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1.
Diabetologia ; 2020 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-32388592

RESUMO

AIMS/HYPOTHESIS: Individuals with longstanding and recent-onset type 1 diabetes have a smaller pancreas. Since beta cells represent a very small portion of the pancreas, the loss of pancreas volume in diabetes is primarily due to the loss of pancreatic exocrine mass. However, the structural changes in the exocrine pancreas in diabetes are not well understood. METHODS: To characterise the pancreatic endocrine and exocrine compartments in diabetes, we studied pancreases from adult donors with type 1 diabetes compared with similarly aged donors without diabetes. Islet cell mass, islet morphometry, exocrine mass, acinar cell size and number and pancreas fibrosis were assessed by immunohistochemical staining. To better understand possible mechanisms of altered pancreas size, we measured pancreas size in three mouse models of insulin deficiency. RESULTS: Pancreases from donors with type 1 diabetes were approximately 45% smaller than those from donors without diabetes (47.4 ± 2.6 vs 85.7 ± 3.7 g), independent of diabetes duration or age of onset. Diabetic donor pancreases had decreased beta cell mass (0.061 ± 0.025 vs 0.94 ± 0.21 g) and reduced total exocrine mass (42.0 ± 4.9 vs 96.1 ± 6.5 g). Diabetic acinar cells were similar in size but fewer in number compared with those in pancreases from non-diabetic donors (63.7 ± 8.1 × 109 vs 121.6 ± 12.2 × 109 cells/pancreas), likely accounting for the difference in pancreas size. Within the type 1 diabetes exocrine tissue, there was a greater degree of fibrosis. The pancreases in three mouse models of insulin deficiency were similar in size to those in control mice. CONCLUSIONS/INTERPRETATION: Pancreases from donors with type 1 diabetes are smaller than normal donor pancreases because exocrine cells are fewer in number rather than smaller in size; these changes occur early in the disease process. Our mouse data suggest that decreased pancreas size in type 1 diabetes is not directly caused by insulin deficiency, but the precise mechanism responsible remains unclear.

2.
J Immunol ; 204(11): 2887-2899, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32295876

RESUMO

CD137 modulates type 1 diabetes (T1D) progression in NOD mice. We previously showed that CD137 expression in CD4 T cells inhibits T1D, but its expression in CD8 T cells promotes disease development by intrinsically enhancing the accumulation of ß-cell-autoreactive CD8 T cells. CD137 is expressed on a subset of FOXP3+ regulatory CD4 T cells (Tregs), and CD137+ Tregs are the main source of soluble CD137. Soluble CD137 suppresses T cells in vitro by binding to the CD137 ligand (CD137L) upregulated on activated T cells. To further study how the opposing functions of CD137 are regulated, we successfully targeted Tnfsf9 (encoding CD137L) in NOD mice using the CRISPR/Cas9 system (designated NOD.Tnfsf9 -/-). Relative to wild-type NOD mice, T1D development in the NOD.Tnfsf9 -/- strain was significantly delayed, and mice developed less insulitis and had reduced frequencies of ß-cell-autoreactive CD8 T cells. Bone marrow chimera experiments showed that CD137L-deficient hematopoietic cells were able to confer T1D resistance. Adoptive T cell transfer experiments showed that CD137L deficiency on myeloid APCs was associated with T1D suppression. Conversely, lack of CD137L on T cells enhanced their diabetogenic activity. Furthermore, neither CD137 nor CD137L was required for the development and homeostasis of FOXP3+ Tregs. However, CD137 was critical for the in vivo T1D-suppressive activity of FOXP3+ Tregs, suggesting that the interaction between CD137 and CD137L regulates their function. Collectively, our results provide new insights into the complex roles of CD137-CD137L interaction in T1D.

3.
Cell Rep ; 29(10): 3073-3086.e5, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31801074

RESUMO

Human genetic studies implicate interleukin-27 (IL-27) in the pathogenesis of type 1 diabetes (T1D), but the underlying mechanisms remain largely unexplored. To further define the role of IL-27 in T1D, we generated non-obese diabetic (NOD) mice deficient in IL-27 or IL-27Rα. In contrast to wild-type NOD mice, both NOD.Il27-/- and NOD.Il27ra-/- strains are completely resistant to T1D. IL-27 from myeloid cells and IL-27 signaling in T cells are critical for T1D development. IL-27 directly alters the balance of regulatory T cells (Tregs) and T helper 1 (Th1) cells in pancreatic islets, which in turn modulates the diabetogenic activity of CD8 T cells. IL-27 also directly enhances the effector function of CD8 T cells within pancreatic islets. In addition to T1D, IL-27 signaling in T cells is also required for lacrimal and salivary gland inflammation in NOD mice. Our study reveals that IL-27 contributes to autoimmunity in NOD mice through multiple mechanisms and provides substantial evidence to support its pathogenic role in human T1D.

