Two-color flow cytometric analysis of monocyte depleted human blood lymphocyte subsets

Flow cytometry data analysis of CD34+/CD133+ stem cells in bone marrow and peripheral blood and T, B, and NK cells after hematopoietic grafting

This article provides flow cytometry information regarding levels of expression for hematopoietic stem cell markers CD34 and CD133 obtained simultaneously of the bone marrow and peripheral blood from recipients of allogeneic and autologous transplants of PB hematoprogenitors for treating hematological malignancies and who were clinically healthy after ≥100 days following the procedure. CD34 and CD133 expression is compared regarding type of transplant (autologous vs. allogeneic) and sample cell source (bone marrow vs. peripheral blood). Patients were conditioned with a reduced-intensity conditioning regimen. Also shown is the flow cytometry analysis of mononuclear cell and lymphocyte populations in the peripheral blood of both types of recipients, as well as the characterization of immune cells, including T lymphocyte antigenic make up markers CD3, CD4 and CD8, B lymphocytes and NK cells, including total NK, bright and dim subtypes in the peripheral blood of both types of recipients. For further information and discussion regarding interpretation and meaning of post-transplant flow cytometry analysis, please refer to the article "Assessment of immune reconstitution status in recipients of a successful hematopoietic stem cell transplant from peripheral blood after reduced intensity conditioning" [1].

Differentiation of alloreactive versus CD3/CD28 stimulated T-lymphocytes using Raman spectroscopy: a greater specificity for noninvasive acute renal allograft rejection detection

Acute rejection (AR) remains problematic in renal transplantation. As a marker, serum creatinine is limited, warranting a more effective screening tool. Raman spectroscopy (RS) can detect T-cell activation with high sensitivity. In this study we explore its specificity. Seventy-five inactivated, 40 alloantigen-activated, and 75 CD3/CD28-activated T cells were analyzed using RS. CD3/CD28-activated peak magnitudes (PM) were 4.3% to 23.9% lower than inactivated PM at positions: 903, 1031, 1069, 1093, 1155, 1326, and 1449 cm(-1), with a difference in peak ratio (PR) observed at the 1182:1195 cm(-1) position (0.91 +/- 0.06 vs. 1.2 +/- 0.01, respectively: P = 0.006). Differences in CD3/CD28- and alloantigen-activated PM were observed at: 903, 1031, 1093, 1155, 1326, and 1449 cm(-1), with no PR differences at the 1182:1195 cm(-1) position (0.91 +/- 0.06 vs. 0.86 +/- 0.09: P = 0.8). Spectral signature separation of CD3/CD28-and alloantigen-activated groups was 100% specific and sensitive. We conclude that RS can differentiate T cells activated by different stimuli with high sensitivity and specificity.

Detection of unseparated human lymphocytes by flow cytometry

The protocol for flow cytometry analysis presented here has been specifically developed for studies of human peripheral blood cells. In this protocol, analysis is performed on unseparated cells in whole peripheral blood, rather than on Ficoll-Hypaque-purified mononuclear cells. The advantage of this approach is that it requires less time, uses smaller blood volumes, and eliminates possible differential blood loss as a result of cell separation techniques. In this regard, B cell recovery using the whole blood method is significantly greater than that obtained using Ficoll-Hypaque-purified mononuclear cells. However, because lymphocytes generally represent a minority of peripheral cells (especially in adults), careful gating of the test samples for lymphocytes is a more critical requirement in this procedure than in other procedures using purified cells.

Corticosteroid and immune responses to cardiac surgery

Serum corticosteroid-binding globulin (CBG) and cortisol levels as well as subsets of circulating immunocompetent cells (ICCs) were measured during cardiac surgery. Closed heart surgery (closed mitral commissurotomy) resulted in an elevation of cortisol levels (up to 32 +/- 5 micrograms/dL by the end of the surgery) with no changes in CBG and ICC levels observed. Open heart surgery (open reconstruction of the mitral valve) in surface-induced hypothermia (without extracorporeal bypass) caused a dramatic drop in CBG activity (from 250 +/- 17 microM before the beginning of anesthesia to 198 +/- 15 microM by the end of cooling (just before cardiac arrest) and 158 +/- 13 microM after 30 min of reperfusion), whereas cortisol levels were only slightly elevated by the end of cooling, and a significant increase (up to 17 +/- 2 micrograms/dL) was observed only at the end of the surgery (60 min of reperfusion and warming). Similar to CBG, a significant decline in circulating ICC contents occurred in response to cooling and circulatory arrest.

