PREPARATION OF A HIGHLY PURIFIED ALLERGEN FROM DIROFILARIA-IMMITIS - REAGINIC ANTIBODY-FORMATION IN MICE

Abstract

A D. immitis protein allergen was purified; it had a MW of 15,000-20,000 and a carbohydrate content of 2%. The allergenic activity of adult Dirofilaria extracts was assayed by passive cutaneous anaphylaxis (PCA) in rats using mouse sera obtained by immunization with various fractions. The mouse-Dirofilaria system was used to study the degree of purification of allergen. The purified Dirofilaria allergen appeared as 1 band after sodium dodecyl sulfate polyacrylamide gel (SDS-gel) electrophoresis and 1 precipitin arc by immunoelectrophoresis (IEP). It was inclined to aggregate in buffered solution. The allergen-reagin axis was a simple single antigen-antibody interaction. Immunological responses to the purified allergen were compared among 4 inbred strains, 2 hybrid strains and 2 outbred strains of mice. They produced relatively high titers of reaginic antibody but did not produce detectable indirect hemagglutinating test (IHA) antibody. Among the strains tested, BALB/c was a high responder and also continued to produce the reaginic antibody for longer than the other strains.