Polycation Coated Polymeric Particles as Vehicles of RNA Delivery Into Immune Cells

2010 ◽  
Author(s):  
Ying Zheng ◽  
Wilson S. Meng
Keyword(s):  
T Cells ◽  
Immune Cells ◽  
Messenger Rna ◽  
Flow Cytometric Analysis ◽  
Confocal Imaging ◽  
Dependent Manner ◽  
Carrier System ◽  
Foxp3 Mrna ◽  
Rna Molecules ◽  
Polymeric Particles

The purpose of this work is to develop a carrier system for delivering RNA molecules aimed to downregulate specific functions in T cells. In many forms of cancer, T cells that express the protein Forkhead Box P3 (Foxp3) are associated with cancer progression. These cells can be identified by CD4 and CD25, molecules express on the cell surface. Studies have shown that downregulation of Foxp3 can increase the ability of other immune cells to destroy tumors. A class of RNA molecules, commonly referred to as “siRNA”, bind to and degrade specific messenger RNA (mRNA) in a sequence-dependent manner such that expression of the encoded protein is terminated. Because mRNA molecules are located inside cells, a carrier system is required to facilitate the uptake of siRNA, which does not passively diffuse through the plasma membrane. To this end, nanosized polymeric particles coated with the polycation, ornithinex10-histidinex6 (or O10H6) were used to adsorb siRNA that bind to the mRNA encoding Foxp3. The RNA-loaded particles are spherical and uniform in size (normally distributed, polydispersity index = 0.072). Loading of RNA to the particles was confirmed using gel electrophoresis. RNA complexed with the particles are protected from serum destabilization: 83.1% of RNA were recovered compared to 36.1% in RNA that were not associated with the particles. Association with the particles increased the uptake of the RNA in mouse T cells from 3.2±0.2% (free RNA) to 20.1±3.9%. Specifically, uptake of the RNA in T cells that express CD4 increased from 2.7±0.2% to 27.1±1.3% when particles were employed. These differences are statistically significant in three experiments conducted (p < 0.01). Internalization of the RNA into T cells was confirmed using confocal imaging. Flow cytometric analysis showed that the particle-complexed RNA reduced the percentage of T cells that express both CD4 and CD25 in mice carrying tumors from 24.0% when free RNA molecules were used to 13.5%. In these cells, the level of Foxp3 mRNA was reduced by 30%. In conclusion, the particles facilitate the uptake of siRNA molecules into a population of T cells that is known to promote cancer growth.

scholarly journals Human Articular Chondrocytes Induce Interleukin-2 Nonresponsiveness to Allogeneic Lymphocytes

Cartilage ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 300-306 ◽  
Author(s):  
Satomi Abe ◽  
Hitoshi Nochi ◽  
Hiroshi Ito
Keyword(s):  
T Cells ◽  
Articular Chondrocytes ◽  
Interleukin 2 ◽  
Flow Cytometric Analysis ◽  
Third Party ◽  
Soluble Form ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Activated T Cells ◽  
Allogeneic Lymphocytes

Introduction We previously showed that articular chondrocytes (ACs) have immune privilege and immunomodulatory functions like those of mesenchymal stem cells. To elucidate these mechanisms, we focused on interleukin-2 (IL-2), which plays critical roles in lymphocyte mitogenic activity. The purpose of this study was to explore whether ACs affect the role of IL-2 underlying immunomodulatory functions. Material and Methods Irradiated human ACs from osteoarthritis donors were used. Third-party ACs were added to the mixed lymphocyte reaction (MLR) with or without recombinant human IL-2 (rhIL-2), and the levels of IL-2 and the soluble form of the IL-2 receptor α (sIL-2Rα) protein in supernatant were measured by enzyme-linked immunosorbent assay. Recombinant human IL-2 (rhIL-2) was also added to the MLR. To detect the expression of IL-2 receptor α (CD25) on lymphocytes in the MLR, flow cytometric analysis was performed. Last, ACs and allogeneic activated CD4+ T cell were co-cultured, and the expression of CD25 on activated T cells was examined by flow cytometry. Results Third-party ACs significantly inhibited the MLR and reduced the level of sIL-2Rα in a dose-dependent manner, but did not affect the concentration of IL-2. Exogenous rhIL-2 accelerated MLR but did not rescue the inhibitory effect of ACs. ACs inhibited the expression of CD25 on activated CD4+ T cells. Discussion Our results showed that third-party ACs inhibited the proliferation of allogeneic activated lymphocytes, thereby inhibiting production sIL-2Rα, although ACs did not affect IL-2 secretion from lymphocytes. Also, ACs inhibited CD25 expression on activated CD4+ T cells. Thus, ACs inhibited the immune response of allogeneic lymphocytes by inducing IL-2 nonresponsiveness.

