Percentage of CD4+ and CD8+ T cells after inoculation of bac-GX0101 and GX0101ΔMeq (n = 4). One-day-old chickens inoculated intra-abdominally with 1000 PFU of bac-GX0101, GX0101ΔMeq viruses or uninfected CEF cultures, cell suspensions from chickens were obtained to analyze the percentage of CD8+ lymphocytes in spleens at days 7, 14, 21 and 28 p.i. On days 21 and 28 p.i., the percentage of CD8+ T cells was drastically reduced (P < 0.05) in bac-GX0101-infected chickens, however, the percentage of CD4+ T cells was increased on days 14 and 21 p.i. (P > 0.05) and signifcantly increased on days 28 p.i. (P < 0.05) in bac-GX0101-infected chickens.