scholarly journals pH homeostasis in human lymphocytes: modulation by ions and mitogen.

1984 ◽  
Vol 98 (3) ◽  
pp. 885-893 ◽  
Author(s):  
C Deutsch ◽  
J S Taylor ◽  
M Price
Keyword(s):  
Intracellular Ph ◽  
Proliferative Response ◽  
Prolonged Exposure ◽  
Ph Regulation ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Ph Homeostasis ◽  
Normal Medium ◽  
Ph Range

Quiescent human peripheral blood lymphocytes have been shown to maintain a relatively constant intracellular pH of 7.0-7.2 over an extracellular pH range of 6.9-7.4. Two methods of measuring intracellular pH were used in these studies, 19F nuclear magnetic resonance and [14C]5,5-dimethyloxazolidine-2,4-dione (DMO) equilibrium distributions. When ATP levels were decreased in these cells, actively maintained pH regulation was abolished and cells exhibited a constant pH gradient of 0.2 pH unit (acid inside relative to outside). Possible mechanisms for pH regulation are discussed. The effects of the Na+ and K+ composition of the medium on pH regulation showed no correlation with their effects on mitogen-induced proliferative response, which we have previously determined (Deutsch, C., and M. Price, 1982, J. Cell. Physiol., 111:73-79). In low-Na+ mannitol medium, pH regulation was similar to that observed for lymphocytes in normal medium, whereas mitogen-induced proliferation was severely inhibited in low-Na+ mannitol. In contrast, high-K+, low Na+ medium caused loss of pH homeostasis, whereas it restored the proliferative response. Loss of pH homeostasis was also observed on prolonged exposure of lymphocytes to mitogen (greater than 6 h in culture). However, mitogen stimulation led to little or no change in intracellular pH in the first few hours of cell culture. Therefore, a shift in intracellular pH is not a necessary or general event in mitogen-stimulated proliferation of lymphocytes.

Intracellular free magnesium in human lymphocytes and the response to lectins

1991 ◽  
Vol 80 (6) ◽  
pp. 539-547 ◽  
Author(s):  
L. L. Ng ◽  
J. E. Davies ◽  
M. C. Garrido
Keyword(s):  
Phaseolus Vulgaris ◽  
Peripheral Blood ◽  
Proliferative Response ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Blood Lymphocytes ◽  
Fluorimetric Method ◽  
Human Peripheral Blood Lymphocytes ◽  
Free Magnesium

1. Intracellular free [Mg2+] was measured in human peripheral blood lymphocytes using a fluorimetric method based on the dye furaptra. It was necessary to correct for the extracellular leakage of the dye by using either 10 mmol/l EDTA or 0.05 mmol/l Mn2+. 2. As the proliferative response of lymphocytes to mitogenic lectins has been linked to a dependence on extracellular Mg2+, the intracellular [Mg2+] was studied in lymphocytes stimulated with various mitogenic and non-mitogenic lectins. 3. Only lymphocytes treated with phytohaemagglutinin-L, a leucoagglutinin from Phaseolus vulgaris that binds to tri- and tetra-antennary complex glycoproteins, showed a marked increase in intracellular [Mg2+]. This effect was partially inhibited by N-acetylgalactosamine. The stimulation by different lectins of the incorporation of [3H]-thymidine into lymphocytes was not correlated to the changes in intracellular [Mg2+]. 4. The proliferative response of lymphocytes to lectins is therefore not wholly dependent on a rise in intracellular [Mg2+].

scholarly journals Investigation of the Immune Modulatory Potential of Zinc Oxide Nanoparticles in Human Lymphocytes

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 629
Author(s):  
Helena Moratin ◽  
Pascal Ickrath ◽  
Agmal Scherzad ◽  
Till Jasper Meyer ◽  
Sebastian Naczenski ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Zinc Oxide Nanoparticles ◽  
Immune Modulation ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Drug Carriers ◽  
Physiological Model ◽  
Peripheral Blood Lymphocytes ◽  
Major Influence ◽  
Oxide Nanoparticles

