scholarly journals CD16+ monocytes control T-cell subset development in immune thrombocytopenia

Blood ◽  
2012 ◽  
Vol 120 (16) ◽  
pp. 3326-3335 ◽  
Author(s):  
Hui Zhong ◽  
Weili Bao ◽  
Xiaojuan Li ◽  
Allison Miller ◽  
Caroline Seery ◽  
...  

Abstract Immune thrombocytopenia (ITP) results from decreased platelet production and accelerated platelet destruction. Impaired CD4+ regulatory T-cell (Treg) compartment and skewed Th1 and possibly Th17 responses have been described in ITP patients. The trigger for aberrant T-cell polarization remains unknown. Because monocytes have a critical role in development and polarization of T-cell subsets, we explored the contribution of monocyte subsets in control of Treg and Th development in patients with ITP. Unlike circulating classic CD14hiCD16− subpopulation, the CD16+ monocyte subset was expanded in ITP patients with low platelet counts on thrombopoietic agents and positively correlated with T-cell CD4+IFN-γ+ levels, but negatively with circulating CD4+CD25hiFoxp3+ and IL-17+ Th cells. Using a coculture model, we found that CD16+ ITP monocytes promoted the expansion of IFN-γ+CD4+ cells and concomitantly inhibited the proliferation of Tregs and IL-17+ Th cells. Th-1–polarizing cytokine IL-12, secreted after direct contact of patient T-cell and CD16+ monocytes, was responsible for the inhibitory effect on Treg and IL-17+CD4+ cell proliferation. Our findings are consistent with ITP CD16+ monocytes promoting Th1 development, which in turn negatively regulates IL-17 and Treg induction. This underscores the critical role of CD16+ monocytes in the generation of potentially pathogenic Th responses in ITP.

2010 ◽  
Vol 79 (2) ◽  
pp. 822-829 ◽  
Author(s):  
Jana Pieper ◽  
Ulrich Methner ◽  
Angela Berndt

ABSTRACTAvian γδ T lymphocytes are frequently found in blood and organs and are assumed to be crucial to the immune defense againstSalmonellainfections of chicks. To elucidate the so-far-unknown immunological features of subpopulations of avian γδ T cells in the course of infection, day-old chicks were infected orally withSalmonella entericaserovar Typhimurium. Until 11 days after infection, the occurrence as well as transcription of the CD8 antigen and immunologically relevant protein genes of CD8α−and CD8α+high(CD8αα+CD8αβ+) γδ cells were analyzed using flow cytometry and quantitative real-time reverse transcription-PCR (RT-PCR) with blood, spleen, thymus, and cecum samples. After infection, an increased percentage of CD8α+highγδ T lymphocytes was found in blood, in spleen, and, with the highest values and most rapidly, in cecum. Within the CD8α+highsubset, a significant rise in the number of CD8αα+cells was accompanied by enhanced CD8α antigen expression and reduced gene transcription of the CD8β chain. CD8αα+and CD8αβ+cells showed elevated transcription for Fas, Fas ligand (FasL), interleukin-2 receptor α (IL-2Rα), and gamma interferon (IFN-γ). While the highest fold changes in mRNA levels were observed in CD8αβ+cells, the mRNA expression rates of CD8αβ+cells never significantly exceeded those of the CD8αα+cells. In conclusion, both CD8α+highγδ T-cell subpopulations (CD8αα+and CD8αβ+) might be a potential source of IFN-γ inSalmonella-infected chicks. However, due to their prominent frequency in blood and organs after infection, the avian CD8αα+γδ T-cell subset seems to be unique and of importance in the course ofSalmonellaTyphimurium infection of very young chicks.


1999 ◽  
Vol 189 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Ya-Hui Chiu ◽  
Jayanthi Jayawardena ◽  
Angela Weiss ◽  
Daniel Lee ◽  
Se-Ho Park ◽  
...  

