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1.
Front Immunol ; 12: 675746, 2021.
Article in English | MEDLINE | ID: mdl-34262563

ABSTRACT

Aims: Recent studies highlight the potentially important role of neoepitopes in breaking immune tolerance in type 1 diabetes. T cell reactivity to these neoepitopes has been reported, but how this response compares quantitatively and phenotypically with previous reports on native epitopes is not known. Thus, an understanding of the relationship between native and neoepitopes and their role as tolerance breakers or disease drivers in type 1 diabetes is required. We set out to compare T cell reactivity and phenotype against a panel of neo- and native islet autoantigenic epitopes to examine how this relates to stages of type 1 diabetes development. Methods: Fifty-four subjects comprising patients with T1D, and autoantibody-positive unaffected family members were tested against a panel of neo- and native epitopes by ELISPOT (IFN-γ, IL-10, and IL-17). A further subset of two patients was analyzed by Single Cell Immune Profiling (RNAseq and TCR α/ß) after stimulation with pools of native and neoepitope peptides. Results: T cell responses to native and neoepitopes were present in patients with type 1 diabetes and at-risk subjects, and overall, there were no significant differences in the frequency, magnitude, or phenotype between the two sets of peptide stimuli. Single cell RNAseq on responder T cells revealed a similar profile in T1D patients stimulated with either neo- or native epitopes. A pro-inflammatory gene expression profile (TNF-α, IFN-γ) was dominant in both native and neoepitope stimulated T cells. TCRs with identical clonotypes were found in T cell responding to both native and neoepitopes. Conclusion/Interpretation: These data suggest that in peripheral blood, T cell responses to both native and neoepitopes are similar in terms of frequency and phenotype in patients with type 1 diabetes and high-risk unaffected family members. Furthermore, using a combination of transcriptomic and clonotypic analyses, albeit using a limited panel of peptides, we show that neoepitopes are comparable to native epitopes currently in use for immune-monitoring studies.


Subject(s)
Diabetes Mellitus, Type 1/immunology , Epitopes/immunology , Insulin-Secreting Cells/immunology , T-Lymphocytes/immunology , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Immune Tolerance , Infant , Male , Receptors, Antigen, T-Cell/immunology , Young Adult
2.
Sci Rep ; 10(1): 18927, 2020 11 03.
Article in English | MEDLINE | ID: mdl-33144616

ABSTRACT

Type 1 diabetes is an autoimmune disease caused by the destruction of the insulin-producing ß-cells. To revert type 1 diabetes, the suppression of the autoimmune attack should be combined with a ß-cell replacement strategy. It has been previously demonstrated that liraglutide, a glucagon-like peptide-1 receptor agonist, restores ß-cell mass in type 1 diabetes, via α-cell transdifferentiation and neogenesis. We report here that treatment with liraglutide does not prevent type 1 diabetes in the spontaneous non-obese diabetic (NOD) mouse model, but it tends to reduce leukocytic islet infiltration. However, in combination with an immunotherapy based on tolerogenic liposomes, it is effective in ameliorating hyperglycaemia in diabetic NOD mice. Importantly, liraglutide is not detrimental for the tolerogenic effect that liposomes exert on dendritic cells from patients with type 1 diabetes in terms of membrane expression of molecules involved in antigen presentation, immunoregulation and activation. Moreover, the in vivo effect of the combined therapy was tested in mice humanised with peripheral blood mononuclear cells from patients with type 1 diabetes, showing no adverse effects in leukocyte subsets. In conclusion, the combination therapy with liraglutide and a liposome-based immunotherapy is a promising candidate strategy for type 1 diabetes.


Subject(s)
Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 1/drug therapy , Insulin-Secreting Cells/cytology , Insulin/administration & dosage , Liraglutide/administration & dosage , Adult , Animals , Combined Modality Therapy , Diabetes Mellitus, Experimental/immunology , Diabetes Mellitus, Type 1/immunology , Female , Humans , Immunotherapy , Insulin/chemistry , Insulin/pharmacology , Insulin-Secreting Cells/drug effects , Liposomes , Liraglutide/pharmacology , Male , Mice , Mice, Inbred NOD , Treatment Outcome , Young Adult
3.
Curr Opin Endocrinol Diabetes Obes ; 27(4): 240-247, 2020 08.
Article in English | MEDLINE | ID: mdl-32618636

