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 serve as a bridge between the innate and adaptive immune responses, activating T cells and initiating a more targeted immune response against pathogens.

5 Must Know Facts For Your Next Test

1. Dendritic cells are found in various tissues throughout the body, including the skin and mucosal surfaces, where they capture pathogens.
2. Upon encountering an antigen, dendritic cells undergo maturation, which enhances their ability to present antigens to T cells in lymph nodes.
3. They express high levels of major histocompatibility complex (MHC) molecules, essential for presenting processed antigens to T cells.
4. Dendritic cells can differentiate into various subtypes, each with specific functions in regulating the immune response.
5. They play a vital role in maintaining immune tolerance by preventing excessive activation of T cells against self-antigens.

Review Questions

• How do dendritic cells connect the innate and adaptive immune systems?
  • Dendritic cells act as a link between the innate and adaptive immune systems by capturing antigens from pathogens and processing them for presentation to T cells. When they detect a pathogen, dendritic cells migrate to lymph nodes where they mature and present these antigens using MHC molecules. This interaction activates T cells, which then mount a specific immune response tailored to eliminate the pathogen.
• Discuss the role of dendritic cell maturation in the activation of T cells.
  • When dendritic cells capture antigens, they undergo a maturation process that enhances their ability to stimulate T cells. During maturation, dendritic cells increase the expression of co-stimulatory molecules and MHC class II molecules on their surface. These changes enable them to effectively present processed antigens to naive T cells in lymph nodes, providing both the necessary signals for activation and promoting the development of a robust adaptive immune response.
• Evaluate the implications of dendritic cell function on vaccine development and immunotherapy.
  • The unique role of dendritic cells in antigen presentation makes them critical targets for vaccine development and immunotherapy strategies. By harnessing their ability to activate T cells, vaccines can be designed to enhance dendritic cell function, leading to stronger immune responses against pathogens or tumors. Moreover, understanding how dendritic cells promote tolerance or activation helps inform approaches in cancer immunotherapy, potentially improving treatment outcomes by directing immune responses more effectively against cancerous cells while minimizing adverse effects.

Related terms

Antigen: A substance that the immune system recognizes as foreign and can provoke an immune response.

T cells: A type of white blood cell that plays a central role in cell-mediated immunity, involved in directly killing infected host cells or helping other immune cells.

Innate immunity: The body's first line of defense against pathogens, consisting of physical barriers and immune responses that are non-specific and immediate.