H antigen

{{Short description|Antigens with different biological functions}}

{{Redirect|H substance|text=The term also historically referred to histamine}}

H antigen can refer to one of the various types of antigens having diverse biological functions:

Also known as substance H, H antigen is a precursor to each of the ABO blood group antigens, apparently present in all people except those with the Bombay Blood phenotype{{cite web|last=Science Of Biogenetics|title=Do you Know Bombay Blood Group|date=18 December 2023 |url=http://www.scienceofbiogenetics.com/do-you-know-bombay-blood-group/}} (see hh blood group). The gene responsible for making H antigen is FUT1, located on the 19th chromosome in humans.
Histocompatibility antigen, a major factor in graft rejection. Even when Major Histocompatibility Complex genotype is perfectly matched, can cause slow rejection of a graft.{{cite book|last=Janeway|first=Charles A.|title=Immunobiology the immune system health & disease|year=2001|publisher=Garland|location=New York|isbn=978-0-8153-3642-6|url=https://archive.org/details/immunobiology00char|edition=5.|accessdate=16 December 2013|url-access=registration}}
major H antigens "encode molecules that present foreign peptides to T cells"
minor H antigens "present polymorphic self peptides to T cells". Includes, e.g. the H-Y antigen
a bacterial flagellar antigen{{cite web|last=Farlex|title=antigen|url=http://medical-dictionary.thefreedictionary.com/antigen|work=The Free Dictionary|accessdate=16 December 2013}}

References