Selective permeability changes in the lungs and airways of sheep after toxic smoke inhalation

The effect of toxic smoke inhalation on selective microvascular sieving of macro-molecules and lymph protein flux was assessed in adult sheep to determine whether the time course of microvascular dysfunction differs between the lung and trachea. Protein flux across the lung increased sixfold 48 h after inhalation of the products of incomplete cotton combustion, whereas tracheal protein flux increased fivefold 8 h after exposure and returned to near base line 48 h after exposure. The lung and trachea selectively retained some sieving to three different protein macromolecules with molecular radii of 36, 54, and 123 A. In the lungs the sieving selectivity for these macromolecules was least 48 h after injury, and in the trachea molecular selectivity was least 8 h after injury. These data suggest that the time course of microvascular injury differs for the trachea and the lung; microvascular changes are detected earlier in the trachea than in the lung. The inhalation injury described thus permits the characterization of the time course of airway and lung microvascular changes.     

Role for IL-4 nonproducing NKT cells in CC-chemokine ligand 2-induced Th2 cell generation

NKT cells from C57Bl/6 mice are known to be the initial cellular source of IL-4 that acts as a trigger for Th2 cell differentiation. CC-chemokine ligand 2 (CCL2) has been described as an initial stimulator of IL-4 production by these cells; however, IL-4 was not produced by NKT cells from BALB/c mice even when Th2 cell responses were established in these mice. In this study, we found a new pathway for CCL2-associated Th2 cell generation in BALB/c mice. Splenic T cells from BALB/c mice produced IL-4 in response to CCL2 stimulation. However, IL-4 production was not seen in cultures of splenic T cells from CD1-/- mice (BALB/c origin), whereas, in the presence of CCL2, splenic T cells from CD1-/- mice produced IL-4 when NKT cells from wild-type mice were added. CCL2 induced IL-4 in cultures of NKT cells cocultured with naive T cells, but IL-4 was not produced by these cells cultured separately with CCL2. Interestingly, IL-4 was produced by naive T cells cocultured with NKT cells that were previously treated with CCL2 (CCL2-NKT cells). In addition, IL-4 was produced by naive T cells supplemented with a culture supernatant of CCL2-NKT cells. These results indicate that, through the production of a soluble factor(s) other than IL-4, NKT cells play a role in the CCL2-associated generation of Th2 cells.     

Towards a comprehensive barcode library for arctic life - Ephemeroptera, Plecoptera, and Trichoptera of Churchill, Manitoba, Canada

Background

In order to understand the role of herbivores in trophic webs, it is essential to know what they feed on. Diet analysis is, however, a challenge in many small herbivores with a secretive life style. In this paper, we compare novel (high-throughput pyrosequencing) DNA barcoding technology for plant mixture with traditional microhistological method. We analysed stomach contents of two ecologically important subarctic vole species, Microtus oeconomus and Myodes rufocanus, with the two methods. DNA barcoding was conducted using the P6-loop of the chloroplast trnL (UAA) intron.

Results

Although the identified plant taxa in the diets matched relatively well between the two methods, DNA barcoding gave by far taxonomically more detailed results. Quantitative comparison of results was difficult, mainly due to low taxonomic resolution of the microhistological method, which also in part explained discrepancies between the methods. Other discrepancies were likely due to biases mostly in the microhistological analysis.

Conclusion

We conclude that DNA barcoding opens up for new possibilities in the study of plant-herbivore interactions, giving a detailed and relatively unbiased picture of food utilization of herbivores.     

M2b monocytes predominated in peripheral blood of severely burned patients

Severely burned patients were shown to be carriers of M2 monocytes, and all of the monocytes isolated from peripheral blood of severely burned patients (19 of 19 patients) were demonstrated as M2b monocytes (IL-12(-)IL-10(+)CCL1(+) monocytes). Low levels of M2a (IL-12(-)IL-10(+)CCL17(+) monocytes) and M2c monocytes (IL-12(-)IL-10(+)CXCL13(+) monocytes) were demonstrated in peripheral blood of severely burned patients (M2a, 2 of 19 patients; M2c, 5 of 19 patients). M2b, M2a, and M2c monocytes were not detected in peripheral blood of healthy donors. However, M2b monocytes appeared when healthy donor monocytes were cultured in media supplemented with burn patient serum (15%). CCL2 was detected in sera of all burn patients, and M2b monocytes were not generated from healthy donor monocytes cultured with media containing 15% burn patient sera that were previously treated with anti-CCL2 mAb. In addition, M2b monocytes were generated from healthy donor monocytes in cultures supplemented with rCCL2. These results indicate that M2b monocytes are predominant in peripheral blood of severely burned patients who are carriers of CCL2 that functions to stimulate monocyte conversion from resident monocytes to M2b monocytes.     

Gene expression analysis in burn wounds of rats

The events occurring early in the burn wound trigger a sequence of local and systemic responses that influence cell and tissue survival and, consequently, wound healing and recovery. Using high-density oligonucleotide arrays we identified gene expression patterns in skin samples taken from a region of injury in the burn rat model. The associated genomic events include the differential expression of genes involved in cell survival and death, cell growth regulation, cell metabolism, inflammation, and immune response. The functional gene cluster detected and their time appearance matched the time sequence known to occur in burn wound healing.     

Role of TNF-alpha in gut mucosal changes after severe burn

Gut epithelial cell death by apoptosis is increased in the gut epithelium after severe burn associated with mucosal atrophy. We hypothesized that tumor necrosis factor (TNF)-alpha-TNF receptor (TNFR) interaction activates apoptosis in small bowel mucosal cells after severe burn. C57BL6 mice received a 30% total body surface area scald burn and were treated with neutralizing anti-TNF-alpha. The proximal small bowel was assessed for mucosal atrophy. Proliferation and apoptosis of mucosal cells were assessed by proliferative cell nuclear antigen-immunostaining and terminal deoxyuridine nick-end labeling assay, respectively. Mucosal height and mucosal cell number decreased after burn. Anti-TNF-alpha-treated mice showed significantly less mucosal atrophy. Proliferation of intestinal cells was not changed with burn or anti-TNF-alpha treatment. An over threefold increase in apoptotic cell number was seen after burn, which was diminished by anti-TNF-alpha treatment. Changes in gut mucosal homeostasis after severe burn are affected, in part, by the activation of apoptosis by TNF-alpha-TNFR interaction.     

TRAIL: a mechanism of tumor surveillance in an immune privileged site

TRAIL is a recently described member of the TNF superfamily. The ability of TRAIL to induce apoptosis in a large number of tumors has stimulated interest in TRAIL as a tumor therapeutic agent. Although TRAIL mRNA is expressed in a number of tissues, its functional significance to various organs is unknown. Because tumors rarely develop in the eye, we have examined this organ for functional TRAIL expression. Our analysis revealed that TRAIL mRNA and protein are constitutively expressed on numerous ocular structures, including the cornea and retina. More importantly, ocular tissue displays functional TRAIL as determined by in vitro killing of TRAIL-sensitive tumor cell lines. Previous studies have shown that ocular tissue also expresses functional Fas ligand (FasL). To assess the contribution of TRAIL and FasL for tumor cell killing in the eye, cell lines susceptible to both TRAIL and FasL were examined. The results show that ocular tissue kills via either ligand, suggesting a compensatory mechanism between TRAIL and FasL. Collectively, these results provide physiological evidence for ocular TRAIL expression, and suggest a role for this molecule in tumor surveillance in an immune privileged site.