Comments on: Connections http://www.iayork.com/MysteryRays/2008/12/12/connections/ Meddling with things mankind is not meant to understand. Also, pictures of my kids Sat, 25 Jun 2011 18:45:54 +0000 hourly 1 http://wordpress.org/?v=3.3 By: iayork http://www.iayork.com/MysteryRays/2008/12/12/connections/comment-page-1/#comment-12016 iayork Mon, 29 Dec 2008 03:30:13 +0000 http://www.iayork.com/MysteryRays/?p=602#comment-12016 <em>how do DCs recognize things that should be presented to T-cells?</em> The simplest answer is that the DC don't recognize them. DC just present everything they come across, blindly. The T cells do all the information processing and decide what to react to. In fact it's not quite that simple; DC do some preliminary filtering and sorting, and they don't become very good at stimulating T cells unless they receive generic viral signals; but the filtering is very broad, and the generic signals are so generic that it seems few if any viruses escape this initial filter. But basically antigen-presenting cells are just as happy to present self antigen as they are to present pathogen antigen. It's up to the T cells to distinguish between them. how do DCs recognize things that should be presented to T-cells?

The simplest answer is that the DC don’t recognize them. DC just present everything they come across, blindly. The T cells do all the information processing and decide what to react to.

In fact it’s not quite that simple; DC do some preliminary filtering and sorting, and they don’t become very good at stimulating T cells unless they receive generic viral signals; but the filtering is very broad, and the generic signals are so generic that it seems few if any viruses escape this initial filter.

But basically antigen-presenting cells are just as happy to present self antigen as they are to present pathogen antigen. It’s up to the T cells to distinguish between them.

]]> By: John Kelsey http://www.iayork.com/MysteryRays/2008/12/12/connections/comment-page-1/#comment-12015 John Kelsey Mon, 29 Dec 2008 03:24:40 +0000 http://www.iayork.com/MysteryRays/?p=602#comment-12015 This is probably a dumb question, but how do DCs recognize things that should be presented to T-cells? If I understand correctly, if the DC (or some other antigen-presenting clee) doesn't present the antigen to helper T cells, the helper T cells won't be able to coordinate any kind of a response, right? So, when the DC comes across some fragment of viral protein or something, how does it know that this is something that needs to be presented? Are there pathogens that escape immune response by just not being caught as "interesting" by the DCs? I apologize if this is some very basic thing everyone else understands--immunology is very far from my own field. Thanks! This is probably a dumb question, but how do DCs recognize things that should be presented to T-cells? If I understand correctly, if the DC (or some other antigen-presenting clee) doesn’t present the antigen to helper T cells, the helper T cells won’t be able to coordinate any kind of a response, right? So, when the DC comes across some fragment of viral protein or something, how does it know that this is something that needs to be presented? Are there pathogens that escape immune response by just not being caught as “interesting” by the DCs?

I apologize if this is some very basic thing everyone else understands–immunology is very far from my own field. Thanks!

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