Doug Reed, PhD
- Associate Professor
Francisella tularensis is a facultative intracellular bacterium that causes tularemia (a.k.a. rabbit fever), which when inhaled causes severe morbidity and mortality in human beings. After inhalation, the bacterium causes a fulminant bacterial pneumonia but also disseminates to a number of other tissues and organs including the spleen, lymph nodes, intestines, liver, kidney, bone marrow, and brain. Although macrophages and dendritic cells are thought to be a primary target of F. tularensis, the pathological mechanisms by which F. tularensis causes disease and death are not understood.
Because of the potential to cause disease when inhaled, tularemia is a potential biological weapon for which there are no licensed vaccines or antibiotics. We have successfully re-established the rabbit as a model of pneumonic tularemia that is relevant to the human disease. Within 3 days of exposure, naïve rabbits develop fever and begin losing weight. Erythrocyte sedimentation rate rises dramatically, an indicator of a robust inflammatory response. CBC results show a marked decline in lymphocytes and platelets in the blood. Radiographs show the development of a severe bacterial pneumonia in the rabbits. Naïve rabbits exposed to aerosolized virulent F. tularensis die between 4-7 days of infection.
In collaboration with Eileen Barry at the University of Maryland-Baltimore, we have used the rabbit model to evaluate attenuated strains of F. tularensis as possible vaccines. Three of these strains provided better protection than the existing vaccine candidate, the Live Vaccine Strain (LVS). The level of protection seen depends on the attenuated strain, the route of vaccination, and the number of vaccinations. Using an aerosol prime-boost vaccine approach we have achieved 83% survival with our lead vaccine candidate while LVS can only extend time to death. Serum IgG and IgM titers against F. tularensis in vaccinated rabbits correspond with the level of protection elicited. We are working with Dr. Barry and Dr. Karsten Hazlett of Albany Medical College to determine the antigens important for protection as well as the role of antigen persistence and inflammation. Our long term goals are 1) to determine the immunological mechanisms of protection responsible for the protection seen with these vaccines in order to design a subunit-based vaccine and 2) to understand the role of the host immune response in the outcome of disease.
In addition to the work on F. tularensis, we work with other investigators to develop animal models for aerosol exposure to infectious agents and to use those models to either understand pathogenesis or evaluate candidate vaccines and therapeutics. This includes not only natural respiratory pathogens (influenza, tuberculosis) but also pathogens that are biodefense threats. This includes development of nonhuman primate models for aerosol exposure to a number of highly pathogenic viruses including Highly Pathogenic Avian Influenza (HPAI), Venezuelan equine encephalitis virus (VEEV), western equine encephalitis virus (WEEV), eastern equine encephalitis virus (EEEV), and Rift Valley Fever virus (RVFV). In addition to doing aerosol exposures, we use radiotelemetry in the nonhuman primates to study the physiological response infection. This response can be used as an early indicator of outcome or as a means for determining efficacy of potential vaccines or therapeutics.