4.
Sci Rep ; 9(1): 16103, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31695065

RESUMO

Type 1 Diabetes (T1D) is an autoimmune disease that is associated with effector T cell (Teff) destruction of insulin-producing pancreatic beta-islet cells. Among the therapies being evaluated for T1D is the restoration of regulatory T cell (Treg) activity, specifically directed toward down-modulation of beta-islet antigen-specific T effector cells. This is also known as antigen-specific adaptive tolerance induction for T1D (T1D ASATI). Tregitopes (T regulatory cell epitopes) are natural T cell epitopes derived from immunoglobulin G (IgG) that were identified in 2008 and have been evaluated in several autoimmune disease models. In the T1D ASATI studies presented here, Tregitope peptides were administered to non-obese diabetic (NOD) mice at the onset of diabetes within two clinically-relevant delivery systems (liposomes and in human serum albumin [HSA]-fusion products) in combination with preproinsulin (PPI) target antigen peptides. The combination of Tregitope-albumin fusions and PPI peptides reduced the incidence of severe diabetes and reversed mild diabetes, over 49 days of treatment and observation. Combining HSA-Tregitope fusions with PPI peptides is a promising ASATI approach for therapy of T1D.

5.
Front Immunol ; 10: 1732, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428087

RESUMO

Previous studies indicate that B-lymphocytes play a key role activating diabetogenic T-lymphocytes during the development of autoimmune diabetes. Recently, two transgenic NOD mouse models were generated: the NOD-PerIg and the 116C-NOD mice. In NOD-PerIg mice, B-lymphocytes acquire an activated proliferative phenotype and support accelerated autoimmune diabetes development. In contrast, in 116C-NOD mice, B-lymphocytes display an anergic-like phenotype delaying autoimmune diabetes onset and decreasing disease incidence. The present study further evaluates the T- and B-lymphocyte phenotype in both models. In islet-infiltrating B-lymphocytes (IIBLs) from 116C-NOD mice, the expression of H2-Kd and H2-Ag7 is decreased, whereas that of BAFF, BAFF-R, and TACI is increased. In contrast, IIBLs from NOD-PerIg show an increase in CD86 and FAS expression. In addition, islet-infiltrating T-lymphocytes (IITLs) from NOD-PerIg mice exhibit an increase in PD-1 expression. Moreover, proliferation assays indicate a high capacity of B-lymphocytes from NOD-PerIg mice to secrete high amounts of cytokines and induce T-lymphocyte activation compared to 116C B-lymphocytes. This functional variability between 116C and PerIg B-lymphocytes ultimately results in differences in the ability to shape T-lymphocyte phenotype. These results support the role of B-lymphocytes as key regulators of T-lymphocytes in autoimmune diabetes and provide essential information on the phenotypic characteristics of the T- and B-lymphocytes involved in the autoimmune response in autoimmune diabetes.

6.
Sci Rep ; 9(1): 4316, 2019 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-30867509

RESUMO

Rodent complex trait genetic studies involving a cross between two inbred strains are usually followed by congenic mapping to refine the loci responsible for the phenotype. However, progressing from a chromosomal region to the actual causal gene remains challenging because multiple polymorphic genes are often closely linked. The goal of this study was to develop a strategy that allows candidate gene testing by allele-specific expression without prior knowledge of the credible causal variant. Tnfrsf9 (encoding CD137) is a candidate gene for the Idd9.3 type 1 diabetes (T1D) susceptibility locus in the nonobese diabetic (NOD) mouse model. A C57BL/10Sn (B10)-derived diabetes resistance Idd9.3 congenic region has been shown to enhance accumulation of CD137+ regulatory T cells and serum soluble CD137 in NOD mice. By combining the power of congenic mapping and nuclease-based gene targeting, we established a system where a pair of F1 hybrids expressed either the B10 or NOD Tnfrsf9 allele mimicking coisogenic strains. Using this approach, we demonstrated that the allelic difference in B10 and NOD Tnfrsf9 alone was sufficient to cause differential accumulation of CD137+ regulatory T cells and serum soluble CD137 levels. This strategy can be broadly applied to other rodent genetic mapping studies.

