scholarly journals Harnessing Tolerogenic Histone Peptide Epitopes From Nucleosomes for Selective Down-Regulation of Pathogenic Autoimmune Response in Lupus (Past, Present, and Future)

2021 ◽  
Vol 12 ◽  
Author(s):  
Syamal K. Datta
Keyword(s):  
Treg Cells ◽  
Autoimmune Response ◽  
Sustained Remission ◽  
Systemic Lupus ◽  
Hematopoietic Stem ◽  
Peptide Epitope ◽  
Peptide Epitopes ◽  
Organ Specific

Autoantigen-directed tolerance can be induced by certain nucleosomal histone peptide epitope/s in nanomolar dosage leading to sustained remission of disease in mice with spontaneous SLE. By contrast, lupus is accelerated by administration of intact (whole) histones, or whole nucleosomes in microparticles from apoptotic cells, or by post-translationally acetylated histone-peptides. Low-dose therapy with the histone-peptide epitopes simultaneously induces TGFβ and inhibits IL-6 production by DC in vivo, especially pDC, which then induce CD4+CD25+ Treg and CD8+ Treg cells that suppress pathogenic autoimmune response. Both types of induced Treg cells are FoxP3+ and act by producing TGFβ at close cell-to-cell range. No anaphylactic adverse reactions, or generalized immunosuppression have been detected in mice injected with the peptides, because the epitopes are derived from evolutionarily conserved histones in the chromatin; and the peptides are expressed in the thymus during ontogeny, and their native sequences have not been altered. The peptide-induced Treg cells can block severe lupus on adoptive transfer reducing inflammatory cell reaction and infiltration in the kidney. In Humans, similar potent Treg cells are generated by the histone peptide epitopes in vitro in lupus patients’ PBMC, inhibiting anti-dsDNA autoantibody and interferon production. Furthermore, the same types of Treg cells are generated in lupus patients who are in very long-term remission (2-8 years) after undergoing autologous hematopoietic stem cell transplantation. These Treg cells are not found in lupus patients treated conventionally into clinical remission (SLEDAI of 0); and consequently they still harbor pathogenic autoimmune cells, causing subclinical damage. Although antigen-specific therapy with pinpoint accuracy is suitable for straight-forward organ-specific autoimmune diseases, Systemic Lupus is much more complex. The histone peptide epitopes have unique tolerogenic properties for inhibiting Innate immune cells (DC), T cells and B cell populations that are both antigen-specifically and cross-reactively involved in the pathogenic autoimmune response in lupus. The histone peptide tolerance is a natural and non-toxic therapy suitable for treating early lupus, and also maintaining lupus patients after toxic drug therapy. The experimental steps, challenges and possible solutions for successful therapy with these peptide epitopes are discussed in this highly focused review on Systemic Lupus.

Role of STAT3 in Immunoregulatory Function of Human Bone Marrow-Derived Mesenchymal Stem Cells.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 3637-3637
Author(s):  
Jinsun Yoon ◽  
Seoju Kim ◽  
Eun Shil Kim ◽  
Byoung Kook Kim ◽  
Young Lee
Keyword(s):  
T Cells ◽  
Conflicts Of Interest ◽  
Hematologic Malignancies ◽  
Treg Cells ◽  
Human Mscs ◽  
Hematopoietic Stem ◽  
The One

Abstract Abstract 3637 Poster Board III-573 The one of the best curative treatment modality in hematologic malignancies is an allogeneic hematopoietic stem cell transplantation (HSCT). However, graft-versus-host disease (GVHD) is a major obstacle of allogeneic HSCT. BM derived human MSCs are known to have immunoregulatory effect in vitro and in vivo via inhibiting alloreactive T lymphocytes, leading to their clinical use for the prevention of GVHD in HSCT. However, the molecular mechanism of immunoregulatory effect of human MSCs is not fully understood. In this study, the signaling of immunoregulatory effect was investigated by co-culture of human MSCs with lymphocytes. The proliferation of allogeneic T cells was inhibited by MSCs. Among the STATs, STAT3 was a key molecule in MLR co-cultured with MSCs. STAT3 siRNA treated MSCs did not inhibit the lymphocyte proliferation. After MSCs were trasnsfected with STAT3 plasmid, the fraction of CD4+CD25+FOXP3+ cells (Treg cells) were increased, while the fraction of CD4+, CD8+, CD25+ was decreased. In addition, Th1-related cytokines (IL-2, IL-12 and INF-γ) and Th17-related cytokines (IL-6, IL-17 and IL-21) were down-regulated, and Th2-related cytokines (GATA-3, IL-4 and IL-10) were up-regulated in MLR co-cultured with STAT3-ablated MSCs, while vice versa in MLR co-cultured with STAT3-transfected MSCs. Furthermore, ELISA showed that concentration of Th1-related cytokine (IL-2) in the supernatant of MLR co-cultured with STAT3-ablated MSCs was higher than that of control; while concentration of Th2-related cytokine (IL-4) was lower than that of control. These results suggested that induction of Th1 to Th2 shift by MSCs might be mediated via STAT3 molecule. In summary, STAT3 may be an indispensable molecule in the immunoregulatory effect in human MSCs via modulation of regulatory T cells. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Nucleosome: a major immunogen for pathogenic autoantibody-inducing T cells of lupus.

