PART 3 : Immunity and Tumor escaping mechanisms (1)

An ancient Chinese practice involving injecting dried smallpox pustules to induce a mild infection and develop immunity.

The first documented vaccination campaign against smallpox, initiated in 1798 by Edward Jenner.

A scientific theory proposed by Louis Pasteur in the 19th century, stating that diseases are caused by microscopic organisms.

The hypothesis that injecting patients with bacteria could shrink tumors, proposed by William Coley in the late 19th century.

A theory proposed by Paul Ehrlich in 1908, suggesting that the immune system constantly monitors and destroys developing cancer cells.

An experiment using mice with identical genetic backgrounds, demonstrating the immune system's ability to distinguish between tumor cells and normal cells.

The immune system's ability to both prevent and support tumor growth. It plays a complex role in cancer development.

A modern therapy inspired by Coley's work, using weakened bacteria (BCG) to stimulate the immune system to fight cancer.

A type of immune response involving T cells and B cells, providing specific recognition and tailored responses to pathogens and other threats.

The process by which T cells recognize antigens by binding to antigen-MHC complexes on the surface of antigen-presenting cells.

The elimination of immature T cells that recognize self-antigens in the thymus, preventing autoimmune reactions.

Immune cells primarily responsible for phagocytosis in the innate immune system, engulfing and destroying pathogens.

A type of T cell that regulates immune responses and suppresses other immune cells, often involved in maintaining immune tolerance and preventing autoimmune diseases.

A molecule essential for antigen presentation on cells, acting as a signpost for the immune system.

A type of immunity that provides a rapid, non-specific response to infection, acting as the first line of defense.

The primary role of B cells in the immune response is to produce antibodies, which target and neutralize pathogens.

A potentially life-threatening condition characterized by excessive and damaging inflammation, caused by an overreactive immune response.

The first phase of the immunoediting process, characterized by the immune system effectively eliminating emerging tumor cells.

A critical rupture point in tumor progression, marking the shift where tumor cells gain the ability to suppress immune responses and escape immune surveillance.

A period of dynamic balance between tumor cells and immune cells, where the immune system continuously attacks the tumor but cannot completely eliminate it.

The process of tumor cells adapting to the immune system's pressure, evolving to evade immune recognition and become less vulnerable to immune attack.

A mutated protein unique to cancer cells, often recognized by the immune system as a target for attack.

A key feature of tumor cell metabolism, characterized by a reliance on glycolysis for energy production, even in the presence of oxygen.

A protective collagen barrier produced by CAFs, forming a shield around tumors and hindering immune cell infiltration.

The process by which tumors downregulate MHC-I expression, making them less visible to cytotoxic T cells.

A molecule that promotes angiogenesis (blood vessel formation), allowing tumors to access oxygen and nutrients and evade the immune system.

A tumor immune evasion strategy where tumors produce FasL to induce apoptosis in immune cells at a distance.

Tumors produce antagonistic ligands for CXCR3, disrupting immune cell navigation and hindering their ability to reach tumor sites.

A cytokine with immunomodulatory effects, suppressing T-cell function and creating an immunosuppressive environment favorable for tumor growth.

Tumor cells use excessive glucose, leading to a decrease in glucose levels in the tumor environment.

Lactic acid, a byproduct of glycolysis, accumulates in the tumor microenvironment, making it acidic.

Acidity in the tumor microenvironment impairs the function of immune cells, hindering their ability to fight cancer.

Hypoxia or low oxygen in the tumor microenvironment limits the function of immune cells because they rely on oxygen for energy.

GLUT1, a glucose transporter, is upregulated by tumor cells to increase glucose uptake.

Lactate accumulation in the TME contributes to the acidic environment, which inhibits immune cell function, benefiting tumor cells.

In a glucose-depleted TME, immune cells become inactive and unable to effectively fight cancer cells, entering an anergic state.

Natural killer (NK) cells and effector T cells are most affected by the acidic and glucose-depleted TME, as they rely on aerobic metabolism.

The Warburg Effect allows tumors to rapidly produce energy through glycolysis, supporting fast growth and outpacing the immune system.

Tumor cells secrete TGF-β, which converts normal fibroblasts into cancer-associated fibroblasts (CAFs).

CAFs build a protective collagen barrier around the tumor, preventing immune cells from reaching the tumor site.

High levels of TGF-β can convert CD4+ T cells into regulatory T cells (Tregs), which suppress immune responses.

Tumors manipulate macrophages by secreting factors that polarize them into pro-tumoral M2 macrophages.

M2 macrophages promote tumor growth by suppressing inflammation and aiding tumor cell survival.

Tregs in the TME primarily suppress effector T cells, which are critical for targeting and eliminating cancer cells.

Tregs play a key role in immune evasion by inhibiting the immune response and protecting the tumor from attack.

