Sex-based differences in microbiota composition and metabolomic profiles associated with altered macrophage function and protection from lupus in BWF1 mice.

Systemic lupus erythematosus (SLE) is a complex and an insidious disease that is still not completely understood, and has very few treatment options. Those that are available are ineffective and/or have serious side effects. Both genetic and environmental factors contribute to the susceptibility and resistance to SLE, and understanding the environmental factors underlying this disease could lead to more effective prevention and/or treatment strategies. Like most autoimmune diseases, SLE is much more prevalent in females than males. While there are numerous factors that contribute to this lupus susceptibility, there is increasing evidence that the microbiota can strongly influence lupus progression, and that sex-based differences in microbiota composition and function may play a role in the sex bias (i.e., susceptibility in females and resistance in males) of disease. The NZBxNZW F1 (BWF1) mouse model of lupus has many of the same disease features seen in humans including the sex bias, making it an ideal model for studying sex-based differences in microbiota and how they affect lupus progression. Previous findings from our laboratory have shown that not only do female and male BWF1 microbiota profiles differ significantly, but male BWF1 microbiota can suppress lupus when cecal contents are transferred into female BWF1 recipients. The overall goal of this dissertation was to identify the players involved and begin to understand the potential mechanisms underlying the suppressive effect of the male microbiota on disease. Three aims were designed to address these issues. The goal of aim 1 was to identify the bacterial populations in the microbiota of female and male BWF1 mice that may either cause or suppress disease. The goal of aim 2 was to analyze the function of female and male microbiota by identifying metabolites that may be involved in the suppression of disease. In aims 1 and 2, we also investigated the impact of androgens on bacterial populations and metabolite profiles, respectively, by comparing intact and castrated male mice. In aim 3, the goal was to investigate the potential immune mechanisms that could underlie the suppression of disease mediated by male microbiota. The results of the first aim indicate that changes in the abundances of Bacteroides, Clostridium, and Alistipes strongly correlated with the ability of transferred male BWF1 microbiota to suppress disease in female BWF1 recipients. We took advantage of a change in animal facility that had a significant impact on our mouse colony and its microbiota populations, and gave us an opportunity to analyze and compare bacterial populations during periods of time when microbiota transfers had varying results. Specifically, we found that Bacteroides (primarily the Bacteroides acidifaciens species) abundance was high, Clostridium (primarily the Clostridium leptum species) abundance was low, and Alistipes was present during the periods when transfer of male microbiota was effective at suppressing disease in female BWF1 mice. Conversely, Bacteroides abundance was low, Clostridium abundance was high, and Alistipes was absent when male microbiota lost that capability. We concluded from our thorough microbiota analyses that a high Bacteroides/Clostridium ratio in the male microbiota may be a reliable predictor of disease-suppressing capability, since it correlated strongly with disease suppression in female recipients of male microbiota. The second aim of the project used analysis of metabolomic profiles to investigate functional differences in female and male BWF1 microbiota. Differential production of immunomodulatory metabolites is a major mechanism by which the gut microbiota influences the immune system. By measuring the fecal metabolite profiles, we identified phytol as a potential mediator of lupus suppression by male microbiota. Phytol is produced by the microbiota and converted into phytanic acid by host enzymes. Both phytol and phytanic acid were significantly more abundant in intact male than either female or castrated male BWF1 mice. Both phytol and phytanic acid have potent RXR and PPARγ agonist properties, all of which can directly influence many different immune functions. The third aim of this project investigated the differences in female and male macrophage efferocytosis (i.e., phagocytosis of apoptotic cells) efficacy and how phytol and/or phytanic acid could affect this immune function. Deficiencies in efferocytosis, particularly by macrophages, are a major risk factor for SLE because they result in the accumulation of debris that stimulates autoantibody production. We found male BWF1 splenic macrophages were more efficient at efferocytosis than female splenic macrophages, and treatment with phytanic acid in vitro or in vivo could enhance female splenic macrophage efferocytosis. Overall, we found that higher Bacteroides and lower Clostridium abundances correlated with lupus suppression in female BWF1 recipients of male microbiota, and speculate that this protection could be due, at least in part, to higher levels of phytol and phytanic acid production in males. Furthermore, phytol and phytanic acid produced by males may suppress disease, again at least in part, via enhancement of macrophage efferocytosis. Taken together, these data may provide the basis for a mechanistic understanding of the impact that the microbiota can have on autoimmune diseases such as lupus, and for the development of novel therapies

Swimming Pool Environment and Respiratory Health Issues Experienced by Masters Swimmers: Results from a Literature Review and Survey of United States Masters Swimming Clubs

After three members of a Masters adult swim club died of lung cancer, both a literature review and survey were conducted with representatives from 746 United States Masters Swimming clubs to explore a possible relationship between swimming and cancers of the respiratory tract. Six other clubs reported known cancers of the respiratory tract among club members, but none of the other 740 clubs reported a similar cluster of lung cancer. More clubs reported cases of chronic respiratory infections and widespread complaints about air quality. While no studies exploring a relationship between swimming and lung cancer could be found in the literature, there were studies that demonstrated damage to the lungs and mutated bladder cells post-swim from the presence of Disinfectant By-Products (DBPs). Few guidelines exist for safe levels of DBPs in the indoor pool environment. Authors urge more guidance regarding the enforcement of pool policies that protect respiratory health

