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Hello SDN!!! I have a question Im really confused about from the EK Bio systems book. Pls help! Thanks!
Negative selection takes place in the corticomedullary junction of the thymus where developing T cells interact with medullary thymic epithelial cells (mTECs). The immature T cells would be expected to display:
A) Self-antigen on class I MHCs
B) Self-antigen on Class II MHCs
C) non-self antigen on Class II MHCs
D) Self-antigen on Class I and Class II MHCs
Answer is D.
My problem with this question is that I dont understand why T cells would display self antigens. I thought that the T cells would recognize self antigens on Class I and Class II MHCs and if they interact then they undergo apoptosis. Why would T cells display these self antigens?
I think the question is meh in terms of trying to get the concept that T cells either possess MHC1 or MHC2. Knowing that T cells display either should have hinted that D is the correct answer.
In terms of negative selection. I think the point they were trying to make is that if cells displayed either of the self-antigen it would NOT select (even though it recognizes the self-antigen) it out. I think its a meh question in terms of wording because this could be misinterpreted to be positive selection.
And if you do, the answer will be based on a passage, not a discrete. The discretes are WAYYYYYYYY easier than this.AAMCs question are check thoroughly to be correct. You won't get a weirdly worded question like this.
And if you do, the answer will be based on a passage, not a discrete. The discretes are WAYYYYYYYY easier than this.