Overview
On October 24, 2025, Yizhe Sun will defend a pivotal dissertation at Karolinska Institutet, delving into the phenotypic features and functional mechanisms of tumor-associated adaptive natural killer (NK) cells. Hosted in Lagerlöf, plan 4, inside the KI campus, the disputation brings together renowned researchers and clinicians to evaluate a significant advance in tumor immunology.
Why Adaptive NK Cells Matter in Cancer
Natural killer cells are a first line of defense against transformed cells. Traditionally viewed as part of the innate immune system, NK cells exhibit adaptive-like features under certain tumor conditions. The focus of this work is the tumor-associated adaptive NK cell population, which can display distinct receptor profiles, altered cytokine production, and unique cytotoxic capabilities. Understanding these cells could illuminate why some tumors evade immunity and how they might be targeted more effectively.
Objectives and Key Questions
The dissertation systematically investigates the following questions: What phenotypic markers distinguish tumor-associated adaptive NK cells from canonical NK subsets? What signals in the tumor microenvironment drive the adaptive reprogramming of NK cells? How do these adaptive NK cells contribute to tumor control or progression, and what are the implications for immunotherapy strategies?
Phenotypic Profiling
Researchers analyze receptor repertoires, transcriptional signatures, and surface markers to define adaptive NK cells within solid and hematologic tumors. The work aims to map heterogeneity across patients and tumor types, identifying subpopulations with divergent functional potentials.
Functional Mechanisms
The study examines how adaptive NK cells respond to cytokines, antibody-dependent cellular cytotoxicity, and interactions with stromal and myeloid cells. By unraveling signaling pathways and effector functions, the research seeks to explain cases of heightened activity or resistance observed in different tumor environments.
Implications for Therapy
Should adaptive NK cells prove to be key players in tumor control, they could become targets or biomarkers for precision immunotherapies. This work could influence approaches such as NK cell-based adoptive therapies, combination regimens with checkpoint inhibitors, or strategies to modulate the tumor microenvironment to favor protective NK cell responses.
The disputation panel and process
The event features a distinguished examination committee, including Yizhe Sun as the candidate and a panel of senior researchers who will critically appraise the data, methods, and interpretations. The committee advisoring the defense includes Huvudhandledare Dhifaf Sarhan and Bihandledare Kaisa Lehti and Mikael Karlsson, with Opponent Yenan Bryceson providing external scrutiny. The Betygsnämnd, comprising Angelica Losskog, Hans Grönlund, and Hong Qian, will render the final judgment. An editorial review by Christina Sundqvist ensures scientific clarity and rigor for publication and dissemination of the findings.
What attendees can expect
Beyond the scientific discourse, the disputation offers insight into career pathways in tumor immunology research and the collaborative nature of modern biomedicine. Attendees will gain a nuanced understanding of how adaptive NK cells are studied—from bench experiments to clinical implications—and how academic mentorship shapes future breakthroughs in cancer therapy.
About Karolinska Institutet and the topic’s relevance
Karolinska Institutet is a global leader in medical research and education. The focus on tumor-associated adaptive NK cells reflects a broader shift toward deciphering immune cell plasticity within the tumor microenvironment. The findings discussed at this disputation could influence ongoing clinical trials and inform therapeutic design for patients facing cancer, underscoring the practical impact of immunology research in the clinic.
Save the date: 2025-10-24, 8:30–13:30, at Lagerlöf, plan 4 (inside the library), Alfred Nobels Allé 8, Stockholm, Sweden. Attendees and colleagues can connect to the event and gain a front-row view of cutting-edge cancer immunology research as it moves from hypothesis to potential therapy.
