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Cross reactive IBV specific T cell subsets in peripheral blood of vaccinated chickens
Tina S. Dalgaard1, Rikke B. Kjærup1, Eva Wattrang2, Lonneke Vervelde3.
1 Dept. of Animal Science, Aarhus University, Denmark
2 National Veterinary Institute, Uppsala, Sweden
3 The Roslin Institute & RSVS, University of Edinburgh, UK
IBV-specific T-cells are involved in local and systemic immune responses upon IBV infection of
chickens. Peripheral blood was used to access IBV vaccine-induced cross-reactive T cells subsets
in inbred chickens from the AU. In total 12 chickens without IBV specific maternal antibodies
were kept in a biosecured facility and were vaccinated against MDV (CVI-988, Rispens strain,
MSD Animal Health) at hatch (subcutanous), IBV (Nobilis IB Ma5 Vet vaccine, MSD Animal
Health) at age 1 day (coarse spray) and 2 weeks (nasally, 1 dose/>3.5 log 10EID50 in 100 ul
destilled water). Furthermore the chickens were vaccinated against NDV (coarse spray, ND-C2,
MSD Animal Health) at weeks 3 and 10 of age. Heparin-stabilised blood was collected from the
jugular vein at 3, 5 and 10 weeks of age corresponding to week 1, 3, 8 post second IBV
vaccination (PV2). Serum was collected from blood samples taken from the jugular vein at 10
weeks of age corresponding to week 8 pv2.
Frequencies of blast frequencies observed after PBMC culture with different IBV antigens are
shown assessed. At week 1 PV2 significantly increased frequencies of blasting CD4+ cells were
found in vaccinated chickens when PBMC were cultured with strains H52 (p=0.002),
M41(p=0.051) and Ma5 (p=0.032) and significantly increased frequencies of CD8α+ cells when
PBMC were cultured with Ma5 (p=0.002). At week 3 PV2 significantly increased frequencies of
blasting CD4+ cells were found in vaccinated chickens when PBMC were cultured with strain 491 (p=0.027) and significantly increased frequencies of blasting CD8α+ cells when PBMC were
cultured with 4-91 (p<0.001), H52 (p<0.001) and Ma5 p<(0.001). At week 8 PV2 no increased
frequencies were observed in the CD4+ population whereas significantly increased frequencies
of blasting CD8α+ cells were observed when culturing PBMC with strains 4-91 (p=0.004),
H51(p=0.023) and Ma-5 (p<0.001). The method is discussed as a potential tool to assess crossreactice IBV specific T cells in peripheral blood from vaccinated/infected animals.