Friday, June 29, 2012

What's Inside of You

The purpose of this email is to provide something provocative for dinner table conversation. Please print and share.
Dedicated to the memory of Stessi Boyd, who passed away this week. (To dedicate a future TT, send an email.)

 I was speaking this week to a man who can be described as follows:

- Graduated at the top of his class from a top university
- Married to a wonderful, caring woman
- Has great kids
- Has a great home to live in
- Is depressed because his income doesn't match his image of "successful"

Question for your table:

What can you tell a guy like that to cheer him up?

I suppose you could ask him to watch this inspirational video of the guy with no arms and no legs:

And then watch this one:

Or you could ask him to read this note from a friend of a friend who is in medical school:

So as you may know, a large component of our immune system consists of specialized cells which can recognize cells of the body which have been infected (perhaps by a virus) or are doing something faulty (i.e. a cancer cell) and terminate them. These are colloquially called "Killer T cells." It's amazing how the body makes them.

First some background on the process. All cells in the body put pieces of the proteins they are producing on the outer surface of their cell membranes. These are presented on the surface by a special "carrier protein" called MHC. Try to envision a cell of your body, with thousands of MHC molecules on its surface, and each MHC molecule is holding a small piece of a protein that is being made inside the cell. Killer T cells recognize these MHC-protein complexes. If the protein is "self" the T cell does nothing; if the protein is "foreign" the T-cell binds to the cell and induces a pathway that results in cell death.

What's amazing is that T-cells have the ability to recognize self vs. non-self. This is created via "T-cell selection." Immature T-cells go to the thymus (located just above the heart) to learn this ability. At first, the body makes T-cells of amazing variety, in fact this number is estimated to be 10^18. That number is beyond comprehension. Essentially the body starts by making a T-cell that would bind to and destroy a molecule of any possible shape.

But we must ensure that mature T-cells only bind and kill cells with MHC bound to foreign objects. The first part of this process involves the T-cells attempting to bind specialized cells covered in MHC molecules. If the T-cell binds to the MHC molecule, it survives; if it does not bind to the MHC molecule it is tagged for destruction. About 90% of the billions and billions of immature T-cells die in this process because T-cells which do not recognize MHC are useless. The second stage of selection occurs by having the T-cells interact will specialized cells which produce random proteins in all parts of the genome and which put these proteins on its surface via MHC molecules. If T-cells bind to the MHC-protein complexes, they are tagged for destruction and if they do not bind they survive because we do not want T-cells which bind to and destroy cells which are producing "self proteins." Another 7-9% of the original T-cells die in this process. Only the select few make it out of the thymus and enter the circulation on the lookout for invaders.

The structure of the thymus is specialized so that no foreign objects may enter. This would be disastrous-- we would program T-cells which thought certain foreign proteins were "self" and could not defend against these foreign invaders. Of course sometimes mistakes (such as in autoimmune disorders) are made but it is amazing that we have a system that provides protection against foreign molecules of essentially any imaginable shape. The body is even protected against molecules which do not exist, but could in theory exist."

Wow. And that's just a tiny slice of what is amazing in this wonderful world we live in.

Question for your table - The Talmud declares that wealth is not measured by how much you have but by how satisfied you are with what you have. Sounds good on paper, but how do you get there?

Shabbat Shalom

PS - Speaking of a wonderful world, check out this rare recording of Satchmo - and try not to smile:

MyPhone app:
Android version:

Bar and Bat Mitzvah gift suggestions at (a service of JSL).

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