Modulation of the phagosome proteome by interferon-gamma.

Macrophages are immune cells that function in the clearance of infectious particles. This process involves the engulfment of microbes into phagosomes where these particles are lysed and degraded. In the current study, we used a large scale quantitative proteomics approach to analyze the changes in protein abundance induced on phagosomes by interferon-gamma (IFN-gamma), an inflammatory cytokine that activates macrophages.

Protein identification and Peptide expression resolver: harmonizing protein identification with protein expression data.

Proteomic discovery platforms generate both peptide expression information and protein identification information. Peptide expression data are used to determine which peptides are differentially expressed between study cohorts, and then these peptides are targeted for protein identification. In this paper, we demonstrate that peptide expression information is also a powerful tool for enhancing confidence in protein identification results.

An evaluation of multidimensional fingerprinting in the context of clinical proteomics.

Multidimensional fingerprinting (MDF) utilizes measurable peptide characteristics to identify proteins. In this study, 3-D fingerprinting, namely, parent protein molecular weight, peptide mass, and peptide retention time on RPLC, is used to identify 331 differentially expressed proteins between normal and human colon cancer plasma membrane samples. A false discovery rate (FDR) procedure is introduced to evaluate the performance of MDF on the colon cancer dataset.

High-throughput technology: green fluorescent protein to monitor cell death.

Reliable assessment of cell death is now pivotal to many research programs aiming at generating new antitumor compounds or at screening cDNA libraries to identify genes with pro- or antiapoptotic functions. Such approaches need to rely on reproducible, easy handling, and rapid microplate-based cytotoxicity assays that are amenable to high-throughput screening technologies. We describe here a method for the direct measurement of cell death, based on the detection of a decrease in fluorescence observed following death induction in cells stably expressing enhanced green fluorescent protein (EGFP).

Evaluation of risk factors associated with endometriosis.

Objective: To investigate the association between several factors such as demographics, personal habits, reproductive factors, menstrual characteristics, contraception, and clinical profile and the probability of having endometriosis.

Setting: Ten clinical institutions in the Montreal area.

Patient(s): A total of 2777 subjects who underwent surgery for diagnostic laparoscopy, tubal ligation, or hysterectomy between January 1998 and July 2002.

Quantitative assessment of human endometriotic tissue maintenance and regression in a noninvasive mouse model of endometriosis.

Endometriosis is a prevalent disease characterized by the estrogen-dependent ectopic growth of endometrial tissue. Most of the current medical therapies consist in inducing a hypoestrogenic state in patients, but these treatments are associated with severe side effects and high recurrence rates. The development of convenient and reliable endometriosis animal models would be instrumental to accelerate the emergence of new therapeutic alternatives.

Concentrations of alpha-fetoprotein, insulin-like growth factor binding protein-3, c-erbB-2, and epidermal growth factor in serum of patients with endometriosis.

Objective: Endometriosis, although it is a benign disorder, shares many similarities with cancer. There is increasing levels of evidence suggesting that some circulating factors involved in gynecologic cancers, such as alpha-fetoprotein (AFP), insulin-like growth factor binding protein-3 (IGFBP-3), c-erbB-2 (HER-2/neu), and epidermal growth factor (EGF), could also play a role in endometriosis. Hence, the present study was aimed at evaluating whether the levels of these molecules are modulated in the serum of patients with endometriosis.

A cell death pathway induced by antibody-mediated cross-linking of CD45 on lymphocytes.

The protein tyrosine phosphatase CD45 is a highly expressed glycoprotein present on all nucleated cells of hematopoietic origin. To date, all the functions attributed to CD45 are inherently coupled to its phosphatase activity. For instance, the regulation of lymphocyte antigen receptor signaling is mediated through the dephosphorylation, and hence activation, of Src-family kinases by CD45.

Serum concentrations of insulin-like growth factor-1, soluble tumor necrosis factor receptor-1 and angiogenin in endometriosis patients.

