000276:immunology*