title: Flow cytometric detection of perforin in normal human lymphocyte subpopulations defined by expression of activation/differentiation antigens.
abstract: We investigated with three-color flow cytometry the expression of perforin (Pf) in normal human lymphocyte subpopulations identified by means of activation and differentiation-related antigens. Interestingly, Pf could be detected in a substantial subset (13 +/- 2%) of memory CD4+ CD45RO+ cells, on relevant percentages of memory (CD45RO+) and naive (CD45RA+) CD8+ cells and on virtually all CD3- CD16+, CD3- CD56+ and NKB1+ natural killer cells, as expected. The analysis of fluorescence intensity showed higher levels of Pf expression on CD8dim and NK cells compared to CD8bright and CD4+ lymphocytes, Pf and CD69, HLA-DR, CD95 and CD25 activation/differentiation-related antigens were never co-expressed. On average, 15 +/- 3% of CD3+ CD28+ cells were found to be Pf+, in line with a previously activated or memory cell type. Comparable percentages of CD8+ CD11b- (cytotoxic) and CD8+ CD11b+ (suppressor) T cells were Pf+. Multiparameter flow cytometry is a powerful tool to detect minute fractions of Pf-expressing cells in heterogeneous populations.
authors.affiliation: Department of Hematology, Catholic University Medical School, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Rutella
authors.forename: C
authors.initials: C
authors.lastname: Rumi
authors.forename: M B
authors.initials: MB
authors.lastname: Lucia
authors.forename: B
authors.initials: B
authors.lastname: Etuk
authors.forename: R
authors.initials: R
authors.lastname: Cauda
authors.forename: G
authors.initials: G
authors.lastname: Leone
mesh_terms: D015415:Biomarkers; D017252:CD3 Complex; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D017252:CD3 Complex; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin