Lymphocytes in the peripheral blood of the dog. Initial data on the presence of receptors for human and canine red blood cells

The authors studied red cells from men and various animals for their capacity to mind to canine peripherical blood lymphocytes and form spontaneous rosettes.     

Studies on nucleoli in rosetting T and B lymphocytes of the human peripheral blood

The incidence of various nucleolar types was studied in human rosetting lymphocytes to provide an information on nucleolar types present in T and B lymphocytes of the peripheral blood. The results clearly demonstrate that both T and B lymphocytes of the peripheral blood mostly contain ring shaped nucleoli ("resting nucleoli") and less frequently other nucleolar types such as nucleoli with nucleolonemata or compact nucleoli ("active nucleoli") and micronucleoli ("inactive nucleoli"). Since all known nucleolar types and particularly micronucleoli may be observed in both T and B lymphocytes, nucleoli in these cells cannot indicate the type or origin of these cells but simply the state of the nucleolar RNA synthesis.     

The effect of oxotremorine on blood pressure and plasma catecholamines in conscious and anesthetized rats.

This review summarizes the evidence suggesting a role for second messengers in the thymus dependent differentiation of lymphocytes. Special emphasis will be placed on the potential for such studies to indicate differences and similarities not only between thymosin and other thumus factors but between the various peptides which are present in thymosin fraction 5.     

Review. Clinical importance of the lymphocyte differentiation in peripheral blood]

The study of the lymphocyte subpopulations appears to be of diagnostic importance in immunodeficiencies and lymphatic disorders. In autoimmune diseases and cancer as well as in various other disease states changes of T and B lymphocytes are detectable, findings that can be of prognostic and therapeutic importance.     

Alkaline phosphatase in human lymphocytes. I. Cytochemical detection of alkaline phosphatase in normal human peripheral blood lymphocytes

The present paper deals with a sensitive cytochemical method of identifying alkaline phosphatase (AP) in rosette-forming lymphocytes gained from the peripheral blood of healthy human beings. The percentage of AP-positive lymphocytes amounts to 5%, with all cells comprising B- and O-lymphocyte population and with T-lymphocytes being negative. In a group of healthy test persons, recently, however, having undergone various inflammatory processes or virus diseases, the number of AP-positive lymphocytes is significantly higher, from 41-73% in B- and O-lymphocytes and from 6-38% in T-lymphocytes. This observation indicates that AP in lymphocytes may have a clinical significance in reactive lymphoproliferative processes, which must be elucidated by further investigations.     

Exposure to asbestos: correlation between blood levels of mesothelin and frequency of micronuclei in peripheral blood lymphocytes

Inhalation of asbestos, a mineral extensively used in a variety of applications, is strongly associated with malignant mesothelioma (MM), a fatal cancer of the pleura. Soluble mesothelin-related peptides (SMRP) are a promising biomarker suggested for the screening of MM in healthy asbestos-exposed subjects. In the present study a comparison of micronucleus (Mn) frequencies in peripheral blood lymphocytes (PBL) between 44 asbestos-exposed and 22 control individuals has been performed, and the correlation with serum SMRP has been examined. SMRP levels were found to be significantly higher in subjects exposed to asbestos and in their various subgroups than in controls. Concerning micronucleated lymphocytes, a statistically significant difference from controls was seen in the percentages of both micronucleated mononucleated lymphocytes (MnMNL) and micronucleated binucleated lymphocytes (MnBNL), but the difference was markedly higher for the percentage of micronucleated polynucleated lymphocytes (MnPNL). With respect to the correlation between the frequency of the three types of micronucleated lymphocytes and serum-SMRP values of asbestos-exposed subjects, it was statistically significant for MnMNL, but not for MnBNL and MnPNL.     

An appraisal of Fc receptors on human peripheral blood B and L lymphocytes.

