B-cell depletion in SIV-infected AGMs. Six sabaeus AGMs were depleted by mAb cM-T807 of CD8⁺ lymphocytes and by mAb rituximab of CD20⁺ lymphocytes (B,D), and 6 AGMs received purified control Ab IgIV (A,C). Absolute B-cell number in peripheral blood (A-B) and percentage of B cells in lymph node cell suspensions (C-D). The ↓ in panels B and D indicate the injection time points of the CD20⁺ lymphocyte-depleting mAb rituximab. p.i. indicates postinfection.