User:Immcarle15/sandbox

I will now be editing Histocompatibility. The B-cell receptor page has a link to an entire page on VDJ recombination.

Here are possible sources to look over:

Dreyer, G.j., A.c. Hemke, M.e.j. Reinders, and J.w. De Fijter. "Transplanting the Elderly: Balancing Aging with Histocompatibility." Transplantation Reviews 29.4 (2015): 205-11. Web.

Leffell, Mary S. "Histocompatibility Testing after Fifty Years of Transplantation." Manual of Molecular and Clinical Laboratory Immunology, 7th Edition 369.1-2 (2011): 1195-197. Web.

"Transplant Pathology Internet Services." Transplant Pathology Internet Services. Accessed February 03, 2016. http://tpis.upmc.com/changebody.cfm?url=/tpis/immuno/wwwHLAtyping.jsp.

Trowsdale, John, and Julian C. Knight. “Major Histocompatibility Complex Genomics and Human Disease.” Annual review of genomics and human genetics 14 (2013): 301–323. PMC. Web. 5 Feb. 2016.

Wang, E. Human leukocyte antigen and human neutrophil antigen systems. In: Hoffman R, Benz EJ Jr, Silberstein LE, Heslop HE, Weitz JI, eds. Hematology: Basic Principles and Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 114. Wang, Jim. Histocompatibility. S.l.: Callisto Reference, 2015.

Here is my summary paragraphs for the Histocompatibility article. I will be adding more to each paragraph in terms of detail in the body paragraphs of the article:

Histocompatibility is the degree of similarity between live tissues, specifically in terms of the number of matching human leukocyte antigen (HLA) alleles between the two tissues. HLA is the human form of the major histocompatibility complex genes found in all vertebrates.  On the population level there are thousands of known alleles for this gene with new ones being continuously discovered.  Each individual inherits two different HLA alleles located on human chromosome 6.  Each of these alleles contain six loci which code for major histocompatibility complex (MHC) class I and class II.  These genes are codominantly expressed so every individual expresses every MHC class I and MHC class II allele, both paternal and maternal.

The similarity or difference of one individual’s alleles to another’s is what allows their tissues to match or not, thus histocompatibility is a critical criteria for whole organ as well as stem cell transplantation.  Certain MHCs are present on every cell type and are a type of self-antigen. This means that the body naturally produces antibodies for their own MHC proteins. The body over time stops producing these antibodies for MHCs.  Introduction of foreign tissue through transplant introduces a new set of MHCs to the body.  The recipient’s immune cells will respond as normal treating the donor tissue as an antigen unless the MHCs present are similar to their own MHCs for which the immune cells have already learned to recognize and not destroy.

Histocompatibility testing has evolved greatly with the technological advances in DNA based molecular typing and solid phase immunoassays.  With this technology it is possible to detect very small amounts of HLA specific antibodies within an individual.  This has produced a major challenge for transplant teams as researchers are trying to find out if such small concentrations of antibodies are clinically relevant.  Different regions of the world follow their own allocation schemes for organ donation, part of which includes variation in histocompatibility.