Assessing cellular and genomic damage from environmental nickel using a GFP containing strain of Caenorhabditis elegans

Nickel is a naturally found mineral that has become widely used for many electronic devices. As use and subsequent discarding of nickel containing products continues exposure to nickel increases. Nickel can cause external superficial symptoms but if it enters the body the potential exists for genomic damage to occur which could lead to mutation and cancer. Nickel can act by generation of reactive oxygen species, interacting with DNA and altering chromatin wrapping. By utilizing a strain of C. elegans with a ced-1::gfp fusion protein, that detects apoptotic cells in the germ line, the deleterious effects of nickel can be analyzed. Analyses of varying concentrations of a water-soluble and an insoluble form of nickel have been done. Insoluble nickel is held to be more hazardous because while soluble easily enters and exits the cell insoluble nickel can remain in the cell for extended periods allowing for much greater damage. The results of this study were inconclusive about the effects of soluble versus insoluble nickel. Previous testing using the C. elegans germline to assess the effects of nickel have used 12 hour exposures (Kezhou et al. 2010). Tests completed in this study exposed animals to lower concentrations of nickel for their full development. A rise in cell deaths is seen as nickel concentration increases which was quantified with ced-1::gfp and Syto12. Analysis using a strain with resistance to heavy metals had no significant increase in engulfments when exposed to nickel, which shows nickel exposure to have been the cause of increased engulfments seen in the wild-type. A lack of increased engulfments in a strain with a mutation to cep-1, the C. elegans homolog of p53, indicated damage from nickel is recognized by the p53 damage pathway.  M.S

The microbiome in wound repair and tissue fibrosis

Bacterial colonization occurs in all wounds, chronic or acute, and the break in epithelium integrity that defines a wound impairs the forces that shape and constrain the microbiome at that site. This review highlights the interactions between bacterial communities in the wound and the ultimate resolution of the wound or development of fibrotic lesions. Chronic wounds support complex microbial communities comprising a wide variety of bacterial phyla, genera, and species, including some fastidious anaerobic bacteria not identified using culture‐based methods. Thus, the complexity of bacterial communities in wounds has historically been underestimated. There are a number of intriguing possibilities to explain these results that may also provide novel insights into changes and adaptation of bacterial metabolic networks in inflamed and wounded mucosa, including the critical role of biofilm formation. It is well accepted that the heightened state of activation of host cells in a wound that is driven by the microbiota can certainly lead to detrimental effects on wound regeneration, but the microbiota of the wound may also have beneficial effects on wound healing. Studies in experimental systems have clearly demonstrated a beneficial effect for members of the gut microbiota on regulation of systemic inflammation, which could also impact wound healing at sites outside the gastrointestinal tract. The utilization of culture‐independent microbiology to characterize the microbiome of wounds and surrounding mucosa has raised many intriguing questions regarding previously held notions about the cause and effect relationships between bacterial colonization and wound repair and mechanisms involved in this symbiotic relationship.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95009/1/path4118.pd

A tale of two sites: how inflammation can reshape the microbiomes of the gut and lungs

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141495/1/jlb0943.pd

A. Casadevall and J.R. Perfect, Cryptococcus neoformans

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43272/1/11046_2004_Article_258903.pd

CCR2 mediates Helicobacter pyloriâ induced immune tolerance and contributes to mucosal homeostasis

BackgroundWe previously demonstrated that H. pylori infection leads to increased induction of regulatory T cells in local and systemic immune compartments. Here, we investigate the role of CCR2 in the tolerogenic programing of dendritic cells in a mouse model of H. pylori infection.Materials and MethodsCCR2 deficient (CCR2KO) mice and wildâ type (Wt) mice infected with H. pylori SS1 strain were analyzed by qPCR and FACS analysis. In vitro, bone marrowâ derived DC on day 6 from CCR2KO and Wt mice cocultured with or without H. pylori were examined to determine the impact of CCR2 signaling on dendritic cells function by qPCR, ELISA, and FACS analyses.ResultsAcute H. pylori infection was associated with a threefold increase in CCR2 mRNA expression in the gastric mucosa. H. pyloriâ infected CCR2KO mice exhibited a higher degree of mucosal inflammation, that is, increased gastritis scores and proâ inflammatory cytokine mRNA levels, but lower degree of H. pylori gastric colonization compared to infected Wt mice. Peripheral H. pyloriâ specific immune response measured in the CCR2KO spleen was characterized by a higher Th17 response and a lower Treg response. In vitro, CCR2KO bone marrowâ derived DC was less mature and shown a lower Treg/Th17 ratio. Moreover, blockade of CCR2 signaling by MCPâ 1 neutralizing antibody inhibited H. pyloriâ stimulated bone marrowâ derived DC maturation.ConclusionsOur results indicate that CCR2 plays an essential role in H. pyloriâ induced immune tolerance and shed light on a novel mechanism of CCR2â dependent DC Treg induction, which appears to be important in maintaining mucosal homeostasis during H. pylori infection.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136416/1/hel12366.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136416/2/hel12366_am.pd

