Immune and inflammatory responses to Leishmania amazonensis isolated from different clinical forms of human leishmaniasis in CBA mice

Leishmania amazonensis causes different diseases depending on the host and parasitic virulence factors. In this study, CBA mice were infected with L. amazonensis isolates from patients with localized (Ba125), diffuse cutaneous (Ba276) or visceral leishmaniasis (Ba109). Mice infected with Ba125 and Ba276 progressed rapidly and lesions displayed an infiltrate rich in parasitized macrophages and were necrotic and ulcerated. Ba109 induced smaller lesions and a mixed inflammatory infiltrate without necrosis or ulceration. Ba109 induced an insidious disease with lower parasite load in CBA mice, similar to human disease. Levels of IFN-γ, IL-4 and IL-10 did not differ among the groups. Because all groups were unable to control the infection, expression of IL-4 associated with low production of IFN-γ in the early phase of infection may account for susceptibility, but others factors may contribute to the differences observed in inflammatory responses and infection progression. Evaluation of some parasitic virulence factors revealed that Ba276 exhibits higher ecto-ADPase and 5'-nucleotidase activities compared to the Ba109 and Ba125 strains. Both Ba276 and Ba125 had higher arginase activity in comparison to Ba109. Finally, these data suggest that the differences in enzyme activities among parasites can account for differences in host inflammatory responses and infection progression.     

Endogenous transplacental transmission of Neospora hughesi in naturally infected horses

Over a 2-yr study period, we investigated possible endogenous transplacental transmission of Neospora hughesi in 74 mare and foal pairs following the diagnosis of neuronal neosporosis in a weanling foal. Presuckle and postsuckle serum of each foal, serum and colostrum of each periparturient mare, and serum of each mare and foal pair, collected at 3-mo intervals thereafter, were tested for N. hughesi using an indirect fluorescent antibody test (IFAT). Furthermore, whole blood and colostrum samples and placentae were tested for the presence of N. hughesi by real-time PCR. The mares' seroprevalence at foaling based on IFAT (titer ≥ 160) was 52 and 6% in 2006 and 2007, respectively. Colostral antibodies against N. hughesi were detected in 96 and 11% of the mares in the 2-yr study. With the exception of 3 foals, all remaining foals were born seronegative to N. hughesi. Passive transfer of colostral antibodies to N. hughesi was documented in 15 foals. Three foals born from 2 different mares had presuckle antibodies at a titer ranging from 2,560 to 20,480. All 3 foals were born healthy. Two foals were born to the same dam that also gave birth to the weanling diagnosed with neuronal neosporosis in 2005. The third foal was born to a second mare with no previous foaling history at the farm. Seroconversion was documented in 10 foals and 9 mares over the 2-yr study. All blood and colostrum samples tested PCR negative for N. hughesi. Only 1 placenta collected in 2007 from the mare with the 2 congenitally infected foals tested PCR positive for N. hughesi. In conclusion, N. hughesi persisted in this population via endogenous transplacental infection.     

Quantitative trait loci for electrical seizure threshold mapped in C57BLKS/J and C57BL/10SnJ mice

We mapped the quantitative trait loci (QTL) that contribute to the robust difference in maximal electroshock seizure threshold (MEST) between C57BLKS/J (BKS) and C57BL10S/J (B10S) mice. BKS, B10S, BKS × B10S F1 and BKS × B10S F2 intercross mice were tested for MEST at 8-9 weeks of age. Results of F2 testing showed that, in this cross, MEST is a continuously distributed trait determined by polygenic inheritance. Mice from the extremes of the trait distribution were genotyped using microarray technology. MEST correlated significantly with body weight and sex; however, because of the high correlation between these factors, the QTL mapping was conditioned on sex alone. A sequential series of statistical analyses was used to map QTLs including single-point, multipoint and multilocus methods. Two QTLs reached genome-wide levels of significance based upon an empirically determined permutation threshold: chromosome 6 (LOD = 6.0 at ～69 cM) and chromosome 8 (LOD = 5.7 at ～27 cM). Two additional QTLs were retained in a multilocus regression model: chromosome 3 (LOD = 2.1 at ～68 cM) and chromosome 5 (LOD = 2.7 at ～73 cM). Together the four QTLs explain one third of the total phenotypic variance in the mapping population. Lack of overlap between the major MEST QTLs mapped here in BKS and B10S mice and those mapped previously in C57BL/6J and DBA/2J mice (strains that are closely related to BKS and B10S) suggest that BKS and B10S represent a new polygenic mouse model for investigating susceptibility to seizures.     

