Dendritic Cells

Definition

Dendritic cells are specialized immune cells that play a crucial role in the body's defense against pathogens by processing and presenting antigens to T cells. They act as a bridge between the innate and adaptive immune systems, helping to activate T cells and stimulate an immune response. Their ability to recognize foreign substances and initiate appropriate immune reactions makes them key players in immunotherapy, particularly in enhancing the effectiveness of treatments for diseases like cancer.

5 Must Know Facts For Your Next Test

1. Dendritic cells are derived from hematopoietic stem cells in the bone marrow and can be found in tissues and organs throughout the body, especially in areas that are in contact with the external environment.
2. These cells are characterized by their long, finger-like projections called dendrites, which increase their surface area for better interaction with antigens and T cells.
3. Upon encountering a pathogen, dendritic cells capture and process the antigen before migrating to lymph nodes, where they present the antigen to naive T cells.
4. The activation of T cells by dendritic cells is critical for generating a specific and robust adaptive immune response, which is essential for effective immunotherapy.
5. In cancer treatments, dendritic cell-based vaccines are being developed to improve the ability of the immune system to recognize and destroy tumor cells.

Review Questions

• How do dendritic cells function as antigen presenting cells in the immune system?
  • Dendritic cells capture antigens from pathogens through phagocytosis or receptor-mediated endocytosis. Once they process these antigens, they present peptide fragments on their surface using major histocompatibility complex (MHC) molecules. This presentation is crucial for activating T cells, as it allows them to recognize specific antigens and mount a targeted immune response.
• Discuss the role of dendritic cells in the development of immunotherapies for cancer treatment.
  • Dendritic cells are pivotal in developing cancer immunotherapies because they can be engineered to present tumor-specific antigens more effectively. By enhancing dendritic cell function through vaccines or other methods, researchers aim to improve the activation of T cells against cancer. This approach not only helps in targeting existing tumors but also contributes to building long-lasting immune memory against potential recurrence.
• Evaluate the impact of dendritic cell dysfunction on immune response and its implications for disease progression.
  • Dendritic cell dysfunction can lead to inadequate activation of T cells, resulting in poor immune responses against infections and tumors. For instance, in cancer, if dendritic cells fail to effectively present tumor antigens, T cells may not recognize and attack cancerous cells. This dysfunction can allow tumors to progress unchecked and has significant implications for developing effective therapies, as restoring dendritic cell function is critical for enhancing overall immunity.

Related terms

Antigen Presenting Cells (APCs): Cells that display antigens on their surface to T cells, initiating an immune response. Dendritic cells are a type of APC.

T Cells:

A type of white blood cell that plays a central role in the immune response, recognizing and responding to specific antigens.

Immunotherapy: A treatment that uses the body's own immune system to fight diseases, especially cancer, often by enhancing the action of dendritic cells.