Professional Biography of Jim Litts

I obtained a Bachelor's degree at Oregon State University and Masters and Ph.D. degrees at the University of Minnesota. My doctoral thesis detailed a purification protocol for phytochrome, a plant pigment that regulates photomorphogenetic events in plant development. This work also characterized the hydrodynamic behavior of phytochrome, exploring size and shape parameters and subunit structure, and observed the effects of chemical cross-linking on its phototransformation. This work was extended at the University of California at Davis. Here, with Dr. J. Clark Lagarias, I was able to complete work on purification procedures that resulted in the isolation of phytochrome that was stable and unmodified with respect to in vivo characterizations using conventional protein purification methods.

A brief postdoc position at the University of Minnesota Medical School with Dr. James Howard provided me with an opportunity to adapt a protocol for the anaerobic purification of nitrogenase, and particularly the MoFe containing subunits, from Azotobacter vinlandii. Subsequent work used differential labeling of thiol groups and chromatographic peptide mapping to explore the conservation of structure between Azotobacter and Clostridium nitrogenases.

In 1982 I made a substantial change in the direction of my career by pursuing an opportunity at the Western Regional Research Center of the USDA Agricultural Research Service with Drs. Frank C. Greene and Olin D. Anderson. This afforded an opportunity to be trained in the techniques of molecular biology that were rapidly impacting the fields of biology and biochemistry. Here I learned the methods of cloning, sequencing and genome characterization. I focused a major effort on Southern blotting experiments that attempted to detect single copy genes in the exceptionally large allohexaploid genomes of the bread wheats. The techniques I developed allowed us to dissect a large family of storage protein genes and make chromosomal assignments for their linkage groups. It was necessary to detect attomole levels of DNA molecules in order for these blots to be successful, which at that time was a significant achievement.

In 1985 I accepted a position with Dr. Ralph Quatrano at Oregon State University, now at Washington University, St. Louis, continuing my studies of the wheat genome and focusing on gene families modulated by the plant growth regulator abscisic acid. I participated in the sequencing of cDNAs encoding proteins regulated by ABA, Southern analysis of the gene families, the isolation of genomic clones for these genes, sequencing of the isolated clones, and analyses of the gene sequences which identified putative control regions in their promoters. When Dr. Quatrano left OSU to accept a position with DuPont in New Jersey, I joined a similar group at UC Davis, led by Dr. Raymond Rodriguez, this time exploring the barley and rice genomes. I was particularly drawn to rice as a model cereal genome because of its small size relative to other cereals. This allowed for some very rapid progress characterizing genes regulated during development by plant growth substances, particularly during seed development and germination. The small size of the rice genome allowed us to isolate hundreds of clones over the course of several years using batch probes containing several distinct gene families. These multiplexed probings provided way more genomic material than our small staff was able to characterize, but provided a vivid picture of the power of this technology and a resource base that supported the development of a small company, Applied Phytologics, that later morphed into Ventria Bioscience.

I made a second major change in my career direction in 1991. This shift allowed me to integrate the protein technology and nucleic acid technology that had been largely separated in the two previous eras of my professional life. I accepted a position at Cetus with Dr. Robin Clark to develop approaches to interfere with the replication of papillomavirus. This is the world's most prevalent sexually transmitted disease and a major etiological agent in the development of cervical cancer. This work continued uninterrupted as Cetus merged with Chiron and then ONYX Pharmaceuticals, Inc. was spun out of Chiron. However, in the next year it became clear that, even though we had been quite successful developing high-throughput assays for compounds inhibiting papillomavirus DNA replication, and had found compounds that were fairly specific in not interfering with SV40 DNA replication assays, this project did not fit with the mission of ONYX and limited resources led to its termination.

My success with Baculovirus protein expression and the purification of recalcitrant papillomavirus proteins led to my being offered the leadership position in an emerging protein production group that had been initiated by Dr. Clark. While this group had long demonstrated capabilities in Baculovirus expression and scale-up, purification had not been a major centralized responsibility and no central inventory of proteins was being maintained. As major corporate alliances were being formed with Bayer and Warner-Lambert during this period, it became necessary that both of these functions be developed and integrated with the Baculovirus operation. We also needed to expand our technology into E. coli expression. These corporate deals obliged ONYX to supply assays and all the reagents for high-throughput screening of their partner's chemical libraries searching for drug candidates effective as cancer therapeutics. My group was responsible for supplying all the protein reagents and working with the assay development group to optimize and formulate these reagents. In my last three years with ONYX, we made over 400 individual proteins, though many of these were multiple forms of the same protein. When I left, we were maintaining an inventory of approximately fifty proteins. My department produced all the purified proteins used in assays transferred to our corporate partners (Bayer & Warner-Lambert (Parke-Davis)). These assays were the basis of small molecule drug discovery efforts focused on cancer control targeting the ras signal transduction pathway and cell cycle control proteins. This effort produced the reagents used to identify the Multi–Kinase inhibitor (Nexavar - sorafenib) and the Cyclin–Dependent Kinase inhibitor showing promise in clinical trials.

