Reading #2

Note: I realized after publishing my first blog entry that we were meant to only share our thoughts on each question in three sentences or less--I will attempt to do this from now on and apologize for my obscenely long prior response.

1. Chapter 2 is all about B cells, how they develop, how they react to an antigen, and the various types and structures of immunoglobin proteins which they can produce to carry out this reaction. Particularly, chapter 2 focuses on the gene rearrangement mechanisms which introduce diversity into the antigen receptor portion of the Immunoglobin protein. Chapter 3 goes in to the same subjects as chapter 2 but with respect to T Cells, who share many similarities with B cells in regards to their antigen receptor's structure and the mode by which these receptors gain diversity to recognize many types of foreign molecules (gene rearrangement). Chapter 3 also discusses the MHC which presents antigens to T cells either intra or extracellularly (by either MHC I or MHC II respectively), and is a fundamental difference between B cells (which don't need antigens to be 'presented' to them and which may eject antibodies) and T cells (which depend on MHC to present antigens, and which do not secrete antibodies).


2. I found the highly specific and in depth method of classifying and discussing the various structural aspects of immunoglobin a bit overwhelming, and was often having trouble following the abbreviations used in the text. I found myself a bit confused when trying to differentiate between gene rearrangement, as used to produce Ig and T cell receptors, and the production of MHC which, though the book stresses is not formed by gene rearrangement, nonetheless seems to be drawing genetic information from a large collection of gene families--what is the difference between this and gene rearrangement?


3. I found the diversity of the immunoglobin classes logical and the many methods by which this diversity is achieved quite interesting. I also found the figures at the end of Chapter 2 very helpful in summarizing the structure and genetic origin of immunoglobin, as well as the genetic changes it undergoes throughout a B cell's development. I found chapter 3 more accesible than chapter 2 as it was touching on many ideas which were already described in chapter 2--I think that upon re-reading these chapters many of the genetic subtleties which eluded me on the first run through will make more sense.