TGF-β promotes the conversion of macrophages into the M2 phenotype, which supports tumor growth.

CAFs contribute to immune evasion by forming a physical barrier around the tumor, preventing immune cells from infiltrating the tumor site.

CD8+ cytotoxic T cells, responsible for killing tumor cells, are most susceptible to dysfunction in the hypoxic TME due to their reliance on oxygen for energy.

VEGF, a molecule that promotes angiogenesis (formation of new blood vessels), helps tumors grow and spread, contributing to their ability to evade the immune system.

IL-10, an immunosuppressive cytokine, is produced by tumor cells and macrophages, contributing to an immunosuppressive environment that favors tumor growth.

The area surrounding a tumor that comprises the tumor cells, stromal cells, immune cells, and extracellular matrix. It significantly influences tumor growth, progression, and response to treatment.

A type of fibroblast cell found in the tumor microenvironment that promotes tumor growth and progression by contributing to an immunosuppressive environment and promoting angiogenesis.

A phenomenon where the tumor microenvironment becomes depleted of glucose, primarily due to excessive glucose consumption by tumor cells utilizing the Warburg Effect.

The process by which immune cells, particularly T cells and NK cells, become inactive and unable to effectively target and eliminate tumor cells due to the unfavorable conditions in the TME, such as glucose depletion and acidity.

The process by which tumor cells evade immune surveillance by expressing proteins that are unique to cancer cells and not present in normal cells, making them targets for the immune system.

A type of immune cell that plays a key role in orchestrating and regulating the immune response. In the context of cancer, some T cells can target and destroy tumor cells, while others can suppress the immune system, promoting tumor growth.

A type of immune cell that is directly involved in the destruction of tumor cells by releasing cytotoxic molecules and directly attacking the target cells.

A surface molecule found on cells that presents antigens to T cells, allowing the immune system to recognize and target infected or cancerous cells.

A molecule that stimulates the formation of new blood vessels, a process called angiogenesis. Tumor cells exploit VEGF to create a network of blood vessels, providing them with nutrients and oxygen, essential for their growth and spread.

A protein that binds to the Fas receptor on the surface of cells, triggering a cascade of events that ultimately leads to programmed cell death or apoptosis. Tumor cells can use FasL to eliminate immune cells that are targeting them, contributing to immune evasion.

A receptor on the surface of cells that binds to Fas Ligand (FasL), triggering a cascade of events leading to apoptosis or programmed cell death. Tumor cells can exploit this pathway to eliminate immune cells that are trying to eliminate them.

A type of immune cell responsible for engulfing and destroying pathogens and cellular debris. While macrophages are part of the innate immune system, their role in the tumor microenvironment is complex, as they can both promote tumor growth and fight against it.

A type of macrophage that is activated by the tumor microenvironment and contributes to tumor growth and progression. These macrophages suppress inflammation, promote angiogenesis, and even suppress other immune cells.

A type of macrophage that is activated in response to inflammatory stimuli and plays a role in fighting infection and tumor cells. In the TME, M1 macrophages can activate other immune cells and directly combat tumor cells.

A cytokine that plays a complex role in both immune activation and suppression. In the TME, IL-10 can suppress T-cell activity, promoting an immunosuppressive environment that favors tumor growth.

A molecule primarily associated with the immune system that can be produced by tumor cells and other cells in the TME. It exerts a direct influence on the tumor environment, influencing its growth, angiogenesis, and interactions with immune cells.

A type of immune cell that plays a critical role in the innate immune system. Unlike adaptive immune cells, NK cells do not require prior sensitization and can directly kill tumor cells, but their function can be impaired in the TME.

A signaling pathway that plays a crucial role in cell growth, differentiation, and survival, but can also be manipulated by tumor cells to promote their own growth and evade the immune system.

A type of cell found in the TME that can produce collagen, a fibrous protein that forms a scaffold for various tissues. In the context of cancer, CAFs can form a physical barrier around the tumor, preventing immune cells from entering and attacking cancer cells.

A process by which tumor cells evolve under pressure from the immune system, becoming less susceptible to immune attack. This can involve genetic mutations, changes in gene expression, or other adaptations.

A group of immune cells that are specifically activated to fight a particular pathogen or antigen. In the context of cancer, effector T cells are the main attackers of tumor cells.

A process by which a tumor cell activates a pathway that leads to its own death. While this may seem counterintuitive, tumor cells can use this mechanism to eliminate nearby, non-cancerous cells, creating space for themselves to grow.

Small, membrane-bound vesicles produced by cells that can be released and taken up by other cells. These vesicles can carry various molecules, including proteins, nucleic acids, and lipids, and can influence the behavior of recipient cells. In cancer, tumors can release exosomes that contribute to an immunosuppressive environment and tumor growth.