docarchana
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Activation of cytotoxic T lymphocytes to eliminate virus infected cells requires which of the following?
a, Class I MHC Interferon gamma
b, Class I MHC IL 2
c, Class I MHC IL 4
d, Class II MHC Interferon gamma
e, class II MHC IL 2
f, class II MHC IL 4
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| alexaE
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b
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veni vidi...vincam
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| fox
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B
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| ManuNastai
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hmm, I'm not sure about this, but the correct answer may be E
I think the process in which surface proteins from the virus are presented w/ the Class I MHC to CD8+ T Cells is not what the Q is talking about. I think it refers to the activation, as it clearly states of cytotoxic T Cells, which is done by the Th1 cells.
Th are presented w/ the processed antigen by APCs and it turns into Th1 cells which secrete IL-2 and activates cytotoxics. The ones that recognize the antigen in combination w/ class I MHC on the bod cells are already activated, right? I'm not sure and I'd like some expert in Immuno to clear this for me
thaks
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| ManuNastai
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so? which one is it?
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| blueocean
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I guess is C- http://www.biocarta.com/pathfiles/m_tcytotoxicPat...
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| yasmeen
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ITS B ACTIVATION OF CTCS REQUIRE IL-2
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| penzy
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it is b
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| girl^interrupted
Forum Elite
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B.
One can get confused with E. too. Manu nastai's explanation is good. But since , we have 2 choices. Class-1 refers to the frst signal of CTL activation while the 2nd signal is supported by cytokines release from TH1 (Class-II MHC) thats is IL-2 in the answer. If we chose , class 2 and IL-2 it would not cover the answer completely and merely point at the SAME second signal, omitting the frst signal..following is a good explanation:
The activation of cytotoxic T cells is dependent on several simulanteous interactions between molecules expressed on the surface of the T cell and molecules on the surface of the antigen presenting cell (APC). For instance, consider the two signal model for TC cell activation. The first signal occurs when the TcR of the TC cell strongly interacts with a peptide-bound MHC class I molecule on the APC. There is a second interaction between the CD8 coreceptor and the class I MHC molecule to stablize this signal. The second signal comes from an interaction between the CD28 molecule on the T cell and either CD80 or CD86 (also called B7-1 and B7-2) on the surface of the APC. CD80 and CD86 are known as costimulators for T cell activation. This second signal can be assisted (or replaced) by stimulating the TC cell with cytokines released from helper T cells. Once activated, the TC cell undergoes clonal expansion with the help of a cytokine called Interleukin-2 (IL-2) that is a growth and differentiation factor for T cells.
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| Liederlich
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The CTL response is initiated when CTL precursors in the lymph node are stimulated by
- binding their TCR and CD8 to the antigenic peptide on MHC Class 1
AND
- a costimulatory signal from IL-2
or CD28 - B7 interaction with dentritic cells or Macrophages
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| drpkaur
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b.........
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