Zinc oxide nanoparticles (ZnO-NP) are commonly used for a variety of applications in everyday life. In addition, due to its versatility, nanotechnology supports promising approaches in the medical sector. NP can act as drug-carriers in the context of targeted chemo- or immunotherapy, and might also exhibit autonomous immune-modulatory characteristics. Knowledge of potential immunosuppressive or stimulating effects of NP is indispensable for the safety of consumers as well as patients. In this study, primary human peripheral blood lymphocytes of 9 donors were treated with different sub-cytotoxic concentrations of ZnO-NP for the duration of 1, 2, or 3 days. Flow cytometry was performed to investigate changes in the activation profile and the proportion of T cell subpopulations. ZnO-NP applied in this study did not induce any significant alterations in the examined markers, indicating their lack of impairment in terms of immune modulation. However, physicochemical characteristics exert a major influence on NP-associated bioactivity. To allow a precise simulation of the complex molecular processes of immune modulation, a physiological model including the different components of an immune response is needed.

scholarly journals Phenotypically and functionally distinct subpopulations of human lymphocytes with T cell markers also exhibit different cytochemical patterns of staining for lysosomal enzymes

Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1067-1071 ◽  
Author(s):  
A Landay ◽  
LT Clement ◽  
CE Grossi
Keyword(s):  
T Cell ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Suppressor Cells ◽  
Peripheral Blood Lymphocytes ◽  
Acid Hydrolases ◽  
Cytochemical Localization ◽  
Cell Markers ◽  
Granular Lymphocytes

Abstract Human peripheral blood lymphocytes that express T cell markers, when reacted for the cytochemical localization of lysosomal acid hydrolases, display two major patterns of staining, i.e., dot-like and scattered granular. Previous attempts to fractionate T cells according to surface markers have yielded populations of cells with heterogeneous patterns of cytochemical staining. In this study, peripheral blood cells forming rosettes with sheep erythrocytes have been fractionated by sequential staining with two monoclonal antibodies, D12 and 2D2, followed by fluorescence-activated cell sorting. These reagents have been shown previously to recognize a subpopulation of cells capable of suppressing T cell proliferation. All of the cells positive for D12 and 2D2 stained for acid hydrolases with the scattered granular pattern, whereas the large majority of the cells negative for both markers stained with the dot-like pattern. It is concluded that suppressor cells within the E+ cell fraction have the cytochemical characteristics of large granular lymphocytes.

The proliferative response of human peripheral blood lymphocytes to group a streptococcal vaccine

1987 ◽  
Vol 43 (3) ◽  
pp. 314-324 ◽  
Author(s):  
Andreas Morell ◽  
Ursula Stoffel-Mazenauer ◽  
Giuseppe Vassalli ◽  
Walter F. Riesen ◽  
Dietmar G. Braun
Keyword(s):  
Peripheral Blood ◽  
Proliferative Response ◽  
Human Peripheral Blood ◽  
Peripheral Blood Lymphocytes ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes ◽  
Group A

Soluble CD14 Protects Human Lymphocytes from Apoptosis

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2566-2566
Author(s):  
Elizabeth Naparstek ◽  
Benjamin Sredni ◽  
Eti Zigman ◽  
Gali Senyor ◽  
Boris Tartakovsky
Keyword(s):  
Human Peripheral Blood ◽  
Protective Efficacy ◽  
Human Lymphocytes ◽  
Membrane Integrity ◽  
Peripheral Blood Lymphocytes ◽  
Apoptotic Cells ◽  
Soluble Cd14 ◽  
Apoptotic Pathway ◽  
Cell Membrane Integrity

Abstract CD14, a 56 Kd glycoprotein, typically present on myeloid cells, has been traditionally associated with innate immunity and pattern recognition. Recently its membrane bound form has been shown to be involved in apoptosis, as a tethering receptor for apoptotic cells on the surface of phagocytes-in this case with the purpose of removing apoptotic cells, and also as a surface molecule involved in protection from apoptosis of monocytes, neutrophils and recently on enterocytes, challenged with LPS. Our aim was to evaluate the possible involvement of the soluble CD14 in the apoptotic pathway of human lymphocytes. Methods: Freshly obtained human peripheral blood lymphocytes were cultured in vitro with gliotoxin, an apoptotic inducer. Human recombinant CD14 was added to the culture at physiological concentrations (10μg/ml-0.5 μg/ml) and apoptosis was assessed by cell membrane integrity using 7AAD, mitochondrial membrane potential by DiOC6(3) and cytoplasm shrinkage by cell size scatter analysis. Results: Using DiOC6(3) we were able to show that human lymphocytes cultured in the presence of gliotoxin contained 63.8%±21 apoptotic cells, as opposed to 12.2%±11.5 in control cultures. Addition of recombinant human CD14 at a concentration of 10 mg/ml neutralized the apoptotic effect of gliotoxin back to 20.2%±10 (p<0.003). This inhibitory effect was blocked by CD14-specific monoclonal antibodies, but not by control antibodies. We then identified and synthesized the fragment within the CD14 molecule that was responsible for this apoptosis protective effect, and demonstrated its comparable protective efficacy in vitro as shown in figure 1. The figure clearly reveals that this specific peptide, as opposed to the scrambled peptide, protected the lymphocytes form apoptosis, similarly to the full CD14 protein. Same results were obtained using 7AAD and cytoplasm shrinkage. Conclusion: Our data thus suggest that circulating CD14 may play an important role in the prevention of apoptosis of lymphocytes and perhaps of other cells. Figure Figure

