4.1.1: Communicable Diseases: Cell-mediated response Flashcards
What is the cell-mediated response?
The response of T cells to a foreign antigen through binding to antigens on antigen-presenting cells (APCs) and clonal expansion.
This response is specific to antigens presented on cells, not those in body fluids.
What are antigen-presenting cells (APCs)?
Cells that present a non-self antigen on their surface, including:
* Infected body cells presenting viral antigens
* Macrophages that have engulfed pathogens
* Cells of transplanted organs
* Cancer cells with abnormal self-antigens
APCs play a crucial role in initiating the immune response.
What is the role of T helper cells in the cell-mediated response?
T helper cells have receptors that attach to antigens on APCs, leading to their activation and division by mitosis.
This process results in the production of a large number of T cell clones.
What are cytokines?
Signaling molecules produced by T cells that help in their maturation and in the activation of other immune cells.
Cytokines are essential for communication between immune cells.
Fill in the blank: The cell-mediated response is described as ‘_____’ because T cells respond only to antigens presented on cells.
cell-mediated
What happens after a pathogen is engulfed by a phagocyte?
The antigens are presented on the cell surface, creating an antigen-presenting cell (APC).
This is the first step in the activation of T cells.
What do cloned T helper cells differentiate into?
Cloned T helper cells can become:
* Helper cells
* Cytotoxic cells
* Memory cells
* Regulator cells
Each type plays a distinct role in the immune response.
True or False: T cells respond to antigens detached from cells and found in body fluids.
False
What is the function of T killer cells (cytotoxic T cells)?
To track down and destroy cells infected with viruses.
They are crucial for eliminating infected host cells.
What do T memory cells do?
They provide long-term immunity by remembering the specific shaped antigen.
This allows for a faster and more effective response upon re-exposure to the pathogen.
What is the role of interleukins in the immune response?
Interleukins activate T helper cells and stimulate B lymphocytes and macrophages.
They are important for coordinating the immune response.
What is the function of T regulator cells?
To suppress the immune response to ensure it occurs only when pathogens are detected.
This helps prevent overreaction of the immune system.
