Flashcards in Lecture 14 Thrush Deck (27):
Describe importance of cytokines
important mediators of cell to cell communication
generally act locally (paracrine and autocrine)
also capable of endocrine
used to regulate immune response
lymphokines – cytokines produced by lymphocytes (IL-2, IL-4, etc)
monokines – cytokines produced by monocytes/macrophages (IL-1, TNFa, IL-6)
interleukins – cytokines produced by WBCs and act on WBCs [IL-1 through IL-37 (more?)]
chemokines – low molecular weight molecules important in the inflammatory response; chemotaxis (IL-8, RANTES, etc)
Redundant function of cytokines
different cytokines do the same thing
different cytokines work together for a function (Ex: IL 4 and IL 5)
block each other (ex: INF gamma blocks IL4)
Which cytokines are involved in Th1 subset and what type of reaction?
IL-2, IFN gamma, TNF beta
for CMI reaction
Which cytokines are involved in Th2 subset and what type of reaction?
IL-4, IL-5, IL-10
What is Th0 subset dependent upon?
stimulation from APC (cytokines)
What stimulates Th1?
IL- 12 from macrophages
What stimulates Th2?
IL-4 from Th2
What inhibits Th1?
What inhibits Th2?
Explain Leprosy and which subset is better for this?
. Given that leprosy is caused by an intracellular bacterium (Mycobacterium leprae), the Th1 response is generally the better response. Patients who mount a Th1 response show the tuberuloid form of the disease and they generally will survive the infection.
Th2 and leprosy
Individuals who mount the Th2 response, however, develop lepromatous leprosy and the bacteria spread throughout the body causing disseminated disease with a potentially fatal outcome.
What are the cytokine receptors made of?
most made up of 2 or more chains
cytokine specific unit
signal transducing unit
What is the signaling chain for IL 2 family
Higher affinity binding by?
2 or 3 chains
What occurs after cell activation?
increased cytokine receptor expression
What increases in IL 2 family after activation
alpha and beta
Lack of gamma causes?
x linked SCID
How do microbes evade immune system?
they produce cytokines that can skew immune response
For example, knowing that the best response against viruses is a CMI response, some viruses can produce Th2 type cytokines that skew the response towards Th2 cells.
microbes can produce soluable receptors that keep cytokines from binding to the real receptor
How do cytokines produce Bacterial Septic Shock
through LPS (causes high levels of cytokine release)
specifically INF gamma and IL-1 which cause systemic inflammation
How do cytokines produce toxic shock disease?
through superantigens which cause and overproduction of cytokines
Lymphoid and myeloid cancer and cytokines
overproduction of IL 2
Cytokines and Graft survival
produces antibodies that inhbit IL-2 from binding to recpetor IL-2R which stops production of th1 that is important in graft rejection
Take out NK cells activate them outside body (IL-2)