Peptidase inhibitor 16 identifies a human regulatory T-cell subset with reduced FOXP3 expression over the first year of recent onset type 1 diabetes.

CD4 T-cell subsets play a major role in the host response to infection, and a healthy immune system requires a fine balance between reactivity and tolerance. This balance is in part maintained by regulatory T cells (Treg), which promote tolerance, and loss of immune tolerance contributes to autoimmunity. As the T cells which drive immunity are diverse, identifying and understanding how these subsets function requires specific biomarkers.

CD Nomenclature 2015: Human Leukocyte Differentiation Antigen Workshops as a Driving Force in Immunology.

CD (cluster of differentiation) Ags are cell surface molecules expressed on leukocytes and other cells relevant for the immune system. CD nomenclature has been universally adopted by the scientific community and is officially approved by the International Union of Immunological Societies and sanctioned by the World Health Organization. It provides a unified designation system for mAbs, as well as for the cell surface molecules that they recognize.

Immune derived opioidergic inhibition of viscerosensory afferents is decreased in Irritable Bowel Syndrome patients.

Alterations in the neuro-immune axis contribute toward viscerosensory nerve sensitivity and symptoms in Irritable Bowel Syndrome (IBS). Inhibitory factors secreted from immune cells inhibit colo-rectal afferents in health, and loss of this inhibition may lead to hypersensitivity and symptoms. We aimed to determine the immune cell type(s) responsible for opioid secretion in humans and whether this is altered in patients with IBS.

Accumulation of effector memory CD8+ T cells in nasal polyps.

Background: T lymphocytes are prevalent in sinus mucosa and are implicated in chronic rhinosinusitis (CRS) pathogenesis. However, the major T-cell subpopulations, helper (CD4+) and cytotoxic (CD8+), have not been adequately examined in CRS. This study was designed to characterize human sinus mucosa and peripheral blood (PB) CD4+ and CD8+ T cells and their level of differentiation in CRS with nasal polyps (NPs), CRS without NPs, and control patients.

Immune activation in irritable bowel syndrome: can neuroimmune interactions explain symptoms?

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal (GI) tract characterized by pain or discomfort from the lower abdominal region, which is associated with altered bowel habit. Despite its prevalence, there is currently a lack of effective treatment options for patients. IBS has long been considered as a neurological condition resulting from alterations in the brain gut axis, but immunological alterations are increasingly reported in IBS patients, consistent with the hypothesis that there is a chronic, but low-grade, immune activation.

Cytoskeletal protein Flightless (Flii) is elevated in chronic and acute human wounds and wound fluid: neutralizing its activity in chronic but not acute wound fluid improves cellular proliferation.

Chronic non-healing wounds form a medical need which will expand as the population ages and the obesity epidemic grows. Whilst the complex mechanisms underlying wound repair are not fully understood, remodelling of the actin cytoskeleton plays a critical role. Elevated expression of the actin cytoskeletal protein Flightless I (Flii) is known to impair wound outcomes.

Comparison of blood and synovial fluid th17 and novel peptidase inhibitor 16 Treg cell subsets in juvenile idiopathic arthritis.

Objective: Early recognition and treatment of juvenile idiopathic arthritis (JIA) can prevent joint damage and minimize side effects of medication. The balance between proinflammatory and antiinflammatory mechanisms is known to be important in JIA, and we therefore investigated T cell subsets including Th cells, autoaggressive Th17 cells, and regulatory T cells (Treg), including a novel Treg subset in peripheral blood (PB) and synovial fluid (SF) of patients with JIA.

Methods: Fifty children with JIA were enrolled in our study.

PI16 is expressed by a subset of human memory Treg with enhanced migration to CCL17 and CCL20.

The peptidase inhibitor PI16 was shown previously by microarray analysis to be over-expressed by CD4-positive/CD25-positive Treg compared with CD4-positive/CD25-negative Th cells. Using a monoclonal antibody to the human PI16 protein, we found that PI16-positive Treg have a memory (CD45RO-positive) phenotype and express higher levels of FOXP3 than PI16-negative Treg. PI16-positive Treg are functional in suppressor assays in vitro with potency similar to PI16-negative Treg.

Elevated serum cytokine levels using cytometric bead arrays predict culture-positive infections in childhood oncology patients with febrile neutropenia.

Neutropenic patients with bacteraemia need prolonged intravenous antibiotic treatment. Using cytometric bead array technology, we show in children with febrile neutropenia that bacteraemia is associated with an elevation of at least 1 of 3 plasma cytokines plus C-reactive protein. The combination of interleukin (IL)-8, IL-6, IL-10, and C-reactive protein values above operator-defined cutoff levels identified 15 of 16 episodes of bacteraemia, making this a potentially useful technique in identifying high-risk patients who should not be discharged early from hospital.

Reticulin fibres anchor leukaemic blasts in the marrow of patients with acute lymphoblastic leukaemia.

Reticulin fibrosis has been recognized in childhood ALL at diagnosis as part of the altered stromal structure in the bone marrow (BM). Increased fibre density is correlated with a higher concentration of leukaemia cells in the BM and lower numbers of blasts in peripheral blood. We hypothesize that these fibres anchor the leukaemia cells within the BM in close proximity to BM stromal cells (BMSC).

Expression of Toll-like receptors by neonatal leukocytes.

The immune system of neonates is poorly developed; this increases the susceptibility of neonates to infection. For neonates to counter infection effectively, they first need to recognize the presence of pathogens. Toll-like receptors (TLR) are a family of pattern recognition receptors that alert the host to the presence of invading pathogens.

Genome-wide identification of human FOXP3 target genes in natural regulatory T cells.