7.
Front Immunol ; 10: 99, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30766536

RESUMO

Type 1 diabetes (T1D) is a T cell mediated autoimmune disease that affects more than 19 million people with incidence increasing rapidly worldwide. For T cells to effectively drive T1D, they must first traffic to the islets and extravasate through the islet vasculature. Understanding the cues that lead to T cell entry into inflamed islets is important because diagnosed T1D patients already have established immune infiltration of their islets. Here we show that CD11c+ cells are a key mediator of T cell trafficking to infiltrated islets in non-obese diabetic (NOD) mice. Using intravital 2-photon islet imaging we show that T cell extravasation into the islets is an extended process, with T cells arresting in the islet vasculature in close proximity to perivascular CD11c+ cells. Antigen is not required for T cell trafficking to infiltrated islets, but T cell chemokine receptor signaling is necessary. Using RNAseq, we show that islet CD11c+ cells express over 20 different chemokines that bind chemokine receptors expressed on islet T cells. One highly expressed chemokine-receptor pair is CXCL16-CXCR6. However, NOD. CXCR6-/- mice progressed normally to T1D and CXCR6 deficient T cells trafficked normally to the islets. Even with CXCR3 and CXCR6 dual deficiency, T cells trafficked to infiltrated islets. These data reinforce that chemokine receptor signaling is highly redundant for T cell trafficking to inflamed islets. Importantly, depletion of CD11c+ cells strongly inhibited T cell trafficking to infiltrated islets of NOD mice. We suggest that targeted depletion of CD11c+ cells associated with the islet vasculature may yield a therapeutic target to inhibit T cell trafficking to inflamed islets to prevent progression of T1D.


Assuntos
Antígeno CD11c/imunologia , Diabetes Mellitus Tipo 1/imunologia , Ilhotas Pancreáticas/imunologia , Linfócitos T/imunologia , Animais , Feminino , Camundongos Endogâmicos NOD , Camundongos Knockout
8.
J Immunol ; 201(7): 1907-1917, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30127089

RESUMO

In both NOD mice and humans, the development of type 1 diabetes (T1D) is dependent in part on autoreactive CD8+ T cells recognizing pancreatic ß cell peptides presented by often quite common MHC class I variants. Studies in NOD mice previously revealed that the common H2-Kd and/or H2-Db class I molecules expressed by this strain aberrantly lose the ability to mediate the thymic deletion of pathogenic CD8+ T cell responses through interactions with T1D susceptibility genes outside the MHC. A gene(s) mapping to proximal chromosome 7 was previously shown to be an important contributor to the failure of the common class I molecules expressed by NOD mice to mediate the normal thymic negative selection of diabetogenic CD8+ T cells. Using an inducible model of thymic negative selection and mRNA transcript analyses, we initially identified an elevated Nfkbid expression variant as a likely NOD-proximal chromosome 7 region gene contributing to impaired thymic deletion of diabetogenic CD8+ T cells. CRISPR/Cas9-mediated genetic attenuation of Nfkbid expression in NOD mice resulted in improved negative selection of autoreactive diabetogenic AI4 and NY8.3 CD8+ T cells. These results indicated that allelic variants of Nfkbid contribute to the efficiency of intrathymic deletion of diabetogenic CD8+ T cells. However, although enhancing thymic deletion of pathogenic CD8+ T cells, ablating Nfkbid expression surprisingly accelerated T1D onset that was associated with numeric decreases in both regulatory T and B lymphocytes in NOD mice.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Cromossomos Humanos Par 7/genética , Diabetes Mellitus Tipo 1/imunologia , Proteínas I-kappa B/genética , Timo/imunologia , Alelos , Animais , Autoantígenos/imunologia , Diferenciação Celular , Células Cultivadas , Deleção Clonal , Modelos Animais de Doenças , Suscetibilidade a Doenças , Humanos , Proteínas I-kappa B/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Polimorfismo Genético
9.
J Immunol ; 200(10): 3353-3363, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29632144

