Tetsuro Ikegami, PhD

Tetsuro Ikegami, PhD

Department of Pathology
Member, The Sealy Institute for Vaccine Sciences;
Member, The Sealy Center for Vaccine Development
Member, The Center for Biodefense and Emerging Infectious Diseases
Member, Center for Tropical Diseases

Phone: (409) 772-2563
Email: teikegam@utmb.edu

Tetsuro Ikegami, PhD

  • Our research goal is to elucidate the molecular mechanisms of viral virulence factors, and to develop highly efficacious and safe vaccines and antivirals for pathogenic RNA viruses. Our current research interest includes basic studies and countermeasure developments against several pathogenic bunyaviruses including Rift Valley fever virus, Severe Fever with Thrombocytopenia Syndrome virus, Heartland virus, and Oropouche virus: e.g., vaccine developments, antiviral screening, and characterization of host-virus interactions. Those bunyaviruses are maintained by arthropod vectors such as mosquitoes, ticks, or biting midges, while their virological phenotype and virulence can be altered by genetic reassortments of genomic S, M, and L RNA segments with those of other bunyaviruses. The S segment encodes nonstructural S (NSs) proteins, which support viral replication by inhibiting host antiviral immune responses. Some bunyaviral M segments also encode nonstructural M (NSm) proteins, while the biological functions are largely unknown. Our team is highly skilled in reverse genetics approach for bunyaviruses, by which we could generate recombinant bunyavirus strains with NSs and/or NSm gene knockouts. Using high containment facilities at UTMB, we evaluate viral attenuation and virulence in appropriate animal models for vaccine and pathology studies.