The role of ILâ 5 in bleomycinâ induced pulmonary fibrosis

Eosinophils are known to express cytokines capable of promoting fibrosis. Interleukinâ 5 (ILâ 5) is important in regulating eosinophilopoiesis, eosinophil recruitment and activation. Lung ILâ 5 expression is elevated in pulmonary fibrosis, wherein the eosinophil is a primary source of fibrogenic cytokines. To determine the role of ILâ 5 in pulmonary fibrosis, the effects of antiâ ILâ 5 antibody were investigated in a model of bleomycinâ induced pulmonary fibrosis. Fibrosis was induced in mice by endotracheal bleomycin treatment. Animals were also treated with either antiâ ILâ 5 antibody or control IgG. Lungs were then analyzed for fibrosis, eosinophil influx, chemotactic activity, and cytokine expression. The results show that a primary chemotactic activity at the height of eosinophil recruitment is ILâ 5. Furthermore, antiâ ILâ 5 antibody caused significant reduction in lung eosinophilia, cytokine expression, and fibrosis. These findings taken together suggest an important role for ILâ 5 in pulmonary fibrosis via its ability to regulate eosinophilic inflammation, and thus eosinophilâ dependent fibrogenic cytokine production. J. Leukoc. Biol. 64: 657â 666; 1998.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141191/1/jlb0657.pd

Cell-associated bacteria in the human lung microbiome

Abstract Background Recent studies have revealed that bronchoalveolar lavage (BAL) fluid contains previously unappreciated communities of bacteria. In vitro and in vivo studies have shown that host inflammatory signals prompt bacteria to disperse from cell-associated biofilms and adopt a virulent free-living phenotype. The proportion of the lung microbiota that is cell-associated is unknown. Results Forty-six BAL specimens were obtained from lung transplant recipients and divided into two aliquots: ‘whole BAL’ and ‘acellular BAL,’ the latter processed with a low-speed, short-duration centrifugation step. Both aliquots were analyzed via bacterial 16S rRNA gene pyrosequencing. The BAL specimens represented a wide spectrum of lung health, ranging from healthy and asymptomatic to acutely infected. Bacterial signal was detected in 52% of acellular BAL aliquots, fewer than were detected in whole BAL (96%, p ≤ 0.0001). Detection of bacteria in acellular BAL was associated with indices of acute infection [BAL neutrophilia, high total bacterial (16S) DNA, low community diversity, p < 0.01 for all] and, independently, with low relative abundance of specific taxonomic groups (p < 0.05). When whole and acellular aliquots from the same bronchoscopy were directly compared, acellular BAL contained fewer bacterial species (p < 0.05); whole and acellular BAL similarity was positively associated with evidence of infection and negatively associated with relative abundance of several prominent taxa (p < 0.001). Acellular BAL contained decreased relative abundance of Prevotella spp. (p < 0.05) and Pseudomonas fluorescens (p < 0.05). Conclusions We present a novel methodological and analytical approach to the localization of lung microbiota and show that prominent members of the lung microbiome are cell-associated, potentially via biofilms, cell adhesion, or intracellularity.http://deepblue.lib.umich.edu/bitstream/2027.42/111056/1/40168_2014_Article_75.pd

Role of interferon‐γ and inflammatory monocytes in driving colonic inflammation during acute Clostridium difficile infection in mice

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136491/1/imm12700.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136491/2/imm12700_am.pd

Pulmonary Inflammation Induced by Incomplete or Inactivated Adenoviral Particles

Overview summary The amount of pulmonary inflammation induced in mice by intratracheal administration of high doses of adenoviral vectors was compared to that induced by viral particles that lack the ability to express the genes that they contain. The number of inflammatory cells infiltrating the lung 6 days after particle administration was similar between animals receiving normal versus defective adenoviral particles.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63169/1/hum.1995.6.12-1553.pd