Neutrophils Require Activation to Express Functional Cell-Surface Complement Receptor Immunoglobulin.

The phagocytosis-promoting complement receptor, Complement Receptor Immunoglobulin (CRIg), is exclusively expressed on macrophages. It has been demonstrated that expression in macrophages could be modulated by inflammatory mediators, including cytokines. This raised the possibility that a major phagocyte, the neutrophil, may also express CRIg following activation with inflammatory mediators.

Characterization of the Transient Deficiency of PKC Isozyme Levels in Immature Cord Blood T Cells and Its Connection to Anti-Allergic Cytokine Profiles of the Matured Cells.

Cord blood T cells (CBTC) from a proportion of newborns express low/deficient levels of some protein kinase C (PKC) isozymes, with low levels of PKCζ correlating with increased risk of developing allergy and associated decrease in interferon-gamma (IFN-γ) producing T cells. Interestingly, these lower levels of PKCζ were increased/normalized by supplementing women during pregnancy with n-3 polyunsaturated fatty acids. However, at present, we have little understanding of the transient nature of the deficiency in the neonate and how PKCζ relates to other PKC isozymes and whether their levels influence maturation into IFN-γ producing T cells.

Cord Blood T Cells Expressing High and Low PKCζ Levels Develop into Cells with a Propensity to Display Th1 and Th9 Cytokine Profiles, Respectively.

Low Protein Kinase C zeta (PKCζ) levels in cord blood T cells (CBTC) have been shown to correlate with the development of allergic sensitization in childhood. However, little is known about the mechanisms responsible. We have examined the relationship between the expression of different levels of PKCζ in CBTC and their development into mature T cell cytokine producers that relate to allergy or anti-allergy promoting cells.

Vitamin D upregulates the macrophage complement receptor immunoglobulin in innate immunity to microbial pathogens.

Vitamin D deficiency remains a global concern. This 'sunshine' vitamin is converted through a multistep process to active 1,25-dihydroxyvitamin D (1,25D), the final step of which can occur in macrophages. Here we demonstrate a role for vitamin D in innate immunity.

Perinatal and Early-Life Nutrition, Epigenetics, and Allergy.

Epidemiological studies have shown a dramatic increase in the incidence and the prevalence of allergic diseases over the last several decades. Environmental triggers including risk factors (e.g.

Human Dendritic Cells Express the Complement Receptor Immunoglobulin Which Regulates T Cell Responses.

The B7 family-related protein V-set and Ig containing 4 (VSIG4), also known as Z39Ig and Complement Immunoglobulin Receptor (CRIg), is the most recent of the complement receptors to be identified, with substantially distinct properties from the classical complement receptors. The receptor displays both phagocytosis-promoting and anti-inflammatory properties. The receptor has been reported to be exclusively expressed in macrophages.

Validation of monoclonal anti-PKC isozyme antibodies for flow cytometry analyses in human T cell subsets and expression in cord blood T cells.

T cells from neonates (cord blood) with a tendency to develop allergic diseases express low PKCζ levels. More extensive investigations into PKC isozyme levels in T cell subsets and changes during neonatal T cell maturation are hampered by limitations of Western blot analyses. We have undertaken to validating the specificity of commercially available antibodies marketed for flow cytometry to measure PKCα, βI, βII, δ, ε, η, θ, ζ, ι/λ and μ.

Regulation of endothelial cell survival and death by the MAP kinase/ERK kinase kinase 3 - glyceraldehyde-3-phosphate dehydrogenase signaling axis.

Endothelial cell injury and death precede atherosclerosis development. Thus, it is important to understand the mechanisms that lead to these early changes in endothelial cells. Although members of the MAP kinase/ERK kinase (MEK) kinase 3 (MEKK3)-MEK5-ERK5 module play an essential role in underpinning endothelial cell survival, how they execute these actions remain poorly understood.

Regulating transcriptional activity by phosphorylation: A new mechanism for the ARX homeodomain transcription factor.

Aristaless-related homeobox (ARX) gene encodes a paired-type homeodomain transcription factor with critical roles in development. Here we identify that ARX protein is phosphorylated. Using mass spectrometry and in vitro kinase assays we identify phosphorylation at serines 37, 67 and 174.

Histone modifications and their role in epigenetics of atopy and allergic diseases.