Immunophenotyping of lymphocytes in bronchoalveolar lavage fluid. A new flow cytometric method vs standard immunoperoxidase technique

Characterizing lymphocyte subsets in bronchoalveolar lavage fluid (BALF) by flow cytometry (FC) proper gating of the lymphocyte subpopulation being analyzed is crucial. In order to test lymphocyte gate quality for the first time we used a DNA-dye to evaluate plasmamembrane integrity and thus to mark off fluorescent but not DNA-containing particles (eg, debris). A comparative prospective study between this newly developed FC technique and a standard peroxidase anti-peroxidase (PAP) method was performed. Samples of BALF from 50 patients with various pulmonary diseases were examined. After determination of the total cell yield, a differential cell count was performed. Subsequently, the immunophenotype of pan T lymphocyte CD3-, T-helper lymphocyte CD4-, and T-suppressor lymphocyte CD8-positive lymphocyte subsets was assessed with FC as well as with the PAP method. Both methods showed excellent correlation (CD3: r = 0.81; CD4: r = 0.97; CD8: r = 0.96; p < 0.05, respectively). Comparing the mean +/- SEM, FC tends to overestimate CD3+ cells (90.6 +/- 1.0% vs 85.8 +/- 1.3%). For CD4 (45.0 +/- 3.4% vs 44.4 +/- 3.4%) and CD8 (48.1 +/- 3.5% vs 46.7 +/- 3.5%), there was good agreement. In a clinical setting, the reliability of both methods was equivalent, and FC using a DNA-dye to test lymphocyte gate quality offered a rapid and reliable determination of lymphocyte subsets in BAL.

Selective disbalances of peripheral blood T lymphocyte subsets in human CD3 gamma deficiency

The selection of T lymphocytes in the thymus and their activation upon the encounter with foreign antigens in the periphery require the aggregation and signals of the T cell receptor (TcR)/CD3 complex and several surface molecules termed coreceptors (notably CD4 or CD8 and CD45). The spatial arrangement and interactions of the different molecules in the resulting multimolecular recognition structure are mostly unknown. Here we report, from studies on a healthy human CD3 gamma deficiency, that the lack of the CD3 gamma component of the TcR/CD3 complex is associated with a long-term severe defect of peripheral blood CD4+ CD45RA+ and CD8+ lymphocytes, whereas CD4+CD45RO+, B and natural killer lymphocytes are unaffected. These results suggest that the CD3 gamma site of the TcR/CD3 complex is required for the peripheral representation of certain T cell types.

Smoking, CD45R0+ (memory), and CD45RA+ (naive) CD4+ T cells

The relationship between smoking and percentages and counts of T-cell subsets, in particular CD45R0+ (memory) and CD45RA+ (naive) CD4+ lymphocytes, have been assessed in a sample of 311 middle-aged men working in the Paris area. Percentages of lymphocytes with the phenotypes CD4+, CD8+, CD4+CD45R0+, and CD4+CD45RA+ were determined using double immunofluorescence labeling. All cell counts, including CD4+CD45R0+, and CD4+CD45RA+ lymphocytes increased significantly with tobacco consumption, as did the percentages of lymphocytes with the CD4+CD45R0+ and CD4+ phenotypes. The increase in the percentage of lymphocytes with the CD4+CD45RA+ phenotype, although not significant, was similar to that observed in the percentage of CD4+CD45R0+ lymphocytes. When the proportions of CD4+ cells with the CD45R0+ or the CD45RA+ phenotype were considered, no specific modification of any of these two sub-populations was observed: the effect of smoking on memory and naive Cd4+ lymphocytes seemed to be equivalent.

Flow cytometric analysis of lymphocyte phenotypes in bronchoalveolar lavage fluid: comparison of a two-color technique with a standard immunoperoxidase assay