Human circulating lymphocytes with easily detectable surface immunoglobulin have been divided into two populations, B cells and L cells. This second population lacks membrane-incorporated Ig, but has a receptor for membrane-labile cytophilic IgG. In this study purified B and L lymphocytes were examined for Fc receptors that bind aggregated IgG and IgG complexed to erythrocytes. Purified lymphocyte populations were prepared by nylon columns and by negative selection with rosetting techniques. L lymphocytes bound aggregated guinea pig and human IgG, and formed rosettes with human erythrocytes sensitized with Ripley IgG (EA). Treatment of L lymphocytes with trypsin had no effect on the receptors for IgG. B lymphocytes did not bind EA and attachment of aggregated IgG was variable; up to one-third of these cells fixed aggregated human IgG to the cell membrane. Trypsin treatment abolished binding of Agg-IgG to B cells in sharp contrast to its effect on L cells. Furthermore, double-label immunofluorescence studies showed that cells with both membrane-incorporated Ig and receptors for aggregated guinea pig IgG were rare. These studies indicate that human peripheral blood B lymphocytes lack a high affinity, trypsin-resistant Fc receptor that is present on L lymphocytes.     

Mitogenic receptors on human peripheral blood lymphocytes: the interaction of Phaseolus vulgaris erythroagglutinating phytohemagglutinin and anti-thymocyte globulin on the human peripheral blood lymphocyte membrane.

A horse anti-human thymocyte antibody (ATG) obtained from the Upjohn Company was shown to stimulate DNA synthesis in human lymphocytes with a time course and magnitude of radioactive thymidine uptake comparable to that seen with phytohemagglutinin (E-PHA) and concanavalin A (Con A). Low mitogenic or nonmitogenic concentrations of intact ATG or its Fab fragments inhibited E-PHA-induced mitogenesis, whereas the response to Con A was unaffected. Competitive binding studies with ATG and E-PHA revealed mutual inhibition of binding to lymphocytes suggesting that E-PHA and the ATG share a common receptor site on the cell surface. ATG binding was unaffected by Con A. From the analysis of the binding data and the inhibition of mitogenesis, it appears that at least part of the E-PHA response in human lymphocytes involves receptors that are not acted on by Con A.     

Some observations on the stained blood cellular elements of channel catfish, Ictalurus punctatus

Slides were prepared from blood of channel catfish, Ictalurus punctatus , and evaluated. The cellular blood elements observed were thrombocytes, lymphocytes, neutrophils, monocytes, eosinophils, basophils, granular anucleate bodies, erythrocytes. In channel catfish, thrombocytes, lymphocytes and neutrophils were the predominate leucocytes. Erythrocytes were observed in various stages of development. Smudge cells were observed in all smear preparations. The variations found between the observations in this study and information provided in the literature suggest the need for establishing a standardized terminology.     

Human B-cell activation in vitro. T cell-dependent pokeweed mitogen-induced differentiation of blood B lymphocytes.

Human blood lymphocytes were separated into T and non-T cells and cultured with pokeweed mitogen (PWM). It was found that in the absence of T cells no differentiation of B cells into immunoglobulin-containing blasts and plasma cells took place. Moreover, the cell yields and the rate of DNA synthesis and blast transformation were very low. The influence of T cells on PWM-induced B-lymphocyte differentiation was studied in mixtures of T/non-T cells at various ratios. Addition of even a few T lymphocytes caused a considerable stimulation of B cells by all parameters used. The responses of T/non-T mixtures of the original cellular composition were of the same order as those of cultures of unseparated cells. It is concluded that the differentiation of human blood B lymphocytes into cells actively synthesizing immunoglobulins, as induced by PWM, is strongly dependent upon the presence of T cells.     

Glutamine and glucose metabolism in bovine blood lymphocytes.