scholarly journals Regulation of c-jun gene expression in human T lymphocytes

Blood ◽  
1993 ◽  
Vol 81 (6) ◽  
pp. 1540-1548 ◽  
Author(s):  
D Chauhan ◽  
SM Kharbanda ◽  
E Rubin ◽  
BA Barut ◽  
A Mohrbacher ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Messenger Rna ◽  
Jurkat Cells ◽  
Pokeweed Mitogen ◽  
Mrna Levels ◽  
Dependent Manner ◽  
B Cell Differentiation ◽  
Normal Peripheral Blood ◽  
Mrna Induction

Abstract The present studies have examined the effects of mitogens on induction of early response gene expression in normal peripheral blood T and Jurkat cells. Pokeweed mitogen (PWM) or anti-CD3 significantly increases c-jun messenger RNA (mRNA) levels in T cells. This transient PWM-related increase in c-jun transcripts is maximal after 15 to 30 minutes of exposure of T cells to PWM. PWM induces c-jun gene expression in a concentration-dependent manner. Moreover, PWM similarly induces expression of other genes coding for leucine zipper transcription factors, ie, jun-B and c-fos. Nuclear run on assays demonstrate that PWM treatment is associated with an increased rate of c-jun gene transcription. Transient expression assays with c-jun promoter fragments linked to the chloramphenicol acetyltransferase gene suggest that the PWM-induced increase in transcription is mediated by the AP-1 transcription factor complex. Moreover, treatment of T cells with actinomycin D to block further transcription before their culture with PWM suggests that the increase in c-jun gene expression by PWM is also regulated at least in part by a posttranscriptional mechanism. Cycloheximide does not alter c-jun mRNA induction by PWM. Finally, given that PWM induces B-cell differentiation in an interleukin-6 (IL- 6)-mediated, T-cell-dependent manner, the relationship of c-jun and IL- 6 gene expression in PWM-stimulated T cells was examined. The induction of IL-6 mRNA in T cells stimulated by PWM occurs after maximal induction of c-jun mRNA, at a time when the latter is no longer detectable. These findings suggest that PWM induces c-jun gene expression in T cells by a transcriptional and posttranscriptional mechanism and that AP-1 confers PWM inducibility of this gene. Because the IL-6 promoter has several potential transcriptional control elements, one of which is an AP-1-binding site, future experiments will evaluate the role of c-jun in the regulation of PWM-induced IL-6 synthesis by T cells.

scholarly journals Thiols decrease human interleukin (IL) 4 production and IL-4-induced immunoglobulin synthesis.

1995 ◽  
Vol 182 (6) ◽  
pp. 1785-1792 ◽  
Author(s):  
P Jeannin ◽  
Y Delneste ◽  
S Lecoanet-Henchoz ◽  
J F Gauchat ◽  
P Life ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
T Cells ◽  
T Cell ◽  
Peripheral Blood ◽  
Messenger Rna ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Dependent Manner ◽  
Dose Dependent

N-Acetyl-L-cysteine (NAC) is an antioxidant precursor of intracellular glutathione (GSH), usually given in human as a mucolytic agent. In vitro, NAC and GSH have been shown to act on T cells by increasing interleukin (IL) 2 production, synthesis and turnover of IL-2 receptors, proliferation, cytotoxic properties, and resistance to apoptosis. We report here that NAC and GSH decrease in a dose-dependent manner human IL-4 production by stimulated peripheral blood T cells and by T helper (Th) 0- and Th2-like T cell clones. This effect was associated with a decrease in IL-4 messenger RNA transcription. In contrast, NAC and GSH had no effect on interferon gamma and increased IL-2 production and T cell proliferation. A functional consequence was the capacity of NAC and GSH to selectively decrease in a dose-dependent manner IL-4-induced immunoglobulin (Ig) E and IgG4 production by human peripheral blood mononuclear cells. Interestingly, NAC and GSH also acted directly on purified tonsillar B cells by decreasing the mature epsilon messenger RNA, hence decreasing IgE production. In contrast, IgA and IgM production were not affected. At the same time, B cell proliferation was increased in a dose-dependent manner. Not all antioxidants tested but only SH-bearing molecules mimicked these properties. Finally, when given orally to mice, NAC decreased both IgE and IgG1 antibody responses to ovalbumin. These results demonstrate that NAC, GSH, and other thiols may control the production of both the Th2-derived cytokine IL-4 and IL-4-induced Ig in vitro and in vivo.