ABSTRACT

PURPOSE OF REVIEW: The role of T cells specific for islet autoantigens is proven in pathogenesis of type 1 diabetes. Recently, there has been rapid expansion in the number of T-cell subsets identified, this has coincided with an increase in the repertoire of reported islet antigens mainly through the discovery of novel epitopes. A discussion of how these marry together is now warranted and timely. RECENT FINDINGS: In this review, we will discuss the autoreactivity against neo-epitopes. We then explore the growing array of T-cell subsets for both CD4 T cells, including follicular and peripheral T helper cells, and CD8 T cells, discussing evolution from naïve to exhausted phenotypes. Finally, we detail how subsets correlate with disease stage and loss of ß-cell function and are impacted by immunotherapy. SUMMARY: The expanding list of T-cell subsets may be potentially encouraging in terms of elucidating disease mechanisms and have a role as biomarkers for disease progression. Furthermore, T-cell subsets can be used in stratifying patients for clinical trials and for monitoring immunotherapy outcomes. However, the definition of subsets needs to be refined in order to ensure that there is a uniform approach in designating T-cell subset attributes that is globally applied.


Subject(s)
Diabetes Mellitus, Type 1/immunology , T-Lymphocyte Subsets/physiology , Autoantigens/immunology , Autoantigens/metabolism , CD4-Positive T-Lymphocytes/physiology , CD8-Positive T-Lymphocytes/physiology , Diabetes Mellitus, Type 1/pathology , Disease Progression , Humans , Immunotherapy/adverse effects , Immunotherapy/methods , Islets of Langerhans/immunology , T-Lymphocyte Subsets/immunology
4.
Article in English | MEDLINE | ID: mdl-32477262

ABSTRACT

Type 1 diabetes is an autoimmune disease caused by the destruction of the insulin-producing ß-cells. An ideal immunotherapy should combine the blockade of the autoimmune response with the recovery of functional target cell mass. With the aim to develop new therapies for type 1 diabetes that could contribute to ß-cell mass restoration, a drug repositioning analysis based on systems biology was performed to identify the ß-cell regenerative potential of commercially available compounds. Drug repositioning is a strategy used for identifying new uses for approved drugs that are outside the scope of the medical indication. A list of 28 non-synonymous repurposed drug candidates was obtained, and 16 were selected as diabetes mellitus type 1 treatment candidates regarding pancreatic ß-cell regeneration. Drugs with poor safety profile were further filtered out. Lastly, we selected liraglutide for its predictive efficacy values for neogenesis, transdifferentiation of α-cells, and/or replication of pre-existing ß-cells. Liraglutide is an analog of glucagon-like peptide-1, a drug used in patients with type 2 diabetes. Liraglutide was tested in immunodeficient NOD-Scid IL2rg-/- (NSG) mice with type 1 diabetes. Liraglutide significantly improved the blood glucose levels in diabetic NSG mice. During the treatment, a significant increase in ß-cell mass was observed due to a boost in ß-cell number. Both parameters were reduced after withdrawal. Interestingly, islet bihormonal glucagon+insulin+ cells and insulin+ ductal cells arose during treatment. In vitro experiments showed an increase of insulin and glucagon gene expression in islets cultured with liraglutide in normoglycemia conditions. These results point to ß-cell replacement, including transdifferentiation and neogenesis, as aiding factors and support the role of liraglutide in ß-cell mass restoration in type 1 diabetes. Understanding the mechanism of action of this drug could have potential clinical relevance in this autoimmune disease.


Subject(s)
Cellular Reprogramming , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Type 1/complications , Glucagon-Like Peptide 1/analogs & derivatives , Hyperglycemia/prevention & control , Insulin-Secreting Cells/drug effects , Liraglutide/pharmacology , Animals , Glucagon-Like Peptide 1/administration & dosage , Hyperglycemia/etiology , Hyperglycemia/metabolism , Hyperglycemia/pathology , Hypoglycemic Agents/pharmacology , Male , Mice , Mice, Inbred NOD , Mice, SCID
5.
J Autoimmun ; 112: 102466, 2020 08.
Article in English | MEDLINE | ID: mdl-32414606

