Dendritic Cells

Definition

Dendritic cells are a type of antigen-presenting immune cell that play a crucial role in the body's innate and adaptive immune responses. They act as sentinels, patrolling the body for foreign substances and initiating the appropriate immune reactions against potential threats.

5 Must Know Facts For Your Next Test

1. Dendritic cells are found in various tissues, including the skin, lungs, and intestines, where they can encounter and capture foreign antigens.
2. After capturing an antigen, dendritic cells undergo maturation, upregulating the expression of MHC molecules and co-stimulatory receptors.
3. Mature dendritic cells migrate to lymphoid organs, such as lymph nodes, where they present the captured antigen to naive T cells, initiating the adaptive immune response.
4. Dendritic cells play a crucial role in the innate immune response by recognizing and responding to pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors.
5. In the context of transplantation and cancer immunology, dendritic cells can be manipulated to enhance or suppress the immune response, depending on the clinical scenario.

Review Questions

• Explain the role of dendritic cells in the innate immune response.
  • Dendritic cells are key players in the innate immune response. They express pattern recognition receptors that allow them to detect and respond to pathogen-associated molecular patterns (PAMPs), which are molecules commonly found on the surface of microorganisms. When dendritic cells encounter these PAMPs, they become activated and undergo maturation, upregulating the expression of MHC molecules and co-stimulatory receptors. This enables them to present the captured antigens to T cells, initiating the adaptive immune response against the detected pathogens.
• Describe how dendritic cells facilitate the adaptive immune response.
  • Dendritic cells play a crucial role in bridging the innate and adaptive immune responses. After capturing and processing antigens, mature dendritic cells migrate to lymphoid organs, such as lymph nodes, where they present the antigens to naive T cells. This interaction between the dendritic cell and the T cell, facilitated by the display of MHC-antigen complexes and co-stimulatory signals, activates the T cell and initiates the adaptive immune response. The activated T cells then proliferate and differentiate into effector cells, such as cytotoxic T cells or helper T cells, which can mount a targeted and effective response against the specific pathogen or antigen.
• Discuss the importance of dendritic cells in the context of transplantation and cancer immunology.
  • In the field of transplantation and cancer immunology, dendritic cells have become a focus of research and therapeutic interventions. Due to their ability to present antigens and regulate the immune response, dendritic cells can be manipulated to either enhance or suppress the immune system, depending on the clinical scenario. For example, in the case of organ transplantation, dendritic cells can be used to induce tolerance and prevent rejection by presenting donor-specific antigens to T cells in a way that suppresses the immune response. Conversely, in the context of cancer immunotherapy, dendritic cells can be engineered to present tumor-specific antigens, stimulating a robust anti-cancer immune response and enhancing the body's ability to recognize and eliminate malignant cells.

Related terms

Antigen-Presenting Cells:

Specialized cells that display antigens on their surface, allowing them to interact with and activate T cells as part of the adaptive immune response.

Phagocytosis:

The process by which cells, such as dendritic cells, engulf and digest foreign particles, pathogens, or cellular debris.

Major Histocompatibility Complex (MHC):

A group of genes that encode cell surface proteins responsible for presenting antigens to T cells, enabling the immune system to distinguish self from non-self.