Interleukins 6 and 8 and abdominal fat depots are distinct correlates of lipid moieties in healthy pre- and postmenopausal women.

Unlabelled: Available data associate lipids concentrations in men with body mass index, anabolic steroids, age, and certain cytokines. Data were less clear in women, especially across the full adult lifespan, and when segmented by premenopausal and postmenopausal status.

Subjects: 120 healthy women (60 premenopausal and 60 postmenopausal) in Olmsted County, MN, USA, a stable well studied clinical population.

Serum concentrations of prostate-specific antigen measured using immune extraction, trypsin digestion, and tandem mass spectrometry quantification of LSEPAELTDAVK peptide.

Context: Prostate-specific antigen (PSA) is a 34-kDa glycoprotein with chymotrypsin-like enzyme activity that circulates both in free forms and complexed to various enzyme inhibitors including antichymotrypsin and α2-macroglobulin. Prostate-specific antigen bound to α2-macroglobulin is not detected by commercial PSA immunoassays.

Objective: To develop a mass spectrometry assay that detects the same forms of PSA as the immunoassays, which could serve as a reference for harmonizing PSA immunoassays.

Immunologic and mass-spectrometric estimates of SHBG concentrations in healthy women.

Objective: Sex-hormone binding globulin (SHBG) concentrations across the adult female lifespan are not well defined. To address this knowledge gap, SHBG was quantified by both immunological and criterion methods, viz, mass spectrometry (MS).

Setting: Center for Translational Science Activities (CTSA).

Mass spectrometry measurements of prostate-specific antigen (PSA) peptides derived from immune-extracted PSA provide a potential strategy for harmonizing immunoassay differences.

Objectives: Harmonization of prostate-specific antigen (PSA) immunoassays is important for good patient care. The specificity of the antibodies used to detect circulating PSA could cause differences in the PSA measurements.

Methods: We used mass spectrometry (MS) to quantitate the concentration of five peptides cleaved from trypsin digestion of PSA and compared these measurements with six automated immunoassays.

Immunological and mass spectrometric assays of SHBG: consistent and inconsistent metabolic associations in healthy men.

Context: SHBG concentrations correlate inconsistently with metabolic parameters.

Hypothesis: SHBG assay platforms contribute to nonuniformities according to the literature.

Design: The design of the study was a noninterventional quantification of SHBG by two immuno- and two mass spectrometric assays and abdominal visceral fat by computed tomography scan.

SDF-1α degrades whereas glycoprotein 120 upregulates Bcl-2 interacting mediator of death extralong isoform: implications for the development of T cell memory.

After a primary immune response, T cell memory occurs when a subset of Ag-specific T cells resists peripheral selection by acquiring resistance to TCR-induced death. Recent data have implicated Bcl-2 interacting mediator of death (Bim) as an essential mediator of the contraction phase of T cell immunity. In this article, we describe that stromal-derived factor-1α (SDF-1α) ligation of CXCR4 on activated T cells promotes two parallel processes that favor survival, phospho-inactivation of Foxo3A, as well as Bim extralong isoform (Bim(EL)) degradation, both in an Akt- and Erk-dependent manner.

CXCR4 Tropic HIV-1 gp120 Inhibition of SDF-1α-Induced Chemotaxis Requires Lck and is Associated with Cofilin Phosphorylation.

Objective: HIV gp120 is a pleiotropic protein present in the plasma and tissues of HIV-infected patients, which affects a variety of homeostatic functions. In this report, we examine the mechanism of how gp120 blocks CD4 T cells from migrating towards SDF-1α.

Methods: In vitro treatment of primary CD4 T cells with CXCR4 tropic gp120, SDF, and measurement of chemotaxis and cell signaling.

Protein kinase Cbeta modulates ligand-induced cell surface death receptor accumulation: a mechanistic basis for enzastaurin-death ligand synergy.

