Vaccination and Immunity Theories Quiz

Part 1: Historical Context and Theories

• Ancient Chinese practice involved injecting dry smallpox pustules to induce a mild infection. This is known as variolation.
• Edward Jenner is credited with starting the first vaccination campaigns against smallpox in 1798.
• Louis Pasteur's germ theory proposed that diseases are caused by microscopic organisms.
• William Coley's hypothesis was that inoculating patients with bacteria could shrink tumors.
• Paul Ehrlich proposed the immunosurveillance theory in 1908. This theory suggests the immune system can distinguish tumor cells from normal cells.
• Jenner's vaccination experiments, Ehrlich's antibody research, and the work of Thomas and Burnet with syngeneic mouse models supported the idea that immune cells can distinguish tumor cells from normal cells.
• A major criticism of the immunosurveillance theory was the lack of experimental evidence.
• A true statement about the immune system's role in cancer is that the immune system can both prevent and support tumor growth.

Part 2: Immune System and Cancer

• The adaptive immune response involves T cells and B cells.
• T cells recognize antigens through antigen-MHC complexes.
• If a T cell recognizes a self-antigen in the thymus, it is eliminated.
• Neutrophils and macrophages are primarily responsible for phagocytosis in the innate immune system.
• Regulatory T cells (Tregs) promote a decrease in inflammation.

Part 3: Immunoediting and Tumor Evolution

• The first phase of immunoediting is elimination.
• During the elimination phase, immune cells release IFN-y to kill tumor cells.
• The equilibrium phase of tumor evolution is characterized by a dynamic balance between tumor cells and immune cells.
• The equilibrium phase is closely linked to Darwinian microevolution.
• The escape phase in immunoediting is driven by tumor cells gaining the ability to suppress the immune system. This phase can last for up to 20 years or longer.
• The critical rupture point in tumor progression is when the tumor spreads to distant organs.
• Clinically detectable tumors are commonly associated with the escape phase.
• A neo-antigen is a mutated protein unique to cancer cells.
• During the equilibrium phase, the immune system continuously attacks the tumor but cannot eliminate it entirely.

Part 4: Physical and Molecular Inhibitory Mechanisms

• Cancer-Associated Fibroblasts (CAFs) create a protective collagen barrier around tumors.
• Tumor cells evade T-cell recognition by upregulating MHC-I.
• VEGF promotes angiogenesis in tumors.
• Tumors use VEGF to evade the immune system by reducing endothelial adhesion molecules.
• Tumor cells utilize mechanisms like upregulating FasL to induce immune cell apoptosis at a distance.
• Tumors interfere with immune cell navigation by producing antagonistic ligands for CXCR3.
• IL-10 suppresses T-cell function in the tumor microenvironment (TME).
• The Warburg effect is the preferential use of glycolysis, even in the presence of oxygen by tumor cells.
• Tumors become depleted of glucose due to the Warburg effect, and the byproduct lactic acid, contributes to the acidity of the TME.
• Hypoxia impairs immune cell activity due to their reliance on aerobic metabolism.
• Acidity in the TME impairs immune cell function and induces anergy.
• The tumor microenvironment (TME) favors the survival and growth of the tumor in several ways, impacting immune cells.
• The M2 macrophage phenotype facilitates these processes.
• Regulatory T cells contribute to tumor-promoting and immune evasion roles in the TME, actively suppressing certain immune cell types.

Test your knowledge on the historical context and theories related to vaccination and the immune system. This quiz covers key figures such as Edward Jenner and Paul Ehrlich, their contributions, and critical theories in immunology. Explore the evolution of ideas about immunity, diseases, and cancer.