Human peripheral blood mononuclear cells cultured in serum-free medium: a functional and morphological study using light and scanning electron microscopy.

Mononuclear cells of the human peripheral blood (PBMs), separated by the gradient-centrifugation technique, were cultured in serum-free medium. After separation into adherent cells (A-PBMs) and non-adherent cells (NA-PBMs), morphological differences between the two cell populations were observed. A-PBMs grew in serum-free culture for up to 70 days and the NA-PBMs for 30 days, without loss of viability. Cells were examined for phagocytosis of latex particles and prostaglandin secretion (PGE2 and thromboxane), in particular. Of all cells studied, the young adherent cells (3-7 days in culture) were the most efficient in performing these functions. In mixed cultures, containing A-PBMs and NA-PBMs, attachments between both cell types via elongated cytoplasmic extensions were seen. Toward the end of the culture period, a dense cellular network developed on the substrate of the culture chamber. This phenomenon has not been reported for PBMs culture using conventional serum-enriched media.