Ag recognition via the TCR is necessary for the expansion of specific T cells that then contribute to adaptive immunity as effector and memory cells. Because CD4+ and CD8+ T cells differ in terms of their priming APCs and MHC ligands we compared their requirements of Ag persistence during their expansion phase side by side. Proliferation and effector differentiation of TCR transgenic and polyclonal mouse T cells were thus analyzed after transient and continuous TCR signals. Following equally strong stimulation, CD4+ T cell proliferation depended on prolonged Ag presence, whereas CD8+ T cells were able to divide and differentiate into effector cells despite discontinued Ag presentation. CD4+ T cell proliferation was neither affected by Th lineage or memory differentiation nor blocked by coinhibitory signals or missing inflammatory stimuli. Continued CD8+ T cell proliferation was truly independent of self-peptide/MHC-derived signals. The subset divergence was also illustrated by surprisingly broad transcriptional differences supporting a stronger propensity of CD8+ T cells to programmed expansion. These T cell data indicate an intrinsic difference between CD4+ and CD8+ T cells regarding the processing of TCR signals for proliferation. We also found that the presentation of a MHC class IIrestricted peptide is more efficiently prolonged by dendritic cell activation in vivo than a class I bound one. In summary, our data demonstrate that CD4+ T cells require continuous stimulation for clonal expansion, whereas CD8+ T cells can divide following a much shorter TCR signal.
Differential kinetics of antigen dependency of CD4+ and CD8+ T cells.
Specimen part, Treatment
View SamplesIncreased levels of blood plasma urea were used as phenotypic parameter for establishing novel mouse models for kidney diseases on the genetic background of C3H inbred mice in the phenotype-driven Munich ENU mouse mutagenesis project. The phenotypically mutant line HST014 was established and further analyzed. The causative mutation was detected in the gene Kctd1 which leads to the amino acid exchange Kctd1I27N thereby affecting the functional BTB domain of the protein. This line is the first mouse model harbouring a Kctd1 mutation. Kctd1I27N homozygous mutant mice die perinatally. Standardized, systemic phenotypic analysis of heterozygous mutants was carried out in the German Mouse Clinic. Systematic morphological investigation of the external physical appearance found no mutation-specific differences. Main phenotypic changes were kidney dysfunction, minor cardiovascular and neurological alterations as well as low plasma corticosterone levels. Genome-wide RNA expression analysis at the age of 4 months revealed few regulated genes in brain and heart, and over 100 significantly regulated genes in kidneys of heterozygous mutants.
No associated publication
Age
View SamplesHuman velocardiofacial syndrom/DiGeorg (VCFS/DGS) syndrom is a complex developmental disease with various expression of a large number of phenotypes. Craniofacial, cardiac, behavioural and endocrinological phenotypes are cardinal symptoms liked to the 22Q11.2 deletion occuring in 1/4.000 births. Several genes located within the 1.5 to 3 Mb deletion resemble a number of phenotypes demonstrated in mouse models for these genes including the endothelin receptor A (Ednra) gene. This is the first report on gene dosage effects observed in a dominant mouse model carrying an EdnraY129F point-mutation. EdnraY129F/+ mice are viable despite a strong cardiac phenotype alike to Fallot's tetralogy concomitant with cardiofacial, otolaryngeal phenotypes and deafness.
No associated publication
Sex, Age, Specimen part
View SamplesLysosomal storage diseases are congenital lipid metabolism disorders, often accompaning by male infertility. Sms1, the enzyme, that generates sphingomyelin from ceramides seems to be involved in spermatogeneis and spermiogenesis. Therefore, testis but also muscle and brain of a mouse line carrying an insertional mutation in Sms1 were analysed.
No associated publication
Age, Specimen part
View SamplesPRDM family members encode for progeins functionally associated with the control of cell proliferation, differentiation as well as apoptosis action in cell and tissue-specific menner. As important factors in maintenance and differentiation of human and mouse ES cells several PRDM family members were identified. Prdm11 has and outsider position within the PRDM family due to the lack of zinc-finger domains. However, a zic-finger binding motive i present and likely assue the function of protein-protein interactionl. Prdm11 was described as a candidate for tumor suppresser. However, the function of this gene is still unknown. Our study give evidence a new functional association of Prdm11 in allergic disease and asthma.