Ma, H., Albe, J., Gilliland, T., McMillen, C., Gardner, C.M., Garner, C.M., Boyles, D.A., Cottle, E.L., Dunn. M.D., Lundy, J.D., Salama, N., O’Malley, K.J., Pandrea, I., Teichert, T., Klimstra, W.B., Hartman, A.L., Reed, D.S. 2022. Long-term persistence of viral RNA and inflammation in the CNS of macaques exposed to aerosols containing Venezuelan equine encephalitis virus. PLoS Pathogens 18(6):e1009946. PMID: 35696423
Corry, J., Kettenburg, G., Upadhyay A.A., Wallace, M., Marti, M.M., Wonderlich, E.R., Bissel, S.J., Goss, K., Sturgeon. T.J. Watkins, S.C., Reed. D.S., Bosinger, S.E., Barratt-Boyes, S.M. 2022. Infiltration of inflammatory macrophages and neutrophils and widespread pyroptosis in lung drive influenza lethality in nonhuman primates. PLoS Pathogens Mar 10;18(3):e1010395 PMID: 35271686
Frick, O.M., Livingston, V.A., Whitehouse, C.A., Norris, S.L., Alves, D. A., Reed, D.S., Nalca, A. 2021. The natural history of aerosolized Francisella tularensis infection in cynomolgus macaques. Pathogens May 13;10(5):597 PMID: 34068262
Lovchik, J.A.*, Reed, D.S.*, Hutt, J.A., Xia, F., Stevens, R.L., Modise, T., Wu, T.H. 2021. Analysis of Multiple Francisella tularensis SCHU S4 Variants Identifies a Significantly Attenuated Substrain of SCHU S4. Pathogens May 22;10(6):638 PMID: 34067337 * - equal contribution
Albe, J.R., Ma, H., Gilliland, T., McMillen, C.M., Gardner, C.L., Boyles, D.A., Cottle, E.L., Dunn, M.D., Lundy, J.D., O’Malley, K.J., Salama, N., Walters, A.W., Pandrea, I., Teichert, T., Klimstra, W.B.*, Reed, D.S.*, Hartman. A.L.* 2021. Physiological and immunological changes in the brain associated with severe lethal eastern equine encephalitis virus in macaques. PLoS Path * - equal contribution. PMID: 33534855
Nambulli, S., Xiang, Y., Tilston-Lunel, N., Murphy, L.J., Sang, Z., Klimstra, W., Reed, D.S., Crossland, N.A,. Shi, Y., Duprex, P.W. 2021. Inhalable Nanobody (PiN-21) prevents and treats SARS-CoV-2 infections in Syrian hamsters at ultra-low doses. Science Advances May 26;7(22):eabh0319 PMID: 34039613
Fears, A.C., Klimstra, W.B., Duprex, P., Hartman, A., Weaver, S.C., Plante, K.C., Mirchandani, D., Plante, J.A., Aguilar, P.V., Fernández, D., Nalca A., Totura, A., Dyer, D., Kearney, B., Lackemeyer, M., Bohannon, J.K., Johnson, R., Garry, R.F., Reed, D.S.*, Roy C.J.* 2020. Persistence of Severe Acute Respiratory Syndrome Coronavirus 2 in Aerosol Suspensions. Emer Inf Dis. Jun 22;26(9) PMID: 32568661 * - equal contribution.
Bowling, J.D., O’Malley, K.J., Klimstra, W.B., Hartman, A.L., Reed, D.S. 2019. A vibrating mesh nebulizer as an alternative to the Collison 3-jet nebulizer for infectious disease aerobiology. Applied & Environmental Microbiology. Aug 14;85(17) PMID 31253680
Ma, Henry, Lundy, J., O’Malley, K., Klimstra, W.B., Hartman, A.L., Reed, D.S. 2019. Electrocardiography Abnormalities in Macaques after Infection with Encephalitic Alphaviruses. Pathogens 8, 240; doi:10.3390/pathogens8040240 PMID: 31744158
O’Malley, K., Bowling, J.D., Hazlett, K.R.O., Barry, E.M., Reed, D.S. 2019. Development, characterization and standardization of a nose-only inhalation exposure system for exposure of rabbits to small particle aerosols containing Francisella tularensis. Infection & Immunity. 87(8):e00198-19 PMID: 31085702
O’Malley, K., Bowling, J.D., Stinson, E., Cole, K.S., Mann, B.J., Namjoshi, P., Hazlett, K.R.O.*, Barry, E.M.*, Reed, D.S.* 2018. Aerosol prime-boost vaccination with defined, attenuated mutants of type A Francisella tularensis provides strong protection in outbred rabbits against lethal aerosol challenge with virulent SCHU S4. PLoS ONE Oct 22;13(10):e0205928 PMID: 30346998 * - equal contribution
Wonderlich, E.R., Caroline, A.L., McMillen, C.M., Walters, A.W., Reed, D.S., Barratt-Boyes, S.M., Hartman, A.L. 2018. Peripheral blood biomarkers of disease outcome in a monkey model of Rift Valley Fever encephalitis. J Virol Jan 17;92(3) PMID: 29118127
Aerobiology and pathophysiology of severe respiratory infections. The Reed lab has unique capabilities for exploring research on high-hazard (BSL-3+) respiratory infections like avian influenza viruses, SARS-CoV-2, encephalitic alphaviruses, and tularemia. This includes state-of-the-art, world-class equipment for exposing animals (rodents, ferrets, rabbits, nonhuman primates) to aerosols containing infectious agents to either improve our understanding of how these agents cause disease or to test and evaluate vaccines or therapeutics that may eventually go into human use. In addition to our aerobiology capabilities, we can continuously monitor and record the animal’s physiological response to infection using radiotelemetry devices to monitor body temperature, EKG, EEG, ICP, and activity. Using statistical models, we can determine changes in physiological responses that are outside the norm and quantify that response in a way that we can compare between group, for example to demonstrate that a vaccine protects against disease as well as death. We can monitor changes at discrete intervals in respiratory function using plethysmography chambers for rodents, ferrets, or nonhuman primates.
