Enumeration of Antigen Sites on Cells by Flow Cytometry

Abstract

We evaluated a cytofluorometric method for determining the number of antigens expressed on the cell surface of human lymphocytes. Using beads that have a known number of binding sites for mouse immunoglobulin and monoclonal antibodies specific for various antigens on human lymphocytes, we found that this system is quite reproducible, reliable and technically easy to perform. The greatest source of variation in expression of cell surface antigens is interdonor variability.

Age-related increase of frequency of a new, phenotypically distinct subpopulation of human peripheral blood T cells expressing lowered levels of CD4

“…First, except for the works of Lanzavecchia's group, 12,13 the possibility of even partial modulation of the level of expression of CD4 on T cells is not considered, even in the most recent papers on the subject. 7,8,22 One of these recent papers actually assumes absolute constancy of the numbers of CD4 molecules on T cells and uses this constant as a calibration gauge for estimation of the numbers of CD38 molecules. 8 Second, in healthy young subjects (being studied for the normal values of the CD4 expression), the percentages of CD4 lo cells are usually low (not exceeding 10% to 15% of all CD4 ϩ cells) and are seen in cytometric histograms mostly in the form of an inconspicuous shoulder at the main CD4 ϩ population.…”

Granulocyte Colony-Stimulating Factor Improves Deficient In Vitro Neutrophil Transendothelial Migration in Patients with Advanced Liver Disease

“…Neutrophil populations were identified with forward and right angle light scatter, and the fluorescence emission of 10 4 events/sample was recorded as mean channel number on a logarithmic scale. To calculate the number of receptors per cell, the mean channel number of each cell population was transformed into antibody binding sites per cell with Quantum Simply Cellular microbeads as previously described (15,49). The number of antibody binding sites corresponding to the isotopic immunoglobulin was subtracted from each cell sample.…”

Quantification of cellular adhesion molecules on malignant B cells from non-Hodgkin’s lymphoma

“…However, as adhesion relies not only on the presence of CAMs, but also on their level of expression, 4,14 we quantified their level of expression using a flow cytometric methodology. 24 Our results demonstrated that the expression of CAMs in B cell NHL varied depending on the subtype as defined by the REAL classification, 25 with each subtype showing a unique pattern of expression for the five CAMs tested. Overall, the level of CAM expression was highest in high grade NHL, ie the most activated malignant cells.…”

“…The diagnosis was confirmed by immunological, histological and cytogenetic analysis (data not shown). NHL were classified according to the REAL classification: 25 24 small lymphocytic lymphoma (SLL), 15 mantle cell lymphoma (MCL), 39 follicular lymphoma (FL), four lymphoplasmacytoid lymphoma (LPL), 31 diffuse large cell lymphoma (DLCL) including 22 centroblastic (DLCL-CB) and nine immunoblastic (DLCL-IB) lymphoma. SLL, MCL, FL and LPL are considered as low or intermediate grade NHL, whereas DLCL-CB and DLCL-IB are high grade NHL.…”

“…CAM expression was measured by a quantification method previously described by Dawson et al 24 We used this method with minor modifications as previously described in others reports. 27,28 Briefly, CAM expression was quantified by measuring the mean value of green fluorescence (= CAM fluorescence) on B lymphocytes only; ie after gating on the red fluorescence events (= PE-CD19 + subset).…”