scholarly journals STUDIES ON LYSOSOMES

1968 ◽  
Vol 37 (2) ◽  
pp. 394-411 ◽  
Author(s):  
Günter Brittinger ◽  
Rochelle Hirschhorn ◽  
Steven D. Douglas ◽  
Gerald Weissmann
Keyword(s):  
Acid Phosphatase ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Structural Characteristics ◽  
Gradient Centrifugation ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Hydrolase Activity ◽  
Cell Fractionation ◽  
Acid Hydrolase

Pure suspensions of human lymphocytes were separated from peripheral blood by means of nylon wool, homogenized in 0.34 M sucrose-0.01 M EDTA solution, and fractionated by differential centrifugation. The bulk of acid hydrolase activity was found to be concentrated in a 20,000 g x 20 min granular fraction, whereas nuclear, debris, and supernatant fractions contained lesser concentrations of hydrolases. Acid hydrolase activity present in the granular fraction showed appropriate "latency" as judged by its dose-dependent release into the 20,000 g x 20 min supernatant after exposure to membrane-disruptive agents such as streptolysin S, filipin, and lysolecithin. Heparin proved to be necessary in the suspending medium so that reproducible homogenization and cell fractionation could be obtained. Even excessive contamination of lymphocyte suspensions with platelets did not appreciably alter the acid hydrolase activity of lymphocyte homogenates or the distribution of enzymes in subcellular fractions. Discontinuous density-gradient centrifugation of a 500 g x 10 min supernatant, containing both acid hydrolase-rich organelles and mitochondria, resulted in partial resolution of hydrolase-rich organelles from mitochondria. Fine structural studies of the intact lymphocytes showed the presence of acid phosphatase-positive, membrane-bounded organelles. Electron microscopy of the "large granule" (20,000 g x 20 min) fraction of such lymphocytes demonstrated 80–90% mitochondria, 5–10% platelets, and 5–10% membrane-bounded acid phosphatase-positive structures. The data indicate the presence in human peripheral blood lymphocytes of acid hydrolase-rich granules which possess many of the biochemical and structural characteristics of lysosomes in other tissues.

A mechanistic approach for modulation of chlorpyrifos-induced toxicity in human lymphocytes by melatonin, coenzyme Q10, and vinpocetine

2016 ◽  
Vol 35 (8) ◽  
pp. 839-850 ◽  
Author(s):  
F Ghayomi ◽  
M Navaei-Nigjeh ◽  
M Baeeri ◽  
MA Rezvanfar ◽  
M Abdollahi
Keyword(s):  
Oxidative Stress ◽  
Ache Activity ◽  
Human Peripheral Blood ◽  
Coenzyme Q ◽  
Human Lymphocytes ◽  
Organophosphorus Pesticide ◽  
Peripheral Blood Lymphocytes ◽  
Mitochondrial Activity ◽  
Antioxidant Power ◽  
Tnf Α

