NONSPECIFIC-BINDING OF IGG1 TO HELIGMOSOMOIDES-POLYGYRUS - ADULT WORMHOMOGENATE SUPERANTIGEN IS A TARGET FOR IMMUNOGLOBULIN-INDUCED INHIBITION

Previous evidence had indicated that selected antigens contained in H. polygyrus adult worm homogenate (AWH) could bind non-specifically to mouse IgG1. To determine whether H. polygyrus superantigen was one of these binding molecules, an inhibition assay was carried out using mon oclonal antibodies (MoAb) to block the in vitro superantigen response. The remits indicated that non-specific IgG1 binding could inhibit the cellular response to the superantigen. This assumption was tested usi ng affinity chromatography to extract those antigens which bound non-s pecifically to mouse IgC1. Both the protein fraction which bound to th e column and the unfractionated AWH demonstrated superantigen activity , as described previously. In contrast, the unbound fraction contained no superantigen activity. None of the tested fractions exhibited non- specific mitogen activity. These results indicate that the superantige n produced by H. polygyrus binds to host IgG1 of any specificity and t his binding can inhibit further host recognition of this molecule. Add itionally, it was demonstrated that an apparently similar superantigen is also contained in L-4 homogenate, and is strongly represented in t he excretory/secretory (E/S) proteins produced by both adult and L-4 p arasitic stages. Therefore, it is probable that H. polygyrus superanti gen influences the host during both the L-4 and adult stages of the li fe-cycle.