Although recent studies have indicated that the major histocompatibility complex–like, β2-microglobulin–associated CD1 molecules might function to present a novel chemical class of antigens, lipids and glycolipids, to α/β T cells, little is known about the T cell subsets that interact with CD1. A subset of CD1d-autoreactive, natural killer (NK)1.1 receptor–expressing α/β T cells has recently been identified. These cells, which include both CD4−CD8− and CD4+ T cells, preferentially use an invariant Vα14-Jα281 T cell receptor (TCR) α chain paired with a Vβ8 TCR β chain in mice, or the homologous Vα24-JαQ/Vβ11 in humans. This cell subset can explosively release key cytokines such as interleukin (IL)-4 and interferon (IFN)-γ upon TCR engagement and may regulate a variety of infectious and autoimmune conditions. Here, we report the existence of a second subset of CD1d-restricted CD4+ T cells that do not express the NK1.1 receptor or the Vα14 TCR. Like the Vα14+ NK1.1+ T cells, these T cells exhibit a high frequency of autoreactivity to CD1d, use a restricted albeit distinct set of TCR gene families, and contribute to the early burst of IL-4 and IFN-γ induced by intravenous injection of anti-CD3. However, the Vα14+ NK1.1+ and Vα14− NK1.1− T cells differ markedly in their requirements for self-antigen presentation. Antigen presentation to the Vα14+ NK1.1+ cells requires endosomal targeting of CD1d through a tail-encoded tyrosine-based motif, whereas antigen presentation to the Vα14− NK1.1− cells does not. These experiments suggest the existence of two phenotypically different subsets of CD1d-restricted T cells that survey self-antigens loaded in distinct cellular compartments.


2020 ◽  
Vol 105 (6) ◽  
pp. 1851-1867 ◽  
Author(s):  
Sijie Fang ◽  
Shuo Zhang ◽  
Yazhuo Huang ◽  
Yu Wu ◽  
Yi Lu ◽  
...  

Abstract Purpose The purpose of this article is to investigate the characteristics of Th1-cell and Th17-cell lineages for very severe Graves orbitopathy (GO) development. Methods Flow cytometry was performed with blood samples from GO and Graves disease (GD) patients and healthy controls, to explore effector T-cell phenotypes. Lipidomics was conducted with serum from very severe GO patients before and after glucocorticoid (GC) therapy. Immunohistochemistry and Western blotting were used to examine orbital-infiltrating Th17 cells or in vitro models of Th17 polarization. Results In GD, Th1 cells predominated in peripheral effector T-cell subsets, whereas in GO, Th17-cell lineage predominated. In moderate-to-severe GO, Th17.1 cells expressed retinoic acid receptor-related orphan receptor-γt (RORγt) independently and produced interleukin-17A (IL-17A), whereas in very severe GO, Th17.1 cells co-expressed RORγt and Tbet and produced interferon-γ (IFN-γ). Increased IFN-γ–producing Th17.1 cells positively correlated with GO activity and were associated with the development of very severe GO. Additionally, GC therapy inhibited both Th1-cell and Th17-cell lineages and modulated a lipid panel consisting of 79 serum metabolites. However, in GC-resistant, very severe GO, IFN-γ–producing Th17.1 cells remained at a high level, correlating with increased serum triglycerides. Further, retro-orbital tissues from GC-resistant, very severe GO were shown to be infiltrated by CXCR3+ Th17 cells expressing Tbet and STAT4 and rich in triglycerides that promoted Th1 phenotype in Th17 cells in vitro. Conclusions Our findings address the importance of Th17.1 cells in GO pathogenesis, possibly promoting our understanding of the association between Th17-cell plasticity and disease severity of GO.


Blood ◽  
1997 ◽  
Vol 90 (9) ◽  
pp. 3662-3672 ◽  
Author(s):  
Nobukazu Watanabe ◽  
Stephen C. De Rosa ◽  
Anthony Cmelak ◽  
Richard Hoppe ◽  
Leonore A. Herzenberg ◽  
...  

Abstract We investigated the representation of T cells in patients who had been treated for Hodgkin's disease (HD). We found a marked depletion in both CD4 and CD8 naive T-cell counts that persists up to 30 years after completion of treatment. In contrast, CD4 and CD8 memory T-cell subsets recovered to normal or above normal levels by 5 years posttreatment. Thus, the previously-reported long-term deficit in total CD4 T-cell counts after treatment for HD is due to specific depletion of naive T cells. Similarly, total CD8 T-cell counts return to normal by 5 years only because CD8 memory T cells expand to higher than normal levels. These findings suggest that the treatment (mediastinal irradiation) results in a longterm dysregulation of T-cell subset homeostasis. The profound depletion of naive T cells may explain the altered T-cell function in treated patients, including the poor response to immunization after treatment for HD. Further, in some individuals, we identified expansions of unusual subsets expressing low levels of CD8. Eight-color fluorescence-activated cell sorting analyses showed that these cells largely express CD8αα homodimers and CD57, consistent with the phenotype of potentially extrathymically derived T cells. In addition, these cells, both CD4+ and CD4−, are probably cytotoxic lymphocytes, as they express high levels of intracellular perforin. In adults treated for HD, an increased activity of extrathymic T-cell differentiation may partially compensate for the loss of thymic-derived T cells.


