A method for the identification of human peripheral blood T lymphocytes by sequential immunogold and esterase double staining

A double staining method involving the sequential use of monoclonal OKT hybridoma antibodies applied in the colloidal immunogold method and followed by a simultaneously capturing azo dye method for the detection of acid alpha-naphthyl acetate esterase (ANAE) is described. Mononuclear leukocytes isolated from human peripheral blood using a Ficoll-Hypaque density gradient were stained. M-pattern ANAE-positive monocytes (diffuse staining) were excluded from the lymphocyte counts. 80 +/- 5% of all lymphocytes were T-pattern ANAE positive (dot-like staining) and 77 +/- 3% were OKT3 positive. 86 +/- 6% of all ANAE-positive T-pattern lymphocytes were also OKT3 positive, and 89 +/- 6% of all OKT3-positive lymphocytes were also ANAE positive. This indicates that ANAE is a good marker for total human T lymphocytes. 53 +/- 10% of human peripheral blood lymphocytes were OKT4 positive and 87 +/- 8% of all OKT4-positive lymphocytes were also ANAE positive. 30 +/- 6% of all lymphocytes were OKT8 positive, and only 26 +/- 18% of all OKT8-positive lymphocytes were ANAE negative. This indicates that ANAE cannot be used to distinguish T-helper and T-suppressor lymphocytes as identified by monoclonal antibodies.     

免疫磁珠法分离鼻咽癌基质的T淋巴细胞

肿瘤内环境与肿瘤的发生密切相关.肿瘤细胞周围的组织在癌变发生时不会是一个沉默的旁观者,可能在肿瘤的发生和发展中扮演十分重要的角色.本研究分别采用不同的磁珠分选技术分离T淋巴细胞.采用CK LMP1,CD105和成纤维细胞表面蛋白,结合全血总T细胞试剂盒,间接法分离鼻咽癌基质的T淋巴细胞;采用CD3直接磁分选法分离鼻咽癌基质的T淋巴细胞,然后用免疫组化法鉴定分选的效果和细胞的质量.结果表明,免疫组化显示间接磁分选法分离出来的T淋巴细胞不能完全去除肿瘤细胞,RNA的质量不佳;而直接磁分选分离出来的T淋巴细胞为纯净的T淋巴细胞,而且RNA的质量良好.提示直接磁分选技术是分离鼻咽癌基质T淋巴细胞的首选方法.     

Preparative separation of human B and T lymphocytes by free flow electrophoresis

An electrophoretic method for the quantitative separation of human B and T lymphocytes in a carrier-free system is presented. The method is based on the fact that B and T lymphocytes show marked overlap in their size and density characteristics, but differ sufficiently in surface charge to be separable by electrophoresis. The technique is performed in phosphate-buffered saline and appears to be especially suitable for the enrichment of nonstimulated, functionally intact lymphocytes which can be directly used for further immunological or biochemical studies.     

Micro-Buffy Coats of Whole Blood: A Method for the Electron Microscopic Study of Mononuclear Cells

A method for the electron microscopic study of human peripheral lymphocytes by which very small buffy coats are obtained through centrifugation of heparinized whole blood in glass or plastic microhematocrit tubes is presented. This method is time saving and efficient, yielding well preserved material and a comparatively large number of mononuclear cells (mainly lymphocytes) in each thin section.     

Isolation and fractionation of porcine peripheral lymphocytes

A method is described for the separation and purification of porcine peripheral blood lymphocytes and their subsequent sub-cellular fractionation. The isolated cell population consisted of 99% lymphocytes with a viability of 100% and an overall recovery of 30%. The lymphocyte : thrombocyte ratio was 56 : 1 and the population contained no detectable erythrocytes. The lymphocytes proved resistant to mechanical breakage but a method of homogenisation in a hypotonic medium was developed which resulted in complete cell rupture with minimal damage to sub-cellular components.     

