scholarly journals Altered microRNAs in T Cells from Patients with Acquired Aplastic Anemia

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2940-2940
Author(s):  
Kohei Hosokawa ◽  
Pawel Muranski ◽  
Xingmin Feng ◽  
Keyvan Keyvanfar ◽  
Danielle M. Townsley ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Mirna Expression ◽  
Target Genes ◽  
Pcr Array ◽  
Expression Levels ◽  
Array Platform ◽  
Human T Cell

Abstract Background. Emerging evidence indicates that microRNAs (miRNAs) may regulate immunity. Their role in acquired aplastic anemia (AA), a T cell-mediated autoimmune disease, has not been investigated. We characterized miRNA signatures in patient T cells to identify novel genes involved in the regulation of immune responses of CD4+ and CD8+ T cells in AA. Cells from age-matched healthy donors and patients with myelodysplastic syndrome (MDS) and transfusion-dependent sickle cell disease (SCD) were used for comparison. Method. MiRNAs and mRNAs from flow cytometrically sorted T cells from patients and controls were extracted and subjected to profiling using miRNA PCR array platform (miScript miRNA PCR array, MIHS-111Z, Qiagen Inc). Real-time PCR was employed for validation of specific miRNA expression changes. To define identified miRNA functions, their target genes were predicted using bioinformatic software (TargetScan, miRBase, DIANA-miRPath). MiRNA target gene profilings were performed using custom PCR array platform (Custom PCR array, Qiagen Inc) in CD4+ and CD8+ T cells in AA. MiRNA knockdown (miR-126-3p and/or miR-145-5p) on healthy CD4+ and CD8+ T cells was performed using the Human T Cell Nucleofector kit (Lonza AG). Cell proliferation was estimated by CFSE assays. Effects of miRNA knockdown on the target genes were evaluated by qPCR and immunoblot. MiRNA expression profilings were examined in CD4+ and CD8+ T cells in a mouse model of lymph node cell infusion-induced bone marrow failure (BMF). Results and Discussion. As compared to healthy controls, miRNA expression profiling revealed significant down-regulation of miRNAs in a disease-specific pattern. MiR-199a-5p expression was reduced in CD4+ and CD8+ T cells from patients with all diseases that were tested (AA, MDS, SCD). Reduced expression of miR-223-3p (more than 3 fold change (FC), P <0.05) in T cells was seen in low-risk MDS. Concurrent downregulation of miR-126-3p, miR-145-5p, miR-223-3p and miR-199a-5p (more than 3 FC, P <0.05) was uniquely observed only in CD4+ and CD8+ T cells from AA patients (Figure 1A). Analysis of these four miRNAs in T cells from AA patients after successful immunosuppressive therapy (IST) at 3 or 6 months (N=6) revealed restoration of the expression levels of miR-126-3p and miR-145-5p (more than 2 FC, P <0.05) as compared to those of patients before IST. Bioinformatic analysis predicted MYC, PIK3R2, ETS1, STAT1, CD28, and HIF1A as potential target transcriptomes for these four miRNAs. Gene expression profiling revealed significant up-regulation of MYC in CD4+ T cells (more than 1.5 FC, P <0.05) and PIK3R2 in CD8+ T cells (more than 1.5 FC, P <0.05) in AA patients compared to healthy controls (Figure 1B). qPCR and immunoblot confirmed up-regulation of MYC (~2.0 FC) in CD4+ T cells and PIK3R2 (~2.0 FC) in CD8+ T cells after transfection with anti-miR-145-5p and anti-miR-126-3p, respectively. Knock-down of the miR-126-3p and miR-145-5p promoted proliferation of both CD4+ and CD8+ T cells and increased IFN-γ production in CD8+ T cells, suggesting enhanced effector differentiation and functionality of this subset as a result of reduced activity of both miRNAs. Expression levels of miR-126-3p and miR-145-5p were not decreased in CD4+ and CD8+ T cells in a BMF mouse model. However, expression levels of miR-142-5p and miR-29a-3p, which have been reported as miRNAs associated with allo-reactivity, were decreased (more than 2 FC, P <0.05) in this model, concordant with the mouse models basis in H2 mismatched reactivity. Conclusion. This work describes previously unknown potentially regulatory role of miRNAs 145-5p and 126-3p in T cell activation in AA. Further investigation is warranted to determine the role of these miRNAs in the more general pathogenesis of autoimmune diseases. Understanding these novel pathways might offer new therapeutic strategies and a novel mechanistic insight into the epigenetic control of human T cell effector responses. Figure 1 Figure 1. Disclosures Townsley: GSK: Research Funding.

