Characterization of CD4⁺/CD8⁺ cells in the peripheral blood of FW-pX rats. Peripheral blood from 6-week-old FW-pX rats was used. In each experiment, at least 3 rats were used. Representative data are shown. (A) Peripheral blood cells were stained with FITC-conjugated anti-CD4 (OX-35) and PE-conjugated anti-CD8 (OX-8) Abs, followed by depletion of erythrocytes. CD4/CD8 DP cells were gated to confirm that these cells were mononuclear cells. WBCs indicates white blood cells. (B) Peripheral blood cells were stained with FITC- or PE-conjugated anti-CD4 (OX-35), PerCP-conjugated anti-CD8 (OX-8), and FITC- or PE-conjugated anti-CD3 (G4.18), CD11b/c (OX-42), or NKR-P1A Ab (10/78), followed by depletion of erythrocytes. Painted histograms represent the expression of CD3, CD11b/c, and NKR-P1A on CD4⁺/CD8⁺ cells. Gray histograms represent the expression of these molecules on total PBMCs. (C) Mononuclear cells separated from the spleen of FW-pX rats were cultured in chamber slides at 37°C for 1 hour. Resultant adherent cells were fixed using cold acetone for 5 minutes and then stained for CD68 (ED-1, green), CD4 (OX-35, red), and CD8 (OX-8, blue). The merged image shows the cell stained with 3 colors (total magnification: × 600). (D) Peripheral blood cells were stained with FITC-conjugated anti-CD4 (OX-35) and PE-conjugated anti-CD8 Abs for the α-chain hinge region (OX-8), α-chain Ig V-like region (G28), or β-chain (341) followed by depletion of erythrocytes. Histograms represent reactivity with the anti-CD8 Abs gated on CD4^medium cells.