FIG 1.

Screening for T-cell epitopes in IBV nucleocapsid protein via IFN-γ ELISpot assays. (A) The splenocytes isolated from IBV-immunized chickens were stimulated with either the peptide pool or one of the 40 individual peptides for 24 h at 41°C and 5% CO₂. As a positive control, splenocytes were stimulated with ConA; as a negative control, splenocytes were supplemented with medium alone (NC1). Splenocytes from control chickens that were incubated with the peptide pool were used as another negative control (NC2). Spot counts are expressed as spots/1 × 10⁶ cells. ***, Significant difference compared with NC1 (P < 0.001). (B) Representative images of IFN-γ ELISpot responses.