scholarly journals Human CD8+ T-cells Recognizing Peptides from Mycobacterium tuberculosis (Mtb) Presented by HLA-E Have an Unorthodox Th2-like, Multifunctional, Mtb Inhibitory Phenotype and Represent a Novel Human T-cell Subset

2015 ◽  
Vol 11 (3) ◽  
pp. e1004671 ◽  
Author(s):  
Krista E. van Meijgaarden ◽  
Mariëlle C. Haks ◽  
Nadia Caccamo ◽  
Francesco Dieli ◽  
Tom H. M. Ottenhoff ◽  
...  
Keyword(s):  
T Cells ◽  
Mycobacterium Tuberculosis ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Subset ◽  
T Cell Subset ◽  
Human T Cell

scholarly journals Role of PD-1 during effector CD8 T cell differentiation

2018 ◽  
Vol 115 (18) ◽  
pp. 4749-4754 ◽  
Author(s):  
Eunseon Ahn ◽  
Koichi Araki ◽  
Masao Hashimoto ◽  
Weiyan Li ◽  
James L. Riley ◽  
...  
Keyword(s):  
T Cells ◽  
Cell Differentiation ◽  
T Cell ◽  
Viral Infection ◽  
Cd8 T Cells ◽  
Cell Epitope ◽  
Cd8 T Cell ◽  
T Cell Differentiation ◽  
Lcmv Infection

PD-1 (programmed cell death-1) is the central inhibitory receptor regulating CD8 T cell exhaustion during chronic viral infection and cancer. Interestingly, PD-1 is also expressed transiently by activated CD8 T cells during acute viral infection, but the role of PD-1 in modulating T cell effector differentiation and function is not well defined. To address this question, we examined the expression kinetics and role of PD-1 during acute lymphocytic choriomeningitis virus (LCMV) infection of mice. PD-1 was rapidly up-regulated in vivo upon activation of naive virus-specific CD8 T cells within 24 h after LCMV infection and in less than 4 h after peptide injection, well before any cell division had occurred. This rapid PD-1 expression by CD8 T cells was driven predominantly by antigen receptor signaling since infection with a LCMV strain with a mutation in the CD8 T cell epitope did not result in the increase of PD-1 on antigen-specific CD8 T cells. Blockade of the PD-1 pathway using anti–PD-L1 or anti–PD-1 antibodies during the early phase of acute LCMV infection increased mTOR signaling and granzyme B expression in virus-specific CD8 T cells and resulted in faster clearance of the infection. These results show that PD-1 plays an inhibitory role during the naive-to-effector CD8 T cell transition and that the PD-1 pathway can also be modulated at this stage of T cell differentiation. These findings have implications for developing therapeutic vaccination strategies in combination with PD-1 blockade.

A Crucial Role for Antigen Presenting Cells in Donor CD4+CD25+ Regulatory T Cell Mediated Suppression of Experimental Gvhd.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 688-688
Author(s):  
Isao Tawara ◽  
Tomomi Toubai ◽  
Chelsea Malter ◽  
Yaping Sun ◽  
Evelyn Nieves ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Conflicts Of Interest ◽  
Antigen Presenting Cells ◽  
Class Ii ◽  
Indoleamine 2 ◽  
Effector Phase ◽  
Antigen Presenting

