284: Graft Rejection as a Type I Immune Response Amenable to Modulation by Type II Donor T Cells via an “Infectious” Mechanism

In autoimmune polyglandular syndromes (APS), several organ-specific autoimmune diseases are clustered. Although APS type I is caused by loss of central tolerance, the etiology of APS type II (APS-II) is currently unknown. However, in several murine models, depletion of CD4+ CD25+ regulatory T cells (Tregs) causes a syndrome resembling human APS-II with multiple endocrinopathies. Therefore, we hypothesized that loss of active suppression in the periphery could be a hallmark of this syndrome. Tregs from peripheral blood of APS-II, control patients with single autoimmune endocrinopathies, and normal healthy donors showed no differences in quantity (except for patients with isolated autoimmune diseases), in functionally important surface markers, or in apoptosis induced by growth factor withdrawal. Strikingly, APS-II Tregs were defective in their suppressive capacity. The defect was persistent and not due to responder cell resistance. These data provide novel insights into the pathogenesis of APS-II and possibly human autoimmunity in general.

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Structure of the two promoters of the human lck gene: differential accumulation of two classes of lck transcripts in T cells

Molecular and Cellular Biology ◽

10.1128/mcb.9.5.2173-2180.1989 ◽

1989 ◽

Vol 9 (5) ◽

pp. 2173-2180

Author(s):

T Takadera ◽

S Leung ◽

A Gernone ◽

Y Koga ◽

Y Takihara ◽

...

Keyword(s):

T Cells ◽

T Cell ◽

Cell Lines ◽

Carcinoma Cell ◽

Human Peripheral Blood ◽

Specific Gene ◽

Type I ◽

Type Ii ◽

Carcinoma Cell Lines ◽

Human T Cell

The human T-cell- or lymphocyte-specific gene, lck, encodes a tyrosine kinase and is a member of the src family. In this report we demonstrate that there are two classes of human lck transcripts (types I and II), containing different 5'-untranslated regions, which are expressed from two distinct promoters. No apparent sequence similarity was observed between the 5'-flanking regions of the two promoters. The expression of lck in human T-cell leukemia and carcinoma cell lines and in human peripheral blood T lymphocytes was examined by S1 nuclease and primer extension mapping and by Northern (RNA) blot analysis of total cellular RNA. The following results were obtained. (i) Two RNA start sites in the downstream promoter were used to generate type I transcripts. (ii) The major human type I start site has not been described for the mouse. (iii) At least five RNA start sites in the upstream promoter were used to generate type II transcripts. (iv) In T cells and in two colon carcinoma cell lines, type II transcripts were present in higher amounts than type I transcripts. (v) In T cells treated with phytohemagglutinin, tetradecanoylphorbol acetate, and cyclosporin A, the modulation of lck expression was associated primarily with changes in levels of type II transcripts. The above results suggest that the two human lck promoters are utilized differentially and may be regulated independently during certain physiological states.

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Therapeutic Strategies for Diabetes: Immune Modulation in Pancreatic β Cells

Frontiers in Endocrinology ◽

10.3389/fendo.2021.716692 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sugyeong Jo ◽

Sungsoon Fang

Keyword(s):

Clinical Trials ◽

T Cells ◽

Type Ii Diabetes ◽

Immune Modulation ◽

Therapeutic Strategies ◽

Immune Homeostasis ◽

Type I ◽

Type Ii ◽

Pancreatic Β Cell ◽

Β Cell

Increased incidence of type I and type II diabetes has been prevailed worldwide. Though the pathogenesis of molecular mechanisms remains still unclear, there are solid evidence that disturbed immune homeostasis leads to pancreatic β cell failure. Currently, autoimmunity and uncontrolled inflammatory signaling pathways have been considered the major factors in the pathogenesis of diabetes. Many components of immune system have been reported to implicate pancreatic β cell failure, including helper T cells, cytotoxic T cells, regulatory T cells and gut microbiota. Immune modulation of those components using small molecules and antibodies, and fecal microbiota transplantation are undergoing in many clinical trials for the treatment of type I and type II diabetes. In this review we will discuss the basis of molecular pathogenesis focusing on the disturbed immune homeostasis in type I and type II diabetes, leading to pancreatic β cell destruction. Finally, we will introduce current therapeutic strategies and clinical trials by modulation of immune system for the treatment of type I and type II diabetes patients.

