Researchers Develop Quick Way to Create Human Antibodies

But few, if any, of these monoclonals are human proteins, said Patrick Wilson, of the Oklahoma Medical Research Foundation, who led the new study with Rafi Ahmed of Emory University School of Medicine. Instead, for both ethical and practical reasons, monoclonals are usually made in mice. And that's a problem, because the human immune system recognizes the mouse proteins as foreign and sometimes attacks them instead. The result can be an allergic reaction, and sometimes even death.

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To get around that problem, researchers now "humanize" the antibodies, replacing some or all of mouse-derived pieces with human ones.

Wilson and Ahmed were interested in the immune response to vaccination. Conventional wisdom held that the B-cell response would be dominated by "memory" B cells. But as the study authors monitored individuals vaccinated against influenza, they found that a different population of B cells peaked about one week after vaccination, and then disappeared, before the memory cells kicked in. This population of cells, called antibody-secreting plasma cells (ASCs), is highly enriched for cells that target the vaccine, with vaccine-specific cells accounting for nearly 70 percent of all ASCs.

"That's the trick," said Wilson. "So instead of one cell in 1,000 binding to the vaccines, now it is seven in 10 cells."

All of a sudden, the researchers had access to a highly enriched pool of antibody-secreting cells, something that is relatively easy to produce in mice, but hard to come by for human B cells.

To ramp up the production and cloning of these antibodies, the researchers added a second twist. Mouse monoclonal antibodies are traditionally produced in the lab from hybridomas, which are cell lines made by fusing the antibody-producing cell with a cancer cell. But human cells don't respond well to this treatment. So Wilson and his colleagues isolated the ASC antibody genes and transferred them into an "immortalized" cell line. The result was the generation of more than 100 different monoclonals in less than a year, with each taking just a few weeks to produce.