Effector T cells

Definition

Effector T cells are specialized immune cells that arise from activated T lymphocytes and are crucial for the adaptive immune response. These cells play a significant role in identifying and eliminating infected or malignant cells, primarily through the release of cytokines and direct cytotoxic activity. Their activation leads to a robust immune response that is tailored to specific pathogens or abnormalities.

5 Must Know Facts For Your Next Test

1. Effector T cells can be categorized into different types, including cytotoxic T cells (CD8+) that kill infected cells and helper T cells (CD4+) that assist other immune cells.
2. These cells emerge from naive T cells after they encounter their specific antigen presented by antigen-presenting cells (APCs).
3. Once activated, effector T cells can proliferate rapidly and migrate to sites of infection or inflammation to exert their functions.
4. The action of effector T cells is crucial in controlling viral infections, intracellular bacteria, and tumor growth.
5. After an immune response, most effector T cells die off, but some survive as memory T cells for faster responses in future infections.

Review Questions

• How do effector T cells contribute to the immune response once they are activated?
  • Effector T cells play a key role in the immune response by directly targeting infected or cancerous cells. Once activated, they can release cytokines that help recruit and activate other immune cells, enhancing the overall immune response. Cytotoxic T cells specifically recognize and kill infected host cells, while helper T cells assist B cells and other immune components to produce antibodies and improve the inflammatory response.
• Compare and contrast the roles of cytotoxic T cells and helper T cells as effector T cell types.
  • Cytotoxic T cells (CD8+) primarily focus on directly killing infected or cancerous cells by recognizing specific antigens presented on these cells. In contrast, helper T cells (CD4+) do not kill directly but instead secrete cytokines that aid in activating other immune components like B cells for antibody production and enhancing macrophage activity. Both types are essential for a robust adaptive immune response but function in distinct ways to address different aspects of infection or disease.
• Evaluate the significance of memory T cells in the context of effector T cell function during subsequent infections.
  • Memory T cells are vital for providing long-term immunity following an initial infection. After an effector T cell response clears an infection, most effector T cells die off, but some persist as memory T cells. These memory cells enable a quicker and more effective response if the same pathogen invades again. This rapid recall ability is crucial for preventing reinfections and demonstrates the importance of effector T cell activation in establishing lasting immunity.

Related terms

Cytokines: Signaling molecules secreted by immune cells that mediate and regulate immunity, inflammation, and hematopoiesis.

T lymphocytes:

A type of white blood cell that plays a central role in cell-mediated immunity, which includes both helper T cells and cytotoxic T cells.

Antigen Presentation: The process by which immune cells display foreign antigens on their surface, allowing T cells to recognize and respond to pathogens.