Radioprotective functions of Deinococcus Mn complexes for practical purposes

1.0 Objective: The ongoing Fukushima nuclear disaster in Japan has brought sharp focus on the urgent need for research on the prevention of acute and chronic radiation effects. Radiological terrorist “dirty bombs” and nuclear explosive devices also are among the most devastating potential threats facing Americans and their allies. The acute radiation syndrome (ARS) occurs following a brief exposure to high doses of radiation, and prognosis depends on the dose received. There are currently no effective radioprotective drugs or treatments available to patients overexposed to ionizing radiation. Deinococcus radiodurans, a bacterial species, has evolved remarkable defenses against, and repair of, damage from radiation, effectively neutralizing all measurable biological damage caused by acute and chronic radiation exposures. The major aims of the proposed research are to 1) characterize, export out of the host cell, and reconstitute the radioprotective Mn2+ complexes of D. radiodurans; 2) apply the most radioprotective reconstituted Mn2+ complexes to irradiated mammalian cell lines and mice; and 3) test the ability of the most protective Mn2+ complexes to preserve viral envelope epitopes at supralethal doses (>40 kGy), needed to mount protective immune responses.