L15 - Cancer Immunology Lecture 1 - Christoph Wuelfing Flashcards
1. Tumours need to activate resident innate immunity. How? 2. Dendritic cells need to activate adaptive immunity in the tumour draining lymph nodes. What do T cells recognise? 3. Innate and adaptive immune cells need to infiltrate tumours. Do they? Which immune cells do? 4. The tumour microenvironment interacts with the immune system. How? (114 cards)
Why is tumour immunology considered a challenging field to teach?
📚 Because it’s a dynamic, rapidly changing field with limited textbooks and reviews, relying heavily on primary literature.
Which immune cells are primarily responsible for killing tumour cells?
⚔️ Cytotoxic T cells and natural killer cells are the main killers in the tumour microenvironment.
What is the role of natural killer (NK) cells in tumour immunology?
🛡️ NK cells also kill tumour cells, though they are less prominent compared to cytotoxic T cells.
Why are myeloid cells such as macrophages and dendritic cells important in cancer immunity?
🔧 They shape the tumour microenvironment and support T cell activation, despite not directly killing tumour cells.
How does the tumour microenvironment impact immune responses?
🚧 The microenvironment is largely suppressive, which can hinder effective immune cell activity against tumours.
How is the tumour microenvironment largely suppressive?
🚧 The tumour microenvironment is suppressive because it accumulates immunosuppressive cells (e.g., regulatory T cells and myeloid-derived suppressor cells), secretes inhibitory cytokines (like TGF-β and IL-10), and expresses immune checkpoint molecules (e.g., PD-1, CTLA-4) that dampen effective T cell responses.
What is the significance of inhibitory receptors in the context of tumour immunology?
⛔ Inhibitory receptors (like PD-1 and CTLA-4) are upregulated during persistent stimulation and reduce immune cell function across various cell types.
Do inhibitory receptors affect only T cells?
🔒 No, they also modulate the function of other cells such as myeloid cells, impacting the overall immune response.
Why is understanding dendritic cell and macrophage biology crucial for tumour immunology?
💡 These cells define the environment in which cytotoxic T cells operate, influencing both activation and suppression of immune responses.
What key challenges must the immune system overcome to generate an effective antitumor response?
🛡️ The immune system faces several challenges:
- Activating Innate Immunity: Tumours must first trigger resident innate cells (like macrophages and dendritic cells).
- Priming Adaptive Immunity: Dendritic cells need to capture tumour antigens and migrate to tumour-draining lymph nodes to prime T cells.
- Immune Cell Infiltration: Both innate and adaptive immune cells (e.g., cytotoxic T cells) must be recruited from the blood into the tumour microenvironment.
- Adapting to a Suppressive Environment: Once inside, immune cells must overcome the inhibitory, suppressive signals of the tumour microenvironment to effectively eliminate tumour cells.
What makes the immune system in tumour immunology complex?
🧬 It involves a wide variety of cells—including dendritic cells, macrophages, neutrophils, mast cells, NK cells, T cells, and B cells—that work in concert to mount an antitumor response.
Why is it important to understand immune cell interactions in the context of tumour immunology?
🤝 Immune cells interact closely with one another, and these intercellular communications determine how effectively the immune system can recognize and attack tumour cells.
What does it mean that immune cells can acquire various differentiation states?
🔄 Each immune cell type can differentiate into distinct states (e.g., inflammatory vs. tissue-repair macrophages, Th1 (cell mediated) vs. Th2 (humoral immunity) vs. Th17 (Extracellular pathogens) CD4+ T cells), which influences their function during an antitumor response.
How does the dynamic nature of immune cell states impact tumour immunology?
⚡ Immune cell states are not static; they change in response to the tumour microenvironment, altering their behavior and effectiveness over time.
What is the significance of tumour cell dynamics in immunology?
🌀 Tumour cells are heterogeneous and evolve genetically, meaning the tumour is composed of diverse subpopulations that can adapt and potentially resist immune responses and therapies. ( selection)
Why is a systems-level view essential in understanding tumour immunology?
🔍 A holistic approach is required to integrate the complex interactions among various immune cells, their dynamic states, and the evolving tumour microenvironment for effective therapeutic targeting.
What does the diagram (“Tumour immunity is dynamic”) illustrate?
🔄 It shows how tumour cells and the immune system interact over time in three phases: elimination, equilibrium, and escape.
What happens during the “elimination” phase of tumour immunity?
🛡️ The immune system effectively identifies and destroys most nascent (early) tumour cells, preventing them from progressing.
Why are tumours described as heterogeneous and dynamic?
🌱 Because they contain diverse cell variants that continually acquire new mutations, some of which may resist immune attack.
What is the significance of the “equilibrium” phase?
⚖️ In this phase, the immune system kills some tumour variants while others survive and grow, creating a balance that exerts strong selection pressure on the tumour.
How does the tumour eventually “escape” immune control?
🏃 Tumour cells develop traits (e.g., immune suppression, altered antigens) that help them evade or subvert the immune system, leading to unchecked growth.
Why do clinical tumours pose a bigger challenge to the immune system?
🚧 By the time patients present with tumours, the cancer cells have already passed through immune selection, leaving behind the most immune-resistant variants.
How does this dynamic process influence cancer therapy?
🧩 Therapies must overcome the tumour’s evolved resistance mechanisms, targeting cells that have adapted to evade normal immune responses.
Why is it important to understand the immune system’s early success in tumour elimination?
💡 It highlights that many potential tumours never become clinically evident, and the ones we do see have already “outsmarted” the immune system, guiding us to design more robust treatments.