Shioda Lab/Division of Infectious Disease  Department of Viral Infections

Although we have been studying HIV for more than 20 years, now we are mainly studying mosquito-borne viral diseases such as dengue and chikungunya virus infections. We are conducting epidemiological studies in Thailand and molecular studies in Osaka, Japan. Recently, we are working on SARS-CoV-2.

Molecular characterization of dengue and chikungunya viruses

Dengue and chikungunya viruses are transmitted by Aedesmosquitos and cause febrile diseases. Dengue virus sometimes causes shock syndrome after the decline of fever and chikungunya virus causes arthralgia. We are conducting molecular epidemiology of these viruses in Thailand and Bangladesh by using molecular clock analysis. There are apparent variations in growth kinetics among isolated viruses and we are trying to elucidate factors affecting these differences.

Characterization of anti-dengue antibodies

Anti-dengue antibodies show both neutralizing and enhancing effects on virus infection. We are analyzing several monoclonal antibodies hoping to find neutralizing antibodies without any enhancing effect. There are four serotypes of dengue virus. Some antibodies neutralize all four serotypes while others potently neutralize only one serotype. Antibodies with strong neutralizing activity without any enhancement can be used as antibody-drug. We will also analyze anti-viral antibodies in asymptomatic infection.


We are involved in the development of rapid diagnosis kits, study for the mechanisms of disease progression and phenotype of the isolated virus from patients’ specimens.



  • Fig. 1. Phylogeographical analysis of dengue virus type 2.

  • Fig. 2.A neutralizing antibody (green) and envelope dimer of
    dengue virus type 2 (pale blue and orange). Amino acid resides critical for antibody binding are highlighted with red and blue.

  • The schematic diagram of S protein with sequence of furin cleavage site.
    The cells surrounded by blue line indicate the big fusion caused by SARS-CoV-2 delta lineage infection.


  • Prof.: Tatsuo Shioda
  • Assoc. Prof.: Emi E. Nakayama
  • Asst. Prof.: Tadahiro Sasaki



  • (1) The potential of COVID-19 patients' sera to cause antibody-dependent enhancement of infection and IL-6 production. Shimizu J, et al., Sci Rep. (2021) 11:23713
    (2) Prompt Reduction in CRP, IL-6, IFN-γ, IP-10, and MCP-1 and a Relatively Low Basal Ratio of Ferritin/CRP Is Possibly Associated With the Efficacy of Tocilizumab Monotherapy in Severely to Critically Ill Patients With COVID-19. Hashimoto S, et al., Front Med (Lausanne). (2021) 8:734838
    (3) Hiroi S, Kubota-Koketsu R, Sasaki T, Morikawa S, Motomura K, Nakayama EE, Okuno Y, Shioda T. Infectivity assay for detection of SARS-CoV-2 in samples from patients with COVID-19. Hiroi S, et al., J Med Virol. (2021) 93:5917-5923
    (4) Generation of macrophages with altered viral sensitivity from genome-edited rhesus macaque iPSCs to model human disease. Iwamoto Y, et al., Mol Ther Methods Clin Dev. (2021) 21:262-273
    (5) Promising application of monoclonal antibody against chikungunya virus E1- antigen across genotypes in immunochromatographic rapid diagnostic tests. Suzuki K, et al., Virol J. (2020) 17:90
    (6) A novel sub-lineage of chikungunya virus East/Central/South African genotype Indian Ocean lineage caused sequential outbreaks in Bangladesh and Thailand. Phadungsombat J, et al., Viruses (2020) 12, 1319
    (7) Cytokine expression in dengue fever and dengue hemorrhagic fever patients with bleeding and severe hepatitis. Imad HA, et al., Am J Trop Med Hyg. (2020) 102: 943–950
    (8) Discovery of a small molecule inhibitor targeting dengue virus NS5 RNA-dependent RNA polymerase. Shimizu H., et al. PLos Neg (2019) Trop Dis. 13:e0007894
    (9) Evaluation of novel rapid detection kits for dengue virus NS1 antigen in Dhaka, Bangladesh, in 2017. Suzuki E. et al., Viology Journal (2019) 16:102