Characterization of lymphocytes in bronchoalveolar fluid has provided insight into the pathogenesis of many pulmonary diseases. Identification of lymphocyte phenotypes has become highly successful due to development of specific monoclonal antibodies and reliable methods for detecting labeled cells such as flow cytometry (FCM) and immunocytochemistry. FCM permits rapid screening of many cells, but this analysis may be confounded by heterogeneity in the size and granularity of the cells being evaluated. Such heterogeneity may lead to exclusion of cells of interest and inclusion of unwanted cells. Often peripheral blood leukocytes are used to define the gate for lung lymphocytes, but this gate may be inappropriate due to considerable variation in size and granularity of cells in bronchoalveolar lavage (BAL) fluid. Here we report an alternative method for generating a gate which employed fluorescence and side scatter signals to analyze lymphocyte subsets in BAL fluid by FCM. This gating technique avoids the pitfalls inherent in using the conventional lymphocyte gate to analyze lung cells. To validate this approach, we compared the results generated by this gate and those from the conventional forward/side light scatter gate to results derived from an immunocytochemical technique (ABC) that has been extensively employed in our laboratory to identify lymphocyte subsets in blood and lavage fluid. FCM tended to underestimate the proportions of T-cell subsets compared with ABC when the conventional gate was used. Counting only cells that stained with fluorescein-conjugated anti-CD45 antibody and that had side scatter properties of lymphocytes, however, resulted in excellent agreement between FCM and ABC. It appears that the CD45+/side scatter gate includes the vast majority of lymphocytes in BAL fluid while excluding most of the nonlymphoid cells that contaminate the conventional gate. It was this latter group of cells, and erythrocytes in particular, that led to the artificially low values for lymphocyte phenotypes in BAL fluid by FCM when the conventional lymphocyte gate was used. Although erythrocytes in BAL fluid may be eliminated by hypotonic lysis, this may also result in contamination of the conventional lymphocyte gate with nuclear debris and particulates from macrophages. Despite these advantages, the fluorescence/side scatter gate may not always be optimal for the evaluation of T lymphocytes if BAL fluid contains CD45+, nonlymphoid cells with low side light scatter. In these instances, additional antibodies such as anti-CD14 and anti-CD11 may be employed to determine the size of contaminant monocytic cells and neutrophils.(ABSTRACT TRUNCATED AT 400 WORDS)

Progression of HIV-1 infection. Monitoring of HIV-1 DNA in peripheral blood mononuclear cells by PCR

We present data on the distribution of human immunodeficiency virus (HIV-1) proviral DNA in different subsets of peripheral blood mononuclear cells (PBMCs) over an observation period of eight months. Eleven patients with well documented HIV-1 infection were studied. The PBMCs were obtained at two intervals and purified by fluorescence-activated cell sorting (FACS) after staining with FITC-labelled monoclonal antibodies. Varying numbers of FACS-sorted CD4+ cells, CD8+ cells and peripheral monocytes were assayed for HIV-1 proviral DNA (env and gag region) by PCR. Samples from patients at CDC stages II or III had to contain 10(3)-10(4) cells in order to allow detection of proviral HIV-1 DNA. At CDC stage IV, however, HIV-1 DNA was detected in as few as 100 CD4+ T-lymphocytes. In contrast, in peripheral monocytes HIV-1 DNA was not regularly found. CD8+ cells did not harbor detectable amounts of proviral DNA. During an observation period of eight months, the rate of infected CD4+ T-lymphocytes increased significantly in three patients while staying constant in the remaining eight patients. This increase of the infection rate was paralleled by clinical progression in one patient and by a decrease of the absolute number of CD4+ cells in another patient. The percentage of CD4+ cells harboring the viral genome increases in the course of the disease. These results may help to explain the decrease in CD4+ T-lymphocyte counts during HIV-1 infection.

Lymphocyte subsets in whole blood and isolated mononuclear leucocytes of healthy infants and children

The determination of lymphocyte subsets utilizing monoclonal antibodies and flow cytometry has become essential in the evaluation of immunological status. Using a standardized method it was found that in healthy children the percentage of CD 8+ (Leu 2+) positive cells increases significantly (P less than 0.01) during infancy, whereas the percentage of CD 4+ (Leu 3+) positive cells decreases with age (P less than 0.01). The percentage of CD 3+ (Leu 4+) cells remains constant. The ratio of CD 4/CD 8 positive cells is significantly (P less than 0.001) higher in infants than in older children. Other subpopulations (HLA DR+, Leu 7) were found to be constant in all age groups. For the comparison of data on lymphocyte subsets obtained by flow cytometry a standardized test procedure is important.

Phenotypic analysis of human peripheral blood lymphocytes by automatic sampling flow cytometry after stimulation with mitogens or allogeneic cells

Human peripheral blood lymphocyte (PBL) phenotypes have been analyzed before and after stimulation with phytohemagglutinin (PHA), concanavalin A (ConA) and pokeweed mitogen (PWM) for 3 days and in mixed lymphocyte culture (MLC) for 7 days. PBL labeled with each of 10 fluorescent monoclonal antibodies were automatically sampled for flow cytometry from 96-well microtiter plates using a microsample delivery system. The reference phenotypic ranges were determined in fresh cells and control cultures. PHA was mostly mitogenic for T PBL bearing the CD3, CD5, CD7, CD8 and CD25 differentiation clusters, and a low density of CD1 and CD4 had a small effect on human natural killer cells (HNK) and also did not stimulate B (CD19) and HLA-DR+ PBL. There was an incomplete phenotypic overlapping between PHA- and ConA-stimulated cultures, ConA being more mitogenic for CD4 and less mitogenic for CD8 PBL. The mitogenic effect of PWM was evident on CD3, CD5, CD7, CD4, CD25 and CD8, but not on HNK, HLA-DR and CD19 B PBL, which presumably had already differentiated into antibody-secreting cells. After MLC stimulation all T, B and HNK PBL subsets tested were increased, but the cells bearing CD1, CD4, CD5, CD7, CD25, HNK, CD19 and HLA-DR had the greatest proliferation with respect to the unmixed control PBL. The present approach to the phenotyping of PBL subsets could offer more complete and accurate data for monitoring and follow-up of patients in transplantation and immunopathology hospital wards.