Abstract Abstract 688 Several lines of evidence show that donor derived mature CD4+CD25+Foxp3+ regulatory T cells (Tregs) suppress experimental GVHD. The mechanism of GVHD suppression by donor Tregs is, however, not well understood. Recent observations have brought in a renewed focus on the role of professional antigen presenting cells (APCs) in the induction and maintenance of GVHD by alloreactive T cell effectors (Teffs). But the role of APCs in modulating the responses of Tregs after allogeneic BMT is not known. We first tested the requirement of host APCs in Treg mediated regulation of GVHD. We utilized a clinically relevant CD8+ T cell dependent MHC matched but miHA disparate C3H.SW (H-2b) → wild type (wt) or Class II deficient Abb (II-/-) B6 (H-2b) model of GVHD because host APCs and target tissues from the Abb animals do not express class II and as such donor CD4+CD25+ Tregs will not directly interact with the host tissues while alloreactive CD8+ T cells could still respond to miHA allo-antigens presented by the intact class I on host APCs. The recipient Abb (II-/-) and wt B6 animals were lethally irradiated and transplanted with 2 × 105 CD8+ T cells along with or without CD4+CD25+ Tregs at 1:2 ratio from either syngeneic B6 or allogeneic C3H.SW animals. The wt recipients that received Tregs showed significantly better survival compared with the wt animals that did not receive any Tregs (P< 0.01) while the class II-/- animals showed similar GVHD mortality regardless of Treg infusion (P>0.8). To confirm whether the lack of Treg mediated protection was only due to the absence of interaction with host type APCs and also to exclude the possibility of development of Tregs from the infused BM we thymectomized wt B6 animals and then generated [B6 B6] controls and the [Abb B6] chimeras. These chimeric animals were used as recipients in a second BMT and transplanted with CD8+ Teffs and Tregs from allogeneic C3H.SW mice. Tregs reduced GVHD mortality in the [B6 B6] (P<0.01) but not in the [Abb B6] animals (P>0.7). We next evaluated whether host APC expression of allo-antigens alone was sufficient for Treg mediated GVHD protection in the absence of class II expression on target tissues by generating [B6 B6] and [B6 Abb] chimeras and found that Tregs demonstrated equivalent GVHD protection even when the class II allo-antigens were expressed only on the host APCs. Mechanistic studies demonstrated that Tregs significantly inhibited the expansion of CD8+ Teffs on days +10 and 17 after BMT in the spleens of the WT recipients (P<0.05) but not in the class II-/- animals. However, infused Tregs demonstrated reduced expansion in the class II-/- animals only early after BMT (on day +10) but was equivalent at later time-point (days 17 and 29) to the WT recipients. We further determined the mechanisms by which host APCs might contribute to Treg mediated protection. To this end we used IL-10-/-, indoleamine 2, 3 dioxygenase (IDO)-/- deficient animals and generated [IL-10-/- B6] and [IDO-/- B6] animals as recipients. Tregs mitigated GVHD mortality regardless of the ability of the host APCs to express IL-10 or IDO. We next determined whether Tregs suppressed Teffs in their activation phase at the level of their interaction with host APCs or in the effector phase. C3H.SW CD8+ T cells were primed (both in vivo and ex vivo with B6 allo-antigens) and then infused into the [β2mg-/- B6] animals such that pre-activated CD8 Teffs would still be able to initiate GVHD without the need for host APCs for their activation. Infusion of donor Tregs into [β2mg-/- B6] animals that were transplanted with the pre-activated Teffs mitigated GVHD severity demonstrating that Tregs, once activated by host APCs, were capable of suppressing Teff cells in their effector phase. Collectively our data show (a) host APCs are critical (b) expression of allo-antigens on host target tissues is not obligatory (c) host derived IL-10 and IDO are not critical for Treg mediated GVHD protection and (d) Tregs can mitigate GVHD by suppressing alloreactive Teffs in the effector phase even after they have been activated. Disclosures: No relevant conflicts of interest to declare.