In 1996 I became interested in a functional genomics program that was being initiated at ZymoGenetics in Seattle. I had grown up in the Pacific Northwest and hoped to eventually settle there, so I jumped at the opportunity when an offer was extended to me to join the company. I was to develop a high-throughput capacity to produce proteins in Baculovirus as interesting sequences were found by the bioinformatics group and cloned by the cDNA group. The vision was to produce approximately one hundred proteins each year, probably in multiple forms; for example, epitope tagged on each end to facilitate purification. As my group at ONYX had produced over one hundred proteins per year averaged over the preceeding three years, and I had several ideas on improving that efficiency, this seemed like an exciting but very feasible challenge. It also included the challenge of adapting the system for the production of secreted proteins. I had paid scant attention to secreted proteins at ONYX. The plan was to develop a network of assays and screen proteins for activities that would be therapeutically useful.

I was able to develop a system for processing large batches of cDNAs into Baculovirus constructs; however, for strategic reasons my system was never fully tested. We tested the processing of approximately 20 clones per batch through the system in approximately one months time, but we never obtained sufficient cDNAs to really test our efficiency at a sustained high level. It proved more difficult than anticipated to identify the high number of interesting sequences originally expected and to clone them; and the assay network never was developed to the extent that it could be used as initially hoped. ZymoGenetics then turned away from high-throughput protein production and focused on a much smaller number of proteins. They chose to screen those proteins by other means. After a brief period, which I spent designing an E. coli expression system conceived to deal with production challenges posed by protein production practices at NovoNordisk that sought to remove antibiotic selection from their vectors, I left ZymoGenetics.

I joined Dendreon Corporation in 1999 and worked to produce proteins for their process of ex vivo Antigen Presenting Cell activation that is being developed in efforts to fight cancer and viral infections. This is a unique active immunotherapy that uses the patient's own cells in the production of a cell-based therapeutic vaccine. During my tenure at Dendreon I led the effort to develop processes for two tumor antigens for three trials, a prostate cancer antigen for their lead product, Sipuleucel–T, and a breast cancer antigen for their second line product, Lapuleucel-T. While I was the Director of Manufacturing, I was responsible for producing protein supplies for clinical trials as well as adapting and developing the production process. In that role and later in my role as Director of Process Development, I played a key role as the principal technical lead from Dendreon in bringing one of the largest, if not the largest to-date baculovirus production system (2,000 L bioreactor) online for clinical manufacture. This work was done with the contract manufacturing organization at Covance Biotechnology Services that soon became Fuji Film Diosynth Biotechnologies. Dendreon was successful with their clinical trials and in late April 2010 was granted FDA approval to market sipuleucel-T as Provenge, bringing the first baculovirus-derived product, and more importantly the first cancer immunotherapy to the approved marketplace.

After 6 years with Dendreon, I left and joined Genitope Corporation in the San Francisco Bay area. This is another company dedicated to individualized medicine. In this case, however, the actual protein produced for each patient is unique. The protein is an idiotype molecule, quite similar to a monoclonal antibody, representing the b-cell receptor of the tumor from individual lymphoma patients. Genitope also has a new product line of therapeutic monoclonal antibodies that are based upon the vast collection of idiotype molecules we have isolated in the production of our vaccine product. As Director of Purification Process Development, I have been given a very unique opportunity to develop what could be considered ultimate "platform" processes. This has afforded me an ideal context in which to develop Design of Experiment or Fractional Factorial experimental approaches to downstream process development. It has been great fun and very challenging work to use these statistical approaches to handle the multitude of interactions among the molecular variables provided by individual molecules and the process parameters governing the purification. Genitope has provided me with a wonderful growth opportunity in this area. Unfortunately, the clinical trial failed for their anti-idiotype product, and since most of the company resources had been consumed preparing for its approval, the company failed. Some of the ideas behind this promising approach are being pursued at Bullet Biotechnology in Menlo Park, CA.

My wife, Alison, and I are currently living very happily in Berkeley, California. We're enjoying the unique culture of this city decided upon a major change in our lives toward a simpler life more focused on education and enviornmental issues, and closer to nature. We feel our generation and the next few face a critical responsibility to face such issues as climate change, overpopulation, species extinctions and habitat destruction. Because of this, and with the inspriration of a colleague, Dr. Andrew M Ray, I founded a nonprofit to preserve, protect, restore and educate about the value of wetlands, particularly those of the Klamath Basin. This new organization, Klamath Wetland Education & Research Institute, is in its launch stage as I write this. We are filing the papers for nonprofit status and our draft research program white papers are nearing completion. Tour our site, and wish us well!

Refereed Publications

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