The Ways and Means of the Immune System: May 2011

Thursday, May 26, 2011

It's been a while

It's been a long time since I wrote here. I started blogging as a new postdoc, to vent about the frustrations, and to join the community of scientists on the web who describe the vagaries of the scientific life.

I haven't enjoyed being a postdoc very much, and I'm distinctly ambivalent about still having the same job. There are many ups to being a postdoc and many downs, but I' not going to talk about them anymore, there are so many people who say it better. Besides, all that talking blinded me to why I do it in the first place: I think the immune system is pretty damn awesome, and I find something interesting to read about it nearly every day.

A lot has changed since I last wrote here: I have an energetic toddler, I'm far more downbeat about my ambitions to cure disease, I'm tired, I feel guilty most of time, and I'm afraid I'm losing my spark, the zip that makes my mind interesting and unique. All of which said, I find that I'm still jazzed about immunology, and I'm going to just try and focus on that. The ideas, the innovations and the incredible pace with which our understanding of the immune system progresses.

So the next post will be about my new favorite idea. And will be posted in a time period less than three years.

Welcome and Disclaimer

I am writing here to express my interest in the wide variety of research that goes on in Immunology today. I am NOT a medical professional, and I do not offer medical advice. These are just my personal opinions, formed by the reading of published journal papers. They are not representative of anything other than my private personal opinions. I do not endorse or revile any journal or group or university or researcher. They are shaped by my background in research, and my specialties. I am not omniscient, so I do not know or understand everything. Enjoy!

The Vocabulary

An Antigen is any molecule that is recognized by the specialized cells of the immune system, usually by antigen receptors on the surfaces of these cells. Antigens are picked up and displayed by other specialized cells called antigen presenting cells. Antigens can be recognized by two broad categories of cells, T cells and B cells. T cells detect antigens through an antigen receptor called the T cell receptor, but only when these antigens are bound to antigen presenting molecules called MHC molecules. MHC proteins carrying antigens are found on the surface of antigen presenting cells. B cells make antibodies, which also recognize antigens. Once a B cell recognizes antigens through its antigen receptor, the antibody, it makes many many more of the same antibody and secretes , or spits them out, into the body so that they circulate throught the body. Naive B or T cells are cells that have never seen an antigen, and activated cells are those that have. Effector cells are those cells that have seen antigen and can do something about it, like kill that the cell carrying the antigen. Memory cells are cells that retain a memory of their encounter with an antigen, and can react faster and more effectively the next time they see the same antigen. The immune system consists of a few major lymphoid organs: the thymus, where T cells are made; the bone marrow, where all cells originate; the spleen, where many effector cells reside; and the lymph nodes, which are present at multiple sites throughout the body. Immunes cells spend their lives whizzing around between these various organs in various states of activation. A pathogen is any organism that infects a host, they can be bacteria, viruses or parasites.