Hi Stan, one should clearly distinguish between two major human gamma/delta T cell subpopulations: based on the V delta gene segment usage they express Vdelta1 or Vdelta2 chains. Their tissue localization as well as age dependent changes are virtually reciprocal. In peripheral blood Vd1 gd T cell level drops down after the age of one year and vice versa for Vd2 cells (see J.Exp.Med. 171:1597; also from the Brenner's lab comes the recent important paper dealing with a new group of Vd2 T cell's ligands- Immunity 11:57, there you can find a summary for their values during different infectious diseases, the mean is 8-60% of peripheral blood T cells). Vd2 cells are the major peripheral blood subpopulation of gd T cells. Vd1 are predominant in the thymus and epithelia. Anyway, Vd2 T cell subset variation in the population is very high as pointed out by previous reply. Typically it has been published that 'normal' values are up to 10%, most people having less than 3% of all blood T cells (still this should be the largest uniform population in our bodies recognizing the very same ligands). But you can easily find levels up to 80% of all peripheral blood T cells in apparently healthy donors, I call them healthy patients - there should be something unusual with their immune system. Of course the widespread localization of Vd2 T cell's ligands (small nonpeptidic molecules: alkyl phosphates and alkyl amines are basic bacterial and plant metabolites) predicts these cells to play an important role in the innate immunity as well as to become an interesting target for vaccine development. I think that constitutive antigenic challenge in the group of people having higher numbers of Vd2 cells might protect them better from bacterial infections. On the other hand: is it possible to distinguish between harmless stimulation and potentially harmful, inapparent infection based on the Vd2 cell number? Hope this helps, -- Karel Drbal Laboratory of Leukocyte Antigens Institute of Molecular Genetics Academy of Sciences of the Czech Republic Videnska 1083 142 20 PRAHA 4 Czech Republic, Europe voice: +420-2-4752589 fax: +420-2-44472282 home: +420-2-360016 e-mail: drbal@leuko.biomed.cas.cz WWW: http://leuko.biomed.cas.cz "Ress, S, Stan, Dr" wrote: > > Hi all, > > Does anyone have normal range values for gamma-delta subset from > birth to adulthood? > > I checked ISAC Leukocyte ref data on their site: reference is made to > Clin Immunol + immunopath 1994 70, 152-8, but from the abstract, I > was unclear if GD+ subset was included. > > Any help appreciated. > > Thanks, > > Stan > > Stanley Ress > Head: Clinical Immunology laboratory > Department of Medicine > H47 Old Main Building-room 26 > Groote Schuur Hospital and UCT > Observatory 7925 > Cape Town > South Africa > TEL:INTERN. + 2721-4066201 or 4066197 > FAX: " + 2721-4486815 > e-mail: SRESS@uctgsh1.uct.ac.za
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