CD19-selected B lymphocytes synthesize, secrete and migrate in the presence of IL-8. TNF-alpha and gammaIP-10 are also B lymphocyte migratory factors.

B lymphocytes are responsible for antigen uptake and presentation, as well as antibody production. These reactions require close cell-to-cell contact between B lymphocytes and monocytes. In this study we demonstrate that interleukin 8 (IL-8), gamma-immune protein 10 (gammaIP-10) and tumour necrosis factor alpha (TNF-alpha) all induce a significant chemokinetic response of human B lymphocytes. Among the cytokines tested, rIL-8 was the strongest B lymphocyte migratory factor with a migratory index (MI) of 2.03+/-0.32, (P<0.002), followed by rTNF-alpha (MI=1.89+/-0.17, P<0.001) and rgammaIP-10 (MI=1.63+/-0.17, P<0.001). We did not observe B lymphocyte migration towards rIL-1alpha, rIL-2, rIL-4, rIL-10, interferon gamma (rINF-gamma) or transforming growth factor beta (rTGF-beta). Furthermore, we report that human B lymphocytes have a constitutive IL-8 mRNA expression and protein secretion in vitro. Resting as well as stimulated B lymphocytes secrete on average 1.5 ng IL-8/ml medium/24 h (2x10(6) B lymphocytes). Our data indicate a possible mechanism by which B lymphocytes make contact with other cells, during immuno-inflammatory processes.
(Copyright 1997 Academic Press Limited.)