scholarly journals Inhibitory effects of α-Mangostin on T cell cytokine secretion via ORAI1 calcium channel and K+ channels inhibition

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10973
Author(s):  
Hyun Jong Kim ◽  
Seorin Park ◽  
Hui Young Shin ◽  
Yu Ran Nam ◽  
Phan Thi Lam Hong ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ion Channels ◽  
Calcium Channel ◽  
Immune Cells ◽  
Potassium Ion ◽  
Cytokine Secretion ◽  
Potassium Ion Channels ◽  
Dependent Manner ◽  
Anti Inflammatory

Background As one of the main components of mangosteen (Garcinia mangostana), a tropical fruit, α-mangostin has been reported to have numerous pharmacological benefits such as anti-cancer, anti-inflammatory, and anti-allergic effects through various mechanisms of action. The effects of α-mangostin on intracellular signaling proteins is well studied, but the effects of α-mangostin on ion channels and its physiological effects in immune cells are unknown. Generation of intracellular calcium signaling is a fundamental step for T cell receptor stimulation. This signaling is mediated not only by the ORAI1 calcium channel, but also by potassium ion channels, which provide the electrical driving forces for generating sufficient calcium ion influx. This study investigated whether α-mangosteen suppress T cell stimulation by inhibiting ORAI1 and two kinds of potassium channels (Kv1.3 and KCa3.1), which are normally expressed in human T cells. Methods This study analyzed the inhibitory effect of α-mangostin on immune cell activity via inhibition of calcium and potassium ion channels expressed in immune cells. Results α-mangostin inhibited ORAI1 in a concentration-dependent manner, and the IC50 value was 1.27 ± 1.144 µM. Kv1.3 was suppressed by 41.38 ± 6.191% at 3 µM, and KCa3.1 was suppressed by 51.16 ± 5.385% at 3 µM. To measure the inhibition of cytokine secretion by immune cells, Jurkat T cells were stimulated to induce IL-2 secretion, and α-mangostin was found to inhibit it. This study demonstrated the anti-inflammatory effect of α-mangostin, the main component of mangosteen, through the regulation of calcium signals.

136 Targeting MET with chimeric antigen receptor T cells in hepatocellular carcinoma

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A149-A149
Author(s):  
Yuan Qin ◽  
Anna Qin ◽  
Anna Musket ◽  
Joseph Lee ◽  
Zhi Yao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
T Cell ◽  
Chimeric Antigen Receptor ◽  
Antigen Receptor ◽  
Confocal Imaging ◽  
Dependent Manner ◽  
Car T Cells ◽  
Car T Cell ◽  
Car T

