Marie Louise Max Andersen

Self‐Peptides with Intermediate Capacity to Bind and Stabilize MHC Class I Molecules may be Immunogenic

Thirty self‐peptides were selected on the basis of their predicted binding to H‐2b molecules. The binding of peptides was ascertained experimentally by biochemical (KD measurements) and cellular [major histocompatibility complex class I (MHC‐I) stabilization] assays. A weak, but significant, correlation between KD measurements and MHC‐I stabilization was observed. Mice (n = 99) were immunized with individual peptides. Twenty‐eight peptides were found to induce peptide‐specific cytotoxic activity, and a total of 84 mice developed significant cytotoxic T lymphocyte (CTL) responses after immunization. Only one of the 21 mice immunized with high‐affinity peptides developed a peptide‐specific CTL response of 29 lytic units per 106 splenocytes, whereas 11 of the 42 mice immunized with intermediate‐affinity peptides developed peptide‐specific CTL responses at this level (P < 0.05). These observations suggest the absence of tolerance towards most MHC‐I‐restricted self‐peptides and that strong antiself immunity can be generated preferentially towards self‐peptides with an intermediate affinity for MHC‐I. These data should be considered in the design of tumour vaccines based on MHC‐I‐binding self‐peptides.

Facial image identification using Photomodeler.

We present the results of a preliminary study on the use of 3-D software (Photomodeler) for identification purposes. Perpetrators may be photographed or filmed by surveillance systems. The police may wish to have these images compared to photographs of suspects. The surveillance imagery will often consist of many images of the same person taken from different angles. We wanted to see if it was possible to combine such a suite of images in useful 3-D renderings of facial proportions.Fifteen male adults were photographed from four different angles. Based on these photographs, a 3-D wireframe model was produced by Photomodeler. The wireframe models were then rotated to full lateral and frontal views, and compared to like sets of photographs of the subjects. In blind trials, 9/15 of the wireframe models were assigned to the correct sets of photographs. In five/15 cases, the wireframe models were assigned to several sets, including the correct set. Only in one case was a wireframe model not assigned to a correct set of photographs at all.

Tumor–associated antigens identified by mRNA expression profiling as tumor rejection epitopes

Thirteen H-2b-binding peptides derived from six potentially overexpressed proteins in p53-/- thymoma (SM7) cells were studied for immunogenecity and vaccine-induced prevention of tumor growth in mice inoculated with SM7 tumor cells. Six of the peptides generated specific CTL responses after immunization, but only two of these peptides (RAD23–31 and RAD24–31) were capable of generating a weak vaccination-induced protection against adoptive tumor growth. SM7 inoculated mice treated with a blocking antibody against the inhibitory T cell signal transducing molecule CTLA4 appeared to delay tumor take, suggesting that SM7 thymoma cells are recognized by the adaptive immune system of the host. However, prophylactic vaccination with RAD23–31 and RAD24–31 peptides combined with anti-CTLA4 Ab treatment and did not improve tumor resistance. Our data would indicate that vaccination with immunogenic peptides derived from potentially overexpressed tumor proteins, as identified by mRNA expression profiling of p53-/- thymoma cells, at best results in a weak tumor protection thus questioning this way of detection of new tumor rejection epitopes.

The PTPN22 C1858T gene variant is associated with proinsulin in new-onset type 1 diabetes.

BackgroundThe protein tyrosine phosphatase nonreceptor type 2 (PTPN22) has been established as a type 1 diabetes susceptibility gene. A recent study found the C1858T variant of this gene to be associated with lower residual fasting C-peptide levels and poorer glycemic control in patients with type 1 diabetes. We investigated the association of the C1858T variant with residual beta-cell function (as assessed by stimulated C-peptide, proinsulin and insulin dose-adjusted HbA1c), glycemic control, daily insulin requirements, diabetic ketoacidosis (DKA) and diabetes-related autoantibodies (IA-2A, GADA, ICA, ZnT8Ab) in children during the first year after diagnosis of type 1 diabetes.MethodsThe C1858T variant was genotyped in an international cohort of children (n = 257 patients) with newly diagnosed type 1 diabetes during 12 months after onset. We investigated the association of this variant with liquid-meal stimulated beta-cell function (proinsulin and C-peptide) and antibody status 1, 6 and 12 months after onset. In addition HbA1c and daily insulin requirements were determined 1, 3, 6, 9 and 12 months after diagnosis. DKA was defined at disease onset.ResultsA repeated measurement model of all time points showed the stimulated proinsulin level is significantly higher (22%, p = 0.03) for the T allele carriers the first year after onset. We also found a significant positive association between proinsulin and IA levels (est.: 1.12, p = 0.002), which did not influence the association between PTPN22 and proinsulin (est.: 1.28, p = 0.03).ConclusionsThe T allele of the C1858T variant is positively associated with proinsulin levels during the first 12 months in newly diagnosed type 1 diabetes children.