Although treatment with the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) is known to protect a subset of cells from induction of apoptosis by death ligands such as Fas ligand and tumor necrosis factor-alpha-related apoptosis-inducing ligand, the mechanism of this protection is unknown. This study demonstrated that protection in short term apoptosis assays and long term proliferation assays was maximal when Jurkat or HL-60 human leukemia cells were treated with 2-5 nm PMA. Immunoblotting demonstrated that multiple PKC isoforms, including PKCalpha, PKCbeta, PKCepsilon, and PKC, translocated from the cytosol to a membrane-bound fraction at these PMA concentrations.

CD4 T Cells Treated with gp120 Acquire a CD45R0+/CD45RA+ Phenotype.

HIV-infected patients exhibit quantitative and qualitative defects in CD4 T cells, including having increased numbers of CD4+CD45R0+/CD45RA+ T cells, although it remains unclear how these cells arise. Here we demonstrate that gp120 treatment of activated but not resting primary human CD4 T cells decreases number of cells with single positive CD45R0+/CD45RA- effector memory phenotype while proportionally increasing the subset of cells with double positive CD45R0+/CD45RA+ mixed phenotype. We found that double positive CD45R0+/CD45RA+CD4 T cells preferentially undergo apoptosis while single positive CD45R0+/CD45RA- and CD45R0-/CD45RA+ do not.

HIV gp120 induces, NF-kappaB dependent, HIV replication that requires procaspase 8.

Background: HIV envelope glycoprotein gp120 causes cellular activation resulting in anergy, apoptosis, proinflammatory cytokine production, and through an unknown mechanism, enhanced HIV replication.

Methodology/principal Findings: We describe that the signals which promote apoptosis are also responsible for the enhanced HIV replication. Specifically, we demonstrate that the caspase 8 cleavage fragment Caspase8p43, activates p50/p65 Nuclear Factor kappaB (NF-kappaB), in a manner which is inhibited by dominant negative IkappaBalpha.

Infected cell killing by HIV-1 protease promotes NF-kappaB dependent HIV-1 replication.

Acute HIV-1 infection of CD4 T cells often results in apoptotic death of infected cells, yet it is unclear what evolutionary advantage this offers to HIV-1. Given the independent observations that acute T cell HIV-1 infection results in (1) NF-kappaB activation, (2) caspase 8 dependent apoptosis, and that (3) caspase 8 directly activates NF-kappaB, we questioned whether these three events might be interrelated. We first show that HIV-1 infected T cell apoptosis, NF-kappaB activation, and caspase 8 cleavage by HIV-1 protease are coincident.

Human immunodeficiency virus type 1 protease cleaves procaspase 8 in vivo.

Human immunodeficiency virus type 1 (HIV-1) infection causes apoptosis of infected CD4 T cells as well as uninfected (bystander) CD4 and CD8 T cells. It remains unknown what signals cause infected cells to die. We demonstrate that HIV-1 protease specifically cleaves procaspase 8 to create a novel fragment termed casp8p41, which independently induces apoptosis.

Glycoprotein 120 binding to CXCR4 causes p38-dependent primary T cell death that is facilitated by, but does not require cell-associated CD4.

HIV-1 infection causes the depletion of host CD4 T cells through direct and indirect (bystander) mechanisms. Although HIV Env has been implicated in apoptosis of uninfected CD4 T cells via gp120 binding to either CD4 and/or the chemokine receptor 4 (CXCR4), conflicting data exist concerning the molecular mechanisms involved. Using primary human CD4 T cells, we demonstrate that gp120 binding to CD4 T cells activates proapoptotic p38, but does not activate antiapoptotic Akt.

Protein kinase Calpha (PKCalpha) acts upstream of PKCtheta to activate IkappaB kinase and NF-kappaB in T lymphocytes.

NF-kappaB is an ubiquitous transcription factor that is a key in the regulation of the immune response and inflammation. T-cell receptor (TCR) cross-linking leads to NF-kappaB activation, an IkappaB kinase (IKK)-dependent process. However, the upstream kinases that regulate IKK activity following TCR activation remain to be fully characterized.