RESUMO

Type 1 diabetes (T1D) is characterized by T cell-mediated destruction of the insulin-producing ß cells of the pancreatic islets. Among the loci associated with T1D risk, those most predisposing are found in the MHC region. HLA-B*39:06 is the most predisposing class I MHC allele and is associated with an early age of onset. To establish an NOD mouse model for the study of HLA-B*39:06, we expressed it in the absence of murine class I MHC. HLA-B*39:06 was able to mediate the development of CD8 T cells, support lymphocytic infiltration of the islets, and confer T1D susceptibility. Because reduced thymic insulin expression is associated with impaired immunological tolerance to insulin and increased T1D risk in patients, we incorporated this in our model as well, finding that HLA-B*39:06-transgenic NOD mice with reduced thymic insulin expression have an earlier age of disease onset and a higher overall prevalence as compared with littermates with typical thymic insulin expression. This was despite virtually indistinguishable blood insulin levels, T cell subset percentages, and TCR Vß family usage, confirming that reduced thymic insulin expression does not impact T cell development on a global scale. Rather, it will facilitate the thymic escape of insulin-reactive HLA-B*39:06-restricted T cells, which participate in ß cell destruction. We also found that in mice expressing either HLA-B*39:06 or HLA-A*02:01 in the absence of murine class I MHC, HLA transgene identity alters TCR Vß usage by CD8 T cells, demonstrating that some TCR Vß families have a preference for particular class I MHC alleles.


Assuntos
Diabetes Mellitus Tipo 1/genética , Antígenos HLA-B/genética , Insulina/genética , Timo/metabolismo , Alelos , Animais , Linfócitos T CD8-Positivos/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Modelos Animais de Doenças , Genes MHC Classe I/genética , Antígeno HLA-A2/genética , Células Secretoras de Insulina/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos
10.
Diabetes ; 67(5): 923-935, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29472249

RESUMO

Improved mouse models for type 1 diabetes (T1D) therapy development are needed. T1D susceptibility is restored to normally resistant NOD.ß2m-/- mice transgenically expressing human disease-associated HLA-A*02:01 or HLA-B*39:06 class I molecules in place of their murine counterparts. T1D is dependent on pathogenic CD8+ T-cell responses mediated by these human class I variants. NOD.ß2m-/--A2.1 mice were previously used to identify ß-cell autoantigens presented by this human class I variant to pathogenic CD8+ T cells and for testing therapies to attenuate such effectors. However, NOD.ß2m-/- mice also lack nonclassical MHC I family members, including FcRn, required for antigen presentation, and maintenance of serum IgG and albumin, precluding therapies dependent on these molecules. Hence, we used CRISPR/Cas9 to directly ablate the NOD H2-Kd and H2-Db classical class I variants either individually or in tandem (cMHCI-/-). Ablation of the H2-Ag7 class II variant in the latter stock created NOD mice totally lacking in classical murine MHC expression (cMHCI/II-/-). NOD-cMHCI-/- mice retained nonclassical MHC I molecule expression and FcRn activity. Transgenic expression of HLA-A2 or -B39 restored pathogenic CD8+ T-cell development and T1D susceptibility to NOD-cMHCI-/- mice. These next-generation HLA-humanized NOD models may provide improved platforms for T1D therapy development.


Assuntos
Diabetes Mellitus Tipo 1/genética , Modelos Animais de Doenças , Antígeno HLA-A2/genética , Antígenos HLA-B/genética , Camundongos , Microglobulina beta-2/genética , Animais , Sistemas CRISPR-Cas , Diabetes Mellitus Tipo 1/terapia , Antígenos de Histocompatibilidade Classe I/genética , Humanos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos Transgênicos
11.
J Immunol ; 199(11): 3757-3770, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29055002

RESUMO

In NOD mice and also likely humans, B lymphocytes play an important role as APC-expanding autoreactive T cell responses ultimately causing type 1 diabetes (T1D). Currently, humans at high future T1D risk can only be identified at late prodromal stages of disease indicated by markers such as insulin autoantibodies. When commenced in already insulin autoantibody+ NOD mice, continuous BAFFR-Fc treatment alone or in combination with anti-CD20 (designated combo therapy) inhibited T1D development. Despite eliciting broader B lymphocyte depletion, continuous combo therapy afforded no greater T1D protection than did BAFFR-Fc alone. As previously observed, late disease stage-initiated anti-CD20 monotherapy did not inhibit T1D, and in this study was additionally found to be associated with development of drug-blocking Abs. Promisingly, NOD mice given transient late disease stage BAFFR-Fc monotherapy were rendered T1D resistant. However, combo treatment abrogated the protective effect of transient BAFFR-Fc monotherapy. NOD mice receiving transient BAFF blockade were characterized by an enrichment of regulatory B lymphocytes that inhibit T1D development through IL-10 production, but this population is sensitive to deletion by anti-CD20 treatment. B lymphocytes from transient BAFFR-Fc-treated mice suppressed T cell proliferation to a greater extent than did those from controls. Proportions of B lymphocytes expressing CD73, an ecto-enzyme operating in a pathway converting proinflammatory ATP to anti-inflammatory adenosine, were also temporarily increased by transient BAFFR-Fc treatment, but not anti-CD20 therapy. These collective studies indicate transient BAFFR-Fc-mediated B lymphocyte depletion elicits long-term T1D protection by enriching regulatory B lymphocytes that are deleted by anti-CD20 cotherapy.


