Abstract
In humans delayed hypersensitivity to tuberculin and coccidiodin can be transferred from a skin-test positive donor to a previously nonreactive recipient with a dialyzable fraction of donor peripheral leukocytes. The mechanism by which transfer is effected by this relatively low molecular weight material is unknown. Should transfer with dialysate be accomplished with hypersensitivity to low molecular weight artificial antigens, further characterization of "transfer factor" might be facilitated.A maximal degree of contact sensitivity to a simple chemical, dinitrochlorobenzene, was produced in tuberculin-sensitive human volunteers, who were then used as donors. Seven of the eight donors reacted with 15 mm or more of induration to 0.1 mug of tuberculin, purified protein derivative, while recipients did not react to 5 mug. The dialyzable fraction of peripheral leukocytes from 500 ml of donor blood was injected into each of eight recipients in an attempt at simultaneous transfer of systemic sensitivity to both tuberculin and dinitrochlorobenzene. Transfer of tuberculin sensitivity was accomplished with four of seven dialysates from tuberculin-positive donors but in none of the eight attempts was contact sensitivity transferred with the same dialysates.The results indicate that tuberculin sensitivity and contact type sensitivity to a simple chemical differ in respect to the behavior of transfer factor and that other models are necessary if dialyzable transfer factor is to be studied with nonbacterial antigens.