ABSTRACT

The ready availability of human blood makes it the first choice for immuno-monitoring. However, this has been largely confined to static metrics, particularly resting T cell phenotypes. Conversely, dynamic assessments have mostly relied on cell stimulation in vitro which is subject to multiple variables. Here, immunodynamic insights from the peripheral blood are shown to be obtainable by applying a revised approach to cell-cycle analysis. Specifically, refined flow cytometric protocols were employed, assuring the reliable quantification of T cells in the S-G2/M phases of the cell-cycle (collectively termed "T Double S" for T cells in S-phase in Sanguine: in short "TDS" cells). Without protocol refinement, TDS could be either missed, as most of them layed out of the conventional lymphocyte gates, or confused with cell doublets artefactually displaying high DNA-content. To illustrate the nature of TDS cells, and their relationship to different immunodynamic scenarios, we examined them in healthy donors (HD); infectious mononucleosis (IM) patients versus asymptomatic EBV+ carriers; and recently-diagnosed T1D patients. TDS were reproducibly more abundant among CD8+ T cells and a defined subset of T-regulatory CD4+ T cells, and were substantially increased in IM and a subset of T1D patients. Of note, islet antigen-reactive TDS cell frequencies were associated with an aggressive T cell effector phenotype, suggesting that peripheral blood can reflect immune events within tissues in T1D, and possibly in other organ-specific autoimmune diseases. Our results suggest that tracking TDS cells may provide a widely applicable means of gaining insight into ongoing immune response dynamics in a variety of settings, including tissue immunopathologies where the peripheral blood has often not been considered insightful.


Subject(s)
Cell Cycle Checkpoints/immunology , Monitoring, Immunologic/methods , T-Lymphocytes/immunology , Animals , Flow Cytometry/methods , Humans , Mice , Mice, Transgenic
6.
Diabetologia ; 63(6): 1186-1198, 2020 06.
Article in English | MEDLINE | ID: mdl-32248243

ABSTRACT

AIMS/HYPOTHESIS: Antigen-specific therapy aims to modify inflammatory T cell responses in type 1 diabetes and restore immune tolerance. One strategy employs GAD65 conjugated to aluminium hydroxide (GAD-alum) to take advantage of the T helper (Th)2-biasing adjuvant properties of alum and thereby regulate pathological Th1 autoimmunity. We explored the cellular and molecular mechanism of GAD-alum action in the setting of a previously reported randomised placebo-controlled clinical trial conducted by Type 1 Diabetes TrialNet. METHODS: In the clinical trial conducted by Type 1 Diabetes TrialNet, participants were immunised with 20 µg GAD-alum (twice or three times) or alum alone and peripheral blood mononuclear cell samples were banked at baseline and post treatment. In the present study, GAD-specific T cell responses were measured in these samples and GAD-specific T cell lines and clones were generated, which were then further characterised. RESULTS: At day 91 post immunisation, we detected GAD-specific IL-13+ CD4 T cell responses significantly more frequently in participants immunised with GAD-alum (71% and 94% treated twice or three times, respectively) compared with those immunised with alum alone (38%; p = 0.003 and p = 0.0002, respectively) accompanied by high secreted levels of IL-13, IL-4 and IL-5, confirming a GAD-specific, GAD-alum-induced Th2 response. Of note, GAD-specific, IL-13+ CD4 T cells observed after immunisation co-secreted IFN-γ, displaying a bifunctional Th1/Th2 phenotype. Single-cell transcriptome analysis identified IL13 and IFNG expression in concert with the canonical Th2 and Th1 transcription factor genes GATA3 and TBX21, respectively. T cell receptor ß-chain (TCRB) CDR3 regions of GAD-specific bifunctional T cells were identified in circulating naive and central memory CD4 T cell pools of non-immunised participants with new-onset type 1 diabetes and healthy individuals, suggesting the potential for bifunctional responses to be generated de novo by GAD-alum immunisation or via expansion from an existing public repertoire. CONCLUSIONS/INTERPRETATION: GAD-alum immunisation activates and propagates GAD-specific CD4 T cells with a distinctive bifunctional phenotype, the functional analysis of which might be important in understanding therapeutic responses.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , Diabetes Mellitus, Type 1/immunology , Diabetes Mellitus, Type 1/therapy , Immunotherapy/methods , Th1 Cells/immunology , Th2 Cells/immunology , Cell Line , Cryopreservation , Humans , Randomized Controlled Trials as Topic , Receptors, Antigen, T-Cell/metabolism , Th1 Cells/metabolism , Th2 Cells/metabolism
7.
Sci Rep ; 9(1): 1235, 2019 02 04.
Article in English | MEDLINE | ID: mdl-30718757