A simple trogocytosis-based method to detect, quantify, characterize and purify antigen-specific live lymphocytes by flow cytometry, via their capture of membrane fragments from antigen-presenting cells

We have developed a method exploiting the phenomenon of trogocytosis to detect lymphocytes reacting specifically with target cells by flow cytometry. Trogocytosis is a process by which lymphocytes capture fragments of the plasma membrane from the antigen-presenting cells (APCs) expressing their cognate antigen. For this method, a label (such as a fluorescent lipid or biotin) is first incorporated in the membrane of APCs. These labeled cells are then co-cultured for a few hours with a population of cells containing the lymphocytes to be detected. After this period of stimulation, lymphocytes that have performed trogocytosis are identified by their acquisition of the label initially present on the APC membrane using flow cytometry. A major advantage of this method is its compatibility with the simultaneous detection of phenotypic and/or functional markers on the lymphocytes. Furthermore, cells can be recovered alive and active after detection of trogocytosis, and are therefore available for further characterization or even conceivably for therapeutic purposes.     

Inhibition of erythroid cell growth in irradiated mice by allogeneic lymphoid cells: Specificity of the response

Allogeneic lymphocytes can inhibit proliferation of erythroid cells in the spleens of irradiated mice grafted with syngeneic bone marrow cells. Since there is a linear relationship between the number of injected lymphocytes and erythroid activity, the method is frequently used as a graft-vs-host assay. In this investigation we show that the reduction of erythroid activity is due to both a reaction of the lymphocytes against the tissues of the host and against the grafted bone marrow cells. Thus, reduced erythropoietic activity does not necessarily indicate that the bone marrow targets possess antigens against which the lymphocytes are reactive.     

Estimation of hydrogen sulphide in the human lymphocytes

Hydrogen sulphide (H2S), a signaling gasotransmitter and a potent vasorelaxant is endogenously produced by the enzymes cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE). CBS is a predominant source of H2S in the central nervous system, while CSE is the major H2S producing enzyme in the brain and other nervous tissues. Though the expression of these enzymes in the blood lymphocytes is known, H2S formation in the lymphocytes has not been reported so far. In the present study, H2S levels in the lymphocytes of healthy control subjects were estimated, after suitable modifications in a routine method [Stipanuk M H & Beck P W (1982) Biochem J 206, 267-277] used for detecting tissue levels of H2S. In this method, homocysteine (Hcys) due to its higher solubility was used as the substrate in place of L-cysteine and NaOH was used in place of zinc acetate to increase the entrapment of H2S in the central well. A mean H2S level of 11.64 +/- 6.36 microM/min/mg protein was detected in the lymphocytes of 8 subjects (mean age, 24 +/- 2; 2 male, 6 female). The modified method was found to be more sensitive for H2S estimation in human lymphocytes. As endogenous H2S is reported to be involved in the pathogenesis of various cardiovascular and pulmonary diseases, the levels of H2S in lymphocytes can be a marker of the endogenous tissue levels.     

In vitro cytotoxic drug sensitivity of human normal and malignant lymphocyte-clone-forming cells

Cytotoxic drug sensitivity of normal human lymphocytes and malignant lymphocytes was estimated by a clonogenic method. Malignant T and B lymphocytes were relatively more sensitive than normal T lymphocytes to vincristine and Adriamycin. Since no plateau was observed in the clone survival with associated increasing drug concentration, spontaneous mutants could not be detected. It is suggested that the resistance to "natural product" drugs such as vincristine arises from induced mutations and not from the selection of already existing spontaneous mutants.     

Selective production of hybridoma cells: antigenic-based pre-selection of B lymphocytes for electrofusion with myeloma cells

Methods for pre-selecting B lymphocytes were studied and investigated. First, biotinylated antigen was used for selecting B lymphocytes. These pre-selected B lymphocytes were then combined with biotinylated myeloma cells by adding streptavidin. The final formula of the selected B cell-myeloma cell was as follows: B cell-(antigen-biotin-strept-avidin-biotin)-myeloma cell. Then, this B cell-myeloma cell conjugate was fused by the pulsed electric field (PEF) method, which fused only those conjugated cells. The fusion efficiency obtained by this method was 3-15-times higher than that obtained by the non-specific poly(ethylene glycol) (PEG) fusion method. Second, avidin-antigen conjugate was used to select B lymphocytes. For this purpose, bifunctional cross-linkers such as N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) and m-maleimidobenzoyl N-hydroxysuccinimide (MBS) were chosen. Each reagent contains two heterofunctional groups which can make covalent bond with both Lys and Cys residues. Typical avidin-antigen conjugate is expressed as avidin-SPDP (or MBS)-antigen. Thus, final B cell-myeloma cell conjugate was B cell-antigen-SPDP (or MBS)-avidin-biotin-myeloma cell. The yield of this procedure was of the order of 10(-2). Here, we suggest that the pre-selection of B lymphocytes by biotinylated antigen or avidin-antigen conjugate is a new method of obtaining selected hybridoma cells which produce specific monoclonal antibodies against the antigen used for selecting B lymphocytes.     

