Th17 Cells

Definition

Th17 cells are a subset of T helper cells that play a crucial role in the adaptive immune response. They are characterized by their production of the cytokine interleukin-17 (IL-17) and are involved in the body's defense against extracellular pathogens, as well as the development of autoimmune diseases.

5 Must Know Facts For Your Next Test

1. Th17 cells are named after the cytokine they produce, interleukin-17 (IL-17), which is a key mediator of inflammation.
2. Th17 cells play a crucial role in the body's defense against extracellular pathogens, such as fungi and certain bacteria, by recruiting and activating other immune cells.
3. The differentiation of Th17 cells is regulated by a specific transcription factor, RORγt, which is essential for their development and function.
4. Dysregulation of Th17 cells has been implicated in the pathogenesis of various autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease.
5. Targeting the Th17 cell pathway has become an important therapeutic strategy for the treatment of autoimmune and inflammatory disorders.

Review Questions

• Describe the role of Th17 cells in the adaptive immune response against pathogens.
  • Th17 cells play a crucial role in the adaptive immune response against extracellular pathogens, such as fungi and certain bacteria. They secrete the cytokine interleukin-17 (IL-17), which helps recruit and activate other immune cells, such as neutrophils and macrophages, to the site of infection. This helps enhance the body's defense against these types of pathogens and contributes to the overall adaptive immune response.
• Explain the relationship between Th17 cells and autoimmune diseases.
  • Th17 cells have been implicated in the development and progression of various autoimmune diseases. The dysregulation of Th17 cells, leading to the overproduction of IL-17 and other inflammatory cytokines, can drive chronic inflammation and tissue damage, which are hallmarks of autoimmune conditions. This has made the Th17 cell pathway a key target for therapeutic interventions in the treatment of autoimmune disorders, such as rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease.
• Analyze the importance of the transcription factor RORγt in the differentiation and function of Th17 cells.
  • The transcription factor RORγt (retinoic acid-related orphan receptor gamma t) plays a crucial role in the differentiation and function of Th17 cells. RORγt is essential for the development of Th17 cells, as it directly regulates the expression of genes involved in the production of IL-17 and other Th17-associated cytokines. Without the proper expression of RORγt, Th17 cells would not be able to properly differentiate and carry out their specialized functions in the adaptive immune response, particularly against extracellular pathogens. The importance of RORγt highlights the key regulatory mechanisms that govern the Th17 cell lineage and its impact on both protective immunity and autoimmune pathologies.

Related terms

T Helper Cells: A type of T lymphocyte that helps coordinate the immune response by activating and directing other immune cells, such as B cells and cytotoxic T cells.

Cytokines:

Small signaling proteins secreted by various cells, including immune cells, that regulate the function and behavior of other cells.

Autoimmune Diseases: Conditions in which the immune system mistakenly attacks the body's own healthy tissues, leading to chronic inflammation and tissue damage.