Diversity and affinity from plasma vs. B cells for monoclonal antibody development

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Presentation Time: 11:30 AM - 12:45 PM
Poster Board Number: B815
Abstract ID: 4543

Presenting Author:
David Hawksworth , Principal Scientist II at Abbott Laboratories

Abstract:

Diagnostic assay development requires a diverse panel of high affinity antibodies. Historically, our lab has used splenic CD19⁺ B-cells to generate mouse hybridoma cell lines. However, literature suggests that, as a group, terminally differentiated, CD138⁺ plasma cells secrete the highest affinity antibodies, making these cells an attractive target for hybridoma development. To compare the use of these two lymphocyte populations for generating mouse hybridomas, three fusion experiments were completed whereby cells were separately isolated and fused. Hybridomas were plated in semi-solid media, expanded, and selected based on size and antibody secretion. An average of 246 (+ 73) plasma cell hybridoma colonies were available for selection, per 1x10⁶ specific lymphocytes used for fusion, compared to 19 (+ 13) B cell hybridoma colonies. Cells from selected colonies were transferred to 96-well plates, grown for 7 days and the antibodies screened for antigen binding by enzyme immunoassay. Across the three fusion experiments, 40 (+19)% of the wells with growth from the plasma cell hybridomas were antigen reactive, vs. 6 (+ 0.5)% from the B cell hybridomas. Our data suggests a higher fusion efficiency from the plasma cell population, which allows for a greater sampling of the mouse immune repertoire, leading to identification of more antigen specific antibodies with a wider range of affinities and greater sequence diversity.