Cilomilast counteracts the effects of cigarette smoke in airway epithelial cells

Cigarette smoke extracts (CSE) alter TLR4 expression and activation in bronchial epithelial cells. Cilomilast, a phosphodiesterase-4 inhibitor, inhibits cigarette smoke-induced neutrophilia.This study was aimed to explore whether cilomilast, in a human bronchial epithelial cell line (16-HBE), counteracted CSE effects. In particular, TLR4 expression, IP-10 and IL-8 release, lymphocyte and neutrophil chemotactic activity and ERK and IkBa phosphorylation in CSE and LPS-stimulated 16-HBE were assessed.CSE increased TLR4 expression, reduced IP-10 release and lymphocyte chemotactic activity and increased IL-8 release and neutrophil chemotactic activity. Cilomilast reduced TLR4 expression, IL-8 release and neutrophil chemotactic activity as well as it increased IP-10 release and lymphocyte chemotactic activity. All these cilomilast mediated effects were associated with a reduced ERK1/2 and with an increased IkBa phosphorylation.In conclusion, the present study provides compelling evidences that cilomilast may be considered a possible valid therapeutic option in controlling inflammatory processes present in smokers.     

Beta defensin-2 is reduced in central but not in distal airways of smoker COPD patients

Background

Altered pulmonary defenses in chronic obstructive pulmonary disease (COPD) may promote distal airways bacterial colonization. The expression/activation of Toll Like receptors (TLR) and beta 2 defensin (HBD2) release by epithelial cells crucially affect pulmonary defence mechanisms.

Methods

The epithelial expression of TLR4 and of HBD2 was assessed in surgical specimens from current smokers COPD (s-COPD; n = 17), ex-smokers COPD (ex-s-COPD; n = 8), smokers without COPD (S; n = 12), and from non-smoker non-COPD subjects (C; n = 13).

Results

In distal airways, s-COPD highly expressed TLR4 and HBD2. In central airways, S and s-COPD showed increased TLR4 expression. Lower HBD2 expression was observed in central airways of s-COPD when compared to S and to ex-s-COPD. s-COPD had a reduced HBD2 gene expression as demonstrated by real-time PCR on micro-dissected bronchial epithelial cells. Furthermore, HBD2 expression positively correlated with FEV1/FVC ratio and inversely correlated with the cigarette smoke exposure. In a bronchial epithelial cell line (16 HBE) IL-1β significantly induced the HBD2 mRNA expression and cigarette smoke extracts significantly counteracted this IL-1 mediated effect reducing both the activation of NFkB pathway and the interaction between NFkB and HBD2 promoter.

Conclusions

This study provides new insights on the possible mechanisms involved in the alteration of innate immunity mechanisms in COPD.     

Clinical significance of circulating interleukin-23 as a prognostic factor in breast cancer patients

Little is known about specific IL‐23 alterations associated with breast cancer and the data available are still controversial. Therefore, the evaluation of changes in serum IL‐23 levels may add further information on the role of this cytokine in breast cancer patients. The aim of this study was to evaluate prospectively the prognostic importance of circulating IL‐23 in patients with untreated breast cancer, respect to healthy controls, and the association with clinico‐pathological variables. The study involved 50 women diagnosed with stages I–IV breast cancer and 38 healthy controls. Of the 50 breast cancer patients, 37 women were recruited prior to their initial adjuvant chemotherapy and 13 prior to receive first line chemotherapy for metastatic disease. Adjuvant chemotherapy patients were at least in their 4th week post‐surgery. IL‐23 serum concentrations were measured by a quantitative enzyme immunoassay technique. We found a statistically significant higher systemic cytokine value in women with cancer in comparison with the control group (14.52 ± 11.39 pg/ml vs. 6.35 ± 4.63 pg/ml, P < 0.0001). Patients with shorter overall survival presented higher IL‐23 values, suggesting a negative prognostic correlation. There was no significant differences in IL‐23 levels among patients according to the biomolecular characteristics, the different subtypes and the presence of metastatic disease. This work investigated, for the first time, the role of IL‐23 in breast cancer patients showing a significant increase respect the control group. However, further validations are needed in larger studies to better investigate the implications of IL‐23 increase in these patients. J. Cell. Biochem. 113: 2122–2125, 2012. © 2012 Wiley Periodicals, Inc.     

