Model for the binding of multivalent antigen to cells

IT has been suggested frequently1–4 that antigen must be presented to immunocompetent cells in multivalent or aggregated form in order to stimulate the cells to proliferate and secrete antibodies or otherwise respond. Multivalent antigens, that is antigen molecules with more than one identical epitope per molecule, seem to bind multivalently and irreversibly to the antibody-like receptors on immunocompetent cells5,6, and T cells or their products may serve to aggregate antigen molecules so as to present them to other cells in multivalent forms7. The binding of multivalent ligands to lymphocyte receptors is known to induce receptor-ligand lattice formation and in many cases to induce mitosis and antibody secretion from B cells4,8,9.