Packed Red Blood Cells Suppress T-Cell Proliferation Through a Process Involving Cell–Cell Contact

2010 ◽  
Vol 69 (2) ◽  
pp. 320-329 ◽  
Author(s):  
Andrew Bernard ◽  
Cindy Meier ◽  
Marty Ward ◽  
Tyler Browning ◽  
Ashley Montgomery ◽  
...  
Blood ◽  
2001 ◽  
Vol 97 (10) ◽  
pp. 3152-3160 ◽  
Author(s):  
Ana Mafalda Fonseca ◽  
Graça Porto ◽  
Koji Uchida ◽  
Fernando A. Arosa

Abstract Red blood cells (RBCs) are known to perform one prominent function: to carry and deliver oxygen to the tissues. Earlier studies, however, suggested a role for RBCs in potentiating T-cell proliferation in vitro. Here it is shown that the presence of RBCs in cultures of stimulated human peripheral blood lymphocytes strengthens T-cell proliferation and survival. Analysis of phosphatidylserine externalization and DNA fragmentation showed that RBCs inhibit T-cell apoptosis. This inhibition correlated with a reduction in CD71 but not CD95 expression. RBCs enhanced T-cell proliferation and survival upon activation with phytohemagglutinin and with OKT3 antibodies. Studies aimed at characterizing the cellular and molecular basis of the protection afforded to T cells by RBCs showed that (1) optimal protection required intact RBCs and red cell/T-cell contact but not monocytes; (2) RBCs markedly reduced the level of intracellular reactive oxygen species; and (3) RBCs inhibited the formation of protein-bound acrolein, a peroxidation adduct in biologic systems. Overall, these data indicate that human RBCs protect T cells from activation-induced cell death, at least in part by reducing the pro-oxidant state, and suggest a role for RBCs as conceivable modulators of T-cell homeostasis.


1993 ◽  
Vol 38 (5) ◽  
pp. 435-444 ◽  
Author(s):  
J. R. WESTPHAL ◽  
H. W. WILLEMS ◽  
W. J. M. TAX ◽  
R. A. P. KOENE ◽  
D. J. RUITER ◽  
...  

2021 ◽  
pp. 100487
Author(s):  
Marlene C. Gerner ◽  
Andrea Bileck ◽  
Lukas Janker ◽  
Liesa S. Ziegler ◽  
Thomas Öhlinger ◽  
...  

2000 ◽  
Vol 113 (3) ◽  
pp. 391-400 ◽  
Author(s):  
D.A. Bleijs ◽  
M.E. Binnerts ◽  
S.J. van Vliet ◽  
C.G. Figdor ◽  
Y. van Kooyk

Although ICAM-3 is implicated in both adhesion and signal transduction events of leukocytes, its low affinity for LFA-1 compared to other ligands of LFA-1 has puzzled many investigators. Here we investigated the role of ICAM-3 in supporting LFA-1-mediated ICAM-1 binding and subsequently cell signaling. We observed that although ICAM-3 binds poorly to LFA-1 expressed on resting T cells, it specifically facilitates and increases LFA-1-mediated adhesion to the high affinity ligand of LFA-1, ICAM-1. We demonstrate that low-affinity binding of LFA-1 to ICAM-3 together with ICAM-1 alters the cell surface distribution of LFA-1 dramatically, inducing large clusters of LFA-1 that facilitate ICAM-1 binding after LFA-1 activation. We found that LFA-1-mediated ICAM-1 cell-cell interactions such as T cell proliferation greatly depend on low affinity LFA-1/ICAM-3 interactions that enhance stable LFA-1/ICAM-1 cell-cell contact. Taken together, these data demonstrate that low affinity LFA-1 binding to ICAM-3 regulates strong LFA-1/ICAM-1-mediated adhesion by driving LFA-1 into clusters to facilitate cell-cell interactions that take place in the immune system.


