so thank you. I was so hard to understand this whole thing only reading the textbook, but now I completely understand by your nice, easily explained video!!
Question: If a b cell only "needs" to produce IgM or IgD antibodies, does class switching simply not occur? Because in the scenario shown in the video, the regions for the m and d heavy chain were removed meaning the b cell couldn't produce anymore IgM or IgD antibodies..?
Class switching occurs only when some B cell clone recognizes its specific antigen and starts an immune reaction against that antigen. Depending on which class of the antibodies is the most effective against that particular antigen, follicular helper T cell will release different cytokines that will stimulate isotype switching in that activated B cell. For example if a follicular helper T cell releases interferon gamma the activated B cell will undergo class switching and start producing exclusively IgG2 antibodies and if follicular helper T cell releases interleukine 4 the activated B cell will also undergo class switching but it will start producing exclusively IgE antibodies, So they won't be able to produce IgM and IgD anymore. However all the other naive B cells which aren't specific for that particular antigen still express IgM and IgD antibodies because they didn't undergo class switching.
Can anyone let me know what causes the subsequent transcript of C-gamma to be not-sterile, but containing a start codon? Is it the start codon present upstream of V-h gene region?
