Twenty-year persistence of WT1-specific cytotoxic T lymphocytes in peritumoral brain tissue by peptide vaccine therapy: Transcriptomic evidence for resident memory T-cell induction

Jun Nakata; Natsuki Nakamura; Daisuke Motooka; Chisato Yokota; Yoshiaki Hayashi; Ryuichi Hirayama; Fumihiro Fujiki; Soyoko Morimoto; Toru Umehara; Hiroko Nakajima; Yusuke Oji; Akihiro Tsuboi; Yoshihiro Oka; Atsushi Kumanogoh; Noriyuki Kijima; Haruhiko Kishima; Haruo Sugiyama

doi:10.1093/noajnl/vdag176

Twenty-year persistence of WT1-specific cytotoxic T lymphocytes in peritumoral brain tissue by peptide vaccine therapy: Transcriptomic evidence for resident memory T-cell induction

Neurooncol Adv. 2026 Jul 9;8(1):vdag176. doi: 10.1093/noajnl/vdag176. eCollection 2026 Jan-Dec.

Authors

Jun Nakata¹, Natsuki Nakamura², Daisuke Motooka³, Chisato Yokota², Yoshiaki Hayashi³, Ryuichi Hirayama², Fumihiro Fujiki⁴, Soyoko Morimoto⁵, Toru Umehara², Hiroko Nakajima⁶, Yusuke Oji¹, Akihiro Tsuboi⁴, Yoshihiro Oka⁵, Atsushi Kumanogoh⁷, Noriyuki Kijima², Haruhiko Kishima², Haruo Sugiyama⁶

Affiliations

¹ Department of Clinical Laboratory and Biomedical Sciences, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
² Department of Neurosurgery, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
³ Genome Information Research Center, Research Institute for Microbial Diseases, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
⁴ Department of Cancer Immunotherapy, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
⁵ Department of Cancer Stem Cell Biology, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
⁶ Department of Cancer Immunology, Graduate School of Medicine, The University of Osaka, Osaka, Japan.
⁷ Department of Respiratory Medicine, Allergy and Rheumatic Disease, Graduate School of Medicine, The University of Osaka, Osaka, Japan.

Abstract

Background: Sustained immune surveillance at tumor sites is considered essential for effective cancer immunotherapy; however, direct evidence of immune surveillance in humans is limited due to difficulty obtaining tumor and peritumoral tissues through invasive procedures.

Methods: Peritumoral brain tissue was obtained during reoperation from a patient with diffuse astrocytoma who had received continuous Wilms' tumor gene 1 (WT1) peptide vaccination for 20 years. WT1 tetramer-positive CD8+ T cells were analyzed by flow cytometry, followed by T-cell receptor repertoire analysis and single-cell RNA sequencing.

Results: A high level of T-cell infiltration was observed in peritumoral brain tissue, despite the immune-privileged nature of the central nervous system. Notably, 38.4% of CD8⁺ T cells were WT1-tetramer positive, exhibiting an oligoclonal pattern similar to that observed in peripheral blood. Single-cell RNA sequencing demonstrated that WT1-specific cytotoxic T lymphocytes (CTLs) were predominantly composed of resident memory T cells (Trm) and terminally differentiated effector memory T cells (TEMRA), along with a small fraction of cycling T cells. Interestingly, Trm-like subsets were also detected among WT1-specific CTLs in peripheral blood.

Conclusion: These findings provide in situ evidence of long-term persistence of WT1-specific CTLs in the human brain by continuous WT1 peptide vaccination. Such local immune surveillance may have contributed to the prevention of relapse in this patient. Single-cell RNA sequencing suggests that long-lived Trm may contribute to the persistence of immune surveillance through self-renewal and generation of cytotoxic TEMRA. This study offers insights into long-term anti-tumor immunity and may inform future optimization of cancer vaccine therapy.

Keywords: WT1 peptide vaccine; glioma; oligoclonal expansion; resident memory T cells; tumor-infiltrating lymphocytes.