Respiratory immune response to aerosolized keyhole limpet hemocyanin in primate lungs

Keyhole limpet hemocyanin: structural and functional characterization of two different subunits and multimers

Keyhole limpet hemocyanin (KLH), the large respiratory glycoprotein from the primitive gastropod mollusc, Megathura crenulata, is a potent immunogen used classically as a carrier protein for haptens and more recently in human vaccines and for immunotherapy of bladder cancer. Two KLH isoforms were identified and isolated by high-performance anion exchange chromatography. Subsequent analyses disclosed that these isoforms--designated KLH-A and KLH-B--were composed of distinct subunits that differed in primary structure, molecular weight (KLH-A was 449,000 and KLH-B was 392,000), polymerization/reassociation characteristics, and O2-binding constants (KLH-A had a P50 of 7.32 and KLH-B had a P50 of 2.46). Both subunits appear to be composed of eight oxygen binding domains, and reassociate in solution only with like subunits. These results support the concept that structural and functional heterogeneity is a common feature of molluscan hemocyanins, and provide a rational basis for studying and optimizing the immunostimulatory properties of KLH.

Immediate-type hypersensitivity to keyhole limpet haemocyanin in the dog

A model of immediate-type hypersensitivity (ITH) in the dog using keyhole limpet haemocyanin (KLH) as the antigen was studied. Long-lasting ITH was induced in fifteen of sixteen dogs by the i.v. (Kepron & Tse, 1975), intradermal (Rockey, Schwartzmann & Halliwell, 1971), inhalation (Patterson & Kelley, 1974) and i.d. plus inhalation (Rockey et al., 1971) routes. This ITH was demonstrated by direct skin reactivity, acute respiratory reactions and peripheral blood leucocyte and respiratory cell histamine release. The reaginic antibodies considered to mediate these reactions were larger than canine IgG, heat labile, 2-mercaptoethanol sensitive, and are probably canine IgE. In addition to cutaneous and respiratory reactions, these reagins were shown to mediate systemic reactions. In the course of these studies, an unexpected finding was the occurrence of ITH to KLH in three dogs which had had no prior experimental exposure to KLH. This ITH was of sufficient intensity to be associated with acute airway reactions to the inhaled antigen.