BackgroundHepatocellular carcinoma (HCC) is the leading cause of cancer mortality worldwide. While HBV/HCV infection is the primary cause of HCC, overexpression of MET, the receptor of hepatocyte growth factor (HGF), occurs in 50% HCC patients, and is an indicator of poor prognosis. Although the multi-target MET tyrosine kinase inhibitor cabozantinib is FDA approved for treating advanced HCC, the long-term efficacy versus toxicity remains unknown. Our study is to develop specific MET-targeting chimeric antigen receptor T (CAR-T) cells for treating HCC with MET overexpression.MethodsBased on a well-established anti-MET monoclonal antibody, we synthesized and cloned the single-chain variable fragment (ScFv) sequence into two retroviral based 2nd generation CAR vectors (MET-CAR.CD28.ζ. and MET-CAR.4-1BB.ζ.). A MET-CAR without CD3ζ domain (MET-CARΔ) served as a negative control. To produce MET-CAR-T cells, healthy PBMCs were stimulated with anti-CD3/CD28 antibodies in the presence of IL-7/IL-15 followed by transduction with MET-CAR viral particles. T cell transduction efficacy was determined using flow cytometry. HCC cell lines with variable MET expression from high/positive (MHCC97H, C3A, and JHH5) to MET low/negative (SNU398) were used to determine MET-specific CAR T cells specificity and effector function using MTS assay. We also collected media from the tumor-T cell co-cultures and determined IL-2 and IFNγ secretion using ELISA. Finally, real-time confocal imaging (24 h) was performed to record the progress of MET-CAR T cell mediated killing activity against MHCC97H/mCherry cells.ResultsWe show that both MET-CAR.CD28.ζ and MET-CAR.4-1BB.ζ -T cells significantly killed MHCC97H, C3A, and JHH5 cells in antigen dependent manner. MET-CAR T cell killing is MET dependent as we observed no killing of MET-negative SNU398 cells. In addition, MET-CAR.4-1BB.ζ and MET-CAR.CD28.ζ- T cells secreted IL-2 and IFNγ when co-cultured with MHCC97H, C3A, JHH5 cells, but not SNU398. Confocal imaging studies showed that both MET-specific CAR T cells migrated toward MHCC97H/mCherry cells, formed aggregations, and induced tumor cell death, while MET-CARΔ T cells failed to do so.ConclusionsHere we demonstrate that MET-CAR.4-1BB.ζ and MET-CAR.CD28.ζ- T cells specifically recognize and kill MET-positive HCC cells in vitro. While animal studies are required to validate the efficacy in vivo, our study has produced a novel therapeutic CAR T cell target for treating malignant HCC and other type of cancers with MET overexpression.AcknowledgementsThis independent research was supported by the Gilead Sciences Research Scholars Program in Liver Disease- The Americas, and Department of Defense (DoD) Ideal Award (to QX)Ethics ApprovalThe study was approved by East Tennessee State University’s Ethics Board, approval number #0619.3s.

scholarly journals Neuroinflammation is associated with infiltration of T cells in Lewy body disease and ɑ-synuclein transgenic models.

2020 ◽  
Author(s):  
Michiyo Iba ◽  
Changyoun Kim ◽  
Michelle Sallin ◽  
Somin Kwon ◽  
Anjali Verma ◽  
...  
Keyword(s):  
T Cells ◽  
Immune System ◽  
Immune Cells ◽  
Flow Cytometric Analysis ◽  
Lewy Bodies ◽  
Lewy Body Disease ◽  
Immunohistochemical Analysis ◽  
Peripheral Immune System ◽  
Adaptive Immune Cells ◽  
Close Proximity

Abstract Background: ɑ-synuclein (ɑ-syn) is a presynaptic protein which progressively accumulates in neuronal and non-neuronal cells in neurodegenerative diseases such as Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy. Recent evidence suggests that aberrant immune activation may be involved in neurodegeneration in PD/DLB. While previous studies have often focused on the microglial responses, less is known about the role of the peripheral immune system in these disorders.Methods: To understand the involvement of the peripheral immune system in PD/DLB, we evaluated T cell populations in the brains of ɑ-syn transgenic (tg) mice (eg: Thy1 promoter line 61) and DLB patients.Results: Immunohistochemical analysis showed perivascular and parenchymal infiltration by CD3+/CD4+ helper T cells, but not cytotoxic T cells (CD3+/CD8+) or B cells (CD20+), in the neocortex, hippocampus, and striatum of ɑ-syn tg mice. CD3+ cells were found in close proximity to the processes of activated astroglia, particularly in areas of the brain with significant astrogliosis, microgliosis, and pro-inflammatory cytokines. In addition, a subset of CD3+ cells co-expressed interferon γ. Flow cytometric analysis of immune cells revealed that CD1d+ T cells were also increased in the brains of ɑ-syn tg mice and matched an expression profile consistent with natural killer T cells. In post-mortem DLB brains, we similarly detected CD3+ T cells that expressed CD4+ or CD1d+ in close proximity with blood vessels.Conclusion: These results suggest that infiltrating adaptive immune cells play an important role in neuroinflammation and neurodegeneration in synucleinopathies and that modulating peripheral T cells may be a viable therapeutic strategy for PD/DLB.

scholarly journals RAMP1 in Kupffer cells is a critical regulator in immune-mediated hepatitis

2018 ◽  
Author(s):  
Tomoyoshi Inoue ◽  
Yoshiya Ito ◽  
Nobuyuki Nishizawa ◽  
Koji Eshima ◽  
Ken Kojo ◽  
...  
Keyword(s):  
T Cells ◽  
Liver Injury ◽  
Kupffer Cells ◽  
Immune Cells ◽  
Critical Role ◽  
Dependent Manner ◽  
Immune Mediated ◽  
A Subunit ◽  
Sensory Nervous System ◽  
Deficient Mice