Avian influenza viruses and sarbecoviruses. Highly pathogenic avian influenza viruses such as H5N1 or H7N9 have a high mortality rate (30-60%) in human cases. There is concern that a HPAI could be the next pandemic. Vaccines and treatments are urgently needed. Along with the Barratt-Boyes lab in GSPH, we developed the first nonhuman primate model of lethal acute respiratory disease syndrome (ARDS) following H5N1 infection. We are using this model to explore the pathogenesis of these viruses, as well as collaborating with other groups to test potential vaccines and therapeutics, including a universal flu vaccine and a broadly-neutralizing antibody against the conserved stem region of the flu hemagglutinin. Using our aerobiology capabilities, along with some newer equipment, we are exploring the stability of avian influenza viruses as well as sarbecoviruses in the environment and in aerosols and the implications for this on transmission via aerosol.
Alphaviruses. Encephalitic alphaviruses are naturally transmitted by mosquito but can be infectious when aerosolized and there is concern they could be used as a biological weapon. Vaccines and therapeutics are needed to protect against this threat. In collaboration with Dr. William Klimstra in the Center for Vaccine Research, we have developed improved mouse and nonhuman primate models for aerosol exposure to Venezuelan equine encephalitis and eastern equine encephalitis viruses. This includes the use of infectious clones of these viruses, IVIS imaging of the infection, and pioneering the use of radiotelemetry to monitor changes in EEG power bands and intracranial pressure as these viruses penetrate the central nervous system. Most recently, we have demonstrated that ferrets are also a good model for the CNS disease caused by inhalation by these viruses. We have funded projects to continue the development of all three models, evaluating virus persistence in the CNS, new vaccine candidates, and potential antiviral compounds for therapeutic use. For the antiviral compounds, we are exploring aerosol delivery of the antiviral to mice and ferrets using a new inhalation tower.
Tularemia. Tularemia (a.k.a. rabbit fever) is a severe zoonotic infection caused by a gram-negative facultative intracellular bacterium, Francisella tularensis. As few as 15 cfu can cause disease when inhaled and there is substantial concern that tularemia could be used as a biological weapon. In a collaboration with Dr. Eileen Barry at the University of Maryland-Baltimore, we have demonstrated that the New Zealand White rabbit is a relevant model of human tularemia, particularly after inhalation of virulent F. tularensis. Using that model, we have demonstrated that attenuated strains of F. tularensis that Dr. Barry had developed could provide good protection in the rabbits against a robust aerosol challenge. Collaborating with Dr. Barry and Dr. Karsten Hazlett at Albany Medical College, we have explored antibody and cell-mediated immune responses in the rabbits to identify potential immune correlates. In addition, we have begun to explore the pathogenesis of virulent F. tularensis in the rabbits as a tool for understanding the human disease. Using a combination of microbiology, pathology, flow cytometry, and transcriptomics, we have identified potential key elements in the host response that may be responsible for the outcome of tularemia infection.
Potential projects for rotating students include the following:
1. Aerosol delivery of vaccines, mAbs, antivirals (encephalitic alphaviruses)
2. Evaluate potential vaccines and therapeutic mAb (encephalitic alphaviruses, avian influenza viruses)
3. Host-pathogen interactions in avian influenza, including physiological responses to infection (EKG, activity)
4. Virus persistence and host response to encephalitic alphaviruses in ferret and nonhuman primate models
5. Stability & survival of BSL-3 viruses in aerosol and on surfaces (avian influenza viruses, SARS-CoV-2, encephalitic alphaviruses, monkeypox)