Immunology And Immune Response to Cancer: Antigen presentation, Activation of Immune cells

Summary

The immune system plays a crucial role in detecting and eliminating cancer cells. Cancer cells arise from genetic mutations and produce abnormal proteins that the immune system recognizes as foreign. The process involves antigen presentation, immune cell activation, and cancer cell elimination. Key players include antigen-presenting cells, T-cells, cytotoxic T-cells, and helper T-cells. However, tumor cells can evade immune detection through immune checkpoint proteins and immunosuppressive environments. Immunotherapies, such as immune checkpoint inhibitors, can enhance the immune response, providing promising strategies for overcoming tumor resistance and improving cancer treatment outcomes.

Takeaways

• 😀 The immune system plays a crucial role in identifying and eliminating cancer cells.
• 😀 Cancer cells arise from genetic mutations in normal cells, producing abnormal proteins or antigens.
• 😀 The immune system recognizes these abnormal antigens as foreign, triggering an immune response against cancer.
• 😀 Antigen-presenting cells, like dendritic cells and macrophages, play a key role in initiating the immune response by presenting cancer cell antigens.
• 😀 T-cells are the primary effectors in the immune response to cancer, recognizing cancer antigens and becoming activated.
• 😀 Activated T-cells undergo clonal expansion and differentiate into cytotoxic T-cells and helper T-cells.
• 😀 Cytotoxic T-cells directly kill cancer cells by inducing apoptosis (programmed cell death).
• 😀 Helper T-cells support cytotoxic T-cells and activate other immune cells, such as B cells that produce antibodies against cancer antigens.
• 😀 Natural killer (NK) cells are another type of immune cell capable of directly killing cancer cells.
• 😀 Tumor cells can evade immune recognition by downregulating MHC molecules or producing immune checkpoint proteins like PD-1 or CTLA-4, which inhibit T-cell activation.
• 😀 Immune checkpoint inhibitors, such as anti-PD-1 or anti-CTLA-4 antibodies, can block checkpoint proteins and enhance the immune response to cancer.
• 😀 The tumor microenvironment can create an immunosuppressive environment, with immune suppressor cells and secreted factors inhibiting the immune response.
• 😀 Strategies to overcome the immunosuppressive tumor microenvironment include immune stimulatory cytokines, depletion of suppressor cells, or using oncolytic viruses to kill tumor cells and stimulate the immune response.

Q & A

What role does the immune system play in cancer detection?

The immune system plays an essential role in identifying and eliminating cancer cells, which arise from normal cells that undergo genetic mutations, leading to the production of abnormal proteins or antigens.

What are cancer antigens and how do they relate to the immune system?

Cancer antigens are abnormal proteins produced by cancer cells that are not normally present in the body. These antigens can be recognized as foreign by the immune system, triggering an immune response.

How do antigen presenting cells (APCs) contribute to the immune response against cancer?

Antigen presenting cells, such as dendritic cells and macrophages, process cancer cell antigens and present them on their surface in association with major histocompatibility complex molecules, thereby initiating the immune response.

What is the role of T-cells in the immune response to cancer?

T-cells are the primary effector cells in the immune response to cancer. They recognize cancer cell antigens and become activated, undergoing clonal expansion and differentiating into cytotoxic T-cells and helper T-cells that target and destroy cancer cells.

How do cytotoxic T-cells eliminate cancer cells?

Cytotoxic T-cells directly kill cancer cells by inducing apoptosis, or programmed cell death, effectively eliminating the cancer cells from the body.

What is the function of helper T-cells in the immune response to cancer?

Helper T-cells support cytotoxic T-cells in killing cancer cells and also activate other immune cells, such as B cells, which produce antibodies targeting cancer antigens.

What are natural killer (NK) cells and how do they contribute to cancer immune surveillance?

Natural killer (NK) cells are another type of immune cell that can directly kill cancer cells. They play a critical role in the innate immune response to cancer.

How can cancer cells evade the immune system?

Cancer cells can evade immune recognition by downregulating major histocompatibility complex molecules or by producing immune checkpoint proteins, such as programmed cell death protein 1 (PD-1) or cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), which inhibit T-cell activation.

What are immune checkpoint inhibitors, and how do they help in cancer treatment?

Immune checkpoint inhibitors, such as anti-PD-1 or anti-CTLA-4 antibodies, block checkpoint proteins that inhibit T-cell activation, thereby enhancing the immune response and helping the immune system target and eliminate cancer cells.

What is the tumor microenvironment, and how does it impact the immune response to cancer?

The tumor microenvironment can be immunosuppressive, with tumors recruiting immune suppressor cells like regulatory T-cells and myeloid-derived suppressor cells. They also secrete factors that inhibit the immune response, making it harder for the immune system to eliminate cancer cells.

What strategies are used to overcome the immunosuppressive tumor microenvironment?

Strategies to overcome the immunosuppressive tumor microenvironment include the use of immune stimulatory cytokines, depletion of immune suppressor cells, or the use of oncolytic viruses to selectively kill tumor cells and stimulate the immune response.