Priming the prophenoloxidase system of <i>Artemia franciscana</i> by heat shock proteins protects against <i>Vibrio campbellii</i> challenge

Like other invertebrates, the brine shrimp Artemia franciscana relies solely on innate immunity, which by definition lacks adaptive characteristics, to combat against invading pathogens. One of the innate mechanisms is melanisation of bacteria mediated by the activation of the prophenoloxidase (proPO) system. The 70 kDa heat shock proteins (Hsp70) derived from either prokaryote (Escherichia coli) or eukaryote (Artemia), well conserved and immune-dominant molecules, protect Artemia against Vibrio campbellii. However, the molecular mechanisms by which these proteins protect Artemia against Vibrio campbellii infection are unknown. Here we demonstrated that feeding gnotobiotically grown Artemia with either Artemia Hsp70 or the E. coli Hsp70 equivalent DnaK, each overproduced in E. coli, followed by V. campbellii challenge enhanced the proPO system, at both mRNA and protein activity levels. Additionally, the Artemia fed with these proteins survived well in a Vibrio challenge assay. These results indicated that Hsp70s derived from either prokaryotic or eukaryotic sources generate protective immunity in the crustacean Artemia against V. campbellii infection by priming the proPO system. This is apparently the first in vivo report on priming activity of Hsp70 in an invertebrate

Exposure of gnotobiotic <i>Artemia franciscana</i> larvae to abiotic stress promotes heat shock protein 70 synthesis and enhances resistance to pathogenic <i>Vibrio campbellii</i>

Larvae of the brine shrimp Artemia franciscana serve as important feed in fish and shellfish larviculture; however, they are subject to bacterial diseases that devastate entire populations and consequently hinder their use in aquaculture. Exposure to abiotic stress was shown previously to shield Artemia larvae against infection by pathogenic Vibrio, with the results suggesting a mechanistic role for heat shock protein 70. In the current report, combined hypothermic/hyperthermic shock followed by recovery at ambient temperature induced Hsp70 synthesis in Artemia larvae. Thermotolerance was also increased as was protection against infection by Vibrio campbellii, the latter indicated by reduced mortality and lower bacterial load in challenge tests. Resistance to Vibrio improved in the face of declining body mass as demonstrated by measurement of ash-free dry weight. Hypothermic stress only and acute osmotic insult did not promote Hsp70 expression and thermotolerance in Artemia larvae nor was resistance to Vibrio challenge augmented. The data support a causal link between Hsp70 accumulation induced by abiotic stress and enhanced resistance to infection by V. campbellii, perhaps via stimulation of the Artemia immune system. This possibility is now under investigation, and the work may reveal fundamental properties of crustacean immunity. Additionally, the findings are important in aquaculture where development of procedures to prevent bacterial infection of feed stock such as Artemia larvae is a priority

Diversity, structure, and expression of the gene for p26, a small heat shock protein from <i>Artemia</i>

p26, a small heat shock protein, is thought to protect Artemia embryos from stress during encystment and diapause. Full-length p26 cDNAs were compared and used to determine phylogenetic relationships between several Artemia species. The a-crystallin domain of p26 was the most conserved region of the protein and p26 from each Artemia species contained characteristic amino-terminal WD/EPF and carboxy-terminal VPI motifs. Sequence conservation suggested the importance of p26 to oviparously developing Artemia embryos and indicated common functions for the protein during development and stress resistance, although as shown by modeling some species-specific p26 amino acid substitutions may have adaptive significance. The p26 gene obtained from A. franciscana exhibited a unique sHSP intron arrangement with an intron in the 5'-untranslated region. Computer-assisted analysis revealed heat shock elements and other putative cis regulatory sequences but their role in gene regulation is unknown. In contrast to previous results for which Northern blots were analyzed, p26 gene expression was observed in ovoviviparous embryos by use of PCR-based methodology, but the p26 protein was not detected

DOP086 Intestinal resection in Crohn's disease is associated with significant and durable improvement in health related quality of life although to a lesser extent in women and smokers. Results from the POCER study

Background: Health-related QoL (HRQoL) measures perceptions, illness experience, and functional status. Crohn’s disease patients have lower HRQoL, poorer function and more emotional distress than healthy individuals, even when in remission. HRQoL improves with medically or surgically induced remission. We evaluated the effects of surgery on HRQoL. Methods: Mucosal healing was the target in the Post-Operative Crohn’s Endoscopic Recurrence (POCER) treat-to-target study. Drug treatments included metronidazole, and thiopurine or adalimumab for high risk patients (smoker, perforating disease, 2nd operation). Patients were randomised to colonoscopy at 6 months with intensified treatment for endoscopic recurrence (“active care”) or no colonoscopy (“standard care”). All patients were colonoscoped at 18 months. HRQoL was assessed with a general (SF36) and disease-specific (IBDQ) questionnaire pre-operatively and at 6, 12 and 18 months. CRP, CDAI and faecal calprotectin (FC) were measured longitudinally. Results: 174 patients (median age 38, 55% female) were included. HRQoL was poor pre-operatively: median SF36 = 40 (where maximum = 100, Australian normal = 70 90) and IBDQ = 120 (maximum = 224, average score in Australian Crohn’s disease patients=156). For all patients both SF36 and IBDQ improved significantly at 6 months to 78 and 178 respectively, and this was sