INDUCTION OF BOTH REAGINIC AND BLOCKING ANTIBODIES WITH A LOW MOLECULAR WEIGHT FRACTION OF TIMOTHY POLLEN EXTRACT

In preliminary studies to evaluate the potential of the nonprecipitating antigen D for treatment of timothy-sensitive patients, a group of 8 nonallergic individuals was given a series of intracutaneous injections of antigen D at weekly intervals for 4 weeks. Each of the persons had no clinical history of allergy and gave negative skin reactions to antigen D, crude pollen extract (WST), and allergens A and B of timothy pollen. Four weeks after the last injection of antigen D, 6 of the 8 volunteers gave positive skin reactions when skin tested with various timothy allergens. Passive transfer studies with sera obtained from these volunteers not only showed significant blocking antibody titers but also varying amounts of reaginic antibody titers up to 1/25. The successful induction of homocytotropic antibodies in rhesus monkeys by repeated intracutaneous injections with antigen D was demonstrated by both direct skin reactions and histamine release from passively sensitized monkey lung fragments. The homocytotropic antibodies produced in both man and rhesus monkeys are heat labile, persist at sensitized sites for at least 48 hours, and can be passively transferred by sera. © 1969 The C. V. Mosby Company.