Recent activities of AFRRI's Military Medical Operations Department:
- Taught the Medical Effects of Ionizing Radiation (MEIR) course to over 1300 Department of Defense personnel annually, in locations around the world.
- Maintained a globally deployable Medical Radiobiology Advisory Team (MRAT) of a Health Physicist and a Physician. Their mission is to provide Joint Staffs and the Joint Task Force Commander with expert advice during the response to a radiation incident. AFRRI participated in the 2011 response to the Fukushima Daiichi nuclear disaster, and was also involved in the response to the 2001 anthrax attacks in Washington DC.
- Collaborated in the development of research projects that improve operational capacity and capability for combat forces, to include Medical Countermeasures, Dose Determinations, and Triage & Medical Care algorithms.
- Participated in the Federal and Global Radiation Enterprise; ensuring expert oversight of policy development, exercise planning and execution, educational product delivery, and forensic investigation.
Pioneering AFRRI research on the use of growth factors and cytokines as radiation countermeasures recently led to the first FDA approvals of medical countermeasures against ARS: Neupogen® (G-CSF) and Neulasta® (pegylated G-CSF).
Recent achievements by AFRRI researchers:
Development of a panel of seven efficacious radiation countermeasure candidates against acute radiation syndrome (ARS). These agents have low toxicity and practical routes of administration. They are ready for advanced development by other DOD agencies when resources become available. All are at Technology Readiness Level (TRL) 3 or above. This is the level for which AFRRI is funded (DOD S&T activities 6.2 and 6.3). One candidate (genistein or BIO-300) is at TRL 5, and another (5-AED) is at TRL 6.
- Five of these countermeasure candidates were conceived at AFRRI, and research and development initiated at AFRRI. These are 5-AED, tocols, genistein (BIO 300), ciprofloxacin (CIPRO), and ghrelin.
- Two were researched at early stages in collaboration with companies: Ex-Rad® and CDX-301.
- Three have FDA Investigational New Drug (IND) status for ARS: 5-AED, genistein (BIO 300), and Ex-Rad®.
- Six have human safety trials: 5-AED, genistein (BIO 300), Ex-Rad®, CDX-301, CIPRO, and Ghrelin.
- The seventh (tocols) has very low toxicity in non-GLP studies (administered in a manner suitable for an ARS countermeasure).
- All enhance survival in irradiated animals in robust studies repeated multiple times.
- Four of these countermeasure candidates are dual use, i.e., approved or being developed for mainstream medical indications:
- CIPRO: antibiotic
- Ghrelin: cachexia, hemodialysis, seizures, gastroparesis
- CDX-301: hematopoietic stem cell transplantation
- BIO 300: lung cancer, prostate cancer
Establishment of a panel of blood biomarkers to assess severity of radiation injury and predict outcome. Rapid, easy assessments of radiation injury are required to guide medical treatment, especially in a mass casualty scenario. Successful biomarkers have been identified in a variety of species. Mathematical algorithms were developed that utilize multiple parameters to predict clinical outcome after radiation exposure. AFRRI is working with a private company to produce a portable instrument that can rapidly assess these biomarkers outside the hospital environment.
Documentation that circulating interleukin-18 and interleukin-18 binding protein are reliable biomarkers for whole body radiation exposure.
Discovery that a novel parameter, cell-cycle progression index, is useful for radiation dose absorbed estimation in the premature chromosome condensation assay.
Demonstration that gene expression, cell function, and cell cycle of endothelial cells and hematopoietic cells are influenced by radiation and by interactions between the two cell types. These interactions involve modulation of MAPKs p38 and p44/42 (ERK1/2), growth factors, angiopoietin 2, activated caspase 3, and apoptosis. These phenomena may affect the success of therapies for ARS and cancer.
Expansion of knowledge of Vitamin E-related molecules (tocols) as radiation countermeasures. It was demonstrated that tocols can be used to mobilize blood-forming cells from bone marrow, and that these cells can be used to enhance survival after radiation exposure.
Elucidation of intracellular signaling molecules involved in injury and recovery from radiation. These signals mediate effects of some of AFRRI's leading radiation countermeasure candidates. An example of this is the demonstration that delta tocotrienol protects human and mouse cells from radiation damage through suppression of IL-1β-induced NFκB/microRNA-30 signaling. Mechanistic knowledge will be required for licensure of countermeasures by the FDA.