A Rapid Method for Determining T Lymphocyte Levels Using Acid Alpha-Naphthyl Acetate Esterase

A method for rapidly determining levels of T lymphocytes in humans is presented. The method involves staining lymphocytes in peripheral blood or buffy coat smears for acid alpha-naphthylacetate esterase for 1 hr at 37 C. After counterstaining with Wright's stain, the percentage of esterase positive cells is quantitated microscopically. The entire procedure takes less than 2 hours. Data are presented which show that the percentage of esterase-positive lymphocytes accurately reflects the percentage of lymphocytes forming E rosettes with sheep erythrocytes.     

Measurement of micronuclei in lymphocytes

The micronucleus technique has been proposed as a method for measurement of chromosomal damage in mitogen-stimulated human lymphocytes. Micronuclei require one cell division to be expressed and, consequently, the conventional micronucleus technique is very imprecise since the cells which have undergone only one division, and the micronuclei in them, cannot be identified separately from the total population of lymphocytes. To overcome this problem, two methods were developed to identify cells which have undergone their first mitosis. Using an autoradiographic technique, lymphocytes were pulse-labelled with [3H]thymidine at 48 h of culture, allowed to proceed through mitosis, identified by autoradiography between 72 and 84 h and micronuclei were scored in them. It was not possible to select a concentration of radiolabel which did not itself produce micronuclei and consequently the method was of no value for measuring pre-existing chromosomal damage present in vivo. However, it was capable of quantitating micronuclei produced by irradiation of lymphocytes in vitro. In the second method, cytokinesis was blocked using cytochalasin B. Micronuclei were scored in cytokinesis-blocked cells. These were easily recognisable owing to their binucleate appearance and a large number could be accumulated by adding 3.0 micrograms/ml cytochalasin B at 44 h and scoring at 72 h. Cytochalasin B did not itself produce micronuclei. The cytokinesis-block method was simple to perform; the 'in vivo' micronucleus frequency in normal individuals was 4.4 +/- 2.6 micronuclei/500 cytokinesis-blocked cells; and for lymphocytes irradiated in vitro there was a linear relationship between dose of radiation and number of induced micronuclei. The cytokinesis-block method appears to be the procedure of choice for quantitating micronuclei in lymphocytes.     

Dynamic activity of the splenic lymphocytes during the modelling of chronic denervation-delymphatization of the kidneys in mice

In experiments on mice CBA the activity of spleen lymphocytes was investigated in sham-operated mice and in mice with denervation-delymphatization of the both kidneys. The activity of lymphocytes was determined by registration of amounts of colony-formed elements by the method of Till and McCulloch. Periodic increase of the lymphocytes activity has been observed in mice with denervation-delymphatization kidneys. It is supposed that the periodic activation of lymphoid system, induced by denervation-delymphatization, may be one of triggering mechanisms of transplant rejection.     

Preparative Electrophoresis of Human Lymphocytes I. Purification of Non-Immunoglobulin-Bearing Lymphocytes by Electrophoretic Levitation

When 10–30 × 10⁶ human peripheral lymphocytes are electrophoresed in an upward direction in a vertical column for 1 to 1–1/2 hour at 12 V/cm at pH 7.1, the fastest migrating fraction of 3–10 × 10 lymphocytes consists of 98–100%. non-immunoglobulin-bearing lymphocytes, as determined by immunofluorescence with anti-human immunoglobulin conjugate. The method can be applied to fresh human lymphocytes as well as to lymphocytes that have been frozen and thawed and, if glycerol is added to the buffer as a cryoprotectant, the fast “T” cell fraction can be frozen immediately, to be stored for later use. Similar separations can be obtained with lymphocytes from human tonsils.     

Immunofluorescence studies of the immunoglobulin receptors of B-lymphocytes]

The surface membrane Ig receptors of B lymphocytes in patients with atopic pollen asthma were studied by the direct immunofluorescence method. Use was made of labelled sera against human IgE, and IgG. It was shown that on the average 2.1 +/- 0.33% lymphocytes had IgE receptors, 8.4 +/- 0.63% IgG receptors and 18.7 +/- 1.16% human globulin receptors. A specific nature of B lymphocytes is suggested.     