ABSTRACT

Non-genetic factors are crucial in the pathogenesis of type 1 diabetes (T1D), a disease caused by autoimmunity against insulin-producing ß-cells. Exposure to medications in the prenatal period may influence the immune system maturation, thus altering self-tolerance. Prenatal administration of betamethasone -a synthetic glucocorticoid given to women at risk of preterm delivery- may affect the development of T1D. It has been previously demonstrated that prenatal betamethasone administration protects offspring from T1D development in nonobese diabetic (NOD) mice. The direct effect of betamethasone on the immature and mature immune system of NOD mice and on target ß-cells is analysed in this paper. In vitro, betamethasone decreased lymphocyte viability and induced maturation-resistant dendritic cells, which in turn impaired γδ T cell proliferation and decreased IL-17 production. Prenatal betamethasone exposure caused thymus hypotrophy in newborn mice as well as alterations in immune cells subsets. Furthermore, betamethasone decreased ß-cell growth, reduced C-peptide secretion and altered the expression of genes related to autoimmunity, metabolism and islet mass in T1D target tissue. These results support the protection against T1D in the betamethasone-treated offspring and demonstrate that this drug alters the developing immune system and ß-cells. Understanding how betamethasone generates self-tolerance could have potential clinical relevance in T1D.


Subject(s)
Autoimmunity/drug effects , Betamethasone/administration & dosage , Diabetes Mellitus, Type 1/prevention & control , Glucocorticoids/administration & dosage , Immune Tolerance/drug effects , Animals , C-Peptide/immunology , C-Peptide/metabolism , Cell Survival/drug effects , Cell Survival/immunology , Diabetes Mellitus, Type 1/immunology , Disease Models, Animal , Female , Humans , Inclusion Bodies/drug effects , Insulin-Secreting Cells/drug effects , Insulin-Secreting Cells/immunology , Insulin-Secreting Cells/metabolism , Lymphocyte Activation , Maternal Exposure , Mice , Mice, Inbred NOD , Obstetric Labor, Premature/prevention & control , Pregnancy
8.
J Clin Invest ; 128(8): 3460-3474, 2018 08 01.
Article in English | MEDLINE | ID: mdl-29851415

ABSTRACT

In type 1 diabetes, cytotoxic CD8+ T cells with specificity for ß cell autoantigens are found in the pancreatic islets, where they are implicated in the destruction of insulin-secreting ß cells. In contrast, the disease relevance of ß cell-reactive CD8+ T cells that are detectable in the circulation, and their relationship to ß cell function, are not known. Here, we tracked multiple, circulating ß cell-reactive CD8+ T cell subsets and measured ß cell function longitudinally for 2 years, starting immediately after diagnosis of type 1 diabetes. We found that change in ß cell-specific effector memory CD8+ T cells expressing CD57 was positively correlated with C-peptide change in subjects below 12 years of age. Autoreactive CD57+ effector memory CD8+ T cells bore the signature of enhanced effector function (higher expression of granzyme B, killer-specific protein of 37 kDa, and CD16, and reduced expression of CD28) compared with their CD57- counterparts, and network association modeling indicated that the dynamics of ß cell-reactive CD57+ effector memory CD8+ T cell subsets were strongly linked. Thus, coordinated changes in circulating ß cell-specific CD8+ T cells within the CD57+ effector memory subset calibrate to functional insulin reserve in type 1 diabetes, providing a tool for immune monitoring and a mechanism-based target for immunotherapy.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Diabetes Mellitus, Type 1/immunology , Immunologic Memory , Insulin-Secreting Cells/immunology , Adult , CD8-Positive T-Lymphocytes/pathology , Child , Diabetes Mellitus, Type 1/pathology , Diabetes Mellitus, Type 1/therapy , Female , Humans , Insulin-Secreting Cells/pathology , Male
9.
Front Immunol ; 9: 253, 2018.
Article in English | MEDLINE | ID: mdl-29491866

