Severely burned patients are highly susceptible to opportunistic infections and sepsis, owing to the loss of the protective skin barrier and immunological dysfunction. Interleukin-15 (IL-15) belongs to the IL-2 family of common gamma chain cytokines and stimulates the proliferation and activation of T (specifically memory CD8), NK and NKT cells. It has been shown to preserve T cell function and improve survival during cecal ligation and puncture (CLP)-induced sepsis in mice. However, the therapeutic efficacy of IL-15 or IL-15 superagonist (SA) during infection after burn injury has not been evaluated. Moreover, very few, if any, studies have examined, in detail, the effect of burn injury and infection on the adaptive immune system. Thus, we examined the effect of burn and sepsis on adaptive immune cell populations and the effect of IL-15 SA treatment on the host response to infection.
Methods
Mice were subjected to a 35% total body surface area burn, followed by wound infection with Pseudomonas aeruginosa. In some experiments, IL-15 SA was administered after burn injury, but before infection. Leukocytes in spleen, liver and peritoneal cavity were characterized using flow cytometry. Bacterial clearance, organ injury and survival were also assessed.
Results
Burn wound infection led to a significant decline in total white blood cell and lymphocyte counts and induced organ injury and sepsis. Burn injury caused decline in CD4+ and CD8+ T cells in the spleen, which was worsened by infection. IL-15 treatment inhibited this decline and significantly increased cell numbers and activation, as determined by CD69 expression, of CD4+, CD8+, B, NK and NKT cells in the spleen and liver after burn injury. However, IL-15 SA treatment failed to prevent burn wound sepsis-induced loss of CD4+, CD8+, B, NK and NKT cells and failed to improve bacterial clearance and survival.
Conclusion
Cutaneous burn injury and infection cause significant adaptive immune dysfunction. IL-15 SA does not augment host resistance to burn wound sepsis in mice despite inducing proliferation and activation of lymphocyte subsets. 相似文献
Early biomarker-based diagnosis of focal cortical dysplasia (FCD) represents a major clinical challenge. The aim of this study was to identify novel brain microRNAs (miRNAs) in patients with refractory epilepsy and FCD as potential biomarkers. We evaluated serum hsa-miR-4521 as a promising novel biomarker in patients with FCD. Tissue for microarray was obtained from nine patients with temporal lobe refractory epilepsy who underwent surgery to remove epileptic foci identified by cortical video electroencephalogram monitoring. Control tissue was collected from eight patients with hypertension who required emergency surgery to remove an intracranial hematoma. The Affymetrix® GeneChip® Command Console® Software (Affymetrix miRNA 4.0) was used to compare miRNA expression in the cerebral cortex of experimental and control patients. Temporal cortex tissue and serum samples were taken from the same patients for verification of hsa-miR-4521 expression by real-time quantitative polymerase chain reaction (RT-qPCR). The experimental and control patients did not differ significantly in terms of age and gender. 19.4 % (148/764) of the total miRNAs were differentially expressed in experimental and control tissue, which is in agreement with the existing literature. We selected miRNA-4521 for further analysis; the fold-change in expression was 14.4707 and the q value was almost 0, which confirmed up-regulation. Significant up-regulation of hsa-miR-4521 was further validated by RT-qPCR. miRNA microarrays can efficiently and conveniently identify differentially expressed miRNAs in epilepsy brain tissue. This is the first study to identify differential expression of hsa-miR-4521 in brain tissue and serum of refractory epilepsy patients and suggests that serum hsa-miR-4521 may represent a potential diagnostic biomarker for FCD with refractory epilepsy.
Various insects require intracellular bacteria that are restricted to specialized cells (bacteriocytes) and are transmitted vertically via the female ovary, but the transmission mechanisms are obscure. We hypothesized that, in the whitefly Bemisia tabaci, where intact bacteriocytes (and not isolated bacteria) are transferred to oocytes, the transmission mechanism would be evident as cellular and molecular differences between the nymph (pre-adult) and adult bacteriocytes. We demonstrate dramatic remodelling of bacteriocytes at the developmental transition from nymph to adulthood. This transition involves the loss of cell–cell adhesion, high division rates to constant cell size and onset of cell mobility, enabling the bacteriocytes to crawl to the ovaries. These changes are accompanied by cytoskeleton reorganization and changes in gene expression: genes functioning in cell–cell adhesion display reduced expression and genes involved in cell division, cell motility and endocytosis/exocytosis have elevated expression in adult bacteriocytes, relative to nymph bacteriocytes. This study demonstrates, for the first time, how developmentally orchestrated remodelling of gene expression and correlated changes in cell behaviour underpin the capacity of bacteriocytes to mediate the vertical transmission and persistence of the symbiotic bacteria on which the insect host depends. 相似文献
A total of 17 species of Fissocantharis Pic is recorded from Guangxi, China. Six species are described new to science, Fissocantharissinensomima
sp. n., Fissocantharissexcostata
sp. n., Fissocantharisbasilaris
sp. n., Fissocanthariseschara
sp. n., Fissocantharislatipalpa
sp. n. and Fissocantharisbiprojicientis
sp. n., and two previously known species are redescribed, Fissocantharisgracilipes (Pic, 1927) and Fissocantharissinensis (Wittmer, 1988). These species are presented with habitus of males, abdominal sternites VIII of females and genitalia of both sexes. Fissocantharisflavofacialis (Pic, 1926) is synonymized with Fissocantharisangusta (Fairmaire, 1900); both were originally described in the genus Podabrus Westwood. Additionally, a key and a checklist of all the species of Fissocantharis from Guangxi are provided. 相似文献
A new species is described, Themus (Themus) dimorphus
sp. n. from Yunnan, China. Themus (Themus) testaceicollis Wittmer, 1983 is redescribed and compared with the new species. The two species are illustrated with habitus and genitalia of both sexes and abdominal sternites VIII of female. 相似文献
The recent expansion of genetic and genomic tools for metabolic engineering has accelerated the development of microorganisms for the industrial production of desired compounds. We have used transposable elements to identify chromosomal locations in the obligate methanotroph Methylomonas sp. strain 16a that support high-level expression of genes involved in the synthesis of the C40 carotenoids canthaxanthin and astaxanthin. with three promoterless carotenoid transposons, five chromosomal locations—the fliCS, hsdM, ccp-3, cysH, and nirS regions—were identified. Total carotenoid synthesis increased 10- to 20-fold when the carotenoid gene clusters were inserted at these chromosomal locations compared to when the same carotenoid gene clusters were integrated at neutral locations under the control of the promoter for the gene conferring resistance to chloramphenicol. A chromosomal integration system based on sucrose lethality was used to make targeted gene deletions or site-specific integration of the carotenoid gene cluster into the Methylomonas genome without leaving genetic scars in the chromosome from the antibiotic resistance genes that are present on the integration vector. The genetic approaches described in this work demonstrate how metabolic engineering of microorganisms, including the less-studied environmental isolates, can be greatly enhanced by identifying integration sites within the chromosome of the host that permit optimal expression of the target genes. 相似文献