Cytokines, Chemokines, and Their Receptors Flashcards
What are cytokines?
Proteins secreted by cells that mediate functions of immune system. They initiate communication between immune cells.
They regulate the intensity and duration of the immune response.
Which cells can produce cytokines?
• Any of innate & adaptive immune system, lymphocytes, macrophages, endo/epithelium
What is a chemokine?
Essentially chemokines are chemotactic cytokines.
They are small, soluble proteins
They work primarily in paracrine or endocrine manner.
Primary role is to regulate migration of cells to peripheral tissues or to lymph nodes.
What are the 6 general properties of cytokines?
- Cytokine secretion is brief and self-limited
- Cytokine action is pleitropic and redundant
- Cytokines influence each other
- Cytokines can act locally and systemically
- Cytokines initiate their actions by binding to specific membrane-bound receptors.
- Cytokine receptor ligation leads to gene expression which alters cellular function.
Which cytokines have a more predominant activity in the innate immune system?
IL-12
TNF
IL-1
Chemokines
Which cytokines are more predominant in adaptive immunity?
IL-2
IL-4
Which cytokines are predominant in innate and adaptive immunity?
IFN-Gamma
Which cytokines are considered proinflammatory?
TNF-alpha, IL-1 alpha and beta, IL-6, IL-12, IFN
Which cytokines are considered anti-inflammatory?
IL-10, TGF-Beta
What does TNF-α do? What cell makes it? Which cell responds to it?
Function:
The principal mediator of the acute inflammatory response to Gram-negative bacteria (as well as other infectious microbes), endotoxic shock, and chronic inflammatory conditions.
Produced by
- monocytes
- macrophages
- NK cells
- some DC cells
- T cells =primary source
Cells that respond Stimulate recruitment to site of infection: -neutrophils -monocytes -macrophages -activated T cells
What does IL-1 do? What cell makes it? Which cell responds to it?
Function:
recruitment
Produced by:
- monocytes/macrophages
- dendritic cells
- neutrophils
Cells that respond:
Activate immune cells (like TNF-alpha)
-inc expression of selectins/integrins on endothelial cells
no systemic effects
What does IL-6 do? What cell makes it? Which cell responds to it?
Function:
Involved with induction of inflammatory response (can have similar effects as TNF-α and IL-1).
But, primarily involved with induction of the acute phase response.
Produced by:
- macrophages
- T cells
Cells that respond:
Activate immune cells (like TNF-alpha)
-inc expression of selectins/integrins on endothelial cells
Which cytokine is a major contributor to septic shock?
TNF-α
What induces the feeling of being sick?
IL-1 and IL-6
Which cytokine induces the formation of Th1 cells?
IFNγ (and IL-2)