Assuntos
Fator Ativador de Células B/antagonistas & inibidores , Linfócitos B Reguladores/imunologia , Diabetes Mellitus Tipo 1/imunologia , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Imunoterapia/métodos , Rituximab/uso terapêutico , Linfócitos T/imunologia , Animais , Receptor do Fator Ativador de Células B/genética , Receptor do Fator Ativador de Células B/uso terapêutico , Proliferação de Células , Células Cultivadas , Terapia Combinada , Humanos , Fragmentos Fc das Imunoglobulinas/genética , Imunossupressão , Interleucina-10/metabolismo , Depleção Linfocítica , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD
12.
Comp Med ; 67(4): 335-343, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28830580

RESUMO

Segmented filamentous bacterium (SFB) a gram-positive, anaerobic, and intestinal commensal organism directly influences the development of Th17 helper cells in the small intestine of mice. In NOD mice, SFB colonization interferes with the development of type 1 diabetes (T1D), a T-cell-mediated autoimmune disease, suggesting that SFB may influence Th17 cells to inhibit Th1 populations associated with the anti-ß-cell immune response. This effect is a serious concern for investigators who use NOD mice for diabetes research because the expected incidence of disease decreases markedly when they are colonized by SFB. A room housing mice for T1D studies at The Jackson Laboratory was determined by fecal PCR testing to have widespread SFB colonization of multiple NOD strains after a steady decline in the incidence of T1D was noted. Rederivation of all NOD-related mouse strains was not feasible; therefore an alternative treatment using antibiotics to eliminate SFB from colonized mice was undertaken. After antibiotic treatment, soiled bedding from NOD mouse strains housed in SFB-free high-health-status production barrier rooms was used to reintroduce the gastrointestinal microbiota. Over the past 16 mo since treating the mice and disinfecting the mouse room, regular PCR testing has shown that no additional SFB colonization of mice has occurred, and the expected incidence of T1D has been reestablished in the offspring of treated mice.


Assuntos
Ampicilina/farmacologia , Antibacterianos/farmacologia , Diabetes Mellitus Tipo 1/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Infecções por Bactérias Gram-Positivas/veterinária , Intestinos/efeitos dos fármacos , Criação de Animais Domésticos/métodos , Animais , Descontaminação/métodos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Modelos Animais de Doenças , Monitoramento Ambiental/métodos , Fezes/microbiologia , Predisposição Genética para Doença , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/imunologia , Infecções por Bactérias Gram-Positivas/microbiologia , Interações Hospedeiro-Patógeno , Intestinos/imunologia , Intestinos/microbiologia , Camundongos Endogâmicos NOD , Fenótipo , Células Th1/imunologia , Células Th1/microbiologia , Células Th17/imunologia , Células Th17/microbiologia , Fatores de Tempo
13.
J Immunol ; 198(11): 4255-4267, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28461573

RESUMO

B lymphocytes play a key role in type 1 diabetes (T1D) development by serving as a subset of APCs preferentially supporting the expansion of autoreactive pathogenic T cells. As a result of their pathogenic importance, B lymphocyte-targeted therapies have received considerable interest as potential T1D interventions. Unfortunately, the B lymphocyte-directed T1D interventions tested to date failed to halt ß cell demise. IgG autoantibodies marking humans at future risk for T1D indicate that B lymphocytes producing them have undergone the affinity-maturation processes of class switch recombination and, possibly, somatic hypermutation. This study found that CRISPR/Cas9-mediated ablation of the activation-induced cytidine deaminase gene required for class switch recombination/somatic hypermutation induction inhibits T1D development in the NOD mouse model. The activation-induced cytidine deaminase protein induces genome-wide DNA breaks that, if not repaired through RAD51-mediated homologous recombination, result in B lymphocyte death. Treatment with the RAD51 inhibitor 4,4'-diisothiocyanatostilbene-2, 2'-disulfonic acid also strongly inhibited T1D development in NOD mice. The genetic and small molecule-targeting approaches expanded CD73+ B lymphocytes that exert regulatory activity suppressing diabetogenic T cell responses. Hence, an initial CRISPR/Cas9-mediated genetic modification approach has identified the AID/RAD51 axis as a target for a potentially clinically translatable pharmacological approach that can block T1D development by converting B lymphocytes to a disease-inhibitory CD73+ regulatory state.


