Flow cytometric analysis of activation markers on stimulated T cells and their correlation with cell proliferation.
The expression of activation antigens, namely CD25, CD69, CD71, and HLA-DR on T cells from 15 healthy individuals stimulated with different mitogens and specific antigens was evaluated by immunofluorescence assay and flow cytometric analysis and compared with cell proliferation as a function of [3H]thymidine incorporation. CD69 was the earliest expressed antigen on stimulated cells, while HLA-DR was the latest. Regardless of the stimulus used, lymphocytes expressing CD25 and CD71 were always more numerous than cells expressing CD69 and HLA-DR. Variations in the proportion of CD4+ and CD8+ T cells expressing each activation marker were observed with different antigenic stimuli. The expression of each activation marker showed overall agreement with the [3H]thymidine incorporation assay in discriminating between positive and negative immune response. However, no correlation was observed between the percentage of CD25-, CD69-, CD71-, and HLA-DR-positive T cells and the amount of [3H]thymidine incorporation. Moreover, low doses of mitogens and antigens as well as short time of stimulation were sufficient to induce T cells to express activation antigens but not to proliferate. Our data show that results obtained by flow cytometry and [3H]thymidine incorporation may differ qualitatively, at least under certain conditions; this suggests that the 2 assays are complementary, and when combined, may gives a clearer understanding of events leading to efficient cell-mediated immune response.
Caruso
A
A
Institute of Microbiology, University of Brescia Medical School, Italy.
Licenziati
S
S
Corulli
M
M
Canaris
A D
AD
De Francesco
M A
MA
Fiorentini
S
S
Peroni
L
L
Fallacara
F
F
Dima
F
F
Balsari
A
A
Turano
A
A
D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000096:biosynthesis*; D002455:Cell Division; D002478:Cells, Cultured; D004247:DNA / Q000096:biosynthesis; D005434:Flow Cytometry / Q000379:methods*; D006684:HLA-DR Antigens / Q000096:biosynthesis*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets; D008934:Mitogens / Q000494:pharmacology; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000276:immunology*; D013936:Thymidine / Q000378:metabolism
D015703:Antigens, CD; D006684:HLA-DR Antigens; D008934:Mitogens; D004247:DNA; D013936:Thymidine