Association of PD-1+ Treg/PD-1+ CTL Ratio and Tertiary Lymphoid Structures with Prognosis and Response in Advanced Gastric Cancer
April, 2025
Researchers used advanced imaging and analysis tools from TissueGnostics to detect and quantify two cell types, the PD-1+ regulatory T cells (Treg)/PD-1+CD8+ cytotoxic T cells (CTL) ratio, and tertiary lymphoid structure (TLS) presence in tumor tissue.
Despite recent significant advances in its treatment, gastric cancer remains a major health concern worldwide. Recent estimates suggest that stomach cancers accounted for 660,000 deaths in 2022 alone, making it the fifth highest ranking disease, in terms of mortality, worldwide.1
It’s clear that substantial further study of the disease will be necessary in order to significantly improve prognoses for patients.
Study of the tumor microenvironment has led to breakthroughs in the treatment of cancer. This environment plays a critical role in determining the body’s ability to fight and/or support cancer. Through understanding its complex responses, there is a hope that we can more accurately predict patient outcomes, and create more effective treatment plans.
In one such study, researchers used advanced imaging and analysis tools from TissueGnostics to detect and quantify two cell types, the PD-1+ regulatory T cells (Treg)/PD-1+CD8+ cytotoxic T cells (CTL) ratio, and tertiary lymphoid structure (TLS) presence in tumor tissue, as an indicator for patient outcomes.2
Case Study: The Role of Tertiary Lymphoid Structures (TLS)
Tertiary lymphoid structures (TLS) are well-organized immune structures which act as “immune hubs”. They emerge outside of secondary lymphoid tissues in response to chronic inflammation, autoimmune response, and immune response against tumor.3
TLS facilitate the movement of immune cells into the tumor site, enhancing the body’s immune response. This ability to promote the access of immune cells to the tumor site has made them a key focus in advancing cancer treatment.4
The presence of TLS in tumors has been linked to enhanced immune response and improved treatment outcomes in relation to gastric cancer.2
The Role of PD-1+ Tregs and PD-1+ CTLs
The study examined the ratio between PD-1+ regulatory T cells (Tregs) and PD-1+CD8+ cytotoxic T lymphocytes (CTLs).
Tregs, a subset of T lymphocytes, are intended to suppress the immune response. Whilst they play a vital role in preventing autoimmunity, in the context of cancer, elevated Treg levels risk inhibiting the anti-tumor responses. CTLs, by comparison, attack the cancerous cells directly. An elevated number of CTLs would indicate that the body is actively working to destroy the tumor.
PD-1 (programmed death 1) is a protein expressed by both Tregs and CTLs and is used to regulate the immune response. By analyzing PD-1 expression in these two types of immune cells, the researchers were able to assess whether the immune system was suppressing or activating the immune system in response to treatment.
Recent Findings in Advanced Gastric Cancer
The research team investigated the role of TLS and the ratio of PD-1+ regulatory T cell (Treg) / PD-1+CD8+ cytotoxic T cell (CTL) populations and any indication they might provide to the likely outcomes of treatment for advanced gastric cancer patients.2
Tumor samples were taken from 10 gastric cancer patients before and after administering a pre-operative conversion therapy. Using multiplex immunofluorescence (mIF), they were able to stain the samples for multiple immune markers, such as CD20, CD3, CD8, PD-1, and FOXP3, allowing the scientists to trace the presence of different immune cells, including Tregs and CTLs.
High resolution images of the slides were produced using a TissueFAXS SL scanner, allowing the team to identify and quantify the cells present in the sample. StrataQuest software was then used to analyze the images and calculate cell density across different immune cell types, including Tregs and CTLs, and detect the presence of TLS within the tumor tissue.
The researchers observed a significant increase in survival of the gastric cancer patients with abundant presence of TLS and CTL, indicating a more active immune response and suggesting that these patients would benefit more from the neoadjuvant therapy.
This study represents another positive step forward in cancer research, improving the treatment and prognosis of gastric cancers. It also highlights the vital role that whole-slide imaging and image analysis continue to play in medical advancement.
From Figure 5. Liu X, Xu D, Zhou C, Zhong Y, Geng H, Huang C, Shen Y, Xia X, Wang C, Zhu C, Cao H. Association of PD-1 + Treg/PD-1 + CD8 ratio and tertiary lymphoid structures with prognosis and response in advanced gastric cancer patients receiving preoperative treatment.
Advanced Imaging and Analysis Tools in Cancer Research
The integration of state-of-the-art imaging and analysis tools has allowed scientists to gather precise, reliable data from within the tissue microenvironment. With TissueFAXS SL and StrataQuest software, researchers worldwide are making significant strides in understanding and improving cancer treatments.
TissueGnostics provides cutting-edge tools and software that support medical research, helping scientists develop more personalized treatment plans and, ultimately, enhance better patient outcomes.
TissueFAXS SL
The researchers in this study were able to use the TissueFAXS SL scanning system to automatically scan whole slides. This fully automated, high-throughput slide scanner is capable of imaging up to 120 standard slides in a single run, ensuring efficient imaging of reliable and reproducible data in every study.5 The system can also be upgraded with multispectral- or confocal mode to further enhance imaging capabilities.
StrataQuest
The team also employed StrataQuest software to provide cell density data for CD8+ cells, CD3+ cells, FOXP3+ cells, CD20+ cells, PD1+ CD3+ cells, PD-1+ CD8+ cells, PD-1+ FOXP3+ cells and PD-1+ CD20+ cells. They were able to automatically detect TLS, using B- and T-cell markers such as CD20 and CD3/CD8, either within the tumor itself or in direct contact with the tumor cells at the margins of the tumors. Additionally, they measured the distance between TLS and tumor as another variable for the follow-up analysis.
StrataQuest is an advanced imaging solution from TissueGnostics that combines data mining, spatial analysis, and phenotyping tools to provide analysis of the tissues and cells examined across a range of scientific disciplines, including cancer research. AI tools allow for the classification of structures found within the tissues, dramatically reducing the time required for analysis.
The newest version of the software allows users to explore and visualize complex datasets with integrated tools, including visualization features like t-SNE and UMAP, to provide even deeper insights into immune response and related fields.
The Future of Cancer Research
Understanding the tumor microenvironment will undoubtedly continue to play a critical role in the research of cancer progression and treatment. Through studying components of the immune response, such as TLS and the relationships between immune cells, treatments and therapies will be further refined, leading to an ultimate decline in patient mortality.
This study is just one example of how advanced imaging tools from TissueGnostics can generate robust, reliable data that can enhance our understanding of cancer. Technologies like TissueFAXS SL and StrataQuest will continue to play an important role in advancing cancer research and patient care, leading to a future of more effective treatment.
To find out more about the tools on offer, contact a member of the TissueGnostics team today.
References
1. Bray et al. (2024) Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries, CA: A Cancer Journal for Clinicians, 7:3.
2. Lui et al. (2024) Association of PD-1 + Treg/PD-1 + CD8 ratio and tertiary lymphoid structures with prognosis and response in advanced gastric cancer patients receiving preoperative treatment, J Transl Med., 22:1152.
3. Chen et al. (2025) Role of tertiary lymphoid structures and B cells in clinical immunotherapy of gastric cancer, Front Immunol., 15:1519034.
4. Schumacher T N, Thommen D S (2022) Tertiary Lymphoid Structures in Cancer, Science, 375:6576
5. TissueFAXS SL SLIDE LOADER [online] Tissue Gnostics, Available at: https://tissuegnostics.com/products/high-throughput-cytometer/tissuefaxs-sl (Accessed 5th March 2025)