Intrathecal long-term gene expression by self-complementary adeno-associated virus type 1 suitable for chronic pain studies in rats

BACKGROUND: Intrathecal (IT) gene transfer is an attractive approach for targeting spinal mechanisms of nociception but the duration of gene expression achieved by reported methods is short (up to two weeks) impairing their utility in the chronic pain setting. The overall goal of this study was to develop IT gene transfer yielding true long-term transgene expression defined as ≥ 3 mo following a single vector administration. We defined "IT" administration as atraumatic injection into the lumbar cerebrospinal fluid (CSF) modeling a lumbar puncture. Our studies focused on recombinant adeno-associated virus (rAAV), one of the most promising vector types for clinical use. RESULTS: Conventional single stranded rAAV2 vectors performed poorly after IT delivery in rats. Pseudotyping of rAAV with capsids of serotypes 1, 3, and 5 was tested alone or in combination with a modification of the inverted terminal repeat. The former alters vector tropism and the latter allows packaging of self-complementary rAAV (sc-rAAV) vectors. Combining both types of modification led to the identification of sc-rAAV2/l as a vector that performed superiorly in the IT space. IT delivery of 3 × 10e9 sc-rAAV2/l particles per animal led to stable expression of enhanced green fluorescent protein (EGFP) for ≥ 3 mo detectable by Western blotting, quantitative PCR, and in a blinded study by confocal microscopy. Expression was strongest in the cauda equina and the lower sections of the spinal cord and only minimal in the forebrain. Microscopic examination of the SC fixed in situ with intact nerve roots and meninges revealed strong EGFP fluorescence in the nerve roots. CONCLUSION: sc-rAAVl mediates stable IT transgene expression for ≥ 3 mo. Our findings support the underlying hypothesis that IT target cells for gene transfer lack the machinery for efficient conversion of the single-stranded rAAV genome into double-stranded DNA and favor uptake of serotype 1 vectors over 2. Experiments presented here will provide a rational basis for utilizing IT rAAV gene transfer in basic and translational studies on chronic pain

In situ detection of boron by ChemCam on Mars

We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater

Are categorical deniers different? Understanding demographic, personality, and psychological differences between denying and admitting sex offenders

The purpose of this study was to establish whether there were demographic, personality, or psychological differences between a sample of 40 incarcerated sex offenders in categorical denial and 37 sex offenders admitting responsibility in an Australian minimum-security unit. Categorical deniers had lower IQs, were older, and were more likely to be child molesters. Criminogenically, there were no differences between categorical deniers and those who admitted their offences in relation to Static-99 risk scores. Psychologically, offenders denying their offences were significantly more shame-prone, and likely to use externalization as a method of impression-management. They were also more compulsive than those admitting their offences, but less antisocial and sadistic, when compared on personality indices. The study is limited by the small sample size however implications for further research and the treatment of categorical deniers are discussed

Search for R-Parity Violating Decays of Scalar Fermions at LEP

A search for pair-produced scalar fermions under the assumption that R-parity is not conserved has been performed using data collected with the OPAL detector at LEP. The data samples analysed correspond to an integrated luminosity of about 610 pb-1 collected at centre-of-mass energies of sqrt(s) 189-209 GeV. An important consequence of R-parity violation is that the lightest supersymmetric particle is expected to be unstable. Searches of R-parity violating decays of charged sleptons, sneutrinos and squarks have been performed under the assumptions that the lightest supersymmetric particle decays promptly and that only one of the R-parity violating couplings is dominant for each of the decay modes considered. Such processes would yield final states consisting of leptons, jets, or both with or without missing energy. No significant single-like excess of events has been observed with respect to the Standard Model expectations. Limits on the production cross- section of scalar fermions in R-parity violating scenarios are obtained. Constraints on the supersymmetric particle masses are also presented in an R-parity violating framework analogous to the Constrained Minimal Supersymmetric Standard Model.Comment: 51 pages, 24 figures, Submitted to Eur. Phys. J.

Measurement of the Hadronic Photon Structure Function F_2^gamma at LEP2

The hadronic structure function of the photon F_2^gamma is measured as a function of Bjorken x and of the factorisation scale Q^2 using data taken by the OPAL detector at LEP. Previous OPAL measurements of the x dependence of F_2^gamma are extended to an average Q^2 of 767 GeV^2. The Q^2 evolution of F_2^gamma is studied for average Q^2 between 11.9 and 1051 GeV^2. As predicted by QCD, the data show positive scaling violations in F_2^gamma. Several parameterisations of F_2^gamma are in agreement with the measurements whereas the quark-parton model prediction fails to describe the data.Comment: 4 pages, 2 figures, to appear in the proceedings of Photon 2001, Ascona, Switzerlan