ABSTRACT

Type 1 diabetes (T1D) is a metabolic disease caused by the autoimmune destruction of insulin-producing ß-cells. With its incidence increasing worldwide, to find a safe approach to permanently cease autoimmunity and allow ß-cell recovery has become vital. Relying on the inherent ability of apoptotic cells to induce immunological tolerance, we demonstrated that liposomes mimicking apoptotic ß-cells arrested autoimmunity to ß-cells and prevented experimental T1D through tolerogenic dendritic cell (DC) generation. These liposomes contained phosphatidylserine (PS)-the main signal of the apoptotic cell membrane-and ß-cell autoantigens. To move toward a clinical application, PS-liposomes with optimum size and composition for phagocytosis were loaded with human insulin peptides and tested on DCs from patients with T1D and control age-related subjects. PS accelerated phagocytosis of liposomes with a dynamic typical of apoptotic cell clearance, preserving DCs viability. After PS-liposomes phagocytosis, the expression pattern of molecules involved in efferocytosis, antigen presentation, immunoregulation, and activation in DCs concurred with a tolerogenic functionality, both in patients and control subjects. Furthermore, DCs exposed to PS-liposomes displayed decreased ability to stimulate autologous T cell proliferation. Moreover, transcriptional changes in DCs from patients with T1D after PS-liposomes phagocytosis pointed to an immunoregulatory prolife. Bioinformatics analysis showed 233 differentially expressed genes. Genes involved in antigen presentation were downregulated, whereas genes pertaining to tolerogenic/anti-inflammatory pathways were mostly upregulated. In conclusion, PS-liposomes phagocytosis mimics efferocytosis and leads to phenotypic and functional changes in human DCs, which are accountable for tolerance induction. The herein reported results reinforce the potential of this novel immunotherapy to re-establish immunological tolerance, opening the door to new therapeutic approaches in the field of autoimmunity.


Subject(s)
Apoptosis/immunology , Dendritic Cells/immunology , Diabetes Mellitus, Type 1/immunology , Immune Tolerance/immunology , Phosphatidylserines/immunology , Adolescent , Adult , Autoantigens/immunology , Cells, Cultured , Female , Humans , Immunotherapy/methods , Liposomes , Male , Middle Aged , Molecular Mimicry/immunology , Phagocytosis , Young Adult
10.
Biochem Biophys Rep ; 12: 198-205, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29090282

ABSTRACT

The pathophysiology of inflammatory bowel disease (IBD) reflects a balance between mucosal injury and reparative mechanisms. Some regenerating gene (Reg) family members have been reported to be expressed in Crohn's disease (CD) and ulcerative colitis (UC) and to be involved as proliferative mucosal factors in IBD. However, expression of all REG family genes in IBD is still unclear. Here, we analyzed expression of all REG family genes (REG Iα, REG Iß, REG III, HIP/PAP, and REG IV) in biopsy specimens of UC and CD by real-time RT-PCR. REG Iα, REG Iß, and REG IV genes were overexpressed in CD samples. REG IV gene was also overexpressed in UC samples. We further analyzed the expression mechanisms of REG Iα, REG Iß, and REG IV genes in human colon cells. The expression of REG Iα was significantly induced by IL-6 or IL-22, and REG Iß was induced by IL-22. Deletion analyses revealed that three regions (- 220 to - 211, - 179 to - 156, and - 146 to - 130) in REG Iα and the region (- 274 to- 260) in REG Iß promoter were responsible for the activation by IL-22/IL-6. The promoters contain consensus transcription factor binding sequences for MZF1, RTEF1/TEAD4, and STAT3 in REG Iα, and HLTF/FOXN2F in REG Iß, respectively. The introduction of siRNAs for MZF1, RTEF1/TEAD4, STAT3, and HLTF/FOXN2F abolished the transcription of REG Iα and REG Iß. The gene activation mechanisms of REG Iα/REG Iß may play a role in colon mucosal regeneration in IBD.

