Clinical dextrans lack mitogenic activity for normal human lymphocytes in vitro

In vitro studies on mitogenic stimulation of lymphocytes from a panel of normal volunteers revealed no transformation in response to the presence of dextran 40, 70, 110 or 150 at concentrations ranging from 0.8 to 8,000 microgram/ml. High molecular weight native dextran B512 was mitogenic in 1 individual only. In addition, neither Leuconostoc-derived nor fermentation medium-derived moieties, sometimes present in clinical dextrans, were implicated as lymphocyte mitogens. It is concluded on the basis of these findings that clinical dextrans of average molecular weight 40,000--150,000 are not B- or T-cell mitogens.