1993 ◽  
Vol 177 (5) ◽  
pp. 1367-1381 ◽  
Author(s):  
C Mohan ◽  
S Adams ◽  
V Stanik ◽  
S K Datta
Keyword(s):  
T Cells ◽  
T Cell ◽  
B Cells ◽  
Autoimmune Response ◽  
Th Cells ◽  
Variable Regions ◽  
Peptide Epitopes ◽  
Autoreactive T Cell

Only a fraction (12%) of 268 "autoreactive" T cell clones derived from lupus-prone mice can selectively induce the production of pathogenic anti-DNA autoantibodies in vitro and accelerate the development of lupus nephritis when transferred in vivo. The CDR3 loops of T cell receptor beta chains expressed by these pathogenic T helper (Th) clones contain a recurrent motif of anionic residues suggesting that they are selected by autoantigens with cationic residues. Herein, we found that approximately 50% of these pathogenic Th clones were specific for nucleosomal antigens, but none of them responded to cationic idiopeptides shared by variable regions of pathogenic anti-DNA autoantibodies. Nucleosomes did not stimulate the T cells as a nonspecific mitogen or superantigen. Only the pathogenic Th cells of lupus responded to nucleosomal antigens that were processed and presented via the major histocompatibility class II pathway. Although the presentation of purified mononucleosomes to the Th clones could be blocked by inhibitors of endosomal proteases, neither of the two components of the nucleosomes--free DNA or histones by themselves--could stimulate the Th clones. Thus critical peptide epitopes for the Th cells were probably protected during uptake and processing of the nucleosome particle as a whole. The nucleosome-specific Th clones preferentially augmented the production of IgG autoantibodies to histone-DNA complex in vitro. In vivo, nucleosome-specific, CD4+ T cells were not detectable in normal mice, but they were found in the spleens of lupus-prone mice as early as 1 mo of age, long before other autoimmune manifestations. Immunization of young, preautoimmune lupus mice with nucleosomes augmented the production of autoantibodies and markedly accelerated the development of severe glomerulonephritis. Previously, crude preparations containing nucleosomes were shown by others to have polyclonal mitogenic activity for B cells from normal as well as lupus mice. Identification here of pure mononucleosome as a lupus-specific immunogen for the Th cells that selectively help the pathogenic anti-DNA autoantibody producing B cells of lupus could lead to the design of specific therapy against this pathogenic autoimmune response.

scholarly journals Chloroquine Autophagic Inhibition Rebalances Th17/Treg-Mediated Immunity and Ameliorates Systemic Lupus Erythematosus

2017 ◽  
Vol 44 (1) ◽  
pp. 412-422 ◽  
Author(s):  
Ning An ◽  
Yanwen Chen ◽  
Chao Wang ◽  
Chen Yang ◽  
Zhi-hong Wu ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Immune Response ◽  
Lupus Erythematosus ◽  
Treg Cells ◽  
Healthy Controls ◽  
Systemic Lupus ◽  
Immune Imbalance ◽  
The Impact