AbstractThe significanceF of the relationship between the nervous and immune systems with respect to disease course is increasingly apparent. Immune cells in the liver and spleen are responsible for the development of acute liver injury, yet the regulatory mechanisms of the interactions remain elusive. Calcitonin gene-related peptide (CGRP), which is released from the sensory nervous system, regulates innate immune activation via receptor activity-modifying protein 1 (RAMP1), a subunit of the CGRP receptor. Here, we show that RAMP1 in Kupffer cells (KCs) plays a critical role in the etiology of immune-mediated hepatitis. RAMP1-deficient mice with concanavalin A (ConA)-mediated hepatitis, characterized by severe liver injury accompanied by infiltration of immune cells and increased secretion of pro-inflammatory cytokines by KCs and splenic T cells, showed poor survival. Removing KCs ameliorated liver damage, while depleting T cells or splenectomy led to partial amelioration. Adoptive transfer of splenic T cells from RAMP1-deficient mice led to a modest increase in liver injury. Co-culture of KCs with splenic T cells led to increased cytokine expression by both cells in a RAMP1-dependent manner. Thus, immune-mediated hepatitis develops via crosstalk between immune cells. RAMP1 in KCs is a key regulator of immune responses.

scholarly journals Selective Expression of a Stable Cell Surface Molecule on Type 2 but Not Type 1 Helper T Cells

1998 ◽  
Vol 187 (5) ◽  
pp. 787-794 ◽  
Author(s):  
Damo Xu ◽  
Woon Ling Chan ◽  
Bernard P. Leung ◽  
Fang-ping Huang ◽  
Rachel Wheeler ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Leishmania Major ◽  
Flow Cytometric Analysis ◽  
Dependent Manner ◽  
Cell Surface Molecule ◽  
Ifn Γ

T helper cell type 1 (Th1) and 2 (Th2) are central to immune regulation. However, no stable cell surface marker capable of distinguishing and separating these two subsets of CD4+ cells has yet been found. Using differential display PCR, we have identified a gene encoding a cell membrane bound molecule, originally designated ST2L, T1, DER4, or Fit, expressed constitutively and stably on the surface of murine Th2s, but not Th1s even after stimulation with a range of immunological stimuli. Antibody against a peptide derived from ST2L strongly and stably labeled the surface of cloned Th2s but not Th1s, and Th2s but not Th1s derived from naive T cells of ovalbumin T cell receptor–α/β transgenic mice. Three-color single cell flow cytometric analysis shows that cell surface ST2L coexpressed with intracellular interleukin (IL)-4, but not with interferon (IFN)-γ. The antibody selectively lysed Th2s in vitro in a complement-dependent manner. In vivo, it enhanced Th1 responses by increasing IFN-γ production and decreasing IL-4 and IL-5 synthesis. It induced resistance to Leishmania major infection in BALB/c mice and exacerbated collagen-induced arthritis in DBA/1 mice. Thus, ST2L is a stable marker distinguishing Th2s from Th1s and is also associated with Th2 functions. Hence, it may be a target for therapeutic intervention.

Galectin-9 Ameriorates Acute GVHD by Inducing T-Cell Apoptosis and Increasing Regulatory T Cell.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1338-1338
Author(s):  
Kazuki Sakai ◽  
Eri Kawata ◽  
Eishi Ashihara ◽  
Akira Yamauchi ◽  
Shinya Kimura ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Regulatory T Cells ◽  
Cell Apoptosis ◽  
Flow Cytometric Analysis ◽  
Recipient Mouse ◽  
Dependent Manner ◽  
T Cell Apoptosis ◽  
Splenic Cells ◽  
Dose Dependent

