Peptide‐based systems analysis of inflammation induced myeloid‐derived suppressor cells reveals diverse signaling pathways

A better understanding of molecular signaling between myeloid‐derived suppressor cells (MDSC), tumor cells, T‐cells, and inflammatory mediators is expected to contribute to more effective cancer immunotherapies. We focus on plasma membrane associated proteins, which are critical in signaling and intercellular communication, and investigate changes in their abundance in MDSC of tumor‐bearing mice subject to heightened versus basal inflammatory conditions. Using spectral counting, we observed statistically significant differential abundances for 35 proteins associated with the plasma membrane, most notably the pro‐inflammatory proteins S100A8 and S100A9 which induce MDSC and promote their migration. We also tested whether the peptides associated with canonical pathways showed a statistically significant increase or decrease subject to heightened versus basal inflammatory conditions. Collectively, these studies used bottom‐up proteomic analysis to identify plasma membrane associated pro‐inflammatory molecules and pathways that drive MDSC accumulation, migration, and suppressive potency.     

Probiotics and mastitis: evidence-based marketing?

Probiotics are defined as live micro-organisms, which when administered in adequate amounts, confer health benefits on the host. Scientists have isolated various strains of Lactobacilli from human milk (such as Lactobacillus fermentum and Lactobacillus salivarius), and the presence of these organisms is thought to be protective against breast infections, or mastitis.Trials of probiotics for treating mastitis in dairy cows have had mixed results: some successful and others unsuccessful. To date, only one trial of probiotics to treat mastitis in women and one trial to prevent mastitis have been published. Although trials of probiotics to prevent mastitis in breastfeeding women are still in progress, health professionals in Australia are receiving marketing of these products.High quality randomised controlled trials are needed to assess the effectiveness of probiotics for the prevention and/or treatment of mastitis.     

Congenic Strains Confirm the Pleiotropic Effect of Chromosome 4 QTL on Mouse Femoral Geometry and Biomechanical Performance

A pleiotropic quantitative trait locus (QTL) for bone geometry and mechanical performance in mice was mapped to distal chromosome 4 via an intercross of recombinant congenic mice HcB-8 and HcB-23. To study the QTL in isolation, we have generated C3H.B10-(rs6355453-rs13478087) (C.B.4.3) and C3H.B10-(rs6369860-D4Mit170) (C.B.4.2) congenic strains that harbor ~20 Mb and ~3 Mb, respectively, of chromosome 4 overlapping segments from C57BL/10ScSnA (B10) within the locus on a C3H/DiSnA (C3H) background. Using 3-point bend testing and standard beam equations, we phenotyped these mice for femoral mid-diaphyseal geometry and biomechanical performance. We analyzed the results via 2-way ANOVA, using sex and genotype as factors. In the C.B.4.3 strain, we found that homozygous B10/B10 male mice had smaller cross sectional area (CSA) and reduced total displacement than homozygous C3H/C3H mice. Sex by genotype interaction was also observed for maximum load and stiffness for C3H/C3H and B10/B10 mice, respectively. In C.B.4.2 strain, we found that homozygous B10/B10 mice had lower total displacement, post-yield displacement (PYD), stiffness, yield load and maximum load than mice harboring C3H allele. Sex by genotype interaction was observed in B10/B10 mice for perimeter, outer minor axis (OMA) and CSA. There were no significant differences in tissue level mechanical performance, which suggest that the QTL acts primarily on circumferential bone size. These data confirm the prior QTL mapping data and support other work demonstrating the importance of chromosome 4 QTL on bone modeling and bone responses to mechanical loading.     

Ambulatory Blood Pressure Monitoring in Individuals with HIV: A Systematic Review and Meta-Analysis

Introduction

Abnormal diurnal blood pressure (BP) rhythms may contribute to the high cardiovascular disease risk in HIV-positive (HIV⁺) individuals. To synthesize the current literature on ambulatory BP monitoring (ABPM) in HIV⁺ individuals, a systematic literature review and meta-analysis were performed.

Methods

Medical databases were searched through November 11, 2015 for studies that reported ABPM results in HIV⁺ individuals. Data were extracted by 2 reviewers and pooled differences between HIV⁺ and HIV-negative (HIV^-) individuals in clinic BP and ABPM measures were calculated using random-effects inverse variance weighted models.

