Gangliosides and glycophorin inhibit T-lymphocyte activation

1990 ◽  
Vol 68 (4) ◽  
pp. 735-744 ◽  
Author(s):  
Frances J. Sharom ◽  
Anita L. H. Chiu ◽  
T. Elaine Ross

Increased levels of gangliosides in the serum have been linked to tumour-induced immunosuppression in vivo. Both bovine brain gangliosides and human erythrocyte glycophorin were potent inhibitors of concanavalin A, periodate, and phorbol ester – ionomycin induced activation of murine T-lymphocytes. Structurally complex gangliosides were more inhibitory, while simpler glycolipids caused less inhibition. Lymphocytes exposed to these molecules for up to 24 h could still proliferate after washing. Substantial inhibition was observed only when gangliosides and glycophorin were present during the first 18 h of activation. Studies using Quin-2 showed that gangliosides did not block the initial rapid rise in cytoplasmic Ca2+ following mitogen stimulation. Interleukin-2 (IL-2) production by ganglioside- and glycophorin-treated lymphocytes was unchanged. After treatment with gangliosides for 24 h, lymphocytes proliferated normally in response to added IL-2. These results suggest that the first round of signal transduction in response to mitogen was unaffected by gangliosides. Addition of gangliosides to activated lymphocytes in the presence of IL-2 resulted in complete inhibition of proliferation. Immunosuppression by gangliosides and glycophorin thus appears to occur at the IL-2-dependent stage of proliferation and may be partially due to IL-2 binding to these molecules. However, high levels of IL-2 failed to reverse inhibition and IL-2-dependent cell lines were much less sensitive to ganglioside inhibition than T-lymphocytes, suggesting that more than one mechanism of inhibition likely exists.Key words: gangliosides, glycophorin, T-lymphocyte, interleukin-2, interleukin-2 receptor.

Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 614-619 ◽  
Author(s):  
R Foa ◽  
M Giovarelli ◽  
C Jemma ◽  
MT Fierro ◽  
P Lusso ◽  
...  

Abstract The capacity of T lymphocytes from patients with B cell chronic lymphocytic leukemia (B-CLL) to release interleukin 2 (IL 2) and interferon (IFN)-gamma was assessed following various stimuli. The spontaneous release of IL 2 and IFN-gamma was practically absent both with B-CLL and normal T lymphocytes. By contrast, after stimulation with phytohemagglutinin (PHA) or with PHA plus 12-O- tetradecanoylphorbol-13-acetate, the production of IL 2 and IFN-gamma by B-CLL T lymphocytes was similar to that of normal T lymphocytes, irrespective of the reversed T lymphocyte subset distribution (OKT4/OKT8 ratio) observed in B-CLL. However, the titer of IL 2 was greatly reduced when autologous leukemic B cells were added to the culture system. Unlike IL 2, the presence of leukemic B cells did not affect the titer of IFN-gamma in the culture supernatants. The indication that IL 2 may be adsorbed in vivo by the neoplastic B cells was further confirmed by the demonstration of the IL 2 receptor (revealed by anti-Tac monoclonal antibody) on the leukemic B cells, particularly following mitogenic stimulation, and by the evidence that exogenous IL 2 can be directly absorbed by untreated B-CLL T lymphocytes to release IFN-gamma and IL 2 is preserved, but that IL 2 may be rapidly removed by the neoplastic B-CLL cells, thus contributing to the well-documented T lymphocyte abnormalities present in this disease.


Blood ◽  
1985 ◽  
Vol 66 (3) ◽  
pp. 614-619 ◽  
Author(s):  
R Foa ◽  
M Giovarelli ◽  
C Jemma ◽  
MT Fierro ◽  
P Lusso ◽  
...  

The capacity of T lymphocytes from patients with B cell chronic lymphocytic leukemia (B-CLL) to release interleukin 2 (IL 2) and interferon (IFN)-gamma was assessed following various stimuli. The spontaneous release of IL 2 and IFN-gamma was practically absent both with B-CLL and normal T lymphocytes. By contrast, after stimulation with phytohemagglutinin (PHA) or with PHA plus 12-O- tetradecanoylphorbol-13-acetate, the production of IL 2 and IFN-gamma by B-CLL T lymphocytes was similar to that of normal T lymphocytes, irrespective of the reversed T lymphocyte subset distribution (OKT4/OKT8 ratio) observed in B-CLL. However, the titer of IL 2 was greatly reduced when autologous leukemic B cells were added to the culture system. Unlike IL 2, the presence of leukemic B cells did not affect the titer of IFN-gamma in the culture supernatants. The indication that IL 2 may be adsorbed in vivo by the neoplastic B cells was further confirmed by the demonstration of the IL 2 receptor (revealed by anti-Tac monoclonal antibody) on the leukemic B cells, particularly following mitogenic stimulation, and by the evidence that exogenous IL 2 can be directly absorbed by untreated B-CLL T lymphocytes to release IFN-gamma and IL 2 is preserved, but that IL 2 may be rapidly removed by the neoplastic B-CLL cells, thus contributing to the well-documented T lymphocyte abnormalities present in this disease.