Background: Imbalanced cellular immunity is critical to the pathogenesis of systemic lupus erythematosus (SLE). Recently, autophagy has emerged as a key homeostatic mechanism in T lymphocytes. This study was conducted to explore the impact of autophagy on the Th17/ regulatory T (Treg) immune imbalance in SLE. Methods: Peripheral Th17 and Treg cells from newly diagnosed patients with SLE and healthy controls were detected by flow cytometry. Additionally, the effects of chloroquine (CQ) autophagic inhibition on the Th17/Treg immune response were investigated in vitro. In addition, hydroxychloroquine (HCQ) treatment of the Th17/Treg immune response and the disease progression of lupus MRL/lpr mice were studied in vivo. Results: Compared with healthy controls, both peripheral Th17 and Treg cells of patients with SLE exhibited activated autophagy, resulting in a heightened Th17 proinflammatory response and diminished Treg immunosuppression. Furthermore, in vitro experiments indicated that CQ autophagic inhibition effectively rebalanced the Th17/Treg immune responses in patients with SLE. In vivo studies of MRL/lpr mice similarly confirmed that HCQ treatment decisively inhibited the autophagy of Th17/Treg cellular subsets, restoring the immune balance, lowering the serum levels of inflammatory cytokines and autoantibodies, and improving renal histopathology. Conclusion: Activated autophagy contributed to the Th17/Treg immune imbalance in SLE, and chloroquine autophagic inhibition rebalanced Th17/ Treg-mediated immunity and ameliorated SLE.

Immnuoregulatory Effect of Human Mesenchymal Stem Cell Is Mediated Via STAT3 Molecule

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 4741-4741
Author(s):  
Jinsun Yoon ◽  
Seoju Kim ◽  
Eun Shil Kim ◽  
Byoungbae PARK ◽  
Junghye Choi ◽  
...  
Keyword(s):  
T Cells ◽  
Stem Cell ◽  
T Lymphocytes ◽  
Human Mesenchymal Stem Cells ◽  
Human Mesenchymal Stem Cell ◽  
Treg Cells ◽  
Human Mscs ◽  
Hematopoietic Stem

Abstract The best curative treatment modality in hematologic malignancies is allogeneic hematopoietic stem cell transplantation (HSCT). Graft-versus-host disease (GVHD) is a major obstacle of allogenic HSCT. Bone marrow derived human mesenchymal stem cells (MSCs) is known to have immunoregulatory effect in vitro and in vivo via inhibiting alloreactive T lymphocytes, leading to their clinical use for the prevention of GVHD in HSCT. However, the molecular mechanism of immunoregulatory effect of human MSCs is not fully understood. In this study we investigated the signaling of immunoregulatory effect by co-culture of human MSCs with lymphocytes. The proliferation of allogeneic T cells was strongly inhibited. The fraction of CD4+CD25+Foxp3+ cells (Treg cells) was increased, while the fraction of CD4+, CD8+, CD25+ was decreased. In addition, induction of Th1 to Th2 shift was observed. Western blot study showed that phosphorylation of STAT1, STAT3, STAT6 was up-regulated, but STAT1, STAT4, ERK, AKT, NF-κB (p65, p50 subunits) was down-regulated. While expression of STAT3 was observed in culture of MSCs only, no expression of STAT3 was shown in co-cultured human MSCs with lymphocytes. In order to validate our results, expression of STAT3 in human MSCs co-cultured with lymphocytes was ablated using small interfering RNA. As a result, inhibition of CD4+CD25+FoxP3+ cells, proliferation of allogenic T lymphocytes, inhibited induction of Th1 to Th2 shift and proliferation of CD4+, CD8+, CD25+ cells. Furthermore, expressions of Th1 and Th17-related cytokines were increased, while expressions of Th2-related cytokines were decreased. In summary, these results suggest that STAT 3 may be an indispensable molecule in the immunoregulatory effects in human MSCs via modulation of regulatory T cells.

Strategies to Protect Hematopoietic Stem Cells from Culture-Induced Stress Conditions

2020 ◽  
Vol 15 ◽  
Author(s):  
Fatima Aerts-Kaya
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Ex Vivo ◽  
Stress Conditions ◽  
Stress Factors ◽  
Hematopoietic Stem ◽  
Induced Stress

