Although CD8 T-cell-mediated autoimmune β cell destruction occurs in type 1 diabetes (T1D), the target epitopes processed and presented by β cells are unknown. To identify them, we combined peptidomics and transcriptomics strategies. Inflammatory cytokines increased peptide presentation in vitro, paralleling upregulation of human leukocyte antigen (HLA) class I expression. Peptide sources featured several insulin granule proteins and all known β cell antigens, barring islet-specific glucose-6-phosphatase catalytic subunit-related protein. Preproinsulin yielded HLA-A2-restricted epitopes previously described. Secretogranin V and its mRNA splice isoform SCG5-009, proconvertase-2, urocortin-3, the insulin gene enhancer protein ISL-1, and an islet amyloid polypeptide transpeptidation product emerged as antigens processed into HLA-A2-restricted epitopes, which, as those already described, were recognized by circulating naive CD8 T cells in T1D and healthy donors and by pancreas-infiltrating cells in T1D donors. This peptidome opens new avenues to understand antigen processing by β cells and for the development of T cell biomarkers and tolerogenic vaccination strategies.

Whether cancer is maintained by a small number of stem cells or is composed of proliferating cells with approximate phenotypic equivalency is a central question in cancer biology. In the stem cell hypothesis, relapse after treatment may occur by failure to eradicate cancer stem cells. Chronic myeloid leukaemia (CML) is quintessential to this hypothesis. CML is a myeloproliferative disorder that results from dysregulated tyrosine kinase activity of the fusion oncoprotein BCR-ABL. During the chronic phase, this sole genetic abnormality (chromosomal translocation Ph(+): t(9;22)(q34;q11)) at the stem cell level causes increased proliferation of myeloid cells without loss of their capacity to differentiate. Without treatment, most patients progress to the blast phase when additional oncogenic mutations result in a fatal acute leukaemia made of proliferating immature cells. Imatinib mesylate and other tyrosine kinase inhibitors (TKIs) that target the kinase activity of BCR-ABL have improved patient survival markedly. However, fewer than 10% of patients reach the stage of complete molecular response (CMR), defined as the point when BCR-ABL transcripts become undetectable in blood cells. Failure to reach CMR results from the inability of TKIs to eradicate quiescent CML leukaemia stem cells (LSCs). Here we show that the residual CML LSC pool can be gradually purged by the glitazones, antidiabetic drugs that are agonists of peroxisome proliferator-activated receptor-γ (PPARγ). We found that activation of PPARγ by the glitazones decreases expression of STAT5 and its downstream targets HIF2α and CITED2, which are key guardians of the quiescence and stemness of CML LSCs. When pioglitazone was given temporarily to three CML patients in chronic residual disease in spite of continuous treatment with imatinib, all of them achieved sustained CMR, up to 4.7 years after withdrawal of pioglitazone. This suggests that clinically relevant cancer eradication may become a generally attainable goal by combination therapy that erodes the cancer stem cell pool.

The human leukocyte antigen (HLA)-A2-restricted zinc transporter (ZnT)8186–194 and other islet epitopes elicit interferon-γ secretion by CD8+ T cells preferentially in type 1 diabetes (T1D) patients compared with controls. Here, we show that clonal ZnT8186–194-reactive CD8+ T cells express private T-cell receptors and display equivalent functional properties in T1D and healthy subjects. Ex-vivo analyses further revealed that CD8+ T cells reactive to ZnT8186–194 and other islet epitopes circulate at similar frequencies and exhibit a predominantly naïve phenotype in age-matched T1D and healthy donors. Higher frequencies of ZnT8186–194-reactive CD8+ T cells with a more antigen-experienced phenotype were detected in children vs. adults, irrespective of disease status. Moreover, some ZnT8186–194-reactive CD8+ T-cell clonotypes were found to cross-recognize a Bacteroides stercoris mimotope. While ZnT8 was poorly expressed in thymic medullary epithelial cells, variable thymic expressions levels of islet antigens did not modulate the peripheral frequency of their cognate CD8+ T cells. In contrast, ZnT8186–194-reactive cells were enriched in the pancreata of T1D donors vs. non-diabetic and type 2 diabetic controls. Thus, islet-reactive CD8+ T cells circulate in most individuals, but home to the pancreas preferentially in T1D patients. We conclude that the activation of this common islet-reactive T-cell repertoire and progression to T1D likely require defective peripheral immunoregulation and/or a pro-inflammatory islet microenvironment.

Loci in the major histocompatibility complex (MHC) on chromosome 6 and the insulin (INS) region on chromosome 11 have been implicated in susceptibility to insulin-dependent diabetes mellitus (IDDM) through candidate gene investigations, but they may account for less than 50% of genetic risk for the disease. Genome-wide linkage studies have led to localization of more than 10 susceptibility loci for insulin-dependent diabetes in the non-obese diabetic (NOD) mouse and the BB rat. Similar studies are now possible in humans through the development of dense genetic maps of highly informative microsatellite loci obtained using polymerase chain reaction analysis. We have applied microsatellite markers from recent Généthon maps, and other highly informative markers, in a genome-wide linkage study in IDDM. Here we report evidence for the localization of a previously undetected susceptibility locus for IDDM in the region of the FGF3 gene on chromosome 11q. Our results shows the potential of genome-wide linkage studies to detect susceptibility loci in IDDM and other multifactorial disorders.