2003 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Adam F. Cunningham ◽  
Kai-Michael Toellner

The paradigm of T helper-1 (Th-1) and Th-2 cells developing from non-committed naïve precursors is firmly established. Th1 cells are characterized by IFN production and, in mice, the selective switching to IgG2a. Conversely IL-4 production and selective switching to IgG1 and IgE characterize Th2 cells. Analysis of Th2 inductionin vitroindicates that this polarization develops gradually in T cells activated by anti-CD3 in the presence of IL-4; conversely anti-CD3 and IFN induce Th1 cells. In this report, we explore evidence that indicates that the T helper cell polarizationin vivocannot solely be explained by the cytokine environment. This is provided by studying the early acquisition of Th1 and Th2 activities during responses to a mixture of Th1 and Th2-inducing antigens. It is shown that these divergent forms of T cell help can rapidly develop in cells within a single lymph node. It is argued that early polarization to show Th-1 or Th-2 behavior can be induced by signals delivered during cognate interaction between virgin T cells and dendritic cells, in the absence of type 1 or type 2 cytokines. This contrasts with the critical role of the cytokines in reinforcing the Th-phenotype and selectively expanding T helper clones.


2005 ◽  
Vol 202 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Indira Guleria ◽  
Arezou Khosroshahi ◽  
Mohammed Javeed Ansari ◽  
Antje Habicht ◽  
Miyuki Azuma ◽  
...  

Fetal survival during gestation implies that tolerance mechanisms suppress the maternal immune response to paternally inherited alloantigens. Here we show that the inhibitory T cell costimulatory molecule, programmed death ligand 1 (PDL1), has an important role in conferring fetomaternal tolerance in an allogeneic pregnancy model. Blockade of PDL1 signaling during murine pregnancy resulted in increased rejection rates of allogeneic concepti but not syngeneic concepti. Fetal rejection was T cell– but not B cell–dependent because PDL1-specific antibody treatment caused fetal rejection in B cell–deficient but not in RAG-1–deficient females. Blockade of PDL1 also resulted in a significant increase in the frequency of IFN-γ–producing lymphocytes in response to alloantigen in an ELISPOT assay and higher IFN-γ levels in placental homogenates by ELISA. Finally, PDL1-deficient females exhibited decreased allogeneic fetal survival rates as compared with littermate and heterozygote controls and showed evidence of expansion of T helper type 1 immune responses in vivo. These results provide the first evidence that PDL1 is involved in fetomaternal tolerance.


2015 ◽  
Vol 213 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Arata Takeuchi ◽  
Mohamed El Sherif Gadelhaq Badr ◽  
Kosuke Miyauchi ◽  
Chitose Ishihara ◽  
Reiko Onishi ◽  
...  

Naive T cells differentiate into various effector T cells, including CD4+ helper T cell subsets and CD8+ cytotoxic T cells (CTL). Although cytotoxic CD4+ T cells (CD4+CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4+ T cells that express class I–restricted T cell–associated molecule (CRTAM) upon activation possesses the characteristics of both CD4+ and CD8+ T cells. CRTAM+ CD4+ T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM+ T cells are the precursor of CD4+CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4+CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM+ T cells traffic to mucosal tissues and inflammatory sites and developed into CD4+CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4+CTL through the induction of Eomes and CTL-related gene.


Author(s):  
Runzi Sun ◽  
Yixian Wu ◽  
Huijun Zhou ◽  
Yanshi Wu ◽  
Zhongzhou Yang ◽  
...  

