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 nem atode Heligmosomoides polygyrus. IMF inhibited antibody production in murin e and human 'T-helper (Th-2) driven' immunoassays. The effects were mediate d via T lymphocytes as T cell-depleted cultures Sailed to respond to IMF, a result confirmed by prepulsing discrete cell subsets with the immunomodula nt. Although the molecular nature and mode of action of IMF has yet to be d etermined it would appear to be a relatively small nonproteinaceous molecul e. From this data, we suggest that H. polygyrus secretes a systemically-act ive IMF from the intestinal lumen, to down-regulate Th-2 cell development i ll order to promote its survival in a potentially immunologically hostile e nvironment.