Soluble lung tumor antigen activity, as determined by the leukocyte adherence inhibition (LAI) assay, was enriched by physicochemical methods from chemically-defined spent medium of a lung cancer cell line (NCI-H69). To identify the polypeptide carrying the antigenic determinant, BALB/c mice were immunized with the enriched isolate and their splenic lymphocytes were fused with mouse plasmacytoma cells. / Eight hybrids were cloned and produced MAbs that immunoprecipitated principally a single chain of MW 40,000 (p40) as well as minor chains of MW 25,000 (p25) and MW 13,000 (p13) which were probably degradation products of p40. On 2D gels, p40 was composed of 7 spots with a pI of 6.1 to 7.6, which was not altered by neuraminidase digestion. Affinity chromatography with MAb anti-p40 absorbed p40 and LAI activity. The bound and recovered fraction was enriched for p40 and LAI activity. Affinity-purified p40 contained the previously identified p25 and p13 as well as a MW 32,000 polypeptide (p32). MAb anti-p40 was directed to a common framework determinant on p40 since MAb anti-p40 bound to cancer cells from other organs. The lung cancer organ-specific determinant recognized by leukocytes from lung cancer patients was not recognized by the MAb. Affinity purified p40 triggered the LAI response for leukocytes from patients with lung cancer but not for leukocytes from control subjects or patients with colon cancer or malignant melanoma in blind testing. Partial cross-reactivity was observed with leukocytes from patients with breast cancer. Thus, a p40 molecule has been purified that is expressed on the membranes of lung cancer cells and triggers immunologically-mediated LAI.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.75432 |
| Date | January 1986 |
| Creators | Durko, Margaret |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Division of Experimental Medicine.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000550593, proquestno: AAINL44301, Theses scanned by UMI/ProQuest. |
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