Cytokines Flashcards
How can cytokine release be elicited (framkallas)?
1) In response to external stimuli (e.g. Toll-like receptor in activation in macrophages)
2) Passively (owing to tissue damage or other forms of cell necrosis)
What are the three different ways that cytokines can act in response to an activating stimulus and upon binding to their receptor?
1) Autocrine manner: acting on the cells that produce it.
2) Paracrine manner: acting on cells nearby those that produce it.
3) Endocrine manner: secreted by on tissue into the blood, and then acting on different tissue.
What are the cytokine traits?
- Pleiotropy: Many different effects e.g. activation, differentiation, proliferation on different cell types by the same cytokine.
- Redundancy: Different cytokines can have the same effect on one cell type.
- Synergy: The effect of two cytokines together on one cell type is greater than the effect of one cytokine alone.
- Antagonism: The effects of one cytokine inhibit those of another.
What can you tell about cytokines and the innate immune system ?
Mediators and regulators of innate immunity are produced mainly by mono-nuclear phagocytes in response to infectious agents.
Cytokines:
Type I interferon
Interleukin (IL-1, IL-6)
Tumor necrosis factor (TNF)
What can you tell about cytokines and the adaptive immune system ?
Mediators and regulators of adaptive immunity are produced mainly by T lymphocytes in response to specific recognition of foreign antigens.
Cytokines:
Interferon-gamma
IL-2, IL-4, IL-5
What are the three roles of cytokines in inflammation?
1) Destruct invading microorganisms
2) Induce local blood clotting (to limit the spread of infection in the bloodstream)
3) Repair injured tissue
What are chemokines and what cells carry chemokine receptors?
Chemokines are specialized subgroups of secreted proteins that act as chemo-attractants.
Neutrophils and monocytes have chemokine receptors and are attracted by chemokines into the infected tissue from the bloodstream.