Tissue Parenchymal Cell Expression of B7-H1 Inhibits Infiltrating T Cell Expansion and Prevents Persistence of Graft-Versus-Host Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2974-2974
Author(s):  
Xiaofan Li ◽  
Wei He ◽  
Ruishu Deng ◽  
Can Liu ◽  
Miao Wang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cell Expansion ◽  
Cd8 T Cell ◽  
Target Tissue ◽  
T Cell Expansion ◽  
Parenchymal Cells

Abstract Abstract 2974 Alloreactive donor CD8+ T cells facilitate engraftment and mediate graft versus leukemia (GVL) effects but also cause graft versus host disease (GVHD) in murine and human recipients after allogeneic hematopoietic cell transplantation (HCT). B7-H1 (PD-L1) expression by antigen-presenting cells has an important role in tolerizing activated T cells by binding to PD-1. We and others previously reported that disruption of binding between B7-H1 and PD-1 augments acute GVHD. Parenchymal cells do not usually express B7-H1 but can be induced by inflammatory cytokines (i.e. IFN-g) to express B7-H1. The role of B7-H1 expression by parenchymal tissue cells in regulating the expansion and persistence of donor CD8+ cells in tissues of mice with GVHD has not yet been evaluated. In the current studies, we evaluated the role of B7-H1 expression by GVHD target tissues in regulating donor CD8+ T cell function in 3 different experimental GVHD systems, using in vivo bioluminescent imaging (BLI), in vivo BrdU-labeling, and in vitro proliferation assays. The first system evaluated the role of B7-H1 expression in TBI-conditioned recipients. In these recipients, injected donor CD8+ T cells showed two waves of expansion that correlated with two phases of clinical GVHD. The first wave of donor CD8+ T cell expansion was associated with upregulated expression of B7-H1 in GVHD target tissues and only weak clinical GVHD. The second wave of donor CD8+ T cell expansion was associated with loss of B7-H1 expression, vigorous donor CD8+ T proliferation and expansion in the GVHD target tissues, and lethal GVHD. In a gain-of-function experiment, B7-H1 expression was induced in hepatocytes by hydrodynamic injection of B7-H1 cDNA during the second wave of T cell expansion in mice with GVHD; this subsequently decreased T cell expansion in the liver and ameliorated GVHD. The second system evaluated the role of B7-H1 expression in anti-CD3-conditioned recipients. In wild-type recipients, injected donor CD8+ T cells had only a single wave of expansion, and the mice had no signs of GVHD. B7-H1 expression by tissue cells (i.e. hepatocytes) was up-regulated, and the tissue infiltrating donor CD8+ T cells were anergic. In B7-H1−/− recipients, injected donor CD8+ T cells proliferated vigorously in GVHD target tissues and caused lethal GVHD.The third system evaluated the role of B7-H1 in unconditioned Rag-2−/− recipients after administration of blocking anti-B7-H1 and in the B7-H1−/−Rag-2−/− chimeras with B7-H1 sufficient Rag-2−/− bone marrow cells, in which B7-H1 deficiency was only in tissue parenchymal cells. Both blockade of B7-H1 and B7-H1 deficiency in parenchymal cells resulted in vigorous donor CD8+ T proliferation in GVHD target tissues and caused lethal GVHD. Taken together, these results show that expression of B7-H1 in GVHD target tissue parenchymal cells plays an important role in regulating the proliferation of infiltrating donor CD8+ T cells and preventing the persistence of GVHD. Our studies also indicate that TBI but not anti-CD3 conditioning can lead to loss of GVHD target tissue cell expression of B7-H1 and persistence of GVHD. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Broadly targeted human cytomegalovirus-specific CD4+ and CD8+ T cells dominate the memory compartments of exposed subjects

2005 ◽  
Vol 202 (5) ◽  
pp. 673-685 ◽  
Author(s):  
Andrew W. Sylwester ◽  
Bridget L. Mitchell ◽  
John B. Edgar ◽  
Cara Taormina ◽  
Christian Pelte ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Human Cytomegalovirus ◽  
Cd8 T Cells ◽  
Viral Infections ◽  
Infectious Agent ◽  
Cross Reactivity ◽  
T Cell Response ◽  
Open Reading Frames ◽  
Human T Cell

