Hans A Schlößer appointed for the Heisenberg Professorship in Immuno-Oncology of the Upper Gastrointestinal Tract
Dept. of General, Visceral, Thoracic and Transplant Surgery at Cologne University Hospital and the Medical Faculty of the University of Cologne
In mid-January, Hans Anton Schlößer was appointed to the W2 Heisenberg Professorship for Immuno-Oncology of the Upper Gastrointestinal Tract at the Department of General, Visceral, Thoracic and Transplant Surgery at Cologne University Hospital and the Faculty of Medicine at the University of Cologne.
He is responsible for the Surgery of the upper gastrointestinal tract at the Department of General, Visceral, Thoracic and Transplant Surgery Cologne, which is one of the largest centers for the treatment of esophago-gastric adenocarcinoma in Europe.
Schlößer - a former awardee of the prestigious CMMC Career Advancement Program (CAP) - leads a research group at the Center for Molecular Medicine Cologne since 2018. His research focuses on the mechanisms of tumor detection, immune evasion, and immunotherapy resistance in gastrointestinal cancers. His goal is to better understand immune escape as a key mechanism of primary and secondary resistance to immune checkpoint inhibition (CKI).
Immune checkpoint inhibition (CKI) has shown remarkable efficacy in various types of cancer, representing a significant breakthrough in cancer therapy. These therapies are unique, as the primary target is not the tumor cell itself, but the crosstalk between immune cells and cancer cells in the tumor microenvironment. Successful recognition of tumor cells by immune cells is crucial for the therapeutic efficacy of CKI.
This recognition depends on a broad spectrum of immune-related tumor cell intrinsic or extrinsic aspects and can so far only be predicted partially by surrogate markers (e.g. tumor mutational burden). Hence, multidimensional analyses of tumor immunogenicity including the immune infiltrate, private and shared neoantigens, tumor specific immune response and immune escape are crucial to further improve therapeutic efficacy and translational research in this field.
As Schlößer explains: "Immunotherapy is successful in many types of cancer, but is often only effective in a small proportion of patients. In gastroesophageal adenocarcinoma, resistance to immunotherapy is very common, and the goal of our research is to understand how tumor cells evade recognition by the immune system. Our aim is to identify the most relevant and potentially vulnerable immune escape mechanisms in GI-cancers. We ultimately aim to overcome these mechanisms with combined immunotherapies."
Hans Schlößer´s Group
The research of Hans Schlößer's group is focused on tumor-specific immune responses and immune escape in gastrointestinal cancer. Their research provides valuable insights into how immune cells organize in the TME, how they recognize tumor cells, how tumor cells evade immune responses in untreated patients and which immune evasion mechanisms contribute to I/O-resistance.
Since his PostDoc in Michael von Bergwelt-Baildon’s group (former Cologne, now Ludwig-Maximilian-University of Munich), he has a special interest for the role of B cells in the tumor microenvironment. Tumor-associated B cells organize in tertiary lymphoid structures (TLS, Schlößer et al. 2019, Schlößer et al. 2015), which resemble lymphoid follicles in secondary lymphoid organs (Lehmann et al., 2024). In addition to their well-known role in humoral immune responses, B cells are professional antigen-presenting cells. Antigen-presenting B cells are highly enriched in the TME of cancer patients (Wennhold et al., 2021) and can enhance tumor-specific immune responses in-vitro (Wennhold et al. 2021 and Thelen et al., 2022). The group aims to further dissect the role of B cells in cancer and to exploit B cells for cancer therapy. Tumor-specific B-cell responses, T-cell responses and the resulting immune evasion are closely related and their interaction is the major interests of the Schlößer Group. Tumor cells (or more precisely the tumor microenvironment) and tumor-specific immune responses undergo continuous reciprocal shaping. This is exemplified by the increased cancer-risk of post-transplant patients, who reveive systemic immunosuppression leading to remarkably reduced immune infiltrates in the TME (Datta et al., 2022). Co-inhibitory molecules (e.g. PD-L1) mediate immune evasion in cancer patients and Hans Schlößer’s group is particularly interested in their role in GI-cancer (Schlößer et al., 2016, Thelen et al., 2019). The Schlößer group elucidated the role of shared antigens, which elicit tumor-specific immune responses in EGA patients (Thelen et al., 2022). The current goal of the group is to better understand mechanisms supporting or inhibiting these immune responses (e.g. HLA-homozygosity, Garcia-Marquez et al., 2024) and to identify the most relevant mechanism of immune escape contributing to immunotherapy resistance in EGA patients. Material from patients treated with radio-immuno-chemotherapy in the investigator-initiated RICE trial (Schlößer et al., ESMO 2023), which Hans Schlößer designed and conducted together with Thomas Zander (Department of Internal Medicine I) will provide important insights, which they hope to translate into improved immunotherapy of EGA.
Beyond his research, Schlößer is deeply committed to interdisciplinary approaches to solid cancer treatment, where surgery plays a pivotal role especially for patients treated with curative intent.
Who ist Hans Anton Schlößer?
Hans Anton Schlößer has an exceptional academic and professional background, with notable achievements in surgery, immunology, and clinical research.
Schlößer has held pivotal roles as a Principal Investigator at the Center for Molecular Medicine Cologne since 2018 and awardee of “CMMC´s Career Advancement Program” in 2019. He has been awarded the Heisenberg Program by the German Research Foundation. His Heisenberg Professorship started in January 2025 and will allow to continue his work as a Clinician Scientist.
Schlößer is a consultant at the Department of General, Visceral, Thoracic and Transplantation Surgery at the University of Cologne since 2018. Schlößer became board-certified in “Visceral Surgery” in 2016 and “Special Visceral Surgery” in 2022. Upper gastrointestinal cancers are his clinical and scientific focus.
In 2018, Schlößer earned his Venia Legendi for his work on "Immune Escape in Gastrointestinal Cancer." His medical journey includes fellowships at the University of Cologne and the University of Bonn, and he is interested in tumor immunology since his Dr. med. (MD), which he obtained from the University of Regensburg in 2009 (AG Mackensen).
Schlößer has been an influential educator and mentor, supervising students in fields ranging from PhD, Master’s, and Bachelor’s programs to MD theses. He has contributed to the academic community through lectures in courses such as “Molecular Mechanisms of Human Diseases” or “Research Track” at the University of Cologne and “Red Biotechnology” at FH Aachen.
Hans Anton Schlößer has authored several significant publications in the field of immuno-oncology in gastrointestinal cancer.