Partial Remission Definition: Validation based on the insulin dose-adjusted HbA1c (IDAA1C) in 129 Danish Children with New-Onset Type 1 Diabetes †

To validate the partial remission (PR) definition based on insulin dose‐adjusted HbA1c (IDAA1c).

Association between autoantibodies to the Arginine variant of the Zinc transporter 8 (ZnT8) and stimulated C-peptide levels in Danish children and adolescents with newly diagnosed type 1 diabetes

The zinc transporter 8 (ZnT8) was recently identified as a common autoantigen in type 1 diabetes (T1D) and inclusion of ZnT8 autoantibodies (ZnT8Ab) was found to increase the diagnostic specificity of T1D.

Proinsulin, GLP-1, and glucagon are associated with partial remission in children and adolescents with newly diagnosed type 1 diabetes

Kaas A, Max Andersen ML, Fredheim S, Hougaard P, Buschard K, Petersen JS, de Beaufort C, Robertson KJ, Hansen L, Mortensen HB, Nielsen LB, On behalf of The Hvidoere Study Group on childhood diabetes. Proinsulin, GLP‐1, and glucagon are associated with partial remission in children and adolescents with newly diagnosed type 1 diabetes.

Disease progression and search for monogenic diabetes among children with new onset type 1 diabetes negative for ICA, GAD- and IA-2 Antibodies.

BackgroundTo investigate disease progression the first 12 months after diagnosis in children with type 1 diabetes negative (AAB negative) for pancreatic autoantibodies [islet cell autoantibodies(ICA), glutamic acid decarboxylase antibodies (GADA) and insulinoma-associated antigen-2 antibodies (IA-2A)]. Furthermore the study aimed at determining whether mutations in KCNJ11, ABCC8, HNF1A, HNF4A or INS are common in AAB negative diabetes.Materials and methodsIn 261 newly diagnosed children with type 1 diabetes, we measured residual β-cell function, ICA, GADA, and IA-2A at 1, 6 and 12 months after diagnosis. The genes KCNJ11, ABCC8, HNF1A, HNF4A and INS were sequenced in subjects AAB negative at diagnosis. We expressed recombinant K-ATP channels in Xenopus oocytes to analyse the functional effects of an ABCC8 mutation.ResultsTwenty-four patients (9.1%) tested AAB negative after one month. Patients, who were AAB-negative throughout the 12-month period, had higher residual β-cell function (P = 0.002), lower blood glucose (P = 0.004), received less insulin (P = 0.05) and had lower HbA1c (P = 0.02) 12 months after diagnosis. One patient had a heterozygous mutation leading to the substitution of arginine at residue 1530 of SUR1 (ABCC8) by cysteine. Functional analyses of recombinant K-ATP channels showed that R1530C markedly reduced the sensitivity of the K-ATP channel to inhibition by MgATP. Morover, the channel was highly sensitive to sulphonylureas. However, there was no effect of sulfonylurea treatment after four weeks on 1.0-1.2 mg/kg/24 h glibenclamide.ConclusionGAD, IA-2A, and ICA negative children with new onset type 1 diabetes have slower disease progression as assessed by residual beta-cell function and improved glycemic control 12 months after diagnosis. One out of 24 had a mutation in ABCC8, suggesting that screening of ABCC8 should be considered in patients with AAB negative type 1 diabetes.

Genetic Risk Score Modelling for Disease Progression in New-Onset Type 1 Diabetes Patients: Increased Genetic Load of Islet-Expressed and Cytokine-Regulated Candidate Genes Predicts Poorer Glycemic Control

Genome-wide association studies (GWAS) have identified over 40 type 1 diabetes risk loci. The clinical impact of these loci on β-cell function during disease progression is unknown. We aimed at testing whether a genetic risk score could predict glycemic control and residual β-cell function in type 1 diabetes (T1D). As gene expression may represent an intermediate phenotype between genetic variation and disease, we hypothesized that genes within T1D loci which are expressed in islets and transcriptionally regulated by proinflammatory cytokines would be the best predictors of disease progression. Two-thirds of 46 GWAS candidate genes examined were expressed in human islets, and 11 of these significantly changed expression levels following exposure to proinflammatory cytokines (IL-1β + IFNγ + TNFα) for 48 h. Using the GWAS single nucleotide polymorphisms (SNPs) from each locus, we constructed a genetic risk score based on the cumulative number of risk alleles carried in children with newly diagnosed T1D. With each additional risk allele carried, HbA1c levels increased significantly within first year after diagnosis. Network and gene ontology (GO) analyses revealed that several of the 11 candidate genes have overlapping biological functions and interact in a common network. Our results may help predict disease progression in newly diagnosed children with T1D which can be exploited for optimizing treatment.

Disease progression among 446 children with newly diagnosed type 1 diabetes located in Scandinavia, Europe, and North America during the last 27 yr

To clarify whether the rate of decline in stimulated C‐peptide (SCP) from 2 to 15 months after diagnosis has changed over an interval of 27 yr.