Fig. 4.

Fcwf-4 CU cells differ in morphology and IFN-responsiveness from Fcwf-4 ATCC. A) Single-cell morphology of feline bone marrow-derived macrophages (fBMDMs), Fcwf-4 CU, and Fcwf-4 ATCC cells determined by Wright-Giemsa stain following cytospin preparation. Images were taken at 100 × . B) Interferon stimulated gene (ISG) 54 transcript levels from Fcwf-4 ATCC (grey) and Fcwf-4 CU (black) cell lines stimulated with increasing concentrations of feline type I interferon (IFNα). After 6 h, total RNA was extracted and analyzed by qPCR for ISG54 and feline beta-actin. ISG54 mRNA expression was normalized to β-actin via the delta Ct method (2^-ΔCt[ΔC_t=C_{t(gene of interest)}-C_t(β-actin)]), then presented as relative expression over corresponding mock (basal) expression. Data are representative of three independent experiments performed in triplicate and presented as means ± SD. Values were analyzed by unpaired t-test. * * P < 0.01; * ** P < 0.001; * ** * P < 0.0001.