The phytohemagglutinin response of human peripheral blood lymphocytes as a function of donor age: a re-examination using BrdU-Hoechst flow cytometry.
Mononuclear cells were isolated from peripheral blood by a standard Ficoll-Hypaque technique from 127 healthy donors, ranging in age from newborns to 86 years of age. As a measure of their in vitro growth response, the fraction of non-cycling cells was determined at 48 and 72 h after phytohemagglutinin (PHA) exposure by means of BrdU-Hoechst flow cytometry. This technique provides an optimal assay system for the non-cycling cell fraction, since all cycling cells will have incorporated BrdU thereby quenching the fluorescence of the Hoechst 33258 fluorochrome. Lymphocytes from prepubertal donors showed significantly decreased non-cycling cell fractions, as did lymphocytes from an additional group of 14 adults with hypogonadism due to the 45, XO condition (Turner-Syndrome). Much to our surprise, we found no definitive correlation between donor age and the non-cycling fraction of cells from the adult lymphocyte donors. Nor did we find any age-related increase in the variance of the non-cycling cell fraction. These observations suggest that the previously reported age-related decline in the PHA response of human PBL may reflect an increasing delay, rather than an overall diminution, of the PHA response as a function of donor age.
Schindler
D
D
Department of Human Genetics, University of Würzburg, F.R.G.
Kubbies
M
M
Priest
R E
RE
Hoehn
H
H
Rabinovitch
P S
PS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D001973:Bromodeoxyuridine; D002648:Child; D002675:Child, Preschool; D005434:Flow Cytometry; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008213:Lymphocyte Activation / Q000187:drug effects*; D008875:Middle Aged; D010835:Phytohemagglutinins / Q000494:pharmacology*
D010835:Phytohemagglutinins; D001973:Bromodeoxyuridine