Fig 4.

Calculation of the percentage of CD4⁺fIFN-γ ⁺ and CD8⁺fIFN-γ ⁺ cells in small lymphocyte and lymphoblast populations using two-colour flow cytometry. PBMCs were derived from five FIPV-infected cats without FIP (IIa–IIe were inoculated with the type II FIPV 79-1146 strain), three FIP cats (FIPa–FIPc), and three SPF cats (SPFa, SPFb, and SPFe). The cells were cultured with the heat-inactivated type II FIPV 79-1146 strain (solid bar) or culture medium alone (open bar). A and B represent the percentage of CD4⁺fIFN-γ ⁺ and CD8⁺fIFN-γ ⁺ cells, respectively.