Dendritic Cells

Definition

Dendritic cells are specialized antigen-presenting cells that play a crucial role in the immune system by capturing, processing, and presenting antigens to T cells. They act as a bridge between the innate and adaptive immune responses, enabling the body to recognize and respond to pathogens effectively. Their ability to activate T cells is essential for developing an adaptive immune response against infectious diseases.

5 Must Know Facts For Your Next Test

1. Dendritic cells are found in tissues that are in contact with the external environment, such as the skin and mucosal surfaces, where they can capture pathogens.
2. Upon encountering an antigen, dendritic cells undergo maturation and migrate to lymph nodes, where they present the processed antigens to naive T cells.
3. They produce various cytokines that can influence T cell differentiation and activation, determining the type of immune response that develops.
4. Dendritic cells can also interact with B cells, aiding in antibody production by providing necessary signals and antigen presentation.
5. In addition to their role in immunity, dendritic cells can contribute to tolerance by preventing excessive immune responses against harmless antigens.

Review Questions

• How do dendritic cells link innate and adaptive immunity?
  • Dendritic cells link innate and adaptive immunity by capturing and processing antigens from pathogens encountered in peripheral tissues. Once they have processed these antigens, they migrate to lymph nodes where they present them to naive T cells. This interaction is crucial as it activates T cells, transitioning the immune response from a non-specific, rapid reaction to a more specific and long-lasting adaptive response.
• Discuss the role of dendritic cells in influencing T cell differentiation.
  • Dendritic cells play a vital role in influencing T cell differentiation through the production of specific cytokines during antigen presentation. Depending on the signals they provide, dendritic cells can promote the development of different types of T cells, such as Th1 or Th2 subsets, which are tailored to respond to particular types of infections. This ability to shape the immune response is crucial for effective pathogen clearance and for maintaining immune homeostasis.
• Evaluate the implications of dendritic cell dysfunction in the context of infectious diseases.
  • Dendritic cell dysfunction can significantly impact the body's ability to mount effective immune responses against infectious diseases. If dendritic cells fail to properly capture or present antigens, T cell activation may be insufficient, leading to inadequate immune responses that could result in chronic infections or increased susceptibility to pathogens. Additionally, dysfunction could also lead to autoimmunity if tolerance mechanisms are disrupted. Understanding these implications emphasizes the importance of dendritic cell health in preventing and treating infectious diseases.

Related terms

Antigen: A substance that induces an immune response, often recognized by antibodies or T cell receptors.

T Cells: A type of white blood cell that plays a central role in cell-mediated immunity and can directly kill infected cells or help activate other immune cells.

Innate Immunity: The first line of defense against pathogens, involving physical barriers and immune cells that respond quickly to infections without prior exposure.