It is well known that the characteristics of a cultured cell line do not always remain stable and may change upon continuous passage. Most continuous cell lines, even after cloning, possess several genotypes that are constantly changing. There are numerous selective and adaptive culture processes, in addition to genetic instability, that may promote phenotypic changes in cell growth, virus susceptibility, gene expression, et cetera. Similar detrimental effects of long term passaging of insect cells have also been reported for continuous cell lines. In this paper, we describe the isolation of cell clones from low passage BTI Tn5B1-4 cells (High FiveTM Cells), and report their growth characteristics and high level of recombinant protein production…
Tag: <span>protein expression</span>
The K562 cell line is a human myelogenous leukemic cell which has been used by several groups, including ours, as a vehicle for cell-based vaccines and immuno-gene therapies. The attractiveness of K562 cells is the ease with which they can be cultured, plus the fact that they express very low levels of MHC proteins. Low MHC expression facilitates the use of these cells in patients with different MHC backgrounds, and it may improve the in vivo survival of the cells by delaying immune rejection. Based largely on these properties, we have been developing the K562 cell line as a universal platform for expressing cytokines, tumor antigens, and other immuno-modulating proteins…
Baculovirus expression technology, or BEVS, gained its first broad industry exposure in the early 1980s, primarily through the many papers published by students and post-doctoral fellows in Dr. Max Summers’ laboratory at Texas A&M University (College Station, Texas). This technology fostered popular appeal because of its simplicity and high protein expression capabilities. As more work was done, it became even more evident that this was a very rapid, and relatively inexpensive method for producing proteins. It was also postulated that BEVS would offer a valuable means of producing recombinant proteins for use in human therapy, especially since baculovirus was considered non-infectious to human cells. It was thought that any problems with post-translational modifications of the manufactured proteins could be worked out, and fully functional glycoproteins could be manufactured…