logitech
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a research laboratory is studying mechanism of immunity to babesia microti in mice.cells from immune mice r seperated by flow cytometry,using florecently labelled antibodies directed against a variety of cell surface markers.infected red blood cells r then added to the seperated population of immune cell and observed for lysis in the absence of complement.which of the following cell surface markers would b most useful in identifying a cell capable of lysing infected cells in this system??????
A...CD4
B...CD8
C..CD16
D...CD56
E...CD14
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| Ancylostoma
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Well I dont know for sure but we can make some assumptions, since RBC dont have class 1 or class 2 MHC molecules , it cant be a or b. C and D are natural killer cells and e is the marker from the macrophage.
D
Making a change, the absence of the cd markers makes D a great choice. Besides the fact that I think a I remember the question and it was one that was in USMLE world. The only thing I forgot is that I was taught that cd 16 and cd 56 were nk cells, usmle world is going to say cd 56 is the best choice or something like that .
Edited by Ancylostoma on 01/17/07 - 09:12 PM
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| me007
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d.
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| Palaniappan
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Will go with E...
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| Clozapine
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C?
Markers expressed by NK cells are basically ~ CD 56, CD 16 and CD2. CD 2 and CD 56 act as adhesion molecules (CD 56 = NCAM and CD 2 binds with LFA 3)
Only CD 16 on NK and other phagocytes (PMN and Macrophage) mediates phagocytosis and ADCC.
Ofcourse I didn know anything about NK cell markers 
Ancylostoma or anyone, would you pls pls let us know about the other CD`s except for CD3, 4, 8, 19, 21, 28 and 40
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| me007
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what is correct and why?
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| Clozapine
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pls give us the answer logitech ...
I still think it is C. CD16 .... ref. Kaplan immno NK cells.
To my understanding it is not E b/c CD14 is the marker for macrophages and macrophages would need cytokine stimulation from ThCells but RBC's lack all kind of MHC expressions to activate ThCells
Please correct me if I`m wrong.
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| Ancylostoma
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you are right, but the more specific marker for Nk cells is cd56. this is a usmle world question i'm almost 100% sure now.
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| me007
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it's actually can be CD14 bcs macrophages eliminates RBCs and their parasites in spleen.
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| indidoc1
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i m more inclined towards NK cells... CD56 Even goljan sez CD56 is a NK cell marker.
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| doc179
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D
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| keepgoing
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i also vote for d
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| me007
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old or damaged RBSs are taken by splenic macrophages.
Why not CD14?
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| new_n_lost
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I m more Inclined to CD14 myself.
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| indidoc1
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mmm.. guys.. for flow cytometry, if we r taking a blood sample frm the mice, there r gonna be no macrophages in it. 
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| Mikeland
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I think is D, because CD56 is most specific for NK, more over......
CD 14 is more a LPS receptor, could be CD 16 if CD56 is erease of that anwers (CD56 more specific)
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| jole
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CD56 ithink is much more specific besides as indi said macrophages are in the tissues not peripheral blood.Anybody know the answer for sure?
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| lq2006
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CD14
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