Part 2 of 7 Parts (Please read Part 1 first)
     Earlier this year, Daly and his team at USU published a report on their work to develop an inactivated polio vaccine. They took on this project with the biotechnology company Biological Mimetics, Inc (BMI) which was founded by several scientists from the National Cancer Institute. Greg Tobin is the president of BMI and a virologist who had previously led the SAIC-Frederick’s Gene Expression Regulation Group at the institute. He said, “A lot is known about polio So, if you wanted to pick something to characterize immunity, polio is a pretty good ‘proof of concept.’”
     At the heart of Daly’s new vaccine production techniques is a critical mechanism by which D. radiodurans protects itself from cosmic rays and other forms of ionizing radiation. For many years, the prevailing theory among radiobiologists had been that D. radiodurans utilized active cellular mechanisms for the direct protection of its DNA. This was considered to include novel DNA and RNA repair proteins which were produced in response to radiation exposure. But a couple of decades ago, Daly and his team decided that D. radiodurans has a more indirect approach to defending itself against radiation. Its primary defense mechanism is to protect the repair proteins as they cleanup and repair the genome.
     One way of visualizing the damage that radiation does inside a cell is to consider it as being equivalent to boiling a pot of pasta until all the noodles dissolve into blobs of mush. Gamma rays and x-rays energize and decompose water molecules inside a cell during radioactive bombardment. This generates highly chemically reactive “oxidizing” compounds from all the newly generated hydrogen and oxygen ions. More than the incident radiation, it is these oxidizing compounds that do serious damage to all the little organelles and useful macromolecules inside a living cell.
     In order to combat this threat and protect its repair proteins, each D. radiodurans bacterium manufactures a special oxidant compound that contains positively charged manganese ions. (There are some critical antioxidants in human cells such as the enzyme superoxide dismutase that also employ manganese.) By itself, outside of these compounds, manganese is a powerful antioxidant.
    Daly said, “We’ve shown that these manganese complexes are phenomenally good at protecting proteins from oxidants generated during radiation. But, these same manganese antioxidants, they did not protect DNA or RNA. So, as soon as that became very obvious, I said to myself, ‘It sounds like an ideal way of making a vaccine.’”
     Any good vaccine needs to resemble the infectious microbe that it is training the immune system of the body to search and destroy without doing the damage of the infectious agent. This can be a difficult balancing act. In 2012, the Center for Disease Control and Prevention (CDC) documented about forty two thousand new cases of whooping cough. This was the biggest outbreak since 1955. It was not due to poor access to health care or any antivaxxer movement or the evolution of a more virulent strain of pertussis bacteria but to an unreliable vaccine composed of fragmentary cellular material.
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