Immuno exam 1 - Bailey Cytokines Flashcards
- What are cytokines?
- Proteins secreted by cells that mediate functions of immune system
- Mode of communication
- Which cells can produce cytokines?
• Any of innate & adaptive immune system, lymphocytes, macrophages, endo/epithelium
- What is a chemokine?
- Chemotactic cytokines
* Role: 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 equally important in the adaptive and innate immune system?
INF-gamma
- Which cytokines are considered proinflammatory? Which ones are considered anti-inflammatory?
- Proinflammatory: TFN-alpha, IL-1 alpha and beta, IL-6, IL-12, IFN
- Anti-inflammatory: IL-10, TGF-Beta
Who produces TNF-alpha?
- monocytes
- macrophages
- NK cells
- some DC cells
- T cells =primary source
What cells respond to TNF-alpha?
Stimulate recruitment to site of infection: -neutrophils -monocytes -macrophages -activated T cells Acute inflammatory response to Gm –
Who produces IL-1?
- monocytes/macrophages
- dendritic cells
- neutrophils
What cells respond to IL-1?
Activate immune cells (like TNF-alpha)
-inc expression of selectins/integrins on endothelial cells
no systemic effects
Who produces IL-6?
- macrophages
- T cells
What cells respond to IL-6
Induction of inflammatory response (sim effects as above)
Primarily: induction of acute phase response neutrophils
-monocytes
-macrophages
-activated T cells
- Which cytokine is a major contributor to septic shock?
TNF-alpha
- What cytokine induces the feeling of being sick?
• Il-1 and Il-6
- Which cytokine induces the formation of Th1 cells? Which cytokine is typically increased during a Th1 response?
- IL-12 →CD4+ →TH 1 →IFN gamma →macrophage activated →kill phagocytosed microbes
- TH1: IFN gamma, IL-2
- Activate macrophages!!
- Why is IFN-γ such an important cytokine?
- It activates macrophages to kill intracellular pathogens, increase antigen presentation
- Produced by: NK, T-helper cells, Ctyotoxic T cells
- Which cytokines are involved with Th2 type immunity?
• TH2: IL-4, Il-5, IL-13, (IL-2)
- What’s the primary job of IL-2? Which cells produce it? Which cells respond to it?
- Job: needed for growth, survival, and differentiation of T helper and T cytotoxic cells
- Also, clonal expansion is Il-2 dependent
- Produced by: T helper cells (CD4+)
- What is meant by Th1 and Th2 type immunity? Which one is active against intracellular pathogens? Which one is active against extracellular pathogens?
T helper type 1 – most effective against intracellular pathogen; produce cytokines
Involves macrophages & cytotoxic T cells and IFN-γ & IL-2
T helper type 2 – Most effective against extracellular pathogen (can’t live within cell)
Involves antibodies produced by B cells, mast cells and eosinophils; IL-4, IL-5, IL-13, IL-2
IL-4
Produced by Th2 cells
- Induce naïve Th cells to differentiate into TH2 cells to prod more cytokines
- class switch to IgE
IL-13
Produced by Th2 cells-similar to IL-4
- induce IgE isotype switching
- stimulate mucous production ingut and lung
- facilitate inflammation by increasing adhesion molecule and chemokine expression
IL-5
Produced by Th2 cells-eosinophil differentiation, proliferation, and activation
-eosinophils are necessary for protection against parasites