  • BVSc (DVM equivalent) Azabu University, Kanagawa, Japan Veterinary Medicine 1999
    PhD University of Tokyo, Tokyo, Japan Virology 2003
    Post-Doctoral Fellow The University of Texas Medical Branch at Galveston, TX Virology 2008
  • 2006-2008 The James W. McLaughlin postdoctoral fellowship. The University of Texas Medical Branch.
    2009-2012 Career Development Award, Western Regional Center for Biodefense and Emerging Infectious Diseases Research, NIH/NIAID
  • 1999-PresentJapanese Society for Virology
    2005-PresentAmerican Society for Virology
    2008-PresentAmerican Society for Microbiology
    2008-PresentMember, Sealy Institute for Vaccine Sciences, UTMB
    2010-PresentMember, Center for Biodefense and Emerging Infectious Diseases, UTMB
    2011-PresentMember, Center for Tropical Diseases, UTMB
    2011-PresentAcademic Editor, PLoS ONE
    2013-PresentAssociate Editor, Virology Journal
    2015-PresentEditorial Board Member (Review Editor), Frontiers in Microbiology (Virology)
    2016-PresentEditorial Board Member, npj Vaccines
    2018-PresentEditorial Board Member, Vaccines
    2019-PresentEditorial Board Member, Microorganisms
    2021-PresentEditorial Board Member (Review Editor), Frontiers in Virology (Emerging and Reemerging Viruses)
    1. Ikegami T, Won S, Peters CJ, Makino S. 2006. Rescue of infectious Rift Valley fever virus entirely from cDNA, analysis of virus lacking NSs gene, and expression of a foreign gene. J. Virol. 80: 2933-40. (PMID: 16501102)
    2. Ikegami T, Narayanan K, Won S, Kamitani W, Peters CJ, and Makino S. 2009. Rift Valley fever virus NSs protein promotes post-transcriptional downregulation of protein kinase PKR and inhibits eIF2a phosphorylation. PLoS Pathog 5: e1000287 (PMID: 19197350).
    3. Kalveram B, Lihoradova O, Ikegami T. 2011. NSs protein of Rift Valley fever virus promotes post-translational downregulation of the TFIIH subunit p62. J.Virol., 85:6234-43(PMID: 21543505).
    4. Lihoradova O*, Kalveram B*, Indran SV, Lokugamage N, Juelich TL, Hill TE, Tseng CT, Gong B, Fukushi S, Morikawa S, Freiberg AN, Ikegami T. 2012. The dominant-negative inhibition of dsRNA-dependent protein kinase PKR increases the efficacy of Rift Valley fever virus MP-12 vaccine. J.Virol. 86: 7650-61.
    5. Lokugamage N, Freiberg AN, Morrill JC, Ikegami T. 2012. Genetic subpopulations of Rift Valley fever ZH548, MP-12 and recombinant MP-12 strains. J.Virol 86: 13566-75.
    6. Kalveram B*, Lihoradova O*, Indran SV, Lokugamage N, Head JA, Ikegami T. 2013. Rift Valley fever virus NSs inhibits host transcription independently of the degradation of dsRNA-dependent protein kinase PKR. Virology.435: 415-24.
    7. Kalveram B, Ikegami T. 2013. Toscana virus NSs protein promotes degradation of double-stranded RNA-dependent protein kinase. J.Virol. 87: 3710-8.
    8. Lihoradova O, Indran SV, Kalveram B, Lokugamage N, Head JA, Gong B, Tigabu B, Juelich TL, Freiberg AN, Ikegami T. 2013. Characterization of Rift Valley fever virus MP-12 strain encoding NSs of Punta Toro virus or Sandfly fever Sicilian virus. PLoS Negl.Trop.Dis. 7: e2181.
    9. Indran SV, Lihoradova OA, Phoenix I, Lokugamage N, Kalveram B, Head JA, Tigabu B, Smith JK, Zhang L, Juelich TL, Gong B, Freiberg AN, Ikegami T. 2013. Rift Valley fever virus MP-12 vaccine encoding Toscana virus NSs retains the neuroinvasiveness in mice. J.Gen.Virol. 94: 1441-50.
    10. Ikegami T, Hill TE, Smith JK, Zhang L, Juelich TL, Gong B, Slack OA, Ly HJ, Lokugamage N, Freiberg AN. 2015. Rift Valley fever virus MP-12 vaccine is fully attenuated by a combination of partial attenuations in the S-, M- and L-segments. J. Virol. 89: 7262-76.
    11. Nishiyama S, Lokugamage N, Ikegami T. 2016.The L, M, and S segments of Rift Valley fever virus MP-12 vaccine independently contribute to a temperature-sensitive phenotype. J. Virol. 90: 3735-44.
    12. Phoenix I, Nishiyama S, Lokugamage N, Hill TE, Huante MB, Slack OAL, Carpio VH, Freiberg AN, and Ikegami T. 2016. N-glycans on the Rift Valley fever virus envelope glycoproteins Gn and Gc redundantly support viral infection via DC-SIGN. Viruses 8: e149.
    13. Phoenix I, Lokugamage N, Nishiyama S, Ikegami T. 2016. Mutational analysis of the Rift Valley fever virus glycoprotein precursor proteins for Gn protein expression. Viruses 8: e151.
    14. Nishiyama S, Slack OAL, Lokugamage N, Hill TE, Juelich TL, Zhang L, Smith JK, Perez D, Gong B, Freiberg AN, Ikegami T. 2016. Attenuation of pathogenic Rift Valley fever virus strain through the chimeric S-segment encoding sandfly fever phlebovirus NSs or a dominant-negative PKR. Virulence 7: 871-881.
    15. Lokugamage N, Ikegami T. 2017. Genetic stability of Rift Valley fever virus MP-12 vaccine during serial passages in culture cells, npj Vaccines, 20.
    16. Ly HJ, Lokugamage N, Nishiyama S, Ikegami T. 2017. Risk analysis of inter-species reassortment through a Rift Valley fever phlebovirus MP-12 vaccine strain. PLoS ONE, 12(9):e0185194.
    17. Ly HJ, Nishiyama S, Lokugamage N, Smith JK, Zhang L, Perez D, Juelich TL, Freiberg AN, Ikegami T. 2017. Attenuation and protective efficacy of Rift Valley fever phlebovirus rMP12-GM50 strain. Vaccine, 35: 6634-6642.
    18. Ikegami T, Balogh A, Nishiyama S, Lokugamage N, Saito TB, Morrill JC, Shivanna V, Indran SV, Zhang L, Smith JK, Perez D, Juelich TL, Morozov I, Wilson WC, Freiberg AN, Richt JA. 2017. Distinct virulence of Rift Valley fever phlebovirus strains from different genetic lineages in a mouse model. PLoS ONE, 12: e0189250.
    19. Hallam HJ, Lokugamage N, Ikegami T. 2019. Rescue of infectious Arumowot virus from cloned cDNA: posttranslational degradation of Arumowot virus NSs protein in human cells. PLoS NTD, 13: e0007904.
    20. Ikegami T. 2021. Development of a simian RNA polymerase I promoter-driven reverse genetics for the rescue of recombinant Rift Valley fever virus from Vero cells. J Virol, 95: e02004-20.

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