Cross-Linkage in Lymphocyte Transformation

Abstract

A polymerized fraction of the non-stimulatory univalent Fab' fragment of goat antibody directed to rabbit Fab was as effective as the parent antibody in stimulating transformation of rabbit peripheral lymphocytes. The specificity of the stimulation initiated by the polymerized Fab' was shown by the ability of rabbit IgG to completely block its stirnulatory capacity and by the inability of polymerized non-specific goat IgG or its Fab' fragment to effect transformation. Polymerization of the IgG fraction of goat anti-rabbit Fab resulted in a fraction which was more stimulatory, at low concentrations, than the IgG from which it was derived. The data suggest that bivalence is a requirement for initiation of transformation by antiglobulin reagents. Further, the data suggest that, at low concentrations, the extent of DNA synthesis stimulated by a mitogen may to a large extent be directly related to the valence of the mitogen. It is suggested that stimulation of lymphocyte transformation by antigen is also a function of the valence of the antigen and that antibody may be important in increasing the valence.