A New MAP Kinase Protein Involved in Estradiol-Stimulated Reproduction of the Helminth Parasite Taenia crassiceps

MAP kinases (MAPK) are involved in the regulation of cellular processes such as reproduction and growth. In parasites, the role of MAPK has been scarcely studied. Here, we describe the participation of an ERK-like protein in estrogen-dependent reproduction of the helminth parasite Taenia crassiceps. Our results show that 17β-estradiol induces a concentration-dependent increase in the bud number of in vitro cultured cysticerci. If parasites are also incubated in presence of an ERK-inhibitor, the stimulatory effect of estrogen is blocked. The expression of ERK-like mRNA and its corresponding protein was detected in the parasite. The ERK-like protein was over-expressed by all treatments. Nevertheless, a strong induction of phosphorylation of this protein was observed only in response to 17β-estradiol. Cross-contamination by host cells was discarded by flow cytometry analysis. Parasite cells expressing the ERK-like protein were exclusively located at the subtegument tissue by confocal microscopy. Finally, the ERK-like protein was separated by bidimensional electrophoresis and then sequenced, showing the conserved TEY activation motif, typical of all known ERK 1/2 proteins. Our results show that an ERK-like protein is involved in the molecular signalling during the interaction between the host and T. crassiceps, and may be considered as target for anti-helminth drugs design

Regulation of Intestinal Immune Response by Selective Removal of the Anterior, Posterior, or Entire Pituitary Gland in Trichinella spiralis Infected Golden Hamsters

The influence of anterior pituitary hormones on the gastrointestinal tract of humans and animals has been previously reported. Hypophysectomy (HYPOX) in the rat causes atrophy of the intestinal mucosa, and reduction of gastric secretion and intestinal absorption, as well as increased susceptibility to bacterial and viral infections. However, to our knowledge, no findings have been published concerning the immune response following HYPOX during worm infection, particularly that which is caused by the nematode Trichinella spiralis. The aim of this work was to analyze the effects of total or partial HYPOX on colonization of T. spiralis in the intestinal lumen, together with duodenal and splenic cytokine expression. Our results indicate that 5 days post infection, only neurointermediate pituitary lobectomy (NIL) reduces the number of intestinally recovered T. spiralis larvae. Using semiquantitative inmunofluorescent laser confocal microscopy, we observed that the mean intensity of all tested Th1 cytokines was markedly diminished, even in the duodenum of infected controls. In contrast, a high level of expression of these cytokines was noted in the NIL infected hamsters. Likewise, a significant decrease in the fluorescence intensity of Th2 cytokines (with the exception of IL-4) was apparent in the duodenum of control and sham infected hamsters, compared to animals with NIL surgeries, which showed an increase in the expression of IL-5 and IL-13. Histology of duodenal mucosa from NIL hamsters showed an exacerbated inflammatory infiltrate located along the lamina propria, which was related to the presence of the parasite. We conclude that hormones from each pituitary lobe affect the gastrointestinal immune responses to T. spiralis through various mechanisms

The metabolic switch can be activated in a recombinant strain of Streptomyces lividans by a low oxygen transfer rate in shake flasks

Abstract Background In Streptomyces, understanding the switch from primary to secondary metabolism is important for maximizing the production of secondary metabolites such as antibiotics, as well as for optimizing recombinant glycoprotein production. Differences in Streptomyces lividans bacterial aggregation as well as recombinant glycoprotein production and O-mannosylation have been reported due to modifications in the shake flask design. We hypothetized that such differences are related to the metabolic switch that occurs under oxygen-limiting conditions in the cultures. Results Shake flask design was found to affect undecylprodigiosin (RED, a marker of secondary metabolism) production; the RED yield was 12 and 385 times greater in conventional normal Erlenmeyer flasks (NF) than in baffled flasks (BF) and coiled flasks (CF), respectively. In addition, oxygen transfer rates (OTR) and carbon dioxide transfer rates were almost 15 times greater in cultures in CF and BF as compared with those in NF. Based on these data, we obtained respiration quotients (RQ) consistent with aerobic metabolism for CF and BF, but an RQ suggestive of anaerobic metabolism for NF. Conclusion Although the metabolic switch is usually related to limitations in phosphate and nitrogen in Streptomyces sp., our results reveal that it can also be activated by low OTR, dramatically affecting recombinant glycoprotein production and O-mannosylation and increasing RED synthesis in the process

Effects of neurosurgery on spleen characteristics.

<p>(A) Only HYPOX animals showed a tendency to decrease in spleen weight, and no significant differences in spleen weight were observed in any other group. One-way ANOVA. N = 6−10. *** = P<0.001, ** = P<0.01, * = P<0.05.</p

Th2-type related cytokine expression in the duodenum of hamsters experimentally infected with <i>T. spiralis</i> at 5 days p.

<p>Cytokine production was determined by immunocytochemistry and quantitation of its expression was measured as the fluorescence intensity of various cytokines in the small intestine of hamsters subjected to a variety of treatments. Fluorescence intensity data are presented as mean +/− standard deviation. One-way ANOVA. N = 5−8. *** = P<0.001, ** = P<0.05.</p

Th1-type related cytokine expression in the duodenum of <i>T. spiralis</i> infected hamsters at 5 days pi.

<p>Cytokine production was determined by immunocytochemistry and quantitation of its expression was measured as the fluorescence intensity of various cytokines in the small intestine of hamsters subjected to different treatments. Fluorescence intensity data are presented as mean +/− standard deviation. One-way ANOVA. N = 6−9. *** = P<0.001, * = P<0.05.</p

Expression of TNFα, IL-10 and IL-6 in spleen of hamsters experimentally infected with <i>T. spiralis</i> at 5 days pi.

<p>The 18S was used as control gene of constitutive expression. Optical densitometry (OD) was obtained as a relationship between the genes of interest and 18S, and reported as mean +/− standard deviation. One-way ANOVA. N = 6−15. *** = P<0.001, **P<0.05.</p