Results

Of 597 abstracts reviewed, 8 studies with HIV⁺ cohorts met the inclusion criteria. The 420 HIV⁺ and 714 HIV^- individuals in 7 studies with HIV^- comparison groups were pooled for analyses. The pooled absolute nocturnal systolic and diastolic BP declines were 3.16% (95% confidence interval [CI]: 1.13%, 5.20%) and 2.92% (95% CI: 1.64%, 4.19%) less, respectively, in HIV⁺ versus HIV^- individuals. The pooled odds ratio for non-dipping systolic BP (nocturnal systolic BP decline <10%) in HIV⁺ versus HIV^- individuals was 2.72 (95% CI: 1.92, 3.85). Differences in mean clinic, 24-hour, daytime, or nighttime BP were not statistically significant. I² and heterogeneity chi-squared statistics indicated the presence of high heterogeneity for all outcomes except percent DBP dipping and non-dipping SBP pattern.

Conclusions

An abnormal diurnal BP pattern may be more common among HIV⁺ versus HIV^- individuals. However, results were heterogeneous for most BP measures, suggesting more research in this area is needed.     

Modulation of soluble ovarian adenosine 3',5'-monophosphate-dependent protein kinase activity during prepubertal development in the rat. II. Evaluation of the catalytic subunit inhibitor activity

In a previous report on the ontogeny of the ovarian adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase activity during prepubertal development of the rat, we concluded that the 4-fold decline in cAMP-dependent protein kinase activity observed in ovaries of 21- to 23-day-old rats was due to the presence of a heat-labile inhibitor in the ovarian extracts (Hunzicker-Dunn et al., 1984). We developed an assay for this ovarian kinase inhibitor activity that was based on the observation that ovarian cytosol added to an exogenous catalytic subunit of cAMP-dependent protein kinase caused a time-dependent and ovarian cytosol protein concentration-dependent inhibition of exogenous catalytic subunit phosphotransferase activity. The present studies were conducted to evaluate the basis for this catalytic subunit inhibitor present in soluble rat ovarian extracts of prepubertal-aged rats. This inhibitor activity was absent from cytosol extracts of rat corpora lutea, rat liver, rabbit follicles, and rabbit corpora lutea. Inhibitor activity present in rat ovarian cytosol was not attributable to insufficient levels of the phosphorylation substrate Kemptide. Inhibitor activity was also not related to the presence of the large amount of catalytic subunit-free regulatory subunit of the cAMP-dependent protein kinase present in ovarian extracts of late juvenile-aged rats. Inhibitor activity, however, did correlate with an endogenous adenosine triphosphatase (ATPase) activity that reduced assay ATP concentrations below levels needed to accurately measure phosphotransferase activity, despite the presence of sodium fluoride (an ATPase inhibitor) and ATP concentrations 5- to 15-fold greater than the Km of the kinase for ATP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Development of behavioral competence in youngDrosophila melanogaster adults

We have monitored the ontogeny of several behaviors performed by young Drosophila melanogasteradults. Very young flies are less active than older flies and are less responsive to gravity, light, an odorant, and sucrose applied to their tarsi. In addition, very young males do not consume sucrose or perform any courtship behaviors in response to virgin females, which provide chemical and visual stimuli to courting males. The rate at which flies become maximally competent to respond to stimuli is a function of the behavior. Sensory and motor deficits are not solely responsible for young flies' inability to respond to the stimuli, which suggests that the central nervous system continues to develop after eclosion.Deceased     

Neurons controlling the gill vasculature in five species of teleosts

Summary A plexus of nerve fibers encompassing neuronal perikarya is present within the gill filament; it surrounds the proximal portion of the efferent filament artery and the efferent lamellar arterioles. This innervation resembles the pattern described for the area around the sphincter of the efferent filament artery: acetylcholinesterase-positive neurons and fibers, fast-fading yellow-fluorescent neurons and fibers, long-lasting green-fluorescent fibers. In addition, synaptic contacts between the different components suggest functional interrelationships. Nerves evidently control the efferent limb of the filament circulation including the sphincter of the efferent filament arteries, the proximal portion of the efferent filament arteries proper, and their corresponding efferent lamellar arterioles. However, the distal portion of this system is poorly innervated.     