1. Glutamine and glucose metabolism was studied in bovine blood lymphocytes incubated at 37 degrees C in the presence of Krebs-Ringer bicarbonate buffer (pH 7.4) containing 1 mM [U-14C]glutamine and 5 mM [U-14C]glucose, respectively. 2. The major metabolic products from glutamine were ammonia, glutamate, and to a lesser extent, aspartate and CO2. Glucose was metabolized mainly to lactate and, to a lesser extent, pyruvate and CO2. These findings indicate incomplete oxidation of glutamine and glucose carbons in bovine blood lymphocytes. 3. Glucose provided three-fold greater amounts of energy to bovine blood lymphocytes than did glutamine on the basis of their measured end-products. Glycolysis accounted for 50% of glucose-derived ATP production. 4. Our findings suggest similar metabolic patterns of glutamine and glucose in lymphocytes between ruminants and non-ruminant species (e.g. rats). However, in contrast to rat peripheral lymphocytes, glucose, rather than glutamine, was a major energy substrate for bovine blood lymphocytes.     

Immunological and cytochemical indices of white blood cells in old age

The group of aged subjects being 66 to 97 years old was compared with the middle-age group with regard to various immunological and cytochemical indices related to lymphocytes and neutrophils. The aged showed a lowered count and percentage of T cells, increased count and percentage of "non-B, non-T" lymphocytes, increased percentage of B cells. These alterations in the composition of lymphocyte subpopulation were associated with characteristic patterns of damage affecting the enzyme-positive lysosomal apparatus of lymphocytes with regard to acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase. There was a hundredfold smaller number of cells having intact enzyme-positive lysosomes in the aged than in the group of comparison. The changes mentioned above were also associated with the intracellular accumulation of glycogen in lymphocytes, decreased concentration of IgG and IgM in the serum and various changes in IgA concentration. Neutrophils of the aged were fewer in the blood of the aged than in younger subjects. However, an increased activity of myeloperoxidase, alkaline phosphatase, N-acetyl-beta-D-glucosaminidase, and an increased content of glycogen and lipids could be found in these cells. NBT-positive neutrophil numbers in the aged were lowered if the stimulated test was used and if there were no changes of the spontaneous test.     

Effect of Agrobacterium tumefaciens (Smith and Town). Conn. on the functional properties of human blood lymphocytes

Agrobacterium tumefaciens has been shown to affect the proliferation of intact lymphocytes as well as lymphocytes stimulated by PHA action. Inoculation of bacteria into the cultures of intact lymphocytes and incubation during 72 h resulted in increased incorporation of [3H]-thymidine into the DNA of cultivated cells. The bacteria are capable of inhibition of lymphocytes proliferation stimulated by PHA.     

Thalidomide and the immune system. 2. Changes in receptors on blood cells of a healthy volunteer.

Thalidomide (Thd) was given in two trials (total daily dose: 5 or 8 mg Thd/kg body weight, respectively) for five and three days to a healthy male volunteer, and various receptors were analyzed on white blood cells before, during and after (up to 30 days) the treatment period. There were neither marked deviations in the absolute number of total leukocytes nor in the percentage of total lymphocytes or monocytes throughout the study period. The most pronounced changes were observed in the surface receptors on CD4 ("helper cells") cells and leukocytes bearing the CD11b (Mac 1) and other integrin and adhesion receptors. Other changes included shifts in the ratio cytotoxic cells/suppressor cells as well as a reduction of the receptor density (passage from bright to dim) in T helper cells bearing CD45RO "memory" markers. Simultaneously, the number of B cells was found to be increased as was the percentage of some adhesion receptors on CD8+ cells. Unlike in previous experiments in which Thd was administered to marmoset monkeys, no effect could be seen in cells bearing the CD2 (LFA-2) epitope.     

Effect of Halococcus morrhuae and Halobacterium saccharovorum on the activation of human peripheral blood lymphocytes.

