CD19-SELECTED B-LYMPHOCYTES SYNTHESIZE, SECRETE AND MIGRATE IN THE PRESENCE OF IL-8, TNF-ALPHA AND GAMMA-IP-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-cel l contact between B lymphocytes and monocytes, In this study we demons trate that interleukin 8 (IL-8), gamma-immune protein 10 (gamma IP-10) and tumour necrosis factor alpha (TNF-alpha) all induce a significant chemokinetic response of human B lymphocytes, Among the cytokines tes ted, rIL-8 was the strongest B lymphocyte migratory factor with a migr atory index (MI) of 2.03 +/- 0.32, (P < 0.002), followed by rTNF-alpha . (MI = 1.89 +/- 0.17, P < 0.001) and r gamma IP-10 (MI = 1.63 +/- 0.1 7, P < 0.001), We did not observe B lymphocyte migration towards rIL-1 alpha, rIL-2, rIL-4, rIL-10, interferon gamma (rINF-gamma) or transfo rming growth factor beta (rTGF-beta). Furthermore, we report that huma n B lymphocytes have a constitutive IL-8 mRNA expression and protein s ecretion in vitro, Resting as well as stimulated B lymphocytes secrete on average 1.5 ng IL-8/ml medium/24 h (2 x 10(6) B lymphocytes), Our data indicate a possible mechanism by which B lymphocytes make contact with other cells, during immune-inflammatory processes. (C) 1997 Acad emic Press Limited.