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Structure-based mapping of the TβRI and TβRII receptor binding sites of the parasitic TGF-β mimic, Hp-TGM

10.1101/2020.12.08.416701 ◽

2020 ◽

Author(s):

Ananya Mukundan ◽

Chang-Hyeock Byeon ◽

Cynthia S. Hinck ◽

Danielle J. Smyth ◽

Rick M. Maizels ◽

...

Keyword(s):

T Cells ◽

Chemical Shift ◽

Solution Structure ◽

Adaptive Immune System ◽

Structural Similarity ◽

Binary Complex ◽

Type I ◽

Type Ii ◽

Nmr Chemical Shift ◽

Heligmosomoides Polygyrus

AbstractTGF-β is a secreted signaling protein involved in many physiological processes: organ development, production and maintenance of the extracellular matrix, as well as regulation of the adaptive immune system. As a cytokine, TGF-β stimulates the differentiation of CD4+ T-cells into regulatory T-cells (Tregs) that act to promote peripheral immune tolerance. The murine parasite Heligmosomoides polygyrus takes advantage of this pathway to induce inducing Foxp3+ Tregs in a similar manner using a TGF-β mimic (TGM), comprised of five tandem complement control protein (CCP) domains, designated D1-D5. Despite having no structural homology to TGF-β or to TGF-β family proteins, TGM binds directly to the TGF-β type I and type II receptors, TβRI and TβRII. To further investigate, NMR titration, and SPR and ITC binding experiments were performed, showing that TGM-D2, with the aid of D1, binds TβRI and TGM-D3 binds TβRII. Competition ITC experiments showed that TGM-D3 competes with TGF-β for binding to TβRII, consistent with TGM-D3-induced NMR chemical shift perturbations of TβRII which aligned with the solvent inaccessible areas of TβRII upon binding TGF-β. Thus, TGM-D3 binds to the same edged β-strand of TβRII that is used to bind TGF-β. Competition ITC experiments demonstrated that TGM-D1D2 and TGF-β3:TβRII compete for binding to TβRI, while TGM-D2-induced NMR chemical shift perturbation of TβRI showed that TGM-D2 binds to the same pre-helix extension of TβRI as does the TGF-β/TβRII binary complex. The solution structure of TGM-D3 revealed that while it has the overall structure of a CCP domain, TGM-D3 has an insertion in the hypervariable loop uncommon to CCP domains. These findings suggest that parasitic TGM, despite its lack of structural similarity to TGF-β, evolved to take advantage of the binding regions of the mammalian TGF-β type I and type II receptors. The structure of this TGM domain, along with the predicted structure of other H. polygyrus secreted proteins reported in the literature, suggest that TGM is part of a larger family of evolutionarily-adapted immunomodulatory CCP-containing proteins.

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Longitudinal single-cell immune profiling revealed distinct innate immune response in asymptomatic COVID-19 patients

10.1101/2020.09.02.276865 ◽

2020 ◽

Cited By ~ 1

Author(s):

Xiang-Na Zhao ◽

Yue You ◽

Guo-Lin Wang ◽

Hui-Xia Gao ◽

Xiao-Ming Cui ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

T Cell ◽

Single Cell ◽

Innate Immune Response ◽

Clonal Expansion ◽

Innate Immune ◽

Type I ◽

Severe Condition ◽

Asymptomatic Patients

SUMMARYRecent studies have characterized the single-cell immune landscape of host immune response of coronavirus disease 2019 (COVID-19), specifically focus on the severe condition. However, the immune response in mild or even asymptomatic patients remains unclear. Here, we performed longitudinal single-cell transcriptome sequencing and T cell/B cell receptor sequencing on 3 healthy donors and 10 COVID-19 patients with asymptomatic, moderate, and severe conditions. We found asymptomatic patients displayed distinct innate immune responses, including increased CD56briCD16− NK subset, which was nearly missing in severe condition and enrichment of a new Th2-like cell type/state expressing a ciliated cell marker. Unlike that in moderate condition, asymptomatic patients lacked clonal expansion of effector CD8+ T cells but had a robust effector CD4+ T cell clonal expansion, coincide with previously detected SARS-CoV-2-reactive CD4+ T cells in unexposed individuals. Moreover, NK and effector T cells in asymptomatic patients have upregulated cytokine related genes, such as IFNG and XCL2. Our data suggest early innate immune response and type I immunity may contribute to the asymptomatic phenotype in COVID-19 disease, which could in turn deepen our understanding of severe COVID-19 and guide early prediction and therapeutics.