2021 ◽  
Vol 12 ◽  
Author(s):  
Danielle Minns ◽  
Katie J. Smith ◽  
Gareth Hardisty ◽  
Adriano G. Rossi ◽  
Emily Gwyer Findlay

Neutrophils and T cells exist in close proximity in lymph nodes and inflamed tissues during health and disease. They are able to form stable interactions, with profound effects on the phenotype and function of the T cells. However, the outcome of these effects are frequently contradictory; in some systems neutrophils suppress T cell proliferation, in others they are activatory or present antigen directly. Published protocols modelling these interactions in vitro do not reflect the full range of interactions found in vivo; they do not examine how activated and naïve T cells differentially respond to neutrophils, or whether de-granulating or resting neutrophils induce different outcomes. Here, we established a culture protocol to ask these questions with human T cells and autologous neutrophils. We find that resting neutrophils suppress T cell proliferation, activation and cytokine production but that de-granulating neutrophils do not, and neutrophil-released intracellular contents enhance proliferation. Strikingly, we also demonstrate that T cells early in the activation process are susceptible to suppression by neutrophils, while later-stage T cells are not, and naïve T cells do not respond at all. Our protocol therefore allows nuanced analysis of the outcome of interaction of these cells and may explain the contradictory results observed previously.


Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3319-3319 ◽  
Author(s):  
Shimrit Ringelstein-Harlev ◽  
Irit Avivi ◽  
Shoham Shivtiel-Arad ◽  
Tami Katz

Abstract Introduction: Chronic lymphocytic leukemia (CLL) cells utilize several mechanisms of survival, some propagating proliferation and preventing apoptosis through intrinsic cell cycle signals, and others suppressing anti-tumor immune responses. Patients often present with a predominant population of regulatory T-cells (Tregs), and general features of T-cell exhaustion. Given the unique phenotype of CLL cells and the observed T-cell abnormalities we hypothesized that these cells function as regulatory B-cells (Bregs). Bregs, mostly explored in the autoimmune disease setting, produce interleukin-10 (IL10), which mediates attenuation of effector T-cell responses and enhances regulatory activity. These features have also been suggested to be responsible for weakening of anti-tumor immune responses. Breg activation requires stimulation of various combinations of Toll-like receptors (TLRs), the B-cell receptor (BCR) and CD40. Our previous studies have demonstrated that TLR9-stimulated CLL cells "acquire" Breg markers as well as PD1 and PDL1, which, while not being classic Breg discriminators, are established players in immune modulation. Moreover, such stimulation resulted in inhibition of proliferation of autologous T-cells. The current study aimed to further explore the regulatory characteristics of CLL cells focusing on additional suppressive mechanisms that may have a role in CLL immune evasion, particularly, the PD1/PDL1 axis. Methods: B-cells were isolated from peripheral blood mononuclear cells (PBMCs) of untreated CLL patients (Rai stages 0-IV). These B-CLL cells were stimulated with TLR-9 agonist (ODN) or CD40 ligand (CD40L) followed by their co-culture with isolated autologous CD4+ T cells. The regulatory features of B-CLL cells were studied by testing their effect on T cells. Their proliferation was evaluated using the CFSE method following stimulation with anti-CD3/CD28 antibodies and IL2; induction of Tregs (CD4+CD25highFoxp3+ population) was assessed by FACS analysis. The involvement of the PD1/PDL1 axis was examined by incubating B-cells with antiPD1 neutralizing antibodies prior to co-culture. Cell contact dependence was evaluated by plating B-cells in hanging cell culture inserts denying B and T cell contact while allowing flow of small soluble molecules. Results: CLL cells stimulated with ODN or CD40L, induced a significant increase in Tregs: 1.35±0.1-fold (p=0.03, N=12) for ODN and 1.7±0.2-fold (p=0.008, N=14) for CD40L, occurring in 68% and 80% of patients, respectively, while co-culture with unstimulated B-CLL cells did not result in the expansion of the Treg population. Treg induction was observed only under contact conditions (N=5), suggesting that this regulatory function requires cell-to-cell contact and cannot be carried out solely by secreted factors like IL10. Neutralization of PD1 on CLL B-cells affects both Treg induction and T-cell proliferation. Following CD40L stimulation, a 1.3-fold reduction in Treg percentage was observed when PD1 signaling was blunted (N=10). In contrast, PD1 blockage of ODN-stimulated CLL cells did not reduce Treg induction; however, it did adversely affect inhibition of T-cell proliferation (10%-decrease in inhibited T-cells; N=6). Conclusions: CLL cells "acquire" a Breg phenotype and function, inhibiting T-cell proliferation and inducing Tregs. These properties, while working together to promote immune regulation and cancer evasion, are elicited by different ligands in the cell environment and are likely to be mediated via separate pathways. The involvement of B-cell-associated PD1 in the induction of Tregs and inhibition of T-cell proliferation suggests a biologic role of PD1 signaling in CLL cells, strengthening the Breg phenotype. The current study has shown that CLL cells recruit several mechanisms operating cooperatively to support immune modulation and promote their survival. Disclosures No relevant conflicts of interest to declare.


