Tuesday, April 15, 2008

Experimental Biology 2008, Part 1

So I returned last Wednesday night from a San Diego convention. It's unusual for me to attend a convention in the middle of the quarter, but the timing worked out and I had an able and eager sub waiting to step in and teach for me ... so I went. Culinary highlights include In-N-Out Burger and the best $3.50 chorizo burrito ever. Academic highlights I'll include as a multipart bulleted list. These are what I found "worth it" from the convention, and I'll try to make it general but this is part diary, part blog post:

  • If you get infected with a virus early in life, it may change your cells so that later in life they learn to attack cancer. The reason is that altered-self peptides get put onto your MHC molecules and seen by T cells. Those altered-self peptides happen when great stress happens: viral, bacterial inflection, or cancer-related stress. What I find interesting is that this is an adaptive immunity version of the mechanism I study in innate immunity. Do the two have anything to say to each other?

  • Not only do NK cells have about 10 different kinds of receptors that vary from man to man and mouse to mouse, not only do each of these receptors bind a different array of ligands with different affinities, BUT the receptors (one called 2B4 in particular) can switch from activating the immune system to inhibiting the immune system depending on the number of receptors on the cell surface! AND the same receptor can have an inhibitory tail region or an activating tail region depending on the context! To which I say: yipes. One of the reviewers of my recent grant commented that they’d prefer to see me go around and measure affinities of different receptor-ligand combos so we understand how they work. Maybe I should eventually do that, but if the number of receptors on a cell changes whether it turns things on or off, affinities are obviously only part of the figure (and the most important part to that question is what happens on the surface of a real, live cell – I can only do so much with purified protein). So I’m justifying my current direction, and, after all, that reviewer did give me a good enough score that I got my great renewed, so I guess the objection wasn’t that big.

  • You can measure low-affinity protein-protein interactions using concentrator filters and SDS-PAGE gels. The only problem is the separation the concentrator can do will vary from box to box of concentrators. I still think it’ll make a good undergrad lab.


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