The immunomodulator properties of two species of halophilic Archaebacteria, Halobacterium saccharovorum and Halococcus rnorrhuae, were analysed by the study of lymphocyte activation. Two methods were used to detect activation in lymphocytes, namely incorporation of the radioactive nucleotide [3H]-thymidine, and CD25 expression. H. morrhuae had a stimulatory effect on human lymphocytes, but this action was observed only with the [3H]-thymidine uptake method, whereas H. saccharovorum produced no immunomodulator effect.     

Distinctive functional properties of human blood L lymphocytes: a comparison with T lymphocytes, B lymphocytes, and monocytes.

Human blood lymphocytes with high affinity Fc receptors have been operationally named L lymphocytes because of membrane-labile IgG markers. L lymphocytes lack membrane-incorporated immunoglobulin and do not form rosettes with sheep red blood cells coated with IgM antibody and mouse complement. These lymphocytes are capable of binding IgG in normal human serum at 4 degrees C and will form rosettes with human lymphocytes coated with Ripley IgG. In this study, functional in vitro properties of isolated L lymphocytes were compared with T lymphocytes, B lymphocytes, and monocytes. To obtain these mononuclear populations, first, plastic adherent monocytes were harvested. T lymphocytes were then isolated by centrifugation of E rosette-forming cells, and other rosetting techniques were employed to isolate L and B lymphocytes by negative selection. The functional properties of L lumphocytes were completely unlike those of T cells, B cells, or monocytes. L lymphocytes did not proliferate in response to mitogens, soluble antigens, or cell surface antigens. Moreover, this population could not replace monocytes in helping T lymphocytes respond to concanavalin A and pokeweed mitogen. Once T cells were supplemented with monocytes, however, the addition of L lymphocytes to the culture greatly enhanced the T lymphocytes proliferative response to phytohemagglutinin, concanavalinA, purified protein derivative (PPD), and streptokinase/streptodornase. L lymphocytes were not a subset of B cells. They did not spontaneously develop surface Ig in culture, and pokeweek mitogen could not induce them to transform and generate cytoplasmic Ig detectable by immunofluorescence. Mixtures of B cells and T cells responded to pokeweed mitogen better than do T cells alone. In contrast, enhanced reactivity with L and T cell combinations was not observed. Another sharp difference between these two populations was the stimulator capacity of each in mixed lymphocyte culture. When B and L lymphocytes were carefully monocyte-depleted, only B cells were effective stimulators of autologous and allogeneic lymphocytes. In comparison with T cells, B cells, and monocytes, L lymphocytes were the only effective killers of human blood lymphocytes sensitized with IgG. L lymphocytes, then, have cytotoxic potential, but cannot proliferate in response to various stimulants or become antibody-producing cells. These findings suggest that L lymphocytes comprise a third lymphocyte population.     

Glucocorticoid receptors in purified subpopulations of human peripheral blood lymphocytes.

On the premise that the differential effects of glucocorticoids on various aspects of the immune response may be mediated by differences in the glucocorticoid receptors in the effector cells, subpopulations of human peripheral blood lymphocytes were examined for these receptors as well as for glucocorticoid responsiveness. Purified T and non-T lymphocytes, when studied by a sensitive whole cell assay technique, contained equivalent amounts of specific glucocorticoid receptor, which, by binding affinity and specificity measurements, were indistinguishable from each other. Furthermore, under in vitro incubation conditions, macromolecular synthesis in both of these cell populations was inhibited by glucocorticoid at concentrations which saturated the receptor sites. It is concluded that the putative differential effects of glucocorticoids on T and non-T lymphocyte-associated functions are probably not mediated by differences in the glucocorticoid receptors in these cell populations.     