2006 ◽  
Vol 291 (2) ◽  
pp. G253-G259 ◽  
Author(s):  
Ahmed Metwali ◽  
Tommy Setiawan ◽  
Arthur M. Blum ◽  
Joseph Urban ◽  
David E. Elliott ◽  
...  

This study determined whether Heligmosomoides polygyrus induces intestinal regulatory T cells. Splenic T cells proliferate strongly when cultured with anti-CD3 and antigen-presenting cells (APC). Lamina propria T cells from mice with H. polygyrus mixed with normal splenic T cells from uninfected mice inhibited proliferation over 90%. Lamina propria T cells from mice without H. polygyrus only modestly affected T cell proliferation. The worm-induced regulatory T cell was CD8+ and required splenic T cell contact to inhibit proliferation. The regulation also was IL-10 independent, but TAP-dependent, suggesting that it requires major histocompatibility complex (MHC) class I interaction. Additional studies employed mice with transgenic T cells that did not express functional TGF-β receptors. The lamina propria T regulator inhibited proliferation of these transgenic T cells nearly 100%, suggesting that TGF-β signaling via the T cell was not required. CD8+ T cells were needed for worms to reverse piroxicam-induced colitis in Rag mice (T and B cell deficient) reconstituted with IL-10−/− T cells. Thus H. polygyrus induces a regulatory CD8+ lamina propria T cell that inhibits T cell proliferation and that appears to have a role in control of colitis.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3874-3874
Author(s):  
Shimrit Ringelstein-Harlev ◽  
Irit Avivi ◽  
Lina Bisharat ◽  
Tamar Katz

