Proviral loads in week-8 PBMCs. (A) The HTLV-1 tax gene standard curve was derived by plotting the log copy number versus the mean crossing point (Ct). (B) DNA was extracted from rabbit PBMCs at 8 weeks after inoculation. Proviral loads per 1 μg PBMC DNA were determined with real-time PCR as described in “Materials and methods.” (C) The proviral load per PMBC was calculated as described in “Materials and methods.” Proviral loads in ACH.75-inoculated rabbits were statistically higher compared with ACH.1- and ACH.95-inoculated rabbits (pair-wise comparisons with Bonferroni adjustment, P = .009 and P = .037, respectively).