Chemotactic activity in dialyzable transfer factor.

Dialyzable transfer factor from human leukocytes was found to be strongly chemotactic for granulocytes and weakly chemotactic for monocytes in vitro. Chemotactic properties were also demonstrated in vivo in rhesus monkey skin. Initial purification of the dialyzable transfer factor by Sephadex G-25 chromatography revealed multiple fractions containing material with 255-nm absorbance. The fractions containing chemotactic activity were also capable of transferring delayed hypersensitivity to rhesus monkeys. This chemotactic material has an apparent molecular weight of 5000 daltons or less and was not inactivated by goat antibody to components C3 or C5 of human complement; chemotactic activity was lost after storage for two weeks at 4 degrees and the activity of two of three preparations was decreased by heating for 30 min at 56 degrees . This previously undescribed chemotactic activity of dialyzable transfer factor may have significance in relation to cell-mediated immune responses.