: In contrast to their almost unlimited potential for expansion in vivo and despite years of dedicated research and optimization of expansion protocols, the expansion of Hematopoietic Stem Cells (HSCs) in vitro remains remarkably limited. Increased understanding of the mechanisms that are involved in maintenance, expansion and differentiation of HSCs will enable the development of better protocols for expansion of HSCs. This will allow procurement of HSCs with long-term engraftment potential and a better understanding of the effects of the external influences in and on the hematopoietic niche that may affect HSC function. During collection and culture of HSCs, the cells are exposed to suboptimal conditions that may induce different levels of stress and ultimately affect their self-renewal, differentiation and long-term engraftment potential. Some of these stress factors include normoxia, oxidative stress, extra-physiologic oxygen shock/stress (EPHOSS), endoplasmic reticulum (ER) stress, replicative stress, and stress related to DNA damage. Coping with these stress factors may help reduce the negative effects of cell culture on HSC potential, provide a better understanding of the true impact of certain treatments in the absence of confounding stress factors. This may facilitate the development of better ex vivo expansion protocols of HSCs with long-term engraftment potential without induction of stem cell exhaustion by cellular senescence or loss of cell viability. This review summarizes some of available strategies that may be used to protect HSCs from culture-induced stress conditions.

scholarly journals The role of the PZP domain of AF10 in acute leukemia driven by AF10 translocations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brianna J. Klein ◽  
Anagha Deshpande ◽  
Khan L. Cox ◽  
Fan Xuan ◽  
Mohamad Zandian ◽  
...  
Keyword(s):  
Critical Role ◽  
Cellular Transformation ◽  
Acute Leukemias ◽  
Hematopoietic Stem ◽  
Nucleosome Core ◽  
Stem And Progenitor Cells ◽  
Transforming Activity

AbstractChromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.

scholarly journals Using the Microwell-mesh to culture microtissues in vitro and as a carrier to implant microtissues in vivo into mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melissa E. Monterosso ◽  
Kathryn Futrega ◽  
William B. Lott ◽  
Ian Vela ◽  
Elizabeth D. Williams ◽  
...  
Keyword(s):  
Hair Follicles ◽  
Live Animal ◽  
Nsg Mice ◽  
Animal Imaging ◽  
Organ Specific ◽  
Bioluminescence Signal ◽  
Serial Transplantation ◽  
Live Animal Imaging

AbstractProstate cancer (PCa) patient-derived xenografts (PDXs) are commonly propagated by serial transplantation of “pieces” of tumour in mice, but the cellular composition of pieces is not standardised. Herein, we optimised a microwell platform, the Microwell-mesh, to aggregate precise numbers of cells into arrays of microtissues, and then implanted the Microwell-mesh into NOD-scid IL2γ−/− (NSG) mice to study microtissue growth. First, mesh pore size was optimised using microtissues assembled from bone marrow-derived stromal cells, with mesh opening dimensions of 100×100 μm achieving superior microtissue vascularisation relative to mesh with 36×36 μm mesh openings. The optimised Microwell-mesh was used to assemble and implant PCa cell microtissue arrays (hereafter microtissues formed from cancer cells are referred to as microtumours) into mice. PCa cells were enriched from three different PDX lines, LuCaP35, LuCaP141, and BM18. 3D microtumours showed greater in vitro viability than 2D cultures, but neither proliferated. Microtumours were successfully established in mice 81% (57 of 70), 67% (4 of 6), 76% (19 of 25) for LuCaP35, LuCaP141, and BM18 PCa cells, respectively. Microtumour growth was tracked using live animal imaging for size or bioluminescence signal. If augmented with further imaging advances and cell bar coding, this microtumour model could enable greater resolution of PCa PDX drug response, and lead to the more efficient use of animals. The concept of microtissue assembly in the Microwell-mesh, and implantation in vivo may also have utility in implantation of islets, hair follicles or other organ-specific cells that self-assemble into 3D structures, providing an important bridge between in vitro assembly of mini-organs and in vivo implantation.

scholarly journals Primitive Human Hematopoietic Cells Are Enriched in Cord Blood Compared With Adult Bone Marrow or Mobilized Peripheral Blood as Measured by the Quantitative In Vivo SCID-Repopulating Cell Assay

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 3919-3924 ◽  
Author(s):  
Jean C.Y. Wang ◽  
Monica Doedens ◽  
John E. Dick
Keyword(s):  
Bone Marrow ◽  
Cord Blood ◽  
Peripheral Blood ◽  
Hematopoietic Cells ◽  
Allogeneic Transplantation ◽  
Functional Assay ◽  
Hematopoietic Stem ◽  
Mobilized Peripheral Blood

