antigen presentation - (Mar/06/2005 )
Is there any simple way to tell a given gene, for instance CD68, is an "antigen presentation gene" or not.
Have no idea about those genes named CDxx antigen.
Thanks for any clue.
Well, get yourself a good Immunology book (I personally would recommend A.Abbas' "Cellular and Molecular Immunology" or "Immunobiology" by Charles A., Jr. Janeway) and look them up. CD means Cluster of Differentiation and is an more or less old-fashioned name that is kept to for simplification reasons.
Or you can get yourself a poster from one company or the other where all the known CD's are listed.... And don't forget to look up the PubMed central for papers referring your CD, since this is a fest growing field....
In your case, CD68 is listed as Macrosialin, belonging to the mucin family, expresed by macrophages, DCs, activated T-cells, B-cells. It's a predominantely intracellular protein of unknown function and lysosomal associated.
So, to answer your question: yes and no. It's easy to tell what function a specific CD has, if it's already known. In your case, with CD68, if the function is unknown, there's no easy way.
mike
Thanks a lot, Mike.
One more question, my understanding, it's not impossible that one gene may be identified "antigen presentation gene" later even if it's not so far, is that correct?
Ben
Yes, you're correct. there could be some genes, whose products are involved in antigen presentation, that are not identyfied today or that have no hithero known function.
BUT
antigen presentation is one of the best researched areas in immunology, so this is rather unlikely - but still there maybe some surprises!
another thing , where does antigen presentation start? is the gene that codes for a repressor, that in turn regulates the expression of e.g. MHCI an "antigen presentation gene", or not? 
mike
Appreciate the comments.
As an outsider of immunology, I honestly know nothing on this topic. It's only that some CDxx genes showed up in my research and I have to figure it out.
As to the genes that regulate the expression of antigen presentation genes, my inclination is they are not in this category. To me, it seems more true to group them as transcriptional regulator, translational regulator, etc.