11.
Sci Transl Med ; 9(402)2017 08 09.
Article in English | MEDLINE | ID: mdl-28794283

ABSTRACT

Immunotherapy using short immunogenic peptides of disease-related autoantigens restores immune tolerance in preclinical disease models. We studied safety and mechanistic effects of injecting human leukocyte antigen-DR4(DRB1*0401)-restricted immunodominant proinsulin peptide intradermally every 2 or 4 weeks for 6 months in newly diagnosed type 1 diabetes patients. Treatment was well tolerated with no systemic or local hypersensitivity. Placebo subjects showed a significant decline in stimulated C-peptide (measuring insulin reserve) at 3, 6, 9, and 12 months versus baseline, whereas no significant change was seen in the 4-weekly peptide group at these time points or the 2-weekly group at 3, 6, and 9 months. The placebo group's daily insulin use increased by 50% over 12 months but remained unchanged in the intervention groups. C-peptide retention in treated subjects was associated with proinsulin-stimulated interleukin-10 production, increased FoxP3 expression by regulatory T cells, low baseline levels of activated ß cell-specific CD8 T cells, and favorable ß cell stress markers (proinsulin/C-peptide ratio). Thus, proinsulin peptide immunotherapy is safe, does not accelerate decline in ß cell function, and is associated with antigen-specific and nonspecific immune modulation.


Subject(s)
Diabetes Mellitus, Type 1/therapy , Immunotherapy/methods , Peptides/therapeutic use , Proinsulin/therapeutic use , Adolescent , Adult , Autoantibodies/immunology , Autoantigens/immunology , C-Peptide/metabolism , Diabetes Mellitus, Type 1/metabolism , Double-Blind Method , Female , Humans , Immunophenotyping , Male , Middle Aged , T-Lymphocytes, Regulatory/metabolism , Young Adult
12.
Nanomedicine (Lond) ; 12(11): 1231-1242, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28593827

ABSTRACT

AIM: Based on the ability of apoptosis to induce immunological tolerance, liposomes were generated mimicking apoptotic cells, and they arrest autoimmunity in Type 1 diabetes. Our aim was to validate the immunotherapy in other autoimmune disease: multiple sclerosis. MATERIALS & METHODS: Phosphatidylserine-rich liposomes were loaded with disease-specific autoantigen. Therapeutic capability of liposomes was assessed in vitro and in vivo. RESULTS: Liposomes induced a tolerogenic phenotype in dendritic cells, and arrested autoimmunity, thus decreasing the incidence, delaying the onset and reducing the severity of experimental disease, correlating with an increase in a probably regulatory CD25+ FoxP3- CD4+ T-cell subset. CONCLUSION: This is the first work that confirms phosphatidylserine-liposomes as a powerful tool to arrest multiple sclerosis, demonstrating its relevance for clinical application.


Subject(s)
Autoantigens/administration & dosage , Immunotherapy/methods , Liposomes/chemistry , Multiple Sclerosis/therapy , Myelin-Oligodendrocyte Glycoprotein/administration & dosage , Peptides/administration & dosage , Phosphatidylserines/chemistry , Animals , Autoantigens/immunology , Autoantigens/therapeutic use , Female , Mice, Inbred C57BL , Multiple Sclerosis/immunology , Myelin-Oligodendrocyte Glycoprotein/immunology , Myelin-Oligodendrocyte Glycoprotein/therapeutic use , Peptides/immunology , Peptides/therapeutic use , T-Lymphocytes, Regulatory/immunology
13.
Curr Pharm Des ; 23(18): 2623-2643, 2017.
Article in English | MEDLINE | ID: mdl-28201972

ABSTRACT

Cell-based tolerogenic therapy is a promising approach for the treatment of autoimmune diseases and transplant rejection. Regulatory T cells and tolerogenic dendritic cells have been particularly explored in the treatment of various autoimmune disorders in experimental models of disease. Although some of these cells have already been tested in a limited number of clinical trials, there is still a need for preclinical research on tolerogenic cells in animal models of autoimmunity. This review will focus on the relevance of data obtained from studies in experimental animal models for the use of tolerogenic cell-based therapy in humans. Also, perspectives for further improvement of tolerogenic cell preparation towards enhanced suppressive activity and stability of the cells will be discussed.


Subject(s)
Arthritis, Rheumatoid/therapy , Cell- and Tissue-Based Therapy/methods , Diabetes Mellitus, Type 1/therapy , Disease Models, Animal , Multiple Sclerosis/therapy , Animals , Arthritis, Rheumatoid/immunology , Autoimmunity/drug effects , Autoimmunity/immunology , Diabetes Mellitus, Type 1/immunology , Humans , Immune Tolerance/drug effects , Immune Tolerance/immunology , Immunosuppressive Agents/administration & dosage , Multiple Sclerosis/immunology , Organic Chemicals/administration & dosage , T-Lymphocytes, Regulatory/drug effects , T-Lymphocytes, Regulatory/immunology
14.
N Biotechnol ; 35: 19-29, 2017 Mar 25.
Article in English | MEDLINE | ID: mdl-27810336