Pharmacokinetic studies of radiolabelled rat monoclonal antibodies recognising syngeneic sarcoma antigens

Summary The object of our current investigations is to explore the potential of antibodies for localisation and treatment of disseminated disease, using as a model rat monoclonal antibodies (mAbs) raised against syngeneic tumourspecific antigens. As part of this study, antibodies of differing isotypes with specificity for either HSN or MC24 sarcoma were labelled with¹²⁵iodine and injected intravenously into normal rats or those bearing paired tumours in contralateral flanks. The blood clearance rates of the radiolabelled antibodies were found to be influenced by immunoglobulin subclass (IgG2b > IgG2a > IgG1) and to be increased non-specifically by the presence of growing tumours. The tumour and normal tissue distributions of the antibodies tested were also found to vary according to their apparent degree of interaction with host Fc-receptor-bearing cells, to the extent that tumour specificity in vitro was not necessarily reflected in selectivity of localisation in vivo. Three IgG2b monoclonal antibodies showed preferential uptake in the spleens of syngeneic rats and non-specific accumulation in tumours. This effect was not observed with antibodies of IgG2a or IgG1 subclass, and was abolished by the use of IgG2b F(ab)₂ preparations. In spite of the use of immunoglobulin fragments, varying the assay time and testing tumours of different sizes, specific tumour localisation was low with all seven monoclonal antibodies tested. The maximum uptake achieved was less than 1% of the injected dose of antibody per gram of tumour. Much higher levels of antibody localisation have been reported for human tumour xenografts growing in nude mice, but these are rarely achieved in other systems. We propose that the use of autologous monoclonal antibodies recognising tumour-associated antigens of relatively low epitope density in syngeneic hosts provides a valid alternative model in which to investigate the factors limiting more effective, specific immunolocalisation of malignant disease.     

Pharmacokinetic studies of radiolabelled rat monoclonal antibodies recognising syngeneic sarcoma antigens

In the preceding paper it was suggested that the tumour localisation of 125I-labelled syngeneic rat monoclonal antibodies (mAbs) may be limited in immunocompetent hosts by the presence of competing endogenous serum antibodies. In syngeneic congenitally athymic (nu/nu) and cyclosporin-A-treated rats (both of which fail to mount immune responses to tumour antigens) increased uptake of mAbs in tumour tissue was obtained compared with that in immunocompetent animals. However, in the case of IgG2b and IgG1 mAbs, this appeared to be due primarily to enhanced "non-specific" localisation mediated by Fc binding, since it was abolished by the use of F(ab')2 fragments with two out of three mAbs tested. Normal tissue distribution was also influenced by host immune status: in nu/nu rats the uptake of IgG2b mAbs in the spleen was up to fivefold higher than that previously found in normal animals and the levels in liver were also increased. This effect was not seen in cyclosporin-A-treated hosts, suggesting that the reticuloendothelial system of congenitally athymic animals contains cells with enhanced IgG2b-FcR activity. This hypothesis was strengthened by the observation that splenic uptake was reduced by either the use of F(ab')2 fragments, or prior "blockade" of Fc receptors by "cold competition" with excess unlabelled IgG2b mAbs. This blockade could not be effected by mAbs of any other isotype or by IgG2b F(ab')2 fragments. The former manoeuvre resulted in higher tumour specificity ratios but usually at the expense of reduced levels of tumour associated radiolabelled mAb. The latter was found to increase "absolute" tumour localisation by up to 35%. In an attempt to characterise further and compare the Fc receptor activity of intratumour and intrasplenic host cells. The distribution of IgG2b mAbs was assayed in 3-week, 8-week and 12-week-old rats. We were able operationally to distinguish the activity of these two categories of cells, suggesting that they represent either different lineages or differentially activated subpopulations: the splenic IgG2b binding was fully expressed in weanling nu/nu rats whereas the FcR activity of cells infiltrating MC24 sarcoma was limited in 3-week-old compared with 8-12-week-old hosts. A further difference was apparent in the subclass "preference" of FcR binding: in immunodeprived rats both IgG1 and IgG2b mAbs were able to bind to tumour-infiltrating host cells, but uptake of IgG1 mAbs in the spleen was always low and not reduced further by the use of F(ab')2 fragments.(ABSTRACT TRUNCATED AT 400 WORDS)