Summary: | Thesis (Ph.D.)--Memorial University of Newfoundland, 1993. Medicine Bibliography: leaves 250-275 The objective of this project was to produce bispecific monoclonal antibodies (BsMabs) which recognise both the tumour associated carcinoembryonic antigen (CEA) and the chemotherapeutic agent doxorubicin, as a complementary approach to the use of immunoconjugates for site specific drug delivery. A monoclonal anti-CEA hybridoma (11-285-14) was made sensitive to hypoxanthine, aminopterin and thymidine (HAT) , by back selecting it in increasing concentrations of 8- azaguanine. Eight 8-azaguanine resistant fusion partners were selected based on growth characteristics and continued anti- CEA production. As doxorubicin (Dox) is a hapten, it was conjugated to carrier proteins keyhole limpet hemocyanin (KLH) or bovine serum albumin (BSA) using l-ethyl-3- (dimethyl-aminopropyl) carbodiimide. Dox-KLH arid Dox-BSA conjugates were employed to immunize mice and spleen cells were used for fusions with the HAT sensitive anti-CEA 11-285-14 using standard hybridoma procedures. Enzyme linked immunosorbent assays (ELISAs) were developed to test the hybrids obtained for anti-CEA, anti-Dox, anti-BSA and dual bispecific activity. Sixteen fusions from Dox-KLH immunized mice yielded 621 hybrids of which 47 showed low level bispecificity. Eight fusions with Dox-BSA immunized mice yielded 297 hybrids. Hybrids showing dual activities were cloned and 7 out of 286 of the positive clones have been selected for expansion.
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