Abstract We have previously reported the development of in vivo functional assays for primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of severe combined immunodeficient (SCID) and nonobese diabetic/SCID (NOD/SCID) mice following intravenous transplantation. Accumulated data from gene marking and cell purification experiments indicate that the engrafting cells (defined as SCID-repopulating cells or SRC) are biologically distinct from and more primitive than most cells that can be assayed in vitro. Here we demonstrate through limiting dilution analysis that the NOD/SCID xenotransplant model provides a quantitative assay for SRC. Using this assay, the frequency of SRC in cord blood (CB) was found to be 1 in 9.3 × 105 cells. This was significantly higher than the frequency of 1 SRC in 3.0 × 106 adult BM cells or 1 in 6.0 × 106 mobilized peripheral blood (PB) cells from normal donors. Mice transplanted with limiting numbers of SRC were engrafted with both lymphoid and multilineage myeloid human cells. This functional assay is currently the only available method for quantitative analysis of human hematopoietic cells with repopulating capacity. Both CB and mobilized PB are increasingly being used as alternative sources of hematopoietic stem cells in allogeneic transplantation. Thus, the findings reported here will have important clinical as well as biologic implications.

Computational study for suppression of CD25/IL-2 interaction

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Moein Dehbashi ◽  
Zohreh Hojati ◽  
Majid Motovali-bashi ◽  
Mazdak Ganjalikhani-Hakemi ◽  
Akihiro Shimosaka ◽  
...  
Keyword(s):  
Small Molecules ◽  
Cancer Progression ◽  
Immune Escape ◽  
De Novo ◽  
Computational Study ◽  
Treg Cells ◽  
Homology Search ◽  
Small Interfering Rnas

AbstractCancer recurrence presents a huge challenge in cancer patient management. Immune escape is a key mechanism of cancer progression and metastatic dissemination. CD25 is expressed in regulatory T (Treg) cells including tumor-infiltrating Treg cells (TI-Tregs). These cells specially activate and reinforce immune escape mechanism of cancers. The suppression of CD25/IL-2 interaction would be useful against Treg cells activation and ultimately immune escape of cancer. Here, software, web servers and databases were used, at which in silico designed small interfering RNAs (siRNAs), de novo designed peptides and virtual screened small molecules against CD25 were introduced for the prospect of eliminating cancer immune escape and obtaining successful treatment. We obtained siRNAs with low off-target effects. Further, small molecules based on the binding homology search in ligand and receptor similarity were introduced. Finally, the critical amino acids on CD25 were targeted by a de novo designed peptide with disulfide bond. Hence we introduced computational-based antagonists to lay a foundation for further in vitro and in vivo studies.

scholarly journals Reduced High-Dose Radiation-Induced Residual Genotoxic Damage by Induction of Radioadaptive Response and Prophylactic Mild Dietary Restriction in Mice

Dose-Response ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 155932582098216
Author(s):  
Bing Wang ◽  
Kaoru Tanaka ◽  
Takanori Katsube ◽  
Kouichi Maruyama ◽  
Yasuharu Ninomiya ◽  
...  
Keyword(s):  
Dietary Restriction ◽  
High Dose ◽  
Cancer Treatments ◽  
Hematopoietic Stem ◽  
Beneficial Effects ◽  
Radiation Induced ◽  
Potential Strategy ◽  
Higher Doses

Radioadaptive response (RAR) describes a phenomenon in a variety of in vitro and in vivo systems that a low-dose of priming ionizing radiation (IR) reduces detrimental effects of a subsequent challenge IR at higher doses. Among in vivo investigations, studies using the mouse RAR model (Yonezawa Effect) showed that RAR could significantly extenuate high-dose IR-induced detrimental effects such as decrease of hematopoietic stem cells and progenitor cells, acute radiation hematopoietic syndrome, genotoxicity and genomic instability. Meanwhile, it has been demonstrated that diet intervention has a great impact on health, and dietary restriction shows beneficial effects on numerous diseases in animal models. In this work, by using the mouse RAR model and mild dietary restriction (MDR), we confirmed that combination of RAR and MDR could more efficiently reduce radiogenotoxic damage without significant change of the RAR phenotype. These findings suggested that MDR may share some common pathways with RAR to activate mechanisms consequently resulting in suppression of genotoxicity. As MDR could also increase resistance to chemotherapy and radiotherapy in normal cells, we propose that combination of MDR, RAR, and other cancer treatments (i.e., chemotherapy and radiotherapy) represent a potential strategy to increase the treatment efficacy and prevent IR risk in humans.

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