The transcription factor FOXP3 is essential for the formation and function of regulatory T cells (Tregs), and Tregs are essential for maintaining immune homeostasis and tolerance. This is demonstrated by a lethal autoimmune defect in mice lacking Foxp3 and in immunodysregulation polyendocrinopathy enteropathy X-linked syndrome patients. However, little is known about the molecular basis of human FOXP3 function or the relationship between direct and indirect targets of FOXP3 in human Tregs.

ProNGF mediates death of Natural Killer cells through activation of the p75NTR-sortilin complex.

The common neurotrophin receptor P75NTR, its co-receptor sortilin and ligand proNGF, have not previously been investigated in Natural Killer (NK) cell function. We found freshly isolated NK cells express sortilin but not significant amounts of P75NTR unless exposed to interleukin-12 (IL-12), or cultured in serum free conditions, suggesting this receptor is sequestered. A second messenger associated with p75NTR, neurotrophin-receptor-interacting-MAGE-homologue (NRAGE) was identified in NK cells.

Isolation of whole mononuclear cells from peripheral blood and cord blood.

Peripheral blood is the primary source of lymphoid cells for investigation of the human immune system. Its use is facilitated by Ficoll-Hypaque density gradient centrifugation-a simple and rapid method of purifying peripheral blood mononuclear cells (PBMC) that takes advantage of the density differences between mononuclear cells and other elements found in the blood sample. Thus, cells are distributed in the solution in layers based on the differences in their density/size.

Development of CD4+CD25+FoxP3+ regulatory T cells from cord blood hematopoietic progenitor cells.

Adult stem cells are capable of generating all of the cells of the hematopoietic system, and this process is orchestrated in part by the interactions between these cells and the stroma. T cell progenitors emerge from the stem cell compartment and migrate to the thymus, where their terminal differentiation and maturation occur, and it is during this phase that selection shapes the immune repertoire. Notch ligands, including Delta-like 1 (DL1), play a critical role in this lymphoid differentiation.

High-sensitivity immunofluorescence/flow cytometry: detection of cytokine receptors and other low-abundance membrane molecules.

Cell marker identification by traditional phenotyping techniques is now considered straight-forward and relatively uncomplicated. In immunofluorescence/flow cytometry, the sensitivity, or detection limit, depends on the reagents, staining, and instrument parameters. The sensitivity of the most commonly used procedures, based on fluorescein-conjugated antibodies, approximately 2000 molecules of target antigen per cell, which is adequate for most of the widely used leukocyte markers.

Isolation of whole mononuclear cells from peripheral blood and cord blood.

Peripheral blood is the primary source of lymphoid cells for investigations of the human immune system. Its use is facilitated by the Ficoll-Hypaque density gradient centrifugation method described here. It is a simple and rapid method of purifying peripheral blood mononuclear cells (PBMC) that takes advantage of the density differences between mononuclear cells and other elements found in the blood sample.

Detection of cytokine receptors by flow cytometry.

This unit describes three protocols for detecting cytokine receptors on human peripheral blood mononuclear cells or murine splenic lymphocytes via immunofluorescence labeling. The three protocols have in common the use of phycoerythrin as a highly effective fluorescent dye, multiple-layer staining to increase sensitivity, and selection of reagents for maximum sensitivity. The first procedure uses monoclonal antibody (MAb) against receptor protein, detected with biotinylated anti-Ig (directed against the species in which the MAb is made), which in turn is stained with phycoerythrin-streptavidin (PE-SA).

1D09C3, an mAb specific for MHC-II.

GPC Biotech AG is developing 1D09C3, an anti-MHC class II (HLA-DR) fully human IgG4 antibody isolated by MorphoSys AG (from its HuCAL library of human antibodies), for the potential treatment of hematological malignancies. In December 2006, positive safety data from two phase I clinical trials were reported. Final phase I data were expected in mid-2007; however, no additional data have been released at the time of publication.

Multiple Myeloma Includes Phenotypically Defined Subsets of Clonotypic CD20+ B Cells that Persist During Treatment with Rituximab.

Potential progenitor B cell compartments in multiple myeloma (MM) are clinically important. MM B cells and some circulating MM plasma cells express CD20, predicting their clearance by treatment with anti-CD20. Here we describe two types of clonotypic CD20+ B cell in peripheral blood of myeloma patients, identified by their expression of CD19 and CD20 epitopes, their expression of CD45RA and their light scatter properties.

Isolation, propagation and characterization of cord blood derived CD4+ CD25+ regulatory T cells.

Regulatory T cells (Treg) have recently come to the fore in studies of immune regulation, particularly in autoimmune disease and cancer. While there appear to be several distinct subsets of T cells with regulatory function, a population described as natural Treg and characterized by expression of the transcription factor FOXP3 has attracted particular interest. These cells can be enriched using the surface markers CD4 and CD25, and cord blood is a convenient source of CD25+ Treg.

Medical applications of leukocyte surface molecules--the CD molecules.

Leukocytes are the cells of the immune system and are centrally involved in defense against infection, in autoimmune disease, allergy, inflammation, and in organ graft rejection. Lymphomas and leukemias are malignancies of leukocytes, and the immune system is almost certainly involved in most other cancers. Each leukocyte expresses a selection of cell surface glycoproteins and glycolipids which mediate its interaction with antigen, with other components of the immune system, and with other tissues.

CD molecules 2006--human cell differentiation molecules.

The Human Leucocyte Differentiation Antigens Workshops (HLDA) have since 1984 provided a forum for the characterization and study of leucocyte surface molecules and antibodies against them. HLDA devised the CD nomenclature, which is sanctioned by IUIS. The HLDA Council reviewed and modified the objectives of HLDA in 2004, and changed the name of the organization to Human Cell Differentiation Molecules (HCDM) to reflect the broader objectives.