2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
TF Jones ◽  
A Gutierrez ◽  
del Arroyo ◽  
SM Henson ◽  
GL Ackland

Abstract Introduction Lymphopaenia is common after major surgery and associated with poor outcome. T-lymphocytes restrain damaging innate inflammation. Major surgery impairs T-lymphocyte metabolism in humans, which promotes lymphopaenia. Metformin is known to improve mitochondrial bioenergetics in models of inflammation. Firstly, we hypothesised that a mouse model of major surgery would demonstrate impaired T-lymphocyte metabolism and secondly, that metformin treatment in vivo would reverse the phenotype. Method Male C57Bl/6 mice aged between 8 and 12 weeks were housed in a specific pathogen free environment with free access to food and water. Animals were dosed with either vehicle (phosphate buffered saline, 20 ml/kg) or metformin (250 mg/kg) daily via intraperitoneal injection for four days prior to and after surgery. A partial hepatectomy was performed under isofluorane anaesthesia. Naive littermates were used as controls. All experiments were performed according to the Animals (Scientific Procedures) Act 1986. Splenic T-lymphocytes were isolated by negative selection using magnetic beads. Mitochondrial bioenergetics were measured using a Seahorse Extracellular Flux analyser. Parametric statistical analysis was performed and a p-value < 0.05 was chosen to represent significance. Result T-lymphocytes demonstrated reduced spare respiratory capacity (SRC, 285 vs 497 %, p=0.004) after surgery compared to naive controls. Metformin treatment in vivo reversed this observation and SRC was comparable to naive (437 vs 497 %, p=0.34). Metformin treatment in vitro increased spare respiratory capacity in T-lymphocytes from mice after surgery compared to naive (change from untreated, 187 vs 91 %, p=0.03). Conclusion Perioperative metformin treatment improved T-lymphocyte metabolism in a mouse model of major surgery. Take-home message Metformin is a potential treatment for the lymphocyte metabolic dysfunction observed after surgery.


2011 ◽  
Vol 19 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Alexandre S. de Almeida ◽  
Christina T. Fiske ◽  
Timothy R. Sterling ◽  
Spyros A. Kalams

ABSTRACTExtrapulmonary tuberculosis may be due to underlying immune compromise. Immunosuppressive regulatory T cells (Treg cells), and CD4+T lymphocytes in general, are important in the host immune response toMycobacterium tuberculosis. We evaluated T lymphocytes from patients after recovery from extrapulmonary tuberculosis, which may reflect conditions beforeM. tuberculosisinfection. A case-control study was conducted among HIV-uninfected adults with previously treated extrapulmonary tuberculosis and 3 sets of controls: (i) subjects with previously treated pulmonary tuberculosis, (ii) close tuberculosis contacts withM. tuberculosisinfection, and (iii) close tuberculosis contacts with no infection. Monocyte-depleted peripheral blood mononuclear cells (PBMC-M) were stained for CD4+CD25hiCD127lowFoxP3+cell (Treg cell) and T lymphocyte activation. Both characteristics were compared as continuous variables between groups with the Kruskal-Wallis test. There were 7 extrapulmonary tuberculosis cases, 18 pulmonary tuberculosis controls, 17 controls withM. tuberculosisinfection, and 18 controls withoutM. tuberculosisinfection. The median Treg cell proportion was highest among persons with previous extrapulmonary tuberculosis (1.23%) compared to subjects with pulmonary tuberculosis (0.56%), latentM. tuberculosisinfection (0.14%), or noM. tuberculosisinfection (0.20%) (P= 0.001). The median proportion of CD4+T lymphocytes that expressed the activation markers HLA-DR and CD38 was highest for CD4+T lymphocytes from persons with previous extrapulmonary tuberculosis (0.79%) compared to subjects with pulmonary tuberculosis (0.44%), latentM. tuberculosisinfection (0.14%), or noM. tuberculosisinfection (0.32%) (P= 0.005). Compared with controls, persons with previously treated extrapulmonary tuberculosis had the highest Treg cell frequency, but also the highest levels of CD4+T lymphocyte activation. Immune dysregulation may be a feature of individuals at risk for extrapulmonary tuberculosis.


1994 ◽  
pp. 49-52
Author(s):  
M. Chianelli ◽  
S. J. Mather ◽  
A. Signore ◽  
G. Ronga ◽  
P. Pozzilli ◽  
...  