Assuntos
Linfócitos B Reguladores/imunologia , Proteínas de Transporte/antagonistas & inibidores , Citidina Desaminase/antagonistas & inibidores , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Ativação Linfocitária , Proteínas Nucleares/antagonistas & inibidores , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , 5'-Nucleotidase/imunologia , Animais , Autoanticorpos/imunologia , Sistemas CRISPR-Cas , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Diabetes Mellitus Experimental , Switching de Imunoglobulina , Camundongos , Camundongos Endogâmicos NOD , Proteínas Nucleares/deficiência , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Hipermutação Somática de Imunoglobulina
14.
Immunogenetics ; 69(3): 193-198, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27796442

RESUMO

Type 1 diabetes (T1D) results from complex interactions between genetic and environmental factors. The nonobese diabetic (NOD) mouse develops spontaneous T1D and has been used extensively to study the genetic control of this disease. T1D is suppressed in NOD mice congenic for the C57BL/10 (B10)-derived Idd9 resistance region on chromosome 4. Previous studies conducted by other investigators have identified four subregions (Idd9.1, Idd9.2, Idd9.3, and Idd9.4) where B10-derived genes suppress T1D development in NOD mice. We independently generated and characterized six congenic strains containing B10-derived intervals that partially overlap with the Idd9.1 and Idd9.4 regions. T1D incidence studies have revealed a new B10-derived resistance region proximal to Idd9.1. Our results also indicated that a B10-derived gene(s) within the Idd9.4 region suppressed the diabetogenic activity of CD4 T cells and promoted CD103 expression on regulatory T cells indicative of an activated phenotype. In addition, we suggest the presence of a B10-derived susceptibility gene(s) in the Idd9.1/Idd9.4 region. These results provide additional information to improve our understanding of the complex genetic control by the Idd9 region.


Assuntos
Mapeamento Cromossômico/métodos , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Loci Gênicos/genética , Predisposição Genética para Doença , Linfócitos T Reguladores/imunologia , Animais , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Receptores do Fator de Necrose Tumoral/genética , Receptores do Fator de Necrose Tumoral/imunologia
15.
Diabetes ; 66(3): 710-721, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27920091

RESUMO

Type 1 diabetes development in the NOD mouse model is widely reported to be dependent on high-level production by autoreactive CD4+ and CD8+ T cells of interferon-γ (IFN-γ), generally considered a proinflammatory cytokine. However, IFN-γ can also participate in tolerance-induction pathways, indicating it is not solely proinflammatory. This study addresses how IFN-γ can suppress activation of diabetogenic CD8+ T cells. CD8+ T cells transgenically expressing the diabetogenic AI4 T-cell receptor adoptively transferred disease to otherwise unmanipulated NOD.IFN-γnull , but not standard NOD, mice. AI4 T cells only underwent vigorous intrasplenic proliferation in NOD.IFN-γnull recipients. Disease-protective IFN-γ could be derived from any lymphocyte source and suppressed diabetogenic CD8+ T-cell responses both directly and through an intermediary nonlymphoid cell population. Suppression was not dependent on regulatory T cells, but was associated with increased inhibitory STAT1 to STAT4 expression levels in pathogenic AI4 T cells. Importantly, IFN-γ exposure during activation reduced the cytotoxicity of human-origin type 1 diabetes-relevant autoreactive CD8+ T cells. Collectively, these results indicate that rather than marking the most proinflammatory lymphocytes in diabetes development, IFN-γ production could represent an attempted limitation of pathogenic CD8+ T-cell activation. Thus, great care should be taken when designing possible diabetic intervention approaches modulating IFN-γ production.


Assuntos
Diabetes Mellitus Tipo 1/imunologia , Interferon gama/imunologia , Ativação Linfocitária/imunologia , RNA Mensageiro/metabolismo , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Células Cultivadas , Feminino , Humanos , Interferon gama/genética , Interferon gama/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição STAT4/metabolismo , Baço/citologia , Linfócitos T Reguladores/efeitos dos fármacos
16.
Sci Transl Med ; 8(361): 361ra137, 2016 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-27798262

