Population dynamics of human activated natural killer cells in culture (original) (raw)

The growth kinetics and population dynamics of recombinant interleukin-2 (rlL-2) stimulated human natural killer (NK) cell-enriched populations were studied in vitro. The NK-enriched population was obtained from normal peripheral blood mononuclear cells (PBMNC) by immunomagnetic bead depletion of CD3' and CD5+ T cells. The growth kinetics of NK cells, T cells, monocytes, and total cells are shown. In the absence of PBMNC accessory cells, the NK-enriched population showed limited expansion. In the presence of PBMNC accessory cells, the NK-enriched population expanded threefold more than in the absence of accessory cells due to increased NK cell growth rate and increased duration of exponential growth. Using a Transwell system, which separates two cell populations by a polycarbonate membrane, the accessory cells were shown to act on the NK-enriched population via a diffusible factor. Accessory cell conditioned media was able to replace the accessory cell population t o stimulate NK cell expansion. A monocyte-enriched population prepared by sheep red blood cell rosetting of T cells was extensively phenotyped and compared with the NK-enriched populations. Although the final cultured cells were phenotypically homogeneous for CD56+/CD3-NK cells, the initial NK precursor populations appear to be different. Namely, the NK cell precursors in the monocyte-enriched population were predominantly CD56+/CD2-. Kinetic equations were formulated for this culture system and the effects of major culture variables are investigated.