ABSTRACT

Umbilical cord blood (UCB) transplantation is associated with long periods of aplastic anaemia. This undesirable situation is due to the low cell dose available per unit of UCB and the immaturity of its progenitors. To overcome this, we present a cell culture strategy aimed at the expansion of the CD34+ population and the generation of granulocyte lineage-committed progenitors. Two culture products were produced after either 6 or 14days of in vitro expansion, and their characteristics compared to non-expanded UCB CD34+ controls in terms of phenotype, colony-forming activity and multilineage repopulation potential in NOD-scid IL2Rγnull mice. Both expanded cell products maintained rapid SCID repopulation activity similar to the non-expanded control, but 14-day cultured cells showed impaired long term SCID repopulation activity. The process was successfully scaled up to clinically relevant doses of 89×106 CD34+ cells committed to the granulocytic lineage and 3.9×109 neutrophil precursors in different maturation stages. Cell yields and biological properties presented by the cell product obtained after 14days in culture were superior and therefore this is proposed as the preferred production setup in a new type of dual transplant strategy to reduce aplastic periods, producing a transient repopulation before the definitive engraftment of the non-cultured UCB unit. Importantly, human telomerase reverse transcriptase activity was undetectable, c-myc expression levels were low and no genetic abnormalities were found, as determined by G-banding karyotype, further confirming the safety of the expanded product.


Subject(s)
Cord Blood Stem Cell Transplantation/methods , Fetal Blood/cytology , Anemia, Aplastic/blood , Anemia, Aplastic/etiology , Anemia, Aplastic/prevention & control , Animals , Antigens, CD34/blood , Biotechnology , Cell Differentiation , Cell Lineage , Colony-Forming Units Assay , Cord Blood Stem Cell Transplantation/adverse effects , Female , Fetal Blood/immunology , Graft Enhancement, Immunologic/methods , Granulocytes/cytology , Humans , Interleukin Receptor Common gamma Subunit/deficiency , Interleukin Receptor Common gamma Subunit/genetics , Mice , Mice, Inbred NOD , Mice, Knockout , Mice, SCID , Neutrophils/cytology
15.
Mol Cell Endocrinol ; 426: 101-12, 2016 May 05.
Article in English | MEDLINE | ID: mdl-26911933

ABSTRACT

The transmembrane glycoprotein CD26 or dipeptidyl peptidase IV (DPPIV) is a multifunctional protein. In immune system, CD26 plays a role in T-cell function and is also involved in thymic maturation and emigration patterns. In preclinical studies, treatment with DPPIV inhibitors reduces insulitis and delays or even reverses the new -onset of type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. However, the specific mechanisms involved in these effects remain unknown. The aim of the present study was to investigate how DPPIV inhibition modifies the expression of genes in the thymus of NOD mice by microarray analysis. Changes in the gene expression of ß-cell autoantigens and Aire in thymic epithelial cells (TECs) were also evaluated by using qRT-PCR. A DPPIV inhibitor, MK626, was orally administered in the diet for 4 and 6 weeks starting at 6-8 weeks of age. Thymic glands from treated and control mice were obtained for each study checkpoint. Thymus transcriptome analysis revealed that 58 genes were significantly over-expressed in MK626-treated mice after 6 weeks of treatment. Changes in gene expression in the thymus were confined mainly to the immune system, including innate immunity, chemotaxis, antigen presentation and immunoregulation. Most of the genes are implicated in central tolerance mechanisms through several pathways. No differences were observed in the expression of Aire and ß-cell autoantigens in TECs. In the current study, we demonstrate that treatment with the DPPIV inhibitor MK626 in NOD mice alters the expression of the immune response-related genes in the thymus, especially those related to immunological central tolerance, and may contribute to the prevention of T1D.


