Figure 6: Thymocytes cultured with either primary TEC or OP9-DL1 cells were permissive to in vitro HIV infection. Thymocytes were incubated with HIVcs204, or mock infected and cultured alone or co-cultured with either thymic epithelial cells or OP9-DL1 cells. A) DNA was isolated from the cells 24 hours p.i and the presence of HIV-1 was measured by nested PCR. As a positive control, DNA was isolated from ACH2 cells and water was used as a negative control in the PCR reaction. B) CD4 expression on total thymocytes was measured by flow cytometry.