Depletion of CD4 T lymphocytes in human lymphoid tissue infected ex vivo with doxycycline-dependent HIV-1

We investigated whether CD4(+) T cells that do not produce HIV- 1 are killed in HIV-infected human lymphoid tissue. Tissue blocks were inoculated with high amount of doxycycline-dependent HIV-rtTA. Doxycycline triggered productive infection and loss of CD4(+) T cells in these tissues, whereas without doxycycline, neither productive infection nor CD4(+) T cell depletion was detected in spite of the massive presence of virions in the tissue and of viral DNA in the cells. Thus, HIV- 1 alone is sufficient to deplete productively infected CD4(+) T cells but is not sufficient to cause the death of uninfected or latently infected CD4(+) T cells. Published by Elsevier Inc.