Depletion of LTC-IC, CFU-C, and CD34⁺ cells by HIV-1 (NL4-3). (A) Primitive hematopoietic progenitor cells (LTC-IC) are depleted synchronously with CFU-C and CD34⁺ cells in HIV-1–infected SCID-hu Thy/Liv. (□) CD34⁺ progenitor cells, (▨) CFU-C, and (▪) LTC-IC were determined in parallel 14 to 21 days after infection of grafts with HIV-1 strain, NL4-3. The total number of each is expressed as a percentage of the total number obtained from mock-infected, control grafts. (B) Relative enrichment of all progenitor classes in thymocyte-depleted grafts. Data from experiments in (A) are expressed as cell number per 10⁶surviving thymocytes. (C) Absolute depletion of all progenitor classes in thymocyte-depleted grafts. Data from experiments shown in (A) are now expressed as total number of cells per graft. (□) Control; (▪) NL4-3.