TCRγδ T cells are a major lymphocyte population in chickens, but their response to avian leukosis virus subgroup J (ALV-J) and recognized antigens remain poorly understood. Here, we report an increase in the proportion and activation state of TCRγδ⁺CD8α⁺ T cells in vivo and in ex vivo cultured T cells from 2 chicken lines (MHC homozygous H-B21 lines and outbred G-WL line) with the earlier and stronger proliferative response observed in the H-B21chickens. Activated TCRγδ⁺CD8α⁺ T cells performed ‘cytolytic' potential via detection of transcription levels of cytotoxic genes with quantitative reverse transcription polymerase chain reaction (qRT-PCR), and IFN-γ protein level with ELISPOT and an intracellular cytokine staining (ICS) assays with more significant response in the H-B21 chickens. Consistently, Furthermore, the viral structural proteins Gag and Pol were identified as major target proteins recognized by chicken TCRγδ⁺CD8α⁺ T cells. Further ELISPOT and ICS analyses mapped the key peptides to Gag_187–215 and Pol_417–445 recognized by Chicken TCRγδ⁺CD8α⁺ T cells against ALV-J infection. Collectively, these findings firstly confirmed that TCRγδ⁺CD8α⁺ T cells could recognize viral antigens and revealed the dominant peptides on ALV-J, enhancing our understanding of anti-ALV-J T cell responses and advancing vaccine design strategies against ALV-J.

MHC B21 haplotype chickens  /  ALV-J  /  TCRγδ⁺CD8α⁺T cells  /  chicken T cell culture  /  peptides