Identification of a MHC I-restricted epitope of DsRed in C57BL/6 mice.

Fluorescent proteins can be used to visualize cells and their constituents by various imaging techniques. Adoptive transfer of T cells from C57Bl/6 (B6) mice that expressed DsRed.T3 under the actin promoter lead to frequent rejection of transferred cells.

Strain-dependent differences in bone development, myeloid hyperplasia, morbidity and mortality in ptpn2-deficient mice.

Single nucleotide polymorphisms in the gene encoding the protein tyrosine phosphatase TCPTP (encoded by PTPN2) have been linked with the development of autoimmunity. Here we have used Cre/LoxP recombination to generate Ptpn2(ex2-/ex2-) mice with a global deficiency in TCPTP on a C57BL/6 background and compared the phenotype of these mice to Ptpn2(-/-) mice (BALB/c-129SJ) generated previously by homologous recombination and backcrossed onto the BALB/c background. Ptpn2(ex2-/ex2-) mice exhibited growth retardation and a median survival of 32 days, as compared to 21 days for Ptpn2(-/-) (BALB/c) mice, but the overt signs of morbidity (hunched posture, piloerection, decreased mobility and diarrhoea) evident in Ptpn2(-/-) (BALB/c) mice were not detected in Ptpn2(ex2-/ex2-) mice.

Maintenance of T cell function in the face of chronic antigen stimulation and repeated reactivation for a latent virus infection.

Persisting infections are often associated with chronic T cell activation. For certain pathogens, this can lead to T cell exhaustion and survival of what is otherwise a cleared infection. In contrast, for herpesviruses, T cells never eliminate infection once it is established.

T cell protein tyrosine phosphatase attenuates T cell signaling to maintain tolerance in mice.

Many autoimmune diseases exhibit familial aggregation, indicating that they have genetic determinants. Single nucleotide polymorphisms in PTPN2, which encodes T cell protein tyrosine phosphatase (TCPTP), have been linked with the development of several autoimmune diseases, including type 1 diabetes and Crohn's disease. In this study, we have identified TCPTP as a key negative regulator of TCR signaling, which might explain the association of PTPN2 SNPs with autoimmune disease.

Endoscopic tests for the diagnosis of Helicobacter pylori infection in children: Validation of rapid urease test.

Background: Rapid urease test (CLO-test) is an inexpensive and quick method for diagnosis of Helicobacter pylori infection with controversial results in children. We evaluated the performance of CLO-test in relation to endoscopic and histological findings in children with H. pylori infection.

Selective regulation of tumor necrosis factor-induced Erk signaling by Src family kinases and the T cell protein tyrosine phosphatase.

The proinflammatory cytokine tumor necrosis factor (TNF) modulates cellular responses through the mitogen-activated protein kinase (MAPK) and nuclear factor-kappaB (NF-kappaB) signaling pathways, but the molecular mechanisms underlying MAPK activation are unknown. T cell protein tyrosine phosphatase (TCPTP) is essential for hematopoietic development and negatively regulates inflammatory responses. Using TCPTP-deficient fibroblasts, we show here that TCPTP regulates TNF-induced MAPK but not NF-kappaB signaling.

Mammalian GRIP domain proteins differ in their membrane binding properties and are recruited to distinct domains of the TGN.

The four mammalian golgins, p230/golgin-245, golgin-97, GCC88 and GCC185 are targeted to trans-Golgi network (TGN) membranes by their C-terminal GRIP domain in a G-protein-dependent process. The Arf-like GTPase, Arl1, has been shown to mediate TGN recruitment of p230/golgin245 and golgin-97 by interaction with their GRIP domains; however, it is not known whether all the TGN golgins bind to Arl1 and whether they are all recruited to the same or different TGN domains. Here we demonstrate differences in membrane binding properties and TGN domain recruitment of the mammalian GRIP domain proteins.

Intracellular sorting and transport of proteins.

The secretory and endocytic pathways of eukaryotic organelles consist of multiple compartments, each with a unique set of proteins and lipids. Specific transport mechanisms are required to direct molecules to defined locations and to ensure that the identity, and hence function, of individual compartments are maintained. The localisation of proteins to specific membranes is complex and involves multiple interactions.