Abstract Abstract 3874 Background: Chronic lymphocytic leukemia (CLL) is a mature B-cell malignancy, characterized by distinct immune suppression rendering both tumor cells and invading pathogens invisible to the immune system. However, CLL cells also display profound immune sensitivity as proven by long-term remissions achieved with allogeneic bone marrow transplantation. Many phenotypic properties of B-CLL cells resemble a subset of B-cells, studied mostly in autoimmunity and termed regulatory B cells (Bregs). Bregs are thought to suppress CD4+ T-cell mediated immune responses, directly through cell contact and indirectly through inhibitory cytokines. This study aims to define whether malignant B-CLL cells exhibit Breg suppressive properties, contributing to immune dysfunction in this disease. Methods: B-cells were isolated from peripheral blood mononuclear cells (PBMCs) of untreated CLL patients (Rai stages 0-IV) using immunomagnetic separation (STEMCELL technologies). Naïve cells and those stimulated with B-cell activators TLR-9 agonist or CD40Ligand (CD40L) were analyzed by FACS for Breg phenotypic markers and intracellular IL-10. Additionally, B-CLL cell effects on autologous CD4+ T cells (isolated by immunomagnetic beads; Miltenyi Biotec) were studied. T-cells were stimulated with anti-CD3/CD28 antibodies and IL-2, and exposed to B-cells either directly or through hanging cell culture inserts (Millipore) preventing physical cell-cell contact. T-cell proliferation was assessed using the carboxyfluorescein diacetate succinimidyl ester (CFSE) method and phenotype was analyzed by FACS. Results: B-cell phenotype was studied in 11 patients. Breg markers (CD5, CD38, CD25 and intracellular IL-10) as well as inhibitory molecules PD-1 and PDL-1 were expressed at high levels on B-CLL cells (62%, 37%, 50%, 52%, 29%, 61%, respectively), although not every patient expressed all markers. These expression levels were higher than those reported for normal peripheral blood B-cells. TLR-9 stimulation of B-CLL cells resulted in a 5.7-fold increase in expression of CD25 in 77% of patients. Increments were also observed in IL-10 (1.9-fold; 62% of patients), PDL-1 (1.96-fold; 83% of patients) and PD-1 (2.19-fold; 57% of patients). Of 13 patients whose T-cell proliferation potential was evaluated after exposure to B-CLL cells, proliferation was induced in only 69%; in the other 31% (4 patients) no proliferation was observed; moreover, inhibition was demonstrated in one of them. Among the former group only 33% of patients expressed CD25 on their B-cells, whereas within the latter group, 75% of patients' B-cells were CD25-positive. Stimulation of B-CLL cells with TLR-9 markedly increased their inhibitory capacity (72% of 11 patients tested), while CD40L stimulation caused a weaker effect (50% of 6 patients tested). T-cell proliferation remained unchanged when evaluated using a Transwell system versus a contact system, as demonstrated in 3 of 4 experiments. T-cells exposed to B-CLL cells altered the ratio of CD25high vs. CD25low T-cells in favor of CD25 high cells (2.44-fold increase for stimulation with naïve B-CLL cells, 4.94-fold increase with TLR-9 stimulated cells; in all the 5 tested patients). Conclusions: Previously identified Breg markers as well as PD-1 and PDL-1 were highly expressed in B-CLL cells, supporting the role of these cells in shaping an immune tolerant environment, enabling tumor growth. Stimulation of B-CLL cells with TLR-9 agonist enhanced this phenotype and resulted in consistent inhibition of T-cell proliferation, likely to be independent of cell-to-cell contact. These findings demonstrate the presence of Breg features within the CLL clone. The observed alterations in CD4+CD25+ T-cell populations after exposure to B-CLL cells suggest induction of T-regulatory cells, another mechanism supposedly used by Bregs for immune suppression. The enhancement of Breg properties in B-CLL cells following B-cell activation can serve as a platform for further studies of the innate regulatory mechanisms utilized by tumor cells. Disclosures: No relevant conflicts of interest to declare.


2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Stefania Bruno ◽  
Cristina Grange ◽  
Marta Tapparo ◽  
Chiara Pasquino ◽  
Renato Romagnoli ◽  
...  

Human liver stem cells (HLSCs) are a mesenchymal stromal cell-like population resident in the adult liver. Preclinical studies indicate that HLSCs could be a good candidate for cell therapy. The aim of the present study was to evaluate the immunogenicity and the immunomodulatory properties of HLSCs on T-lymphocytes, natural killer cells (NKs), and dendritic cells (DCs) in allogeneic experimental settings. We found that HLSCs inhibited T-cell proliferation by a mechanism independent of cell contact and dependent on the release of prostaglandin E2 (PGE2) and on indoleamine 2,3-dioxygenase activity. When compared with mesenchymal stromal cells (MSCs), HLSCs were more efficient in inhibiting T-cell proliferation. At variance with MSCs, HLSCs did not elicit NK degranulation. Moreover, HLSCs inhibited NK degranulation against K562, a NK-sensitive target, by a mechanism dependent on HLA-G release. When tested on DC generation from monocytes, HLSCs were found to impair DC differentiation and DCs ability to induce T-cell proliferation through PGE2. This study shows that HLSCs have immunomodulatory properties similar to MSCs, but, at variance with MSCs, they do not elicit a NK response.


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