Heligmosomoides polygyrus immunomodulatory factor (IMF), targets T-lymphocytes

Experiments were performed to investigate the immunological site of action of an immunomodulatory factor (IMF), isolated from the gastrointestinal nematode Heligmosomoides polygyrus. IMF inhibited antibody production in murine and human 'T-helper (Th-2) driven' immunoassays. The effects were mediated via T lymphocytes as T cell-depleted cultures Sailed to respond to IMF, a result confirmed by prepulsing discrete cell subsets with the immunomodulant. Although the molecular nature and mode of action of IMF has yet to be determined it would appear to be a relatively small nonproteinaceous molecule. From this data, we suggest that H. polygyrus secretes a systemically-active IMF from the intestinal lumen, to down-regulate Th-2 cell development ill order to promote its survival in a potentially immunologically hostile environment.