CD4+, CD8+, and CD4- CD8- T cells in CSF and blood of patients with multiple sclerosis and tension headache

Two-colour flow cytometric analysis was performed on paired samples of peripheral blood (PB) and cerebrospinal fluid (CSF) of patients with untreated multiple sclerosis (MS) and, for reference, subjects with muscular tension headache (TH) using anti-CD3, anti-CD4, anti-CD8, and anti-HLA-DR monoclonal antibodies in different combinations. CD4+/CD8+ T-cell ratio was increased in CSF compared to PB in both MS patients and TH subjects to a similar extent. This was mainly due to higher CD4+ T-cell levels in the CSF compartment. The proportion of HLA-DR+ T cells was higher in CSF than PB in both MS and TH; this increase of DR+ T cells in CSF was more prominent in MS. The level of CD4+ CD8+ T cells, which represent a subset of activated T cells, was not different between CSF and PB, either in MS or in TH. The proportion of CD4- CD8- T cells, which were found generally not to be blast cells, was lower in CSF compared to PB in both patient groups. However, their CSF level was higher and their PB level lower in MS compared to TH. Results point to an accumulation of activated T-helper cells in the CSF of both MS patients and healthy subjects. Fetal-type CD4- CD8- T cells bearing the unusual T-cell receptor gamma/delta seem to be selectively recruited to the CSF of MS patients.

B cells expressing CD5 are increased in cerebrospinal fluid of patients with multiple sclerosis

By two-colour flow cytometric analysis, we found increased numbers of B cells co-expressing the pan-T cell marker CD5 and the B cell marker CD19 in cerebrospinal fluid (CSF) of 21 patients with multiple sclerosis (MS), compared with 17 control subjects with muscular tension headache. Only one patient with MS, but nine controls lacked CD5+ B cells in CSF. This difference was not observed in peripheral blood. Numbers of CD5+19+ B cells were increased in CSF compared with blood in MS, but not in the controls. In both groups, CD5+19+ B cells were not restricted to small resting lymphocytes, but were also found among larger-sized lymphocytes. The relative density of CD5 molecules and of CD19 molecules was lower in CD5+19+ than in CD5-19+ B cells and CD5+19- T cells. CD5+ B cells are assumed to be responsible for autoantibody production, and our results suggest a pathogenetic role of such cells, predominantly within the central nervous system, in MS.

Detection of HIV-1 DNA in different subsets of human peripheral blood mononuclear cells using the polymerase chain reaction. Rapid communication

The presence of HIV-1 proviral DNA was determined in CD4 cells, CD8 cells and macrophages/monocytes obtained from peripheral blood of 8 HIV-1 infected persons. Using the polymerase chain reaction (PCR) we were able to detect proviral DNA in the extracts of only 10(2)-10(3) CD4 (T4) cells. In contrast, 10(5) CD8 cells did not contain detectable amounts of proviral DNA. Surprisingly, in four of our eight patients studied no HIV-1 DNA was found in macrophages. In peripheral blood, every hundred T4 cell may be infected with HIV-1.

Procedural guidelines for performing immunophenotyping by flow cytometry

Flow cytometry is a rapidly expanding technology that is moving from the research laboratory into the clinical laboratory. Recent advances in availability and reproducibility of monoclonal antibody reagents specific for a wide range of cell types coupled with lower costs for increasingly automated flow cytometers with powerful and user friendly data analysis capabilities have made flow cytometry the method of choice for immunophenotyping in the clinical laboratory. However, there is great variability in the level and type of quality assurance procedures used from laboratory to laboratory. A subcommittee established by the National Committee for Clinical Laboratory Standards (NCCLS), composed of representatives from industry, academia, professional societies, and regulatory agencies, has drafted consensus procedures which address specific problems and suggested solutions for performance of immunophenotyping by flow cytometry. This paper is based on the authors' discussions with the NCCLS Committee but does not represent an official NCCLS position. The official NCCLS document on this subject (H42) is expected to be published in 1989.