Background: Chlorpyrifos (CP) is an organophosphorus pesticide that induces oxidative stress through the production of free radicals and depletes intracellular antioxidant reserves. In this study, the efficacy of three antioxidants (melatonin, coenzyme Q10 (CoQ10), and vinpocetine) on alleviation of toxic effects of CP was evaluated. Materials and Methods: Cytotoxicity of CP, in the presence or absence of effective doses of melatonin, CoQ10, and vinpocetine, was determined in human peripheral blood lymphocytes after 72-h exposure. The levels of acetylcholinesterase (AChE) activity along with tumor necrosis factor α (TNF-α), as inflammatory index, were measured. Further, the viability and oxidative stress markers including cellular mitochondrial activity, cell death modes (apoptosis vs. necrosis), total antioxidant power (TAP), total thiol molecules (TTM), lipid peroxidation (LPO), and myeloperoxidase (MPO) activity were measured. Results: CoQ10 and also the combination of the three antioxidants were the most notable in opposing toxicity of CP and led to increasing TAP and TTM; improvement of AChE activity; and lowering LPO, MPO, TNF-α, and apoptosis compared to CP alone. Conclusion: CP toxicity overwhelms the intracellular antioxidant defense mechanisms. Exogenous supplementation with antioxidants, such as the ones we have investigated, seems to be effective in the prevention of cytotoxicity of CP.

scholarly journals The Transfer RNA Methylases of Human Lymphocytes. I. Induction by PHA in Normal Lymphocytes

Blood ◽  
1971 ◽  
Vol 37 (3) ◽  
pp. 282-292 ◽  
Author(s):  
DAVID H. RIDDICK ◽  
ROBERT C. GALLO
Keyword(s):  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Transfer Rna ◽  
Normal Peripheral Blood ◽  
Blood Lymphocytes ◽  
Normal Human ◽  
Total Capacity ◽  
Normal Human Peripheral Blood

Abstract Assays were performed that measured both the rate and extent (or total capacity) of transfer RNA methylases in extracts of lymphocytes cultured in the presence and absence of phytohemagglutinin (PHA). The tRNA methylases of human peripheral blood lymphocytes undergoing blastogenesis in culture with PHA had a five- to sixfold increase in rate and a three- to sevenfold increase in extent of methylation of heterologous tRNA. These data suggest that PHA transformed lymphocytes not only contain elevated levels of tRNA methylases, but that the increase includes qualitatively different enzymes from those found in normal peripheral blood lymphocytes. Experiments in which lymphocytes were incubated for various times with PHA revealed that tRNA methylase induction occurred late in or after DNA synthesis and after morphologic transformation, but prior to mitosis. Rate and extent of tRNA methylation increased simultaneously. PHA induction of tRNA methylase activity was dependent on the synthesis of new RNA in lymphocytes cultured from 40 to 45 hours. The increase was not due to different levels of inhibitors or activators or preferential degradation of reaction components. The data suggest that quantitative and qualitative changes occur in the tRNA methylases of the normal human peripheral blood lymphocyte stimulated by PHA to undergo transition to an undifferentiated cell "in cycle." The possible significance of these findings to control of protein synthesis in PHA transformed lymphocytes is discussed.

scholarly journals Genotoxic effects of diazinon on human peripheral blood lymphocytes / Genotoksično djelovanje diazinona na limfocite ljudske periferne krvi

2015 ◽  
Vol 66 (2) ◽  
pp. 153-158 ◽  
Author(s):  
Fulya Dilek Gökalp Muranli ◽  
Martin Kanev ◽  
Kezban Ozdemir
Keyword(s):  
Dna Damage ◽  
Comet Assay ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Human Lymphocytes ◽  
Peripheral Blood Lymphocytes ◽  
Blood Lymphocytes ◽  
Human Peripheral Blood Lymphocytes ◽  
Current Assessment ◽  
High Level

Abstract The aim of this study was to evaluate the genetic damage in human peripheral blood lymphocytes following 24 and 48- hour exposure to a commercial diazinon formulation Basudin 60EM® at concentrations between 0.01 and 40 μg mL-1. For this purpose we used the micronucleus (MN), fluorescence in situ hybridization (FISH), and alkaline single cell gel electrophoresis (comet) assay. Diazinon significantly increased the frequency of micronucleated cells compared to control. Forty-eight-hour exposure increased this frequency even at lower concentrations (0.01-10 μg mL-1). The FISH results revealed aneugenic effects at 10 μg mL-1. The comet assay also confirmed DNA damage at concentrations between 10 and 40 μg mL-1. Our findings have confirmed the genotoxic potential of diazinon and its cytotoxic effect on human lymphocytes. The increased DNA damage in our study raises concern about the current assessment of the health risk posed by this pesticide and calls for a high level of caution in agricultural and household use.

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