Scanning electron microscopy of peripheral blood leukocytes of the chicken

Summary Polymorphonuclear leukocytes, e.g., neutrophilic granulocytes, were enriched from heparinized blood by a Ficoll-step-gradient centrifugation procedure. Scanning electron microscopy (SEM) revealed a surface morphology of narrow ridge-like profiles and small ruffles with occasional microprocesses. Mononuclear leukocytes were isolated by centrifugation over a Ficoll-Metrizoat gradient. The lymphocytes showed varying numbers of microvilli of different length, size and shape. B lymphocytes, characterized by their capability of sheep red blood cell (SRBC)-rosette formation, displayed a similar surface morphology. Completely smooth lymphocytes, described in the literature as T lymphocytes, could not be detected, although many lymphocytes with few microprocesses were observed. Thus, SEM is not a useful tool for distinguishing between B and T lymphocytes in the peripheral blood of chickens. Monocytes were characterized by prominent membrane-like ruffles, but in some cases they closely resembled granulocytes. An influence of the various separation media on the surface morphology of the isolated cells could not be detected when compared with cells isolated by the buffy-coat method.     

Increased sister chromatid exchange in bone marrow and blood cells from Bloom's syndrome.

Bone-marrow cells from a patient with Bloom's syndrome cultured for 48 h in the presence of BudR exhibited a striking increase in the number of sister chromatid exchanges (SCEs) in comparison to that in the marrow cells of a patient with treated polycythemia vera (PV). Thus, it appears that an increased incidence of SCE in Bloom's syndrome occurs in various differentiated types of cells, not just blood lymphocytes, and constitutes the syndrome's most characteristic cytogenetic feature. In contrast, the incidence of SCE was not increased in marrow cells and lymphocytes of the particular PV patient studied here, whose cells did exhibit increased numbers of chromatid and chromosome gaps and breaks, presumably as result of the patient's earlier treatment. An increased frequency of SCE was demonstrated in Bloom's syndrome lymphocytes using both a technique based on BudR incorporation and one based on labeling with tritated deoxycytidine. This observation constitutes evidence against the increase of SCE being due to an unusual reaction to BudR. By conventional cytogenetic techniques, chromosome instability, including chromatid and chromosome breaks, but no homologous chromatid interchanges were also recognized in Bloom's syndrome bone-marrow cells incubated in vitro (without BudR) for either 1.k or 16 h. This observation points to the existence of chromosome instability in vivo.     

Oxidized low density lipoproteins induce apoptosis in PHA-activated peripheral blood mononuclear cells and in the Jurkat T-cell line.

Oxidized low density lipoproteins (oxLDLs) and activated T lymphocytes are present in early atherosclerotic plaques. It has been shown that oxLDLs are cytotoxic to cultured vascular cells but their possible toxic action on T lymphocytes has not been described. Peripheral blood lymphocytes from healthy individuals were stimulated in vitro with the polyclonal activator phytohemagglutinin and treated with various doses of native and mildly oxidized LDLs. Low doses of oxLDLs inhibited cell growth and DNA synthesis after 48 h culture and at 200 microg apoB/ml we observed a loss of cell viability. Dead cells did not exhibit significant increase of alteration of membrane integrity (i.e., necrosis) but showed chromatin fragmentation evaluated by DNA staining with 4', 6-diamidino-2-phenylindole and propidium iodide. This fragmentation increased with TBARS and hydroperoxide levels. The expression of early apoptosis marker Apo2.7 rose among the CD3(+) T-cell population. In addition, morphological analysis showed apoptotic features (cell shrinking, nucleus condensation, and fragmentation). Study of phosphatidylserine expression using Annexin V confirmed that oxLDLs induced apoptosis in activated lymphocytes. In the Jurkat T-cell line cultured with oxLDLs, apoptotic morphological changes (condensation and nucleus fragmentation) were observed and they were accompanied by DNA fragmentation visualized by propidium iodide staining and electrophoresis showing apoptotic ladder.These results demonstrate that mildly oxidized LDLs induce apoptosis in a part of activated and proliferating T cells. T-lymphocyte apoptosis induction in atherosclerotic lesions might contribute to the development of an inappropriate local T cell response.