Subject(s)
Dipeptidyl Peptidase 4/metabolism , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Gene Expression Regulation/drug effects , Indinavir/pharmacology , Animals , Antigen Presentation/genetics , Female , Gene Expression Regulation/immunology , Gene Regulatory Networks , Immunomodulation/genetics , Mice, Inbred NOD , Thymus Gland/drug effects , Thymus Gland/metabolism , Transcriptome
16.
Eur J Immunol ; 46(3): 593-608, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26639224

ABSTRACT

Autoreactive B lymphocytes play a key role as APCs in diaebetogenesis. However, it remains unclear whether B-cell tolerance is compromised in NOD mice. Here, we describe a new B lymphocyte transgenic NOD mouse model, the 116C-NOD mouse, where the transgenes derive from an islet-infiltrating B lymphocyte of a (8.3-NODxNOR) F1 mouse. The 116C-NOD mouse produces clonal B lymphocytes with pancreatic islet beta cell specificity. The incidence of T1D in 116C-NOD mice is decreased in both genders when compared with NOD mice. Moreover, several immune selection mechanisms (including clonal deletion and anergy) acting on the development, phenotype, and function of autoreactive B lymphocytes during T1D development have been identified in the 116C-NOD mouse. Surprisingly, a more accurate analysis revealed that, despite their anergic phenotype, 116C B cells express some costimulatory molecules after activation, and induce a T-cell shift toward a Th17 phenotype. Furthermore, this shift on T lymphocytes seems to occur not only when both T and B cells contact, but also when helper T (Th) lineage is established. The 116C-NOD mouse model could be useful to elucidate the mechanisms involved in the generation of Th-cell lineages.


Subject(s)
B-Lymphocytes/immunology , Clonal Anergy , Diabetes Mellitus, Type 1/immunology , Disease Models, Animal , Immune Tolerance/genetics , Lymphocyte Activation , Th17 Cells/immunology , Animals , Clonal Deletion , Cytokines/genetics , Cytokines/immunology , Immune Tolerance/immunology , Mice, Inbred NOD , Mice, Transgenic , Phenotype , Spleen/anatomy & histology , Spleen/cytology , Spleen/immunology , Transgenes
17.
PLoS One ; 10(11): e0142186, 2015.
Article in English | MEDLINE | ID: mdl-26555789

ABSTRACT

CD26 is a T cell activation marker consisting in a type II transmembrane glycoprotein with dipeptidyl peptidase IV (DPPIV) activity in its extracellular domain. It has been described that DPPIV inhibition delays the onset of type 1 diabetes and reverses the disease in non-obese diabetic (NOD) mice. The aim of the present study was to assess the effect of MK626, a DPPIV inhibitor, in type 1 diabetes incidence and in T lymphocyte subsets at central and peripheral compartments. Pre-diabetic NOD mice were treated with MK626. Diabetes incidence, insulitis score, and phenotyping of T lymphocytes in the thymus, spleen and pancreatic lymph nodes were determined after 4 and 6 weeks of treatment, as well as alterations in the expression of genes encoding ß-cell autoantigens in the islets. The effect of MK626 was also assessed in two in vitro assays to determine proliferative and immunosuppressive effects. Results show that MK626 treatment reduces type 1 diabetes incidence and after 6 weeks of treatment reduces insulitis. No differences were observed in the percentage of T lymphocyte subsets from central and peripheral compartments between treated and control mice. MK626 increased the expression of CD26 in CD8+ T effector memory (TEM) from spleen and pancreatic lymph nodes and in CD8+ T cells from islet infiltration. CD8+TEM cells showed an increased proliferation rate and cytokine secretion in the presence of MK626. Moreover, the combination of CD8+ TEM cells and MK626 induces an immunosuppressive response. In conclusion, treatment with the DPPIV inhibitor MK626 prevents experimental type 1 diabetes in association to increase expression of CD26 in the CD8+ TEM lymphocyte subset. In vitro assays suggest an immunoregulatory role of CD8+ TEM cells that may be involved in the protection against autoimmunity to ß pancreatic islets associated to DPPIV inhibitor treatment.


Subject(s)
CD8-Positive T-Lymphocytes/drug effects , Diabetes Mellitus, Type 1/prevention & control , Dipeptidyl Peptidase 4/drug effects , Dipeptidyl-Peptidase IV Inhibitors/pharmacology , Sitagliptin Phosphate/analogs & derivatives , Animals , Autoantigens/genetics , CD8-Positive T-Lymphocytes/immunology , Diabetes Mellitus, Type 1/immunology , Islets of Langerhans/drug effects , Islets of Langerhans/immunology , Lymphocyte Activation , Mice , Mice, Inbred NOD , Sitagliptin Phosphate/pharmacology , Transforming Growth Factor beta/blood
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