Recent studies have demonstrated that a locus at 11p15.5 confers susceptibility to insulin dependent diabetes mellitus (IDDM). This locus has been shown to lie within a 19 kb region. We present a detailed sequence comparison of the predominant haplotypes found in this region in a population of French Caucasian IDDM patients and controls. Identification of polymorphisms both associated and unassociated with IDDM has allowed us to define further the region of association to 4.1 kb. Ten polymorphisms within this region are in strong linkage disequilibrium with each other and extend across the insulin gene locus and the variable number tandem repeat (VNTR) situated immediately 5' to the insulin gene. These represent a set of candidate disease polymorphisms one or more of which may account for the susceptibility to IDDM.

Clinical characteristics and prognosis of 80 patients (53 women and 27 men) with sporadic medullary thyroid carcinomas (MTC), less than 1 cm in size (micro-MTC), operated on between 1971 and 1996 are reported (73 total and 7 partial thyroidectomies). These patients, obtained from a national database of 899 patients with MTC, were compared with 357 cases of sporadic MTC greater than 1 cm and 149 subjects with familial MTC less than 1 cm (familial micro-MTC). Median age at surgery was 52.5 years, a distribution similar to larger sporadic MTC. Micro-MTC was identified due to elevated calcitonin (47.5%), clinically identified lymph node (10.0%), distant metastases (6.3%) or pathologic finding at surgery (36.2%). Diarrhea and/or flushing were observed in 6 patients including 4 with clinically identified lymph node. Among patients who had lymph node dissection at surgery (68.8%), lymph node involvement with tumor was observed in 30.9%, and was significantly more frequent in multifocal (7/11) than in unifocal micro-MTC (p < 0.03). All sporadic micro-MTC were unilateral. Survival rate was 93.9% +/- 4.4% (SE) at 10 years, greater than that observed in sporadic macro-MTC (p = 0.04). Normal postoperative basal calcitonin (CT) was obtained in 71.1% of micro-MTC patients versus 33.6% in sporadic macro-MTC (p < 0.01). Sporadic micro-MTC is much more frequent than expected, 15% of MTC in our series. Although specific survival rate and percentage of biological cure in micro-MTC are significantly better than for larger tumors, the frequency of lymph node involvement, however, justifies an aggressive surgical approach including total thyroidectomy and bilateral central lymph node dissection.

Summary.We studied the incidence and potential prognostic value of thyroid abnormalities after allogeneic bone marrow transplantation (BMT) without total body irradiation (TBI) conditioning. 77 consecutive patients who received a chemotherapy-alone-based conditioning regimen pretransplant were included. Free serum thyroxine (FT4), free serum triiodothyronine (FT3) and serum thyrotropin (TSH) levels were assayed before and 3 and 14 months after BMT. Patients were classified in three categories: normal thyroid profile if FT3 and FT4 were within the normal range and TSH was normal or low, peripheral thyroid insufficiency (PTI) if TSH was >4 mIU/l, or an 'euthyroid sick syndrome' (ETS) if FT3 and/or FT4 were low and TSH was normal or low. The incidence of thyroid dysfunction at 3 months was 57%, and 29% at 14 months. This was mostly due to the occurrence of ETS which was more frequent at 3 months (48%, 29/61) than at 14 months (19%, 9/48). Furthermore, at 3 months, survival was significantly lower in the ETS group (34 . 5%) than in the euthyroid group (96 . 2%), or in the PTI group (83 . 3%) (P < 0 . 0001). PTI was observed even in the absence of TBI in 11 patients (14%) and was equally distributed at 3 months (n ¼ 6) and 14 months (n ¼ 5).In conclusion, thyroid dysfunction is not a rare complication even without pretransplant TBI conditioning regimen. Hypothyroidism prevalence was 10%, and ETS, which was more frequently observed, displayed a dismal predictive value at 3 months.

The antigenic peptides processed by β-cells and presented through surface HLA class I molecules are poorly characterized. Each HLA variant (e.g., the most common being HLA-A2 and HLA-A3) carries some peptide-binding specificity. Hence, features that, despite these specificities, remain shared across variants may reveal factors favoring β-cell immunogenicity. Building on our previous description of the HLA-A2/A3 peptidome of β-cells, we analyzed the HLA-A3–restricted peptides targeted by circulating CD8+ T cells. Several peptides were recognized by CD8+ T cells within a narrow frequency (1–50/106), which was similar in donors with and without type 1 diabetes and harbored variable effector/memory fractions. These epitopes could be classified as conventional peptides or neoepitopes, generated either via peptide cis-splicing or mRNA splicing (e.g., secretogranin-5 [SCG5]–009). As reported for HLA-A2–restricted peptides, several epitopes originated from β-cell granule proteins (e.g., SCG3, SCG5, and urocortin-3). Similarly, H-2Kd–restricted CD8+ T cells recognizing the murine orthologs of SCG5, urocortin-3, and proconvertase-2 infiltrated the islets of NOD mice and transferred diabetes into NOD/scid recipients. The finding of granule proteins targeted in both humans and NOD mice supports their disease relevance and identifies the insulin granule as a rich source of epitopes, possibly reflecting its impaired processing in type 1 diabetes.