RESUMEN
Our previous study has demonstrated that transfusion of UVB-irradiation-induced apoptotic beta cells effectively prevents type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. However, the limitation of beta cell source would preclude the clinical application of this approach. Therefore, in the present study, we have attempted to establish a more practical approach by utilizing apoptotic non-beta cells to prevent T1D. We find that apoptotic splenic stromal cells significantly suppress beta cell antigen-reactive T cell proliferation in vitro and in vivo. Moreover, beta cell antigen-specific T cells primed by beta cell antigens in the presence of apoptotic stromal cells have markedly reduced responsiveness to the re-stimulation of the same beta cell antigen. We also find that beta cell antigen-specific IL-10-producing CD4+ T cells are induced in the presence of apoptotic splenic stromal cells. As expected, transfusion of apoptotic stromal cells effectively protected NOD mice from developing T1D. Furthermore, the proliferation of adoptively transferred beta cell antigen-specific TCR-transgenic T cells in pancreatic draining lymph nodes is markedly suppressed in UVB-stroma-treated mice, indicating that UVB-stroma treatment induces immune tolerance to multiple beta cell antigens. This study provides an effective and convenient approach for managing T1D by utilizing apoptotic non-beta cells.
Asunto(s)
Diabetes Mellitus Tipo 1/prevención & control , Tolerancia Inmunológica/inmunología , Inmunoterapia Adoptiva/métodos , Bazo/citología , Células del Estroma/inmunología , Linfocitos T/inmunología , Animales , Apoptosis/inmunología , Apoptosis/efectos de la radiación , Autoantígenos/inmunología , Diabetes Mellitus Tipo 1/inmunología , Femenino , Células Secretoras de Insulina/inmunología , Interleucina-10/biosíntesis , Interleucina-10/inmunología , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos NOD , Bazo/efectos de la radiación , Células del Estroma/efectos de la radiación , Rayos UltravioletaRESUMEN
Increasing attention is drawn to the contributions of abnormalities in both innate and acquired immune responses to the pathogenesis of autoimmune diseases, such as type 1 diabetes (T1D). Dendritic cells (DC) are critical immune cells linking innate and acquired immune responses and previous studies in NOD mice suggest abnormalities in these cells. To address DC dysregulation we examined kinetic global gene expression in NOD and B6 GM-CSF/IL-4-induced bone marrow-derived DC following lipopolysaccharide (LPS)-stimulation. We identified expression differences in over 300 genes including a cluster of 16 interferon (IFN-alpha/beta) target genes overexpressed in NOD DC. Mechanistically, heightened IFN-alpha/beta responses were not due to increased production of this cytokine, IFN-gamma priming or increased Syk kinase activity. We found, however, heightened responses to IFN-alpha/beta in NOD versus B6 as demonstrated by increased type 1 IFN target gene expression, for example, IRF-7, in NOD DC and macrophages. Analysis of multiple congenic strains demonstrated that the Idd5 susceptibility region largely governed heightened IFN-alpha responses. Of interest, heightened IFN-alpha/beta response in NOD mice was not confined to hematopoietic cells but was also seen in the pancreas and beta cells. Compounding the IFN-alpha response defect, NOD mice harbor significantly more PDC in spleen in comparison to B6 and produce four- to sixfold more IFN-alpha when stimulated with CpG. Finally, treatment of NOD mice with IFN-alpha inducing agents, for example, high-dose poly I:C accelerates diabetes in both female and male mice. The abnormalities in the IFN-alpha/beta axis appear to play a significant role in T1D pathogenesis.
Asunto(s)
Diabetes Mellitus Tipo 1/etiología , Diabetes Mellitus Tipo 1/inmunología , Inductores de Interferón/farmacología , Células Mieloides/efectos de los fármacos , Poli I-C/farmacología , Animales , Células Dendríticas/inmunología , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/fisiopatología , Femenino , Regulación de la Expresión Génica/inmunología , Lipopolisacáridos/farmacología , Masculino , Ratones , Ratones Congénicos , Ratones Endogámicos NOD , Células Mieloides/patologíaRESUMEN
Our previous work demonstrated peptide-pulsed mature myeloid dendritic cells (DC) presenting beta cell antigens induce tolerance. Here we determine whether immature DC (iDC) presenting dominant (insulin beta9-23 chain, proinsulin C19-A3) or ignored (glutamic acid decarboxylase 65(78-97)) antigen determinants promote tolerance. Nonobese diabetic (NOD) mice were given injections of either unpulsed or peptide-pulsed myeloid iDC beginning at 9 weeks of age for 3 consecutive weeks. Diabetes incidence in recipients of unpulsed iDC was comparable to unmanipulated animals ( approximately 80%), whereas GAD65(78-97) pulsed iDC recipients were protected from the disease (P = 0.05). We also analyzed splenic T cell proliferation responses to the panel of studied peptides in diabetic and nondiabetic recipients. When stimulated with insulin or proinsulin peptide, nondiabetic mice receiving the peptide-pulsed iDC had a 21- to 31-fold or 3.9- to 9.0-fold reduction in T cell response, respectively, as compared to the response of diabetic unpulsed recipients. However, only a 2.6- to 3.1-fold reduction in response to beta chain peptide, and a 1.5- to 3.4-fold reduction in proinsulin response were observed in diabetic mice receiving peptide-pulsed iDC. The reduction was not specific to the immunizing peptide, as reduced proliferation was observed to other diabetes-target peptides. We conclude that protective iDC-based therapies require target antigen presentation, and ignored determinants may be preferable perhaps due to an available naïve T cell repertoire. In addition, iDC presenting peptides induce a nonspecific reduction in T cell responses to beta cell antigens, possibly through the induction of regulatory T cells.