In order to expedite the routine production of human hybridomas, the essence of this research proposal is to develop human cell lines and methods, which are comparable in efficiency to those established for murine systems, but without their intrinsic limitations on specificity and utility of antibodies produced. Recalling that the development of murine hybridomas began with a large set of well-characterized myelomas that secreted immunoglobulins, which were then improved upon by the selection of non-secreting variants, has prompted our selection of a variant of the human lymphoblastoid cell line WI-L2-729-HF2 which does not produce immunoglobulin (Ig) and retains a high tension efficiency. To date, clones that produce no detectable IgM or IgG have been obtained. However, since these clones continue to produce kappa chains, albeit at markedly reduced levels, these are being further selected upon to obtain a variant negative for both heavy and light chains. Ig-negative variants are being tested to determine their fusion efficiency in hybridoma formation, and also to ascertain that endogenous WI-L2-729-HF2 Ig is not re-expressed as a result of fusion. In order to make human hybridomas a routine procedure of general applicability in which specific hybrids may be generated against virtually any antigen requires suitable in vitro immunization procedures. Therefore, a key goal is to develop optimal conditions for generating antigen-specific hybrids, by inducing B-cells in vitro to a stage where they can be immortalized as hybridomas by fusion. The long-term objective is to develop methods and cell lines which will expedite the production of human monoclonal anti-tumor antibodies for use in clinical investigations. Therefore, the preparation of human anti-idiotypic antibodies against a CLL immunoglobulin is proposed as a model system. If successful, this step may provide anti-idiotypic reagents analogous to those being developed for clinical applications using murine hybridoma systems. Finally, experiments involving tumor cell-surface antigens are proposed. Specifically, the in vitro immunization of lymphocytes from normal donors with lung cancer cells obtained from bronchial biopsies will be investigated. These preliminary experiments are expected to provide guidelines for a more rigorous future research plan.
| Heitzmann, J G; Blomberg, B; Cohn, M (1986) The WI-L2-729-HF2 human hybridoma system. Arrangement of lambda genes in monoclonal hybrids. Mol Biol Med 3:339-50 |
