Uninfected haematopoietic progenitor (CD34+) cells purified from the bone marrow of AIDS patients are committed to apoptotic cell death in culture.

OBJECTIVE

To determine the mechanism underlying the poor growth in vitro of haematopoietic progenitor cells isolated from HIV-1-infected patients.

METHOD

Apoptotic death in liquid culture of bone-marrow CD34+ cells obtained from 11 HIV-1-seropositive patients and 18 HIV-1-seronegative donors was quantitatively monitored by a flow cytometry procedure.

RESULTS

No significant differences in the percentage of apoptotic cells were noted between the two groups immediately after purification. When CD34+ cells were placed in liquid cultures supplemented with 2 ng/ml interleukin-3, the number of apoptotic cells progressively and significantly (P < 0.05) increased in all HIV-1-seropositive patients, while it remained constant in HIV-1-seronegative individuals. Although all HIV-1-seropositive patients showed signs of active viral replication in the bone-marrow micro-environment, progenitor CD34+ cells did not show the presence of active and/or latent HIV-1 infection.

CONCLUSION

Our data demonstrate that CD34+ cells isolated from AIDS patients with active HIV-1 replication in bone-marrow accessory cells are committed to apoptotic death without being directly affected by productive infection.