Demonstration that delta-tocotrienol enhances survival during the gastrointestinal subsyndrome of ARS, inhibits production of pro-inflammatory factors interleukin-1β and interleukin-6, and suppresses expression of pro-apoptotic protein tyrosine kinase 6 (PTK6).
Discovery that delta-tocotrienol protects mouse and human hematopoietic progenitors from gamma-irradiation through extracellular signal-regulated kinase (ERK1/2)/mammalian target of rapamycin (mTOR) signaling.
Demonstraton that NFκB plays an essential role in the hematopoietic niche function of bone marrow osteoblasts.
Documentaton that 5-AED promotes survival of cultured, gamma-irradiated human hematopoietic progenitors through induction of NFκB activation and G-CSF expression.
Demonstration that 5-AED enhances survival of irradiated mice in a G-CSF-dependent manner, stimulates innate immune cell function, reduces radiation-induced DNA damage, and induces genes that modulate cell cycle progression and apoptosis.
Discovery, using neutralizing antibodies, that endogenous granulocyte colony-stimulating factor (G-CSF) promotes survival after whole body irradiation in the presence or absence of medical countermeasure administration.
Identification of countermeasures that enhance survival in animals experiencing combined radiation injury and other injuries (“combined injury” or CI). This work is especially challenging because AFRRI investigators showed most countermeasures effective against radiation alone have been ineffective against CI, and some actually decrease survival after CI. AFRRI demonstrated success for combined injury treatment with the following agents: ciprofloxacin (CIPRO, acting via mechanisms other than its well-known antimicrobial action), ghrelin (a gastrointestinal hormone), and tocol-mobilized blood cell progenitors. This is important information for response planners because a high percentage of radiological/nuclear casualties will be affected by CI.
Demonstration that CIPRO induces bone morphogenetic protein 4 (BMP4) in macrophages with receptors to erythropoietin (EPO), EPO mRNA in kidney, and EPO protein in kidney and serum; and ameliorates CI-induced anemia.
Demonstration that CIPRO inhibits reductions of ATP levels in ileum after CI. This is associated with modulation of concentrations of pyruvate dehydrogenase (PDH), PDH phosphorylation, PDH enzymatic activity, PDH kinase 1, and heat-shock protein 70 kDa (HSP-70, a chaperone protein involved in ATP synthesis).
Discovery that traumas such as skin wound or hemorrhage amplify skeletal tissue loss after whole body irradiation.
Determination of which countermeasures enhance survival after exposure to mixed neutron/gamma rays, which would be experienced immediately after a nuclear detonation. Almost all countermeasure work has been done using gamma or X-rays. Neutrons produce a complicated type of injury that is more difficult to repair. Many countermeasures effective against gamma or X-rays are ineffective against mixed neutron/gamma radiation. Response planners must take this into account when preparing for radiological/nuclear incidents.
Demonstration that G-CSF upregulates c-kit (CD117) receptors on bone marrow hematopoietic stem and progenitor cells and enhances survival in mice exposed to mixed neutron/gamma radiation.
Discovery that mixed neutron/gamma-irradiated mice displayed prolonged defects in T-cell populations compared to mice irradiated with pure gamma photons.
Establishment of the minipig as a credible model for studying ARS and testing countermeasures. AFRRI's program inspired the creation of a consortium of labs around the country studying ARS in minipigs. Three other laboratories have now independently confirmed AFRRI's finding that the natural history of ARS is extremely reproducible in minipigs, with identical radiation doses producing similar effects across institutions. The US government is exploring the use of the minipig as a large animal model to support licensure of countermeasures by the FDA.
Demonstration that the standard medical ARS countermeasure, G-CSF, produces effects in irradiated minipigs that are similar to what is observed in other animal models and humans.
Discovery for the first time in a large animal model (minipig) of an ARS subsyndrome intermediate between the hematopoietic and gastrointestinal syndromes. This intermediate syndrome is characterized by systemic inflammatory response syndrome (SIRS) and febrile neutropenia.
Demonstration that Influenza A virus shows minimal activation of the classical NFkB dependent pathway and no activation of the non-canonical NFkB pathway in murine macrophages. MAPK activation appears to be necessary, and possibly essential, for cytokine/chemokine production by macrophages at early times after influenza infection in the absence of NFkB activation.
Demonstration that some metal formulations proposed for military munitions induce rhabdomyosarcoma around implanted pellets simulating shrapnel wounds.