Wolfgang Ebel | PubMed Health

PubMed2006

Human antibodies for immunotherapy development generated via a human B cell hybridoma technology.

Current strategies for the production of therapeutic mAbs include the use of mammalian cell systems to recombinantly produce Abs derived from mice bearing human Ig transgenes, humanization of rodent Abs, or phage libraries. Generation of hybridomas secreting human mAbs has been previously reported; however, this approach has not been fully exploited for immunotherapy development. We previously reported the use of transient regulation of cellular DNA mismatch repair processes to enhance traits (e.g., affinity and titers) of mAb-producing cell lines, including hybridomas. We reasoned that this process, named morphogenics, could be used to improve suboptimal hybridoma cells generated by means of ex vivo immunization and immortalization of antigen-specific human B cells for therapeutic Ab development. Here we present a platform process that combines hybridoma and morphogenics technologies for the generation of fully human mAbs specific for disease-associated human antigens. We were able to generate hybridoma lines secreting mAbs with high binding specificity and biological activity. One mAb with strong neutralizing activity against human granulocyte-macrophage colony-stimulating factor was identified that is now considered for preclinical development for autoimmune disease indications. Moreover, these hybridoma cells have proven suitable for genetic optimization using the morphogenics process and have shown potential for large-scale manufacturing.

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PubMed2005

Morphogenics as a tool for target discovery and drug development.

Mutations in DNA mismatch repair (MMR) genes lead to genetically hypermutable cells. Germline mutations in MMR genes in man have been linked to the genetic predisposition to hereditary nonpolyposis colon cancer and a number of other inherited and sporadic malignancies. The ability to modulate the MMR process (referred to as morphogenics) in model systems offers a powerful tool for generating functional diversity in cells and multicellular organisms via the perpetual genomewide accumulation of randomized point and slippage mutation(s). Morphogenics is a platform process that employs a dominant negative MMR gene to create genetic diversity within defined cellular systems and results in a wide range of phenotypes, thus enabling the development and improvement of pharmaceutical products and the discovery of new pharmaceutical targets. Libraries of morphogenics-derived siblings are generated through random mutagenesis from naturally occurring DNA polymerase-induced mutations that occur during DNA replication. Morphogenic cells are screened in high-throughput assays to identify subclones with desired phenotypes for pathway discovery and/or product development. Morphogenics has been successfully applied to a wide range of hosts, including mammalian cells, transgenic mice, plants, yeast, and bacteria. Manipulation of these systems via morphogenics has led to the discovery of novel disease-associated phenotypes in targeted model systems. Moreover, morphogenics has been successfully applied to antibody-producing cell lines to yield subclones producing antibodies with enhanced binding affinities for therapeutic use, as well as to derive subclones with enhanced titers that are suitable for scaleable manufacturing. The selective manipulation of the MMR process via morphogenics is a platform technology that offers many advantages for the discovery of druggable targets, as well as for the development of novel pharmaceutical products.

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