Molecular determinants of immunogenicity: the immunon model of immune response.

Abstract

The immunological response in vivo to a series of size-fractionated linear polymers of acrylamide substituted with hapten was measured in mice. A sharp threshold was observed in immunogenic response elicited by various polymer preparations. All polymers with less than 12-16 appropriately spaced hapten groups per molecule were nonimmunogenic, while those polymers with greater than this number were fully immunogenic. The immunological response at its most elementary level is quantized, i.e., a minimum specific number of antigen receptors (approximately 12-16) must be connected together as a spatially continuous cluster, an immunon, before an immunogenic signal is delivered to the responding cell.