Treatment with granulocyte colony-stimulating factor decreases the capacity of hematopoietic progenitor cells for generation of lymphocytes in human immunodeficiency virus-infected persons

An obstacle to stem cell gene therapy for AIDS is the limited numbers of he matopoietic progenitors available. Granulocyte colony-stimulating factor (G -CSF) is used for mobilization of progenitors, but little is known about th e functional characteristics of mobilized progenitors, and immature and T c ell progenitors may not be mobilized. This study examined the effect of G-C SF on the function of progenitors. Ten human immunodeficiency virus-infecte d patients received G-CSF (filgrastim, 300 mu g/day) for 5 days. Absolute n umbers of immature and T cell progenitors did not increase. The ability of CD34(+) progenitor cells to generate lymphocytes was examined by use of thy mic organ cultures. The mean number of lymphocytes generated per CD34(+) ce ll on day 0 was 0.72 and on day 4 was 0.09 (P < .003), The number of CD4(+) cells generated per CD34(+) cell was significantly reduced after G-CSF tre atment. Thus, G-CSF increased the number of mature progenitor cells but did not increase T cell progenitors.