No associated publication
Sex, Age, Treatment
View SamplesTetrahydrobiopterin (BH4) is an essential cofactor for several metabolic enzymes, including the aromatic amino acid hydroxylases, alkylglycerol mono-oxygenase and NO synthases. BH4 deficiency due to an autosomal recessive defect in its biosynthetic enzyme 6-pyruvoyltetrahydropterin synthase (PTPS, encoded by the PTS gene) leads to a variant form of hyperphenylalaninemia concomitant with severe deficiency of brain monoamine neurotransmitters. In contrast, augmentation of BH4 by pharmacological supplementation or stimulation of its biosynthesis is thought to correct eNOS dysfunction, to protect from (cardio) vascular disease and/or to prevent from abdominal obesity and development of the metabolic syndrome. We have previously reported that complete Pts knock-out (ko) mice die after birth (Elzaouk et al JBC 2003). Here we generated a murine Pts-knock-in (ki) allele expressing a PTPS-p.Arg15Cys mutant enzyme with low residual activity (12% of wild-type in vitro) and investigated heterozygous Pts-ko/wt, homozygous Pts-ki/ki and compound heterozygous Pts-ki/ko mutant mice. All mice were viable and, depending on the severity of the Pts alleles, exhibited up to 90% reduction of PTPS activity in liver and brain tissues concomitant with high neopterin, but neither an elevation of blood L-Phe, nor a decrease in brain monoamine neurotransmitters dopamine or serotonin. Upon a standard systemic and comprehensive phenotyping of Pts-ki/ki mice, we found alterations in energy metabolites with reduced body mass, higher fat content, lower lean mass, and increased blood glucose and cholesterol in mutant animals. Furthermore, heterozygous Pts-ko/wt and/or homozygous Pts-ki/ki mice exhibited increased body weight and elevated intra-abdominal fat tissue when fed with normal chow or high fat diet. We conclude that a reduced BH4-biosynthetic activity in mice leads to abnormal body fat distribution and abdominal obesity potentially through a mildly compromised eNOS function.
No associated publication
Sex, Age, Specimen part
View SamplesThe generation of optimal immune response requires combined activation of both T- and B-cells. Here, we demonstrate that the cancerous inhibitor of protein phosphatase 2A (CIP2A) is a novel factor that governs activation of both T- and B-cells in vivo. Upon ovalbumin challenge, CIP2A-deficient (CIP2AHOZ) mice show impaired immune response. Furthermore, CIP2AHOZ mice had impaired clearance of Listeria Monocytogenesis (L.m.) infection, combined with decreased numbers of CD8+ T-cells and IFN- secretion. In an ovalbumin model of allergic asthma, CIP2AHOZ B-cells were impaired in IgE and IgG secretion, despite of normal Th2 differentiation and unaffected numbers of inflammatory cells or cytokines in bronchoalveolar lavage. Importantly, the cell-autonomous effect of CIP2A deficiency for both T- and B-cell activation was confirmed by in vitro assays. During the T-cell activation CIP2A, was shown to promote expression of ETS-1, whereas in B-cells CIP2A loss resulted in inhibition of MYC-mediated gene expression. Together these results identify CIP2A as a novel cell-autonomous regulator governing both T- and B-cell activation in vivo. They also identify CIP2AHOZ as a novel murine model for investigation of impaired immune response and allergic asthma.
No associated publication
Sex, Age
View SamplesWe established and characterized a new recessive mutant mouse line kta41 with a point mutation in Scube3 at position 882. The mutant line was detected by screening for morphological abnormalities in the Munich ENU-mutagenesis program. The mutation was mapped by microsatellite markers to mouse chromosome 17, between markers D17MIT29 and D17MIT101. Candidate gene approaches failed due to the low recombination frequency and the high number of genes within the mapped interval. Whole genome sequencing approaches revealed a C to A transversion on position 882 in Scube3 that leads to a missense mutation in the protein (Asn294Lys). We did a broad phenotypic analysis of the mutant mouse line in the German Mouse Clinic (GMC), and followed up the found alterations by detailed phenotypic characterization. Scube3-kta41-/- mice show a series of phenotypic alterations, mainly in the skeleton, behavior and neurological abnormalities as well as changes in physiology, metabolism and immune status.
The First Scube3 Mutant Mouse Line with Pleiotropic Phenotypic Alterations.
Sex, Age
View SamplesSequences encoding DUF1220 protein domains show the most extreme human lineage-specific copy number increase of any coding region in the genome and have been linked to human brain evolution. In addition, DUF1220 copy number (dosage) has been implicated in influencing brain size within the human species, both in normal populations and in individuals associated with brain size pathologies (1q21-associated microcephaly and macrocephaly). More recently, increasing dosage of a subtype of DUF1220 has been linked with increasing severity of the primary symptoms of autism. Despite these intriguing associations, a function for these domains has not been described. As a first step in addressing this question we have developed the first transgenic model of DUF1220 function by removing the single DUF1220 domain (the ancestral form) encoded in the mouse genome. While resulting DUF1220-minus (KO) mice show no obvious anatomical peculiarities, they exhibit a significantly reduced fecundity (2= 19.1, df = 2, p = 7.0 x 10-5). Further extensive phenotypic analyses suggest that DUF1220 KO mice are hyperactive (p < 0.05) relative to wild type litter mates. The linking of DUF1220 loss to a hyperactive phenotype is consistent with separate findings in which DUF1220 over expression results in a down-regulation of mitochondrial function, suggesting a possible role in the prolongation of developmental processes (neoteny) that is most pronounced in the human lineage.
No associated publication
Sex, Age
View SamplesConsecutive caerulein injections induce an acute pancreatitis in mice. Here, we recorded gene expression levels at different stages of pancreatic regeneration in wild-type mice as well as
No associated publication
Specimen part, Time
View Samples