Sustained antigen-specific CD8+ T cell immunity post–mRNA booster requires notch pathway activation

T Takuto Nogimori (National Institutes of Biomedical Innovation, Health and Nutrition) Y Yoshinori Okina (Laboratory of Precision Immunology, Center for Intractable Diseases and ImmunoGenomics, National Institutes of Biomedical Innovation, Health, and Nutrition , Osaka,) Y Yuji Masuta (National Institutes of Biomedical Innovation, Health and Nutrition) M Mayu Kumamoto (National Institutes of Biomedical Innovation, Health and Nutrition) T Tomoka Matsuura (Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,) N Natsuko Kaku (Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University , Osaka,) S Satoko Ohfuji (Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,) T Tetsuo Kase (Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,) K Kyoko Kondo (OMU Core Facilities Life Sciences Section, Osaka Metropolitan University , Osaka,) Y Yu Nakagama (Osaka Metropolitan University, Osaka , Japan) S Sachie Nakagama (Osaka Metropolitan University, Osaka , Japan) Y Yuko Nitahara (Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University , Osaka,) S Shokichi Takahama (Laboratory of Precision Immunology, Center for Intractable Diseases and ImmunoGenomics, National Institutes of Biomedical Innovation, Health, and Nutrition , Osaka,) H Hiroshi Kakeya V Victor Appay (Univ. Bordeaux) W Wakaba Fukushima (Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,) Y Yasutoshi Kido (Osaka Metropolitan University, Osaka , Japan) T Takuya Yamamoto

Abstract

Abstract Messenger RNA (mRNA) vaccines effectively induce protective immunity, but antigen-specific CD8+ T cell responses exhibit limited persistence. In this study, we aimed to assess CD8+ T cell responses following a third dose of the Pfizer BNT162b2 COVID-19 vaccine and identify factors contributing to their longevity. Using HLA tetramers, we analyzed antigen-specific CD8+ T cells in 141 vaccinated individuals (86.5% female) and identified 2 groups: those with strong responses (strong group) and those with weak responses (weak group) 6 mo after the third mRNA vaccination. Transcriptomic analysis revealed that Notch signaling was upregulated in the strong group, and in vitro, the inhibition of Notch signaling significantly reduced CD8+ T cell expansion. These findings suggest that Notch signaling may contribute to maintain long-term antigen-specific CD8+ T cell responses following mRNA vaccination. Targeting this pathway could offer novel strategies for enhancing vaccine-induced cellular immunity and long-lasting protection.

Article Details

Volume / Issue Vol. 215, Issue 6
Published June 07, 2026
ISSN 0022-1767
Publisher American Association of Immunologists

Authors (18)

T

Takuto Nogimori

National Institutes of Biomedical Innovation, Health and Nutrition

Y

Yoshinori Okina

Laboratory of Precision Immunology, Center for Intractable Diseases and ImmunoGenomics, National Institutes of Biomedical Innovation, Health, and Nutrition , Osaka,

Y

Yuji Masuta

National Institutes of Biomedical Innovation, Health and Nutrition

M

Mayu Kumamoto

National Institutes of Biomedical Innovation, Health and Nutrition

T

Tomoka Matsuura

Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,

N

Natsuko Kaku

Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University , Osaka,

S

Satoko Ohfuji

Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,

T

Tetsuo Kase

Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,

K

Kyoko Kondo

OMU Core Facilities Life Sciences Section, Osaka Metropolitan University , Osaka,

Y

Yu Nakagama

Osaka Metropolitan University, Osaka , Japan

S

Sachie Nakagama

Osaka Metropolitan University, Osaka , Japan

Y

Yuko Nitahara

Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka Metropolitan University , Osaka,

S

Shokichi Takahama

Laboratory of Precision Immunology, Center for Intractable Diseases and ImmunoGenomics, National Institutes of Biomedical Innovation, Health, and Nutrition , Osaka,

H

Hiroshi Kakeya

V

Victor Appay

Univ. Bordeaux

W

Wakaba Fukushima

Department of Public Health, Graduate School of Medicine, Osaka Metropolitan University , Osaka,

Y

Yasutoshi Kido

Osaka Metropolitan University, Osaka , Japan

T

Takuya Yamamoto