RESUMO

Autoantibodies can be present years to decades before the onset of disease manifestations in autoimmunity. This finding suggests that the initial autoimmune trigger involves a peripheral lymphoid component, which ultimately drives disease pathology in local tissues later in life. We show that Sjögren's syndrome manifestations that develop in aged NOD.H-2h4 mice were driven by and dependent on peripheral dysregulation that arose in early life. Specifically, elimination of spontaneous germinal centers in spleens of young NOD.H-2h4 mice by transient blockade of CD40 ligand (CD40L) or splenectomy abolished Sjögren's pathology of aged mice. Strikingly, a single injection of anti-CD40L at 4 weeks of age prevented tertiary follicle neogenesis and greatly blunted the formation of key autoantibodies implicated in glandular pathology, including anti-muscarinic receptor antibodies. Microarray profiling of the salivary gland characterized the expression pattern of genes that increased with disease progression and showed that early anti-CD40L greatly repressed B cell function while having a broader effect on multiple biological pathways, including interleukin-12 and interferon signaling. A single prophylactic treatment with anti-CD40L also inhibited the development of autoimmune thyroiditis and diabetes in NOD.H-2h4 and nonobese diabetic mice, respectively, supporting a key role for CD40L in the pathophysiology of several autoimmune models. These results strongly suggest that early peripheral immune dysregulation gives rise to autoimmune manifestations later in life, and for diseases predated by autoantibodies, early prophylactic intervention with biologics may prove efficacious.


Assuntos
Autoimunidade , Antígenos CD40/metabolismo , Sistema Imunitário/patologia , Envelhecimento , Animais , Anticorpos Monoclonais/farmacologia , Autoanticorpos/imunologia , Células da Medula Óssea/metabolismo , Antígenos CD40/genética , Ligante de CD40/antagonistas & inibidores , Ligante de CD40/imunologia , Citocinas/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/imunologia , Modelos Animais de Doenças , Feminino , Ligantes , Linfócitos/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Glândulas Salivares/metabolismo , Síndrome de Sjogren/genética , Síndrome de Sjogren/imunologia , Baço/metabolismo , Tireoidite Autoimune/genética , Tireoidite Autoimune/imunologia
17.
Methods Mol Biol ; 1438: 137-51, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27150089

RESUMO

Similar to the vast majority of cases in humans, the development of type 1 diabetes (T1D) in the NOD mouse model is due to T-cell mediated autoimmune destruction of insulin producing pancreatic ß cells. Particular major histocompatibility complex (MHC) haplotypes (designated HLA in humans; and H2 in mice) provide the primary genetic risk factor for T1D development. It has long been appreciated that within the MHC, particular unusual class II genes contribute to the development of T1D in both humans and NOD mice by allowing for the development and functional activation of ß cell autoreactive CD4 T cells. However, studies in NOD mice have revealed that through interactions with other background susceptibility genes, the quite common class I variants (K(d), D(b)) characterizing this strain's H2 (g7) MHC haplotype aberrantly acquire an ability to support the development of ß cell autoreactive CD8 T cell responses also essential to T1D development. Similarly, recent studies indicate that in the proper genetic context some quite common HLA class I variants also aberrantly contribute to T1D development in humans. This review focuses on how "humanized" HLA transgenic NOD mice can be created and used to identify class I dependent ß cell autoreactive CD8 T cell populations of clinical relevance to T1D development. There is also discussion on how HLA transgenic NOD mice can be used to develop protocols that may ultimately be useful for the prevention of T1D in humans by attenuating autoreactive CD8 T cell responses against pancreatic ß cells.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Diabetes Mellitus Tipo 1/prevenção & controle , Antígenos HLA/genética , Células Secretoras de Insulina/imunologia , Animais , Diabetes Mellitus Tipo 1/imunologia , Modelos Animais de Doenças , Feminino , Antígenos HLA/imunologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos Transgênicos
18.
Diabetes ; 65(7): 1977-1987, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-26961115

RESUMO

While the autoimmune destruction of pancreatic ß-cells underlying type 1 diabetes (1D) development is ultimately mediated by T-cells in NOD mice and also likely humans, B-lymphocytes play an additional key pathogenic role. It appears expression of plasma membrane bound immunoglobulin (Ig) molecules that efficiently capture ß-cell antigens allows autoreactive B-lymphocytes bypassing normal tolerance induction processes to be the subset of antigen presenting cells most efficiently activating diabetogenic T-cells. NOD mice transgenically expressing Ig molecules recognizing antigens that are (insulin) or not (hen egg lysozyme; HEL) expressed by ß-cells have proven useful in dissecting the developmental basis of diabetogenic B-lymphocytes. However, these transgenic Ig specificities were originally selected for their ability to recognize insulin or HEL as foreign, rather than autoantigens. Thus, we generated and characterized NOD mice transgenically expressing an Ig molecule representative of a large proportion of naturally occurring islet-infiltrating B-lymphocytes in NOD mice recognizing the neuronal antigen peripherin. Transgenic peripherin autoreactive B-lymphocytes infiltrate NOD pancreatic islets, acquire an activated proliferative phenotype, and potently support accelerated T1D development. These results support the concept of neuronal autoimmunity as a pathogenic feature of T1D, and targeting such responses could ultimately provide an effective disease intervention approach.