An analysis of DNA secondary structure during lymphocyte activation by mitogens

The DNA structure of human peripheral blood lymphocytes was studied following activation by concanavalin A in vitro. DNA strand breaks were measured by the fluorometric method after DNA alkaline denaturation in cell lysates. Stimulation of lymphocytes proliferation was controlled by 3H-thymidine and 3H-uridine incorporation. It was shown that 1-3 hours after the addition of mitogens the quantity of alkali-labile sites in DNA increased. Cultivation of lymphocytes in vitro without mitogens was accompanied by gradual accumulation of alkali-labile sites in DNA and in 18-72 hours the DNA structure of lymphocytes in the culture was the same. It is possible that the rapid disturbances in the DNA secondary structure of lymphocytes following activation by mitogens is determined by the transmembrane signal transduction and is the one of the early events in genome activation.     

Immunocyte adherence and leukocyte migration inhibition tests in dogs infested with Leishmania donovani. Importance of lymphocyte conservation in liquid nitrogen]

A method of canine lymphocytes isolation and storage in liquid azote with DMSO is described. It was possible to use these lymphocytes in the immunocytoadherence and leucocytes migration inhibition tests in dogs infected with Leishmania donovani. The sensitisation was made with a soluble antigen from promastigotes of L. donovani braid by ultrasounds. The dogs with Leishmaniasis gave positive results. The controls without Leishmaniasis were negative. The tests with conserved lymphocytes were as satisfactory as the same tests with fresh lymphocytes.     

Translational activity of messenger ribonucleic acid isolated from unstimulated and phytohaemagglutinin-activated lymphocytes.

Purified cytoplasmic poly(A)+ RNA isolated from unstimulated pig lymphocytes has the same ability to direct translation in a range of cell-free systems as the corresponding mRNA from 20h phytohaemagglutinin-activated lymphocytes. Additional methylation of the mRNA is not required for maximum protein synthesis in the wheat-germ cell-free system. Misleading results are obtained if the mRNA preparations used are not adequately purified, and a method suitable for routine assessment of the degree of purification achieved is described. Cell-free protein-synthesizing systems from unstimulated lymphocytes translate added lymphocyte mRNA with lower efficiency than do comparable systems from phytohaemagglutinin-activated lymphocytes, whatever the source of the mRNA used.     

The influence of interleukin-2, feeder cells, and timing of irradiation on the radiosensitivity of human T lymphocytes assessed by the colony-forming assay

The radiosensitivity of human lymphocytes was investigated by the method of colony formation in the absence of interleukin-2 (IL2) and feeder cells, both of which enhance growth of T-cell colonies. The shape of the survival curve and the radiosensitivity was shown to depend upon the ability of lymphocytes to produce IL2: the survival curve for lymphocytes that were the most competent producers of IL2 is the closest to linearity; the lymphocytes that were poor producers show biphasic survival curves. The radiosensitivity of the lymphocytes from the first group is less than that of the latter, when the comparison is based on the first part of the biphasic survival curve. This is more easily seen when cultures are irradiated 24 h after stimulation by phytohemagglutinin (the time of the peak IL2 production) than when cultures are irradiated 2 h before stimulation. This study demonstrates that growth conditions influence the response of lymphocytes to irradiation and that optimal growth conditions result in a linear survival curve.     

LYSOSOMES IN RAT THORACIC DUCT LYMPHOCYTES FRACTIONATED BY ZONAL CENTRIFUGATION

A method of zonal centrifugation was developed which separates rat thoracic duct lymphocytes (TDL) mainly according to size. The validity of the fractionation method was supported by light microscope observations, Coulter Counter sizing, and in vivo and in vitro labeling of lymphocytes. The distributions of lysosomal acid hydrolases in TDL fractionated by zonal centrifugation are similar to the distribution obtained for the cells. This result indicates that the large lymphocyte is not the sole bearer of either lysosomes or the large amount of soluble cathepsin D found in homogenates of TDL. Both reside mainly in small lymphocytes. This point was clearly established by fractionating homogenates of purified small lymphocytes by means of differential centrifugation and isopycnic density gradient centrifugation.