Abstract Abstract 1338 Poster Board I-360 Galectins are a family of soluble animal lectins that differ in their affinity for b-galactosides. Fifteen members of the human galectin family have been described to date. Galectin-9 (Gal-9) is a tandem-repeat-type galectin that was recently found to serve as a ligand for T cell immunoglobulin and mucin domain-3 (Tim-3), which is a Th1-specific type 1 membrane protein. Gal-9 modulates immune reactions, such as induction of apoptosis in Th1 cells. We herein investigated the effects of Gal-9 treatment on acute graft-versus-host disease (aGVHD) in a murine model. First, we assessed whether recombinant human (rh) Gal-9 can inhibit the mixed lymphocyte reaction (MLR) by culturing irradiated (30 Gy) splenic cells from 7- to 8-week-old female BDF1 mice with splenic cells from 7- to 8-week-old female C57BL/6J mice in the presence of various concentrations of Gal-9 for 10 days. rhGal-9 inhibited MLR in a dose-dependent manner. We then studied whether this effect was mediated by rhGal-9-induced apoptosis by culturing splenic cells from BDF1 mice with plate-bound anti-CD3 monoclonal antibody and Gal-9. Flow cytometric analysis revealed that rhGal-9 increased the number of Annexin-V+ cells in a dose-dependent manner (Figure. 1A). Thus, rhGal-9 inhibited MLR by inducing splenic cell apoptosis. This suppressive effect of Gal-9 on MLR was inhibited by lactose but not by sucrose (Figure. 1B). Taken together, Gal-9 induces T cell apoptosis through Ca2+ influx induced by binding to b-galactoside, resulting in the suppression of MLR. We then assessed whether rhGal-9 treatment altered aGVHD. Recipient B6D2F1 mice received a myeloablative dose (9 Gy) of total body irradiation from an X-ray irradiator. Six to eight hours later, each recipient mouse was injected i.v. with 4 × 106 TCD-BM cells and 5 × 106 mononuclear splenocytes. aGVHD clinical scores were evaluated once or twice a week. After aGVHD developed, recipient mice were treated with rhGal-9 (30 mg/mouse) or vehicle by i.p. injection for 14 consecutive days. The administration of rhGal-9 significantly attenuated aGVHD as compared to vehicle-treated mice (Figure. 2). Histological analyses also confirmed that aGVHD was declined by rhGal-9 treatment. Additionally, we investigated the effects of Gal-9 treatment on different T ell subsets. To analyze the effect of Gal-9 on donor lymphocytes, splenic mononuclear cells from GFP Tg mice were used for the induction of aGVHD. The gating parameter was first set to isolate the lymphocyte population of peripheral blood leukocytes, and then set for GFP+ cells. Gal-9 treatment decreased the frequency of CD4+/Tim-3+ cells and CD8+/intracellular IFN-g+ cells, whereas CD4+/CD25+ and CD25+/Foxp3+ Treg cells were increased by rhGal-9 treatment. These results suggest that Gal-9 regulates aGVHD by increasing regulatory T cells. In conclusion, Gal-9 ameliorates aGVHD by inducing T-cell apoptosis and also by increasing regulatory T cells. Disclosures No relevant conflicts of interest to declare.

scholarly journals Interleukin-3-induced downregulation of the expression of interleukin-2 receptor beta chain in human T cells

Blood ◽  
1991 ◽  
Vol 78 (11) ◽  
pp. 2908-2917 ◽  
Author(s):  
R Onishi ◽  
T Ishikawa ◽  
T Kodaka ◽  
M Okuma ◽  
T Uchiyama
Keyword(s):  
T Cells ◽  
Interleukin 2 ◽  
Flow Cytometric Analysis ◽  
Surface Expression ◽  
Dependent Manner ◽  
Beta Chain ◽  
Interleukin 3 ◽  
Flow Cytometric ◽  
Cell Clones ◽  
Human T Cells

Abstract We examined the effect of interleukin-3 (IL-3) on human CD4+ cloned T cells, P607 and 1C2. By flow cytometric analysis, we found that IL-3 downregulated the surface expression of IL-2 receptor (R) beta chain in a dose-dependent manner but had little effect on that of IL-2R alpha chain. A simultaneous 125I-labeled IL-2 binding assay showed a decrease in the number of high-affinity, but not of low-affinity, IL-2Rs by IL- 3. The downregulation of the IL-2R beta chain began 3 hours after culture initiation, increased further thereafter, and was completely inhibited by anti-IL-3 antibodies. Expression of mRNA for either alpha or beta chain was not reduced by IL-3, and this suggests that the reduction of surface beta chain expression was not caused by the reduction of beta chain mRNA. IL-3-accelerating internalization of IL- 2R beta chain appeared to be one of the mechanisms for IL-3-induced downregulation of surface IL-2R beta chain expression. IL-3 alone increased the proliferation of T-cell clones but decreased the existing increment of their proliferation by IL-2. Accordingly, IL-3 may be one of the factors acting as a liaison between the hematopoietic and immune systems.

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