In vitro production of immunoglobulins of various classes and subclasses by cord blood B cells in African neonates: modeling and assessment of determination

Cord blood B cells obtained from neonates of healthy Senegalese mothers wer e assayed in vitro for their capacity to fully differentiate and secrete im munoglobulins (Ig) of various classes and subclasses. Stimulation of mononu clear cells with SAC particles or anti-mu antibodies in the presence of IL- 4, or with IL-2 and IL-10 induced a strong production of IgG, provided that an additional CD40/CD40L signal was present, in contrast to adult cell cul tures. Cord blood mononuclear cells differentially stimulated with various cytokines in order to lead to Ig heavy chain switching and production of th e various classes/subclasses consistently produced IgG1, IgG3, IgG4, IgE an d IgA. This system has been applied to immune cells from African neonates t hat have not been extensively studied previously. Estimation of Ig producti on as OD ratios could be applied to cultures where cord blood B cells are s timulated with defined antigens of human pathogens to which the fetus immun e system was primed in utero. (C) 2001 Elsevier Science B.V. All rights res erved.