Cytokines Flashcards
What are cytokines?
Small proteins that are released by immune effector cells and mediate communication between cells during immune responses
What is a cytokine storm?
Inappropriate immune response that is caused by rapidly proliferating and highly activated T cells or NK cells
What are the families of cytokines?
Interleukins - between white blood cells
Colony stimulating factors
Interferons
TNF a and B
What are interleukins?
Made by leukocytes and have effects on other leukocytes
What are colony stimulating factors?
Made by a variety of cells and stimulate granulocyte, monocyte, and dendritic cell production and differentiation
What are interferons?
Produced by leukocytes and fibroblasts
Include alpha, beta, and gamma
Anti viral properties (prevent protein synthesis) and increase MHC expression
What is TNF?
Made by macrophages and T cells
Promote inflammation, apoptosis, angiogenesis, and T cell activation
Describe the general classification system for cytokines with regards to T-helper cells.
Th1 - release cytokines which aid in cell mediated immunity
Th2 - release cytokines which support humoral immunity
Th17 - release cytokines that promote inflammation
Th1 and Th2 can inhibit each other, all influence Th0 cells to give rise to one of the three
Describe cytokine receptors.
Generally consist of 2 or more chains belonging to families characterized by structural homology
Alpha chain determines specificity
Binding of cytokine is followed by internalization, with new receptors being expressed within a few hours
What signaling pathway is used by cytokine receptors?
Many use JAK/STAT
Others use IRAK, G-protein, and TRAF-dependent pathways
What are chemokines?
Cytokines that induce cell movement along a gradient
Two major types: Inflammatory and Lymphoid