19.
Vet Ophthalmol ; 19(4): 319-31, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26096588

RESUMO

Sudden acquired retinal degeneration syndrome (SARDS) is one of the leading causes of currently incurable canine vision loss diagnosed by veterinary ophthalmologists. The disease is characterized by acute onset of blindness due to loss of photoreceptor function, extinguished electroretinogram with an initially normal appearing ocular fundus, and mydriatic pupils which are slowly responsive to bright white light, unresponsive to red, but responsive to blue light stimulation. In addition to blindness, the majority of affected dogs also show systemic abnormalities suggestive of hyperadrenocorticism, such as polyphagia with resulting obesity, polyuria, polydipsia, and a subclinical hepatopathy. The pathogenesis of SARDS is unknown, but neuroendocrine and autoimmune mechanisms have been suggested. Therapies that target these disease pathways have been proposed to reverse or prevent further vision loss in SARDS-affected dogs, but these treatments are controversial. In November 2014, the American College of Veterinary Ophthalmologists' Vision for Animals Foundation organized and funded a Think Tank to review the current knowledge and recently proposed ideas about disease mechanisms and treatment of SARDS. These panel discussions resulted in recommendations for future research strategies toward a better understanding of pathogenesis, early diagnosis, and potential therapy for this condition.


Assuntos
Doenças do Cão/patologia , Degeneração Retiniana/veterinária , Animais , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/patologia , Doenças Autoimunes/terapia , Doenças Autoimunes/veterinária , Cegueira/veterinária , Doenças do Cão/diagnóstico , Doenças do Cão/terapia , Cães , Degeneração Retiniana/diagnóstico , Degeneração Retiniana/patologia , Degeneração Retiniana/terapia
20.
PLoS One ; 10(10): e0140729, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26474487

RESUMO

Invariant Natural Killer T (iNKT) cells are a T cell subset expressing an invariant T Cell Receptor (TCR) that recognizes glycolipid antigens rather than peptides. The cells have both innate-like rapid cytokine release, and adaptive-like thymic positive selection. iNKT cell activation has been implicated in the pathogenesis of allergic asthma and inflammatory diseases, while reduced iNKT cell activation promotes infectious disease, cancer and certain autoimmune diseases such as Type 1 diabetes (T1D). Therapeutic means to reduce or deplete iNKT cells could treat inflammatory diseases, while approaches to promote their activation may have potential in certain infectious diseases, cancer or autoimmunity. Thus, we developed invariant TCR-specific monoclonal antibodies to better understand the role of iNKT cells in disease. We report here the first monoclonal antibodies specific for the mouse invariant TCR that by modifying the Fc construct can specifically deplete or activate iNKT cells in vivo in otherwise fully immuno-competent animals. We have used both the depleting and activating version of the antibody in the NOD model of T1D. As demonstrated previously using genetically iNKT cell deficient NOD mice, and in studies of glycolipid antigen activated iNKT cells in standard NOD mice, we found that antibody mediated depletion or activation of iNKT cells respectively accelerated and retarded T1D onset. In BALB/c mice, ovalbumin (OVA) mediated airway hyper-reactivity (AHR) was abrogated with iNKT cell depletion prior to OVA sensitization, confirming studies in knockout mice. Depletion of iNKT cells after sensitization had no effect on AHR in the conducting airways but did reduce AHR in the lung periphery. This result raises caution in the interpretation of studies that use animals that are genetically iNKT cell deficient from birth. These activating and depleting antibodies provide a novel tool to assess the therapeutic potential of iNKT cell manipulation.


Assuntos
Anticorpos Monoclonais Murinos/farmacologia , Asma/imunologia , Diabetes Mellitus Tipo 1/imunologia , Células T Matadoras Naturais/imunologia , Receptores de Antígenos de Linfócitos T/antagonistas & inibidores , Animais , Anticorpos Monoclonais Murinos/imunologia , Asma/genética , Asma/patologia , Asma/terapia , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Depleção Linfocítica/métodos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NOD , Células T Matadoras Naturais/patologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia
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