Human cytomegalovirus (HCMV) infections of immunocompetent hosts are characterized by a dynamic, life-long interaction in which host immune responses, particularly of T cells, restrain viral replication and prevent disease but do not eliminate the virus or preclude transmission. Because HCMV is among the largest and most complex of known viruses, the T cell resources committed to maintaining this balance have never been characterized completely. Here, using cytokine flow cytometry and 13,687 overlapping 15mer peptides comprising 213 HCMV open reading frames (ORFs), we found that 151 HCMV ORFs were immunogenic for CD4+ and/or CD8+ T cells, and that ORF immunogenicity was influenced only modestly by ORF expression kinetics and function. We further documented that total HCMV-specific T cell responses in seropositive subjects were enormous, comprising on average ∼10% of both the CD4+ and CD8+ memory compartments in blood, whereas cross-reactive recognition of HCMV proteins in seronegative individuals was limited to CD8+ T cells and was rare. These data provide the first glimpse of the total human T cell response to a complex infectious agent and will provide insight into the rules governing immunodominance and cross-reactivity in complex viral infections of humans.

scholarly journals Impaired response to Listeria in H2-M3–deficient mice reveals a nonredundant role of MHC class Ib–specific T cells in host defense

2006 ◽  
Vol 203 (2) ◽  
pp. 449-459 ◽  
Author(s):  
Honglin Xu ◽  
Taehoon Chun ◽  
Hak-Jong Choi ◽  
Bin Wang ◽  
Chyung-Ru Wang
Keyword(s):  
T Cells ◽  
T Cell ◽  
Host Defense ◽  
Cd8 T Cells ◽  
Mhc Class Ib ◽  
Cell Responses ◽  
Mhc Class Ia ◽  
Deficient Mice ◽  
Class Ib

The major histocompatibility complex (MHC) class Ib molecule H2-M3 primes the rapid expansion of CD8+ T cells by presenting N-formylated bacterial peptides. However, the significance of H2-M3–restricted T cells in host defense against bacteria is unclear. We generated H2-M3–deficient mice to investigate the role of H2-M3 in immunity against Listeria monocytogenes (LM), a model intracellular bacterial pathogen. H2-M3–deficient mice are impaired in early bacterial clearance during primary infection, with diminished LM-specific CD8+ T cell responses and compromised innate immune functions. Although H2-M3–restricted CD8+ T cells constitute a significant proportion of the anti-listerial CD8+ T cell repertoire, the kinetics and magnitude of MHC class Ia–restricted T cell responses are not altered in H2-M3–deficient mice. The fact that MHC class Ia–restricted responses cannot compensate for the H2-M3–mediated immunity suggests a nonredundant role of H2-M3 in the protective immunity against LM. Thus, the early H2-M3–restricted response temporally bridges the gap between innate and adaptive immune responses, subsequently affecting the function of both branches of the immune system.

scholarly journals Retrovirally induced CTL degranulation mediated by IL-15 expression and infection of mononuclear phagocytes in patients with HTLV-I–associated neurologic disease

Blood ◽  
2008 ◽  
Vol 112 (6) ◽  
pp. 2400-2410 ◽  
Author(s):  
Yoshimi Enose-Akahata ◽  
Unsong Oh ◽  
Christian Grant ◽  
Steven Jacobson
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd4 T Cells ◽  
Spastic Paraparesis ◽  
Cd8 T Cell ◽  
Mononuclear Phagocytes ◽  
Type I ◽  
Human T Cell ◽  
Ifn Γ

AbstractCD8+ T cells contribute to central nervous system inflammation in human T-cell lymphotropic virus type I (HTLV-I)–associated myelopathy/tropical spastic paraparesis (HAM/TSP). We analyzed CD8+ T-cell dysfunction (degranulation and IFN-γ production) and have demonstrated that CD8+ T cells of patients with HAM/TSP (HAM/TSP patients) spontaneously degranulate and express IFN-γ in ex vivo unstimulated culture. CD8+ T cells of HTLV-I asymptomatic carriers and healthy donors did not. Spontaneous degranulation was detected in Tax11-19/HLA-A*201 tetramer+ cells, but not in CMV pp65 tetramer+ cells. Interestingly, degranulation and IFN-γ production in CD8+ T cells was induced by coculture with autologous CD14+ cells, but not CD4+ T cells, of HAM/TSP patients, which correlated with proviral DNA load in CD14+ cells of infected patients. Moreover, the expression of IL-15, which induced degranulation and IFN-γ production in infected patients, was enhanced on surface of CD14+ cells in HAM/TSP patients. Blockade of MHC class I and IL-15 confirmed these results. Thus, CD8+ T-cell dysregulation was mediated by both virus infection and enhanced IL-15 on CD14+ cells in HAM/TSP patients. Despite lower viral expression than in CD4+ T cells, HTLV-I–infected or –activated CD14+ cells may be a heretofore important but under recognized reservoir particularly in HAM/TSP patients.