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Type I Natural Killer T Cells as Key Regulators of the Immune Response to Infectious Diseases

Clinical Microbiology Reviews ◽

10.1128/cmr.00232-20 ◽

2020 ◽

Vol 34 (2) ◽

pp. e00232-20

Author(s):

Nicolás M. S. Gálvez ◽

Karen Bohmwald ◽

Gaspar A. Pacheco ◽

Catalina A. Andrade ◽

Leandro J. Carreño ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Infectious Diseases ◽

Natural Killer ◽

Nkt Cells ◽

Interleukin 4 ◽

Type I ◽

Inkt Cells ◽

Class I Mhc ◽

Natural Killer T

SUMMARYThe immune system must work in an orchestrated way to achieve an optimal response upon detection of antigens. The cells comprising the immune response are traditionally divided into two major subsets, innate and adaptive, with particular characteristics for each type. Type I natural killer T (iNKT) cells are defined as innate-like T cells sharing features with both traditional adaptive and innate cells, such as the expression of an invariant T cell receptor (TCR) and several NK receptors. The invariant TCR in iNKT cells interacts with CD1d, a major histocompatibility complex class I (MHC-I)-like molecule. CD1d can bind and present antigens of lipid nature and induce the activation of iNKT cells, leading to the secretion of various cytokines, such as gamma interferon (IFN-γ) and interleukin 4 (IL-4). These cytokines will aid in the activation of other immune cells following stimulation of iNKT cells. Several molecules with the capacity to bind to CD1d have been discovered, including α-galactosylceramide. Likewise, several molecules have been synthesized that are capable of polarizing iNKT cells into different profiles, either pro- or anti-inflammatory. This versatility allows NKT cells to either aid or impair the clearance of pathogens or to even control or increase the symptoms associated with pathogenic infections. Such diverse contributions of NKT cells to infectious diseases are supported by several publications showing either a beneficial or detrimental role of these cells during diseases. In this article, we discuss current data relative to iNKT cells and their features, with an emphasis on their driving role in diseases produced by pathogenic agents in an organ-oriented fashion.

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STING: a master regulator in the cancer-immunity cycle

Molecular Cancer ◽

10.1186/s12943-019-1087-y ◽

2019 ◽

Vol 18 (1) ◽

Cited By ~ 28

Author(s):

Yuanyuan Zhu ◽

Xiang An ◽

Xiao Zhang ◽

Yu Qiao ◽

Tongsen Zheng ◽

...

Keyword(s):

Immune Response ◽

T Cells ◽

Immune Responses ◽

Type I Interferons ◽

Type I ◽

Type I Ifn ◽

Negative Effects ◽

Independent Manner ◽

Adaptive Immune ◽

Cancer Immunity

Abstract The aberrant appearance of DNA in the cytoplasm triggers the activation of cGAS-cGAMP-STING signaling and induces the production of type I interferons, which play critical roles in activating both innate and adaptive immune responses. Recently, numerous studies have shown that the activation of STING and the stimulation of type I IFN production are critical for the anticancer immune response. However, emerging evidence suggests that STING also regulates anticancer immunity in a type I IFN-independent manner. For instance, STING has been shown to induce cell death and facilitate the release of cancer cell antigens. Moreover, STING activation has been demonstrated to enhance cancer antigen presentation, contribute to the priming and activation of T cells, facilitate the trafficking and infiltration of T cells into tumors and promote the recognition and killing of cancer cells by T cells. In this review, we focus on STING and the cancer immune response, with particular attention to the roles of STING activation in the cancer-immunity cycle. Additionally, the negative effects of STING activation on the cancer immune response and non-immune roles of STING in cancer have also been discussed.

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