Sustaining efficacious T cell-mediated antitumor immune responses in the tumor tissues is the key to the success of cancer immunotherapy. Current strategies leverage altering the signals T cells sense in the tumor microenvironment (TME). Checkpoint inhibitor-based approaches block inhibitory signals such as PD-1 whereas cytokine-based therapies increase the level of immune-stimulatory cytokines such as IL-2. Besides extrinsic signals, the genetic circuit within T cells also participates in determining the nature and trajectory of antitumor immune responses. Here, we showed that efficacy of the IL33-based tumor immunotherapy was greatly enhanced in mice with T cell-specific Eomes deficiency. Mechanistically, we demonstrated that Eomes deficient mice had diminished proportions of exhausted/dysfunctional CD8+ T cells but increased percentages of tissue resident and stem-like CD8+ T cells in the TME. In addition, the IFNγ+TCF1+ CD8+ T cell subset was markedly increased in the Eomes deficient mice. We further demonstrated that Eomes bound directly to the transcription regulatory regions of exhaustion and tissue residency genes. In contrast to its role in inhibiting T cell immune responses at the tumor site, Eomes promoted generation of central memory T cells in the peripheral lymphoid system and memory recall responses against tumor growth at a distal tissue site. Finally, we showed that Eomes deficiency in T cells also resulted in increased efficacy of PD-1-blockade tumor immunotherapy. In all, our study indicates that Eomes plays a critical role in restricting prolonged T cell-mediated antitumor immune responses in the TME whereas promoting adaptive immunity in peripheral lymphoid organs.


2021 ◽  
Vol 118 (23) ◽  
pp. e2103730118
Author(s):  
Yuka Nakajima ◽  
Kenji Chamoto ◽  
Takuma Oura ◽  
Tasuku Honjo

CD8+ T cells play a central role in antitumor immune responses that kill cancer cells directly. In aged individuals, CD8+ T cell immunity is strongly suppressed, which is associated with cancer and other age-related diseases. The mechanism underlying this age-related decrease in immune function remains largely unknown. This study investigated the role of T cell function in age-related unresponsiveness to PD-1 blockade cancer therapy. We found inefficient generation of CD44lowCD62Llow CD8+ T cell subset (P4) in draining lymph nodes of tumor-bearing aged mice. In vitro stimulation of naive CD8+ T cells first generated P4 cells, followed by effector/memory T cells. The P4 cells contained a unique set of genes related to enzymes involved in one-carbon (1C) metabolism, which is critical to antigen-specific T cell activation and mitochondrial function. Consistent with this finding, 1C-metabolism–related gene expression and mitochondrial respiration were down-regulated in aged CD8+ T cells compared with young CD8+ T cells. In aged OVA-specific T cell receptor (TCR) transgenic mice, ZAP-70 was not activated, even after inoculation with OVA-expressing tumor cells. The attenuation of TCR signaling appeared to be due to elevated expression of CD45RB phosphatase in aged CD8+ T cells. Surprisingly, strong stimulation by nonself cell injection into aged PD-1–deficient mice restored normal levels of CD45RB and ameliorated the emergence of P4 cells and 1C metabolic enzyme expression in CD8+ T cells, and antitumor activity. These findings indicate that impaired induction of the P4 subset may be responsible for the age-related resistance to PD-1 blockade, which can be rescued by strong TCR stimulation.


1994 ◽  
Vol 14 (2) ◽  
pp. 1084-1094
Author(s):  
Z Hanna ◽  
C Simard ◽  
A Laperrière ◽  
P Jolicoeur

The CD4 protein plays a critical role in the development and function of the immune system. To gain more insight into the mechanism of expression of the human CD4 gene, we cloned 42.2 kbp of genomic sequences comprising the CD4 gene and its surrounding sequences. Studies with transgenic mice revealed that a 12.6-kbp fragment of the human CD4 gene (comprising 2.6 kbp of 5' sequences upstream of the transcription initiation site, the first two exons and introns, and part of exon 3) contains the sequences required to support the appropriate expression in murine mature CD4+ CD8- T cells and macrophages but not in immature double-positive CD4+ CD8+ T cells. Expression in CD4+ CD8+ T cells was found to require additional regulatory elements present in a T-cell enhancer fragment recently identified for the murine CD4 gene (S. Sawada and D. R. Littman, Mol. Cell. Biol. 11:5506-5515, 1991). These results suggest that expression of CD4 in mature and immature T-cell subsets may be controlled by distinct and independent regulatory elements. Alternatively, specific regulatory elements may control the expression of CD4 at different levels in mature and immature T-cell subsets. Our data also indicate that mouse macrophages contain the regulatory factors necessary to transcribe the human CD4 gene.


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