This review covers basic aspects of histone modification and the role of posttranslational histone modifications in the development of allergic diseases, including the immune mechanisms underlying this development. Together with DNA methylation, histone modifications (including histone acetylation, methylation, phosphorylation, ubiquitination, etc.) represent the classical epigenetic mechanisms.

Small tumor necrosis factor receptor biologics inhibit the tumor necrosis factor-p38 signalling axis and inflammation.

Despite anti-TNF therapy advancements for inflammatory diseases such as rheumatoid arthritis, the burden of diseases remains high. An 11-mer TNF peptide, TNF, is known to stimulate selective functional responses compared to the parent TNF molecule. Here, we show that TNF binds to the TNF receptor, activating p38 MAP kinase through TNF receptor-associated factor 2.

The role of PKCζ in cord blood T-cell maturation towards Th1 cytokine profile and its epigenetic regulation by fish oil.

While immunodeficiency of immaturity of the neonate has been considered important as the basis for unusual susceptibility to infection, it has also been recognized that the ability to progress from an immature Th2 cytokine predominance to a Th1 profile has relevance in determining whether children will develop allergy, providing an opportunity for epigenetic regulation through environmental pressures. However, this notion remains relatively unexplored. Here, we present evidence that there are two major control points to explain the immunodeficiency in cord blood (CB) T-cells, a deficiency in interleukin (IL)-12 (IL-12) producing and IL-10 overproducing accessory cells, leading to a decreased interferon γ (IFNγ) synthesis and the other, an intrinsic defect in T-cell protein kinase C (PKC) ζ (PKCζ) expression.

The Non-Genomic Actions of Vitamin D.

Since its discovery in 1920, a great deal of effort has gone into investigating the physiological actions of vitamin D and the impact its deficiency has on human health. Despite this intense interest, there is still disagreement on what constitutes the lower boundary of adequacy and on the Recommended Dietary Allowance. There has also been a major push to elucidate the biochemistry of vitamin D, its metabolic pathways and the mechanisms that mediate its action.

Protein kinase cα regulates the expression of complement receptor Ig in human monocyte-derived macrophages.

The complement receptor Ig (CRIg) is selectively expressed by macrophages. This receptor not only promotes the rapid phagocytosis of bacteria by macrophages but also has anti-inflammatory and immunosuppressive functions. Previous findings have suggested that protein kinase C (PKC) may be involved in the regulation of CRIg expression in human macrophages.

Regulation of bone morphogenetic protein signalling and cranial osteogenesis by Gpc1 and Gpc3.

From birth, the vault of the skull grows at a prodigious rate, driven by the activity of osteoblastic cells at the fibrous joints (sutures) that separate the bony calvarial plates. One in 2500 children is born with a medical condition known as craniosynostosis because of premature bony fusion of the calvarial plates and a cessation of bone growth at the sutures. Bone morphogenetic proteins (BMPs) are potent growth factors that promote bone formation.

Identification and functional characterization of two novel mutations in the α-helical loop (residues 484-503) of CYBB/gp91(phox) resulting in the rare X91(+) variant of chronic granulomatous disease.

Chronic granulomatous disease (CGD) is mainly caused by mutations in X-linked CYBB that encodes gp91. We have identified two novel mutations in CYBB resulting in the rare X91(+)-CGD variant, c.1500T>G (p.

Regulation of CRIg expression and phagocytosis in human macrophages by arachidonate, dexamethasone, and cytokines.

Although the importance of the macrophage complement receptor immunoglobulin (CRIg) in the phagocytosis of complement opsonized bacteria and in inflammation has been established, the regulation of CRIg expression remains undefined. Because cellular activation during inflammation leads to the release of arachidonate, a stimulator of leukocyte function, we sought to determine whether arachidonate regulates CRIg expression. Adding arachidonate to maturing human macrophages and to prematured CRIg(+) macrophages caused a significant decrease in the expression of cell-surface CRIg and CRIg mRNA.

Inhibition of atherosclerotic lesion development in the ApoE-/- mouse by a novel β-oxa polyunsaturated fatty acid.

Recent findings that a novel polyunsaturated fatty acid, β-oxa 23:4n-6, inhibits adhesion molecule expression on vascular endothelial cells and leukocyte adhesion led us to examine its ability to inhibit the development of atherosclerosis in the apoE-deficient (apoE) mouse. The mice were kept on normal chow or a high-fat/high-cholesterol diet for various periods and treated with either vehicle or β-oxa 23:4n-6 by the intraperitoneal route. The hearts and aortae were isolated and lesion development at the aortic root was determined.

