A radiographic, morphologic, biochemical and molecular analysis of a case of achondrogenesis type II resulting from substitution for a glycine residue (Gly691->Arg) in the type II collagen trimer

The type II collagenopathies form a continuous spectrum of clinicalseverity, ranging from lethal achond-rogenesis type II and hypochondrogenesis,through spondyloeplphyseal dysplasla, spondyloeplmetaphysealdysplasia and Kniest dysplasia to the Stickler syndrome andfamllial precocious osteoarthropathy at the mildest end of thespectrum. We have carried out a radiographic, morphologic, biochemicaland molecular study In a case of achondrogenesis type II. Electronmicrographs showed inclusion bodies of dilated rough endoplasmicreticulum in the chondrocytes and the presence of sparse collagentibers in the cartilage matrix. Protein analysis of collagenfrom cartilage indicated posttranslational overmodlficationof the major cyanogen bromide peptides, and suggested a mutationnear the carboxyl terminus of the type II collagen molecule.Analysis at the DNA level demonstrated that the phenotype wasproduced by a single base change (G     

IGRP and insulin vaccination induce CD8+ T cell‐mediated autoimmune diabetes in the RIP‐CD80GP mouse

Autoimmune diabetes is characterized by autoantigen‐specific T cell‐mediated destruction of pancreatic islet beta cells, and CD8⁺ T cells are key players during this process. We assessed whether the bitransgenic RIP‐CD80 x RIP‐LCMV‐GP (RIP‐CD80GP) mice may be a versatile antigen‐specific model of inducible CD8⁺ T cell‐mediated autoimmune diabetes. Antigen‐encoding DNA, peptide‐loaded dendritic cells and antigen plus incomplete Freund's adjuvant were used for vaccination. Of 14 pancreatic proteins tested by DNA vaccination, murine pre‐proinsulin 2 (100% of mice; median time after vaccination, 60 days) and islet‐specific glucose‐6‐phosphatase catalytic subunit‐related protein (IGRP) (77%, 58 days) could induce diabetes. Vaccination with DNA encoding for zinc transporter 8, Ia‐2, Ia‐2β, glutamic acid decarboxylase 67 (Gad67), chromogranin A, insulinoma amyloid polypeptide and homeobox protein Nkx‐2.2 induced diabetes development in 25–33% of mice. Vaccination with DNA encoding for Gad65, secretogranin 5, pancreas/duodenum homeobox protein 1 (Pdx1), carboxyl ester lipase, glucagon and control hepatitis B surface antigen (HBsAg) induced diabetes in <20% of mice. Diabetes induction efficiency could be increased by DNA vaccination with a vector encoding a ubiquitin–antigen fusion construct. Diabetic mice had florid T cell islet infiltration. CD8⁺ T cell targets of IGRP were identified with a peptide library‐based enzyme‐linked immunospot assay, and diabetes could also be induced by vaccination with major histocompatibility complex (MHC) class I‐restricted IGRP peptides loaded on mature dendritic cells. Vaccination with antigen plus incomplete Freund's adjuvant, which can prevent diabetes in other models, led to rapid diabetes development in the RIP‐CD80GP mouse. We conclude that RIP‐CD80GP mice are a versatile model of antigen specific autoimmune diabetes and may complement existing mouse models of autoimmune diabetes for evaluating CD8⁺ T cell‐targeted prevention strategies.