Fungal Assemblages Associated with Roots of Halophytic and Non-halophytic Plant Species Vary Differentially Along a Salinity Gradient

Structure of fungal communities is known to be influenced by host plants and environmental conditions. However, in most cases, the dynamics of these variation patterns are poorly understood. In this work, we compared richness, diversity, and composition between assemblages of endophytic and rhizospheric fungi associated to roots of two plants with different lifestyles: the halophyte Inula crithmoides and the non-halophyte I. viscosa (syn. Dittrichia viscosa L.), along a spatially short salinity gradient. Roots and rhizospheric soil from these plants were collected at three points between a salt marsh and a sand dune, and fungi were isolated and characterized by ITS rDNA sequencing. Isolates were classified in a total of 90 operational taxonomic units (OTUs), belonging to 17 fungal orders within Ascomycota and Basidiomycota. Species composition of endophytic and soil communities significantly differed across samples. Endophyte communities of I. crithmoides and I. viscosa were only similar in the intermediate zone between the salt marsh and the dune, and while the latter displayed a single, generalist association of endophytes, I. crithmoides harbored different assemblages along the gradient, adapted to the specific soil conditions. In the lower salt marsh, root assemblages were strongly dominated by a single dark septate sterile fungus, also prevalent in other neighboring salt marshes. Interestingly, although its occurrence was positively correlated to soil salinity, in vitro assays revealed a strong inhibition of its growth by salts. Our results suggest that host lifestyle and soil characteristics have a strong effect on endophytic fungi and that environmental stress may entail tight plant-fungus relationships for adaptation to unfavorable conditions.     

Do restored oyster reefs benefit seagrasses? An experimental study in the Northern Gulf of Mexico

Oyster reefs and seagrass beds are being lost worldwide at alarming rates. These habitats provide many services to humankind and, thus, much effort has been dedicated to their restoration. Here, we examine the efficacy of created oyster reefs at enhancing seagrass beds through the amelioration of hydrographic conditions and water quality. We carried out a field experiment in the Northern Gulf of Mexico where we compared areas shoreward of created reefs with adjacent reef‐free areas over several years using a before‐after control‐impact (BACI) design. The reefs were built with oyster shell, measured 65 m, and were placed at circa 100 m from the shoreline to ensure subtidal conditions and enhance oyster recruitment. The BACI results showed few and disparate effects of the reefs, even when distance from the reef was factored in. However, we found a temporal increase in seagrass cover throughout all the experimental area (i.e. including both reef and control plots) following reef deployment. Interestingly, further analysis with satellite imagery showed the experimental area had higher seagrass cover 5 years after reef deployment than it did before reef deployment, but such increase was not observed for nearby areas. In concert, the results suggest “shadow” effects for the reefs examined, where positive effects on seagrass beds extend beyond the area directly shoreward from the reef. Oyster reef restoration may have positive impacts on shallow seagrass beds in turbid, high‐energy systems; however, more work on the extent and mechanisms for this interaction is needed.     

Kalirin/Trio Rho guanine nucleotide exchange factors regulate a novel step in secretory granule maturation

The molecular mechanisms involved in the maturation of secretory granules, organelles that store hormones and neuropeptides, are poorly understood. As granule content proteins are processed, the composition of granule membranes changes, yielding constitutive-like secretion of immature content proteins and producing secretagogue-responsive mature granules. Constitutive-like secretion was not previously recognized as a process subject to regulation. We show that Kalirin and Trio, homologous Rho guanine nucleotide exchange factors (GEFs), which interact with a secretory granule resident protein, modulate cargo secretion from immature granules. Some of the Kalirin and Trio isoforms expressed in neuroendocrine cells colocalize with immature granules. Overexpression of their N-terminal GEF domain (GEF1) enhances secretion from immature granules, depleting cells of secretory cargo in the absence of secretagogue. This response requires GEF1 activity and is mimicked by Kalirin/Trio substrates Rac1 and RhoG. Accordingly, selective pharmacological inhibition of endogenous GEF1 activity decreases secretagogue-independent release of hormone precursors, accumulating product peptide in mature secretory granules. Kalirin/Trio modulation of cargo secretion from immature granules provides secretory cells with an extra layer of control over the sets of peptides released. Control of this step enhances the range of physiological responses that can be elicited, whereas lack of control could have pathological consequences.