A photo of Koichi Araki.

Member, Division of Infectious Diseases

Assistant Professor, UC Department of Pediatrics


Biography & Affiliation


I received my PhD from Hokkaido University, Japan. During my PhD study, I became interested in infectious diseases and T cell immunity.

In my laboratory, I’ve studied CD8 T cell immunity, which is important for controlling viral infections and intracellular bacterial and parasitic infections. It is now clear that CD8 T cells are also involved in immunity against tumors. There is considerable interest in cancer immunotherapy that stimulates CD8 T cell immunity.

My research focus is to understand the mechanisms of how antigen specific CD8 T cell responses are regulated during acute and chronic infection. I’m looking into investigating the role of 1) translational regulation, 2) mTOR activity, and 3) autophagy in effector, memory and exhausted T cell differentiation. The ultimate goal of my research is to develop novel drugs or strategies from information obtained in my basic studies to cure diseases by modulating the immune system.

My studies of CD8 T cell immunity can help us learn and develop better methods to prevent and treat infectious diseases. It also has applications in immunotherapy for cancer treatment against tumors.

I have been a researcher for more than a decade and began my work at Cincinnati Children’s in 2019.

Academic Affiliation

Assistant Professor, UC Department of Pediatrics

Research Divisions

Infectious Diseases, Inflammation and Tolerance


DVM: School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan, 2000.

PhD: School of Veterinary Medicine, Hokkaido University, Hokkaido, Japan, 2004.

Postdoctoral Fellow: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, 2011.


CD45RB Status of CD8+ T Cell Memory Defines T Cell Receptor Affinity and Persistence. Krummey, SM; Morris, AB; Jacobs, JR; McGuire, DJ; Ando, S; Tong, KP; Zhang, W; Robertson, J; Guasch, SA; Araki, K; et al. Cell Reports. 2020; 30:1282-1291.e5.

Cytokine-Mediated Regulation of CD8 T-Cell Responses During Acute and Chronic Viral Infection. Hashimoto, M; Im, SJ; Araki, K; Ahmed, R. Cold Spring Harbor perspectives in biology. 2019; 11.

Role of PD-1 during effector CD8 T cell differentiation. Ahn, E; Araki, K; Hashimoto, M; Li, W; Riley, JL; Cheung, J; Sharpe, AH; Freeman, GJ; Irving, BA; Ahmed, R. Proceedings of the National Academy of Sciences of the United States of America. 2018; 115:4749-4754.

CD8 T Cell Exhaustion in Chronic Infection and Cancer: Opportunities for Interventions. Hashimoto, M; Kamphorst, AO; Im, SJ; Kissick, HT; Pillai, RN; Ramalingam, SS; Araki, K; Ahmed, R. Annual Review of Medicine. 2018; 69:301-318.

Effector CD8 T cells dedifferentiate into long-lived memory cells. Youngblood, B; Hale, JS; Kissick, HT; Ahn, E; Xu, X; Wieland, A; Araki, K; West, EE; Ghoneim, HE; Fan, Y; et al. Nature: New biology. 2017; 552:404-409.

Translation is actively regulated during the differentiation of CD8+ effector T cells. Araki, K; Morita, M; Bederman, AG; Konieczny, BT; Kissick, HT; Sonenberg, N; Ahmed, R. Nature Immunology. 2017; 18:1046-1057.

Rescue of exhausted CD8 T cells by PD-1-targeted therapies is CD28-dependent. Kamphorst, AO; Wieland, A; Nasti, T; Yang, S; Zhang, R; Barber, DL; Konieczny, BT; Daugherty, CZ; Koenig, L; Yu, K; et al. The Scientific monthly. 2017; 355:1423-1427.

Adenovirus Serotype 5 Vaccination Results in Suboptimal CD4 T Helper 1 Responses in Mice. Lee, J; Hashimoto, M; Im, SJ; Araki, K; Jin, H; Davis, CW; Konieczny, BT; Spies, GA; McElrath, MJ; Ahmed, R. Journal of Virology. 2017; 91.

mTOR Promotes Antiviral Humoral Immunity by Differentially Regulating CD4 Helper T Cell and B Cell Responses. Ye, L; Lee, J; Xu, L; Mohammed, A; Li, W; Hale, JS; Tan, WG; Wu, T; Davis, CW; Ahmed, R; et al. Journal of Virology. 2017; 91.