Problem: Many soluble factors contributing to the pathophysiology of endometriosis are found at abnormal levels in patients suffering from the disease. We postulated that levels of these factors could also be altered in the serum of patients. We compared levels of insulin-like growth factor-1 (IGF-1), soluble form of tumor necrosis factor-alpha (TNF-alpha) receptor-1 (sTNFR-1) and angiogenin in the serum of patients with endometriosis and controls.

Development of a nonsurgical diagnostic tool for endometriosis based on the detection of endometrial leukocyte subsets and serum CA-125 levels.

Objective: To determine whether the proportion of several leukocyte subsets is modulated in the endometrium of patients with endometriosis and, if yes, whether it can be used for diagnostic purposes.

Design: Case-control study.

Setting: Eight clinical institutions of the Montreal area.

An improved mouse model for endometriosis allows noninvasive assessment of lesion implantation and development.

Objective: To test whether fragments of human endometrium transduced with the green fluorescent protein (GFP) cDNA and transplanted into nude mice can be noninvasively visualized.

Design: A murine experimental model for human endometriosis.

Setting: A biotechnology company.

Blood leukocyte subsets are modulated in patients with endometriosis.

Objective: To determine whether blood leukocyte populations could be modulated in endometriosis.

Design: Case-control study.

Setting: Eight clinical institutions of the Montreal area.

Mek2 is dispensable for mouse growth and development.

MEK is a dual-specificity kinase that activates the extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase upon agonist binding to receptors. The ERK/MAP kinase cascade is involved in cell fate determination in many organisms. In mammals, this pathway is proposed to regulate cell growth and differentiation.

Low activation threshold as a mechanism for ligand-independent signaling in pre-T cells.

Pre-TCR complexes are thought to signal in a ligand-independent manner because they are constitutively targeted to lipid rafts. We report that ligand-independent signaling is not a unique capability of the pre-TCR complex. Indeed, the TCR alpha subunit restores development of pT alpha-deficient thymocytes to the CD4(+)CD8(+) stage even in the absence of conventional MHC class I and class II ligands.

Weak agonist self-peptides promote selection and tuning of virus-specific T cells.

Recent progress has begun to define the interactions and signaling pathways that are triggered during positive selection. To identify and further examine self-peptides that can mediate positive selection, we searched a protein-database to find peptides that have minimal homology with the viral peptide (p33) that activates a defined P14 transgenic TCR. We identified four peptides that could bind the restriction element H-2D(b) and induce proliferation of P14 transgenic splenocytes at high concentration.

Monoglycerides induce apoptosis in human leukemic cells while sparing normal peripheral blood mononuclear cells.

A major drawback of the current antineoplastic treatments is their lack of specificity toward cancer cells, because they are most often cytotoxic to normal cells, thus creating related side effects. Hence, the identification of new apoptosis-inducing agents, specifically targeting malignant cells while sparing their normal counterparts, is of crucial interest. We show here that monoglycerides, a family of lipids consisting of a single fatty acid attached to a glycerol backbone, induce cell death in several human leukemic cell lines.

Cellular specificity related to monoglyceride-induced cell death.

We have recently observed that monoglycerides (MGs), a family of lipids consisting of a single fatty acid moiety attached to a glycerol backbone, induce rapid dose-dependent apoptosis in murine thymocytes. In this work, we evaluated the sensitivity of various normal and malignant immune and non-immune cells to MGs. We demonstrate that the propensity to MG-induced death displayed by both T and B lymphocytes is clearly modulated according to their differentiation and activation status.

Apoptosis mediated through CD45 is independent of its phosphatase activity and association with leukocyte phosphatase-associated phosphoprotein.

Besides the well-recognized role of CD45 as a major player in TCR signaling, we and others have demonstrated that cross-linking of CD45 with mAbs can induce cell death in T lymphocytes. To investigate the role of CD45 phosphatase activity in apoptosis induction, we expressed either wild-type or phosphatase-dead CD45 molecules in a CD45-deficient BW5147 T cell line. We show here that the phosphatase activity of CD45 was not required for apoptosis triggering after cross-linking of the molecule.