Molecular cloning of the cDNA encoding pp36, a tyrosine-phosphorylated adaptor protein selectively expressed by T cells and natural killer cells.

Activation of T and natural killer (NK) cells leads to the tyrosine phosphorylation of pp36 and to its association with several signaling molecules, including phospholipase Cgamma-1 and Grb2. Microsequencing of peptides derived from purified rat pp36 protein led to the cloning, in rat and man, of cDNA encoding a T- and NK cell-specific protein with several putative Src homology 2 domain-binding motifs. A rabbit antiserum directed against a peptide sequence from the cloned rat molecule recognized tyrosine phosphorylated pp36 from pervanadate-treated rat thymocytes. When expressed in 293T human fibroblast cells and tyrosine-phosphorylated, pp36 associated with phospholipase Cgamma-1 and Grb2. Studies with GST-Grb2 fusion proteins demonstrated that the association was specific for the Src homology 2 domain of Grb-2. Molecular cloning of the gene encoding pp36 should facilitate studies examining the role of this adaptor protein in proximal signaling events during T and NK cell activation

From ‘Hellstrom Paradox–to anti-adenosinergic cancer immunotherapy

Cancer therapy by endogenous or adoptively transferred anti-tumor T cells is considered complementary to conventional cancer treatment by surgery, radiotherapy or chemotherapy. However, the scope of promising immunotherapeutic protocols is currently limited because tumors can create a ‘hostile–immunosuppressive microenvironment that prevents their destruction by anti-tumor T cells. There is a possibility to develop better and more effective immunotherapies by inactivating mechanisms that inhibit anti-tumor T cells in the tumor microenvironment and thereby protect cancerous tissues from immune damage. This may be now possible because of the recent demonstration that genetic deletion of immunosuppressive A2A and A2B adenosine receptors (A2AR and A2BR) or their pharmacological inactivation can prevent the inhibition of anti-tumor T cells by the hypoxic tumor microenvironment and as a result facilitate full tumor rejection [Ohta A, Gorelik E, Prasad SJ et al (2006) Proc Natl Acad Sci USA 103(35):13132–3137]. This approach is based on in vivo genetic evidence that A2AR play a critical role in the protection of normal tissues from overactive immune cells in acutely inflamed and hypoxic areas. The observations of much improved T-cell-mediated rejection of tumors in mice with inactivated A2AR strongly suggest that A2AR also protects hypoxic cancerous tissues and that A2AR should be inactivated in order to improve tumor rejection by anti-tumor T cells

Effects of Transport Inhibitors on the Cellular Uptake of Carboxylated Polystyrene Nanoparticles in Different Cell Lines

Nanotechnology is expected to play a vital role in the rapidly developing field of nanomedicine, creating innovative solutions and therapies for currently untreatable diseases, and providing new tools for various biomedical applications, such as drug delivery and gene therapy. In order to optimize the efficacy of nanoparticle (NP) delivery to cells, it is necessary to understand the mechanisms by which NPs are internalized by cells, as this will likely determine their ultimate sub-cellular fate and localisation. Here we have used pharmacological inhibitors of some of the major endocytic pathways to investigate nanoparticle uptake mechanisms in a range of representative human cell lines, including HeLa (cervical cancer), A549 (lung carcinoma) and 1321N1 (brain astrocytoma). Chlorpromazine and genistein were used to inhibit clathrin and caveolin mediated endocytosis, respectively. Cytochalasin A and nocodazole were used to inhibit, respectively, the polymerisation of actin and microtubule cytoskeleton. Uptake experiments were performed systematically across the different cell lines, using carboxylated polystyrene NPs of 40 nm and 200 nm diameters, as model NPs of sizes comparable to typical endocytic cargoes. The results clearly indicated that, in all cases and cell types, NPs entered cells via active energy dependent processes. NP uptake in HeLa and 1321N1 cells was strongly affected by actin depolymerisation, while A549 cells showed a stronger inhibition of NP uptake (in comparison to the other cell types) after microtubule disruption and treatment with genistein. A strong reduction of NP uptake was observed after chlorpromazine treatment only in the case of 1321N1 cells. These outcomes suggested that the same NP might exploit different uptake mechanisms to enter different cell types

European consensus statement on diagnosis and treatment of adult ADHD: The European Network Adult ADHD.

BACKGROUND: Attention deficit hyperactivity disorder (ADHD) is among the most common psychiatric disorders of childhood that persists into adulthood in the majority of cases. The evidence on persistence poses several difficulties for adult psychiatry considering the lack of expertise for diagnostic assessment, limited treatment options and patient facilities across Europe. METHODS: The European Network Adult ADHD, founded in 2003, aims to increase awareness of this disorder and improve knowledge and patient care for adults with ADHD across Europe. This Consensus Statement is one of the actions taken by the European Network Adult ADHD in order to support the clinician with research evidence and clinical experience from 18 European countries in which ADHD in adults is recognised and treated. RESULTS: Besides information on the genetics and neurobiology of ADHD, three major questions are addressed in this statement: (1) What is the clinical picture of ADHD in adults? (2) How can ADHD in adults be properly diagnosed? (3) How should ADHD in adults be effectively treated? CONCLUSIONS: ADHD often presents as an impairing lifelong condition in adults, yet it is currently underdiagnosed and treated in many European countries, leading to ineffective treatment and higher costs of illness. Expertise in diagnostic assessment and treatment of ADHD in adults must increase in psychiatry. Instruments for screening and diagnosis of ADHD in adults are available and appropriate treatments exist, although more research is needed in this age group