2012 ◽  
Vol 2 (4) ◽  
pp. 72 ◽  
Author(s):  
Diana Bayer ◽  
Jonathon Jansen ◽  
Lisa A. Beltz

Background: Tea is one of the world’s most highly consumed beverages, second only to water. It is affordable and abundant and thus has great potential for improving health of those in both developed and developing areas. Green, oolong, and black teas differ in the extent of fermentation and types of bioactive polyphenols produced. Green tea and its major polyphenol decrease growth of some cancer cells and effect production of immune system cytokines. This study compares the effects of different types of tea extracts on viability and cytokine production by normal and leukemic human T lymphocytes. Generation of the toxic reactive oxygen species H2O2 by extracts was also examined.Methods: The Jurkat T lymphoblastic leukemia cells and mitogen-stimulated normal human peripheral blood mononuclear cells were used in this study. Cell viability was determined by (3-4,5-dimethylthiamizol-2-yl)-diphenyltetrazolium bromide) assay and production of interleukin-2 by Enzyme-Linked ImmunoSorbent Assay. Levels of H2O2 generated by tea extracts were determined using the xylenol-orange method.Results: We found that green, oolong, and black tea extracts differentially effect the growth and viability of T lymphoblastic leukemia cells and normal peripheral blood mononuclear cells, substantially decreasing both growth and viability of leukemic T lymphocytes and having much lesser effects on their normal counterparts. Tea extracts also had differential effects on the production of the T lymphocyte growth factor interleukin-2, significantly decreasing production by leukemic cells while having only minor effects on normal cells. All three extracts induced H2O2 generation, with green and oolong tea extracts having the greatest effect. Leukemic cells were much more susceptible to growth inhibition and killing by H2O2 than normal lymphocytes. Conclusions: The three tea extracts studied altered leukemic T lymphocyte functions, decreasing cell viability, growth, and production of a major cell growth factor and the H2O2 generated by solutions of extracts may be partially responsible. Normal cells were affected to a far lesser degree by tea extracts and are also more resistant to killing by H2O2 than leukemic cells. This study has implications for using tea extracts for chemotherapeutic and immunomodulatory purposes.Key Words: Tea extracts, interleukin-2, hydrogen peroxide, leukemia, T lymphocytes


2012 ◽  
Vol 32 (4) ◽  
pp. 598-611 ◽  
Author(s):  
Vanessa H Brait ◽  
Thiruma V Arumugam ◽  
Grant R Drummond ◽  
Christopher G Sobey

Following an ischemic stroke, T lymphocytes become activated, infiltrate the brain, and appear to release cytokines and reactive oxygen species to contribute to early inflammation and brain injury. However, some subsets of T lymphocytes may be beneficial even in the early stages after a stroke, and recent evidence suggests that T lymphocytes can also contribute to the repair and regeneration of the brain at later stages. In the hours to days after stroke, T-lymphocyte numbers are then reduced in the blood and in secondary lymphoid organs as part of a ‘stroke-induced immunodeficiency syndrome,’ which is mediated by hyperactivity of the sympathetic nervous system and the hypothalamic—pituitary—adrenal axis, resulting in increased risk of infectious complications. Whether or not poststroke T-lymphocyte activation occurs via an antigen-independent process, as opposed to a classical antigen-dependent process, is still controversial. Although considerable recent progress has been made, a better understanding of the roles of the different T-lymphocyte subpopulations and their temporal profile of damage versus repair will help to clarify whether T-lymphocyte targeting may be a viable poststroke therapy for clinical use.


Blood ◽  
2007 ◽  
Vol 110 (13) ◽  
pp. 4285-4292 ◽  
Author(s):  
Véronique Mateo ◽  
Michael Ménager ◽  
Geneviève de Saint-Basile ◽  
Marie-Claude Stolzenberg ◽  
Bertrand Roquelaure ◽  
...  

Activation-induced cell death (AICD) is involved in peripheral tolerance by controlling the expansion of repeatedly stimulated T cells via an apoptotic Fas (CD95; APO-1)–dependent pathway. The TNFRSF-6 gene encoding Fas is mutated in children suffering from autoimmune lymphoproliferative syndrome (ALPS), which is characterized by lymphoproliferation and autoimmunity. We examined AICD in Fas-deficient T cells from ALPS patients. We showed that primary activated Fas-deficient T cells die by apoptosis after repeated T cell antigen receptor (TCR) stimulation despite resistance to Fas-mediated cell death. This Fas-independent AICD was found to be mediated through a cytotoxic granules-dependent pathway. Cytotoxic granules-mediated AICD was also detected in normal T lymphocytes though to a lesser extent. As expected, the cytotoxic granules-dependent AICD was abolished in T cells from Rab27a- or perforin-deficient patients who exhibited defective granules-dependent cytotoxicity. Supporting an in vivo relevance of the cytotoxic granules-dependent AICD in ALPS patients, we detected an increased number of circulating T lymphocytes expressing granzymes A and B. Altogether, these data indicated that the cytotoxic granules-dependent cell death in ALPS may compensate for Fas deficiency in T lymphocytes. Furthermore, they identified a novel AICD pathway as a unique alternative to Fas apoptosis in human peripheral T lymphocytes.


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