scholarly journals Repression of miR-31 by BCL6 stabilizes the helper function of human follicular helper T cells

2017 ◽  
Vol 114 (48) ◽  
pp. 12797-12802 ◽  
Author(s):  
A. Ripamonti ◽  
E. Provasi ◽  
M. Lorenzo ◽  
M. De Simone ◽  
V. Ranzani ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Helper T Cells ◽  
Follicular Helper T Cells ◽  
Follicular Helper ◽  
Human T Cell ◽  
Helper Function ◽  
Follicular Helper T Cell ◽  
And Function

Follicular helper T cells (TFHs) are a key component of adaptive immune responses as they help antibody production by B cells. Differentiation and function of TFH cells are controlled by the master gene BCL6, but it is largely unclear how this transcription repressor specifies the TFH program. Here we asked whether BCL6 controlled helper function through down-regulation of specific microRNAs (miRNAs). We first assessed miRNA expression in TFH cells and defined a TFH-specific miRNA signature. We report that hsa–miR-31–5p (miR-31) is down-regulated in TFH; we showed that BCL6 suppresses miR-31 expression by binding to its promoter; and we demonstrated that miR-31 inhibits the expression of molecules that control T-helper function, such as CD40L and SAP. These findings identify a BCL6-initiated inhibitory circuit that stabilizes the follicular helper T cell program at least in part through the control of miRNA transcription. Although BCL6 controls TFH activity in human and mouse, the role of miR-31 is restricted to human TFH cell differentiation, reflecting a species specificity of the miR-31 action. Our findings highlight miR-31 as a possible target to modulate human T cell dependent antibody responses in the settings of infection, vaccination, or immune dysregulation.

scholarly journals IL-4 sensitivity shapes the peripheral CD8+ T cell pool and response to infection

2016 ◽  
Vol 213 (7) ◽  
pp. 1319-1329 ◽  
Author(s):  
Kristin R. Renkema ◽  
June-Yong Lee ◽  
You Jeong Lee ◽  
Sara E. Hamilton ◽  
Kristin A. Hogquist ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Cd8 T Cell ◽  
Antigen Specificity ◽  
Th1 Cell ◽  
Memory Cd8 T Cells ◽  
Expression Levels ◽  
Cell Pool

Previous studies have revealed that a population of innate memory CD8+ T cells is generated in response to IL-4, first appearing in the thymus and bearing high expression levels of Eomesodermin (Eomes) but not T-bet. However, the antigen specificity and functional properties of these cells is poorly defined. In this study, we show that IL-4 regulates not only the frequency and function of innate memory CD8+ T cells, but also regulates Eomes expression levels and functional reactivity of naive CD8+ T cells. Lack of IL-4 responsiveness attenuates the capacity of CD8+ T cells to mount a robust response to lymphocytic choriomeningitis virus infection, with both quantitative and qualitative effects on effector and memory antigen-specific CD8+ T cells. Unexpectedly, we found that, although numerically rare, memory phenotype CD8+ T cells in IL-4Rα–deficient mice exhibited enhanced reactivity after in vitro and in vivo stimulation. Importantly, our data revealed that these effects of IL-4 exposure occur before, not during, infection. Together, these data show that IL-4 influences the entire peripheral CD8+ T cell pool, influencing expression of T-box transcription factors, functional reactivity, and the capacity to respond to infection. These findings indicate that IL-4, a canonical Th2 cell cytokine, can sometimes promote rather than impair Th1 cell–type immune responses.

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