Production and characterization of a monoclonal antibody against an Ascaris suum allergenic component

Ascaris suum allergenic components (PIII) separated by gel filtration chrom atography of an adult worm extract were used to immunize BALB/c mice. Popli teal lymph node cells taken from the immunized animals were fused with SP2/ O myeloma cells using polyethylene glycol (MW 1450) as fusogen. The hybrido mas were cultured in HAT-containing medium and cloned at limiting dilutions . Supernatants from the growing hybrids were screened by ELISA using plates coated with PIII or the A. suum crude extract. The monoclonal antibody obt ained, named MAC-3 (mouse anti-A. suum allergenic component), is an IgG1 ka ppa mouse immunoglobulin that specifically recognizes a 29,000 molecular we ight protein (called allergenic protein) with an affinity constant of 1.7 x 10(9) M-1. The A. suum components recognized by MAC-3 induce specific IgE antibody production in immunized BALB/c mice. Ascitic fluid induced in Swis s mice by injecting ip the hybridoma cells and incomplete Freund's adjuvant was purified by affinity chromatography using a protein A-Sepharose column . The purified monoclonal antibody was then coupled to activated Sepharose beads in order to isolate the A. suum allergenic component from the whole e xtract by affinity chromatography.