Regulation of neutrophil-mediated killing of Staphylococcus aureus and chemotaxis by c-jun NH2 terminal kinase.

The role of JNK in neutrophil chemotaxis and killing of microbial pathogens remains unclear. Using a recently described cell-permeable peptide inhibitor of the JNK pathway, based on the JBD of JIP-1, coupled to the protein transduction domain of HIV-TAT (TAT-JIP), in association with control peptides, we demonstrate that the JNK pathway plays a major role in regulating human neutrophil chemotaxis and killing of microbial pathogens. Serum-opsonized Staphylococcus aureus elicited JNK activation and c-jun phosphorylation.

A role for the phosphatidylinositol 3-kinase--protein kinase C zeta--Sp1 pathway in the 1,25-dihydroxyvitamin D3 induction of the 25-hydroxyvitamin D3 24-hydroxylase gene in human kidney cells.

The molecular mechanisms that underlie non-genomic induction of the 25-hydroxyvitamin D3 24-hydroxylase (CYP24) gene promoter by the steroid hormone, 1,25-Dihydroxyvitamin D3 (1,25D), are poorly understood. Although we have previously identified a functional inverted GC-box in the early promoter at -113/-105 bp, it is not known whether this site is important for 1,25D induction of the promoter. Using transfected human embryonic kidney (HEK) 293T cells, we now report the functional characterisation of the GC-box and that 1,25D induction of the promoter requires PI3-kinase, PKCzeta and Sp1 but not Sp3.

The effect of the JNK inhibitor, JIP peptide, on human T lymphocyte proliferation and cytokine production.

Although JNK is a potential target for treating chronic inflammatory diseases, its role in T lymphocyte function remains controversial. To overcome some of the previous limitations in addressing this issue we have used the recently described transactivator of transcription-JNK-interacting protein (TAT-JIP) peptide, a specific inhibitor that was derived from the minimal JNK-binding region of the scaffold protein, JNK-interacting protein 1 (JIP-1), coupled to the short cell-permeable HIV TAT sequence. Pretreatment of purified human T lymphocytes with the TAT-JIP peptide inhibited the phosphorylation of endogenous jun activated by PHA-PMA.

Leukocyte numbers and function in subjects eating n-3 enriched foods: selective depression of natural killer cell levels.

Introduction: While consumption of omega-3 long-chain polyunsaturated fatty acids (n-3 LCPUFA) has been recommended for those at risk of inflammatory disease such as rheumatoid arthritis, the mechanism of their anti-inflammatory effect remains to be clearly defined, particularly in relation to the dose and type of n-3 LCPUFA. The objective of this study was to determine whether varying the levels of n-3 LCPUFA in erythrocyte membrane lipids, following dietary supplementation, is associated with altered numbers and function of circulating leukocytes conducive to protection against inflammation.

Methods: In a double-blind and placebo-controlled study, 44 healthy subjects aged 23 to 63 years consumed either standard or n-3 LCPUFA-enriched versions of typical processed foods, the latter allowing a target daily consumption of 1 gram n-3 LCPUFA.

Antineoplastic agents target the 25-hydroxyvitamin D3 24-hydroxylase messenger RNA for degradation: implications in anticancer activity.

Calcitriol or 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] has antitumor activity and hence its levels in patients may play an important role in disease outcome. Here, we report that the antineoplastic agents, daunorubicin hydrochloride, etoposide, and vincristine sulfate inhibited the ability of 1,25(OH)(2)D(3) to cause the accumulation of mRNA for kidney 25-hydroxyvitamin D(3) 24-hydroxylase (CYP24), an enzyme which catabolizes this hormone. This was not due to a drug-induced cytotoxic effect, reduction in the expression of the vitamin D receptor or inhibition of the vitamin D receptor-mediated activation of the mitogen-activated protein kinases or CYP24 promoter activity.

Regulation of the NADPH oxidase activity and anti-microbial function of neutrophils by arachidonic acid.

Arachidonic acid (AA), a second-messenger molecule released from membrane phospholipids by phospholipase A(2) in activated cells, is a stimulator of neutrophil responses, including the oxygen-dependent respiratory burst. The polyunsaturated fatty acid is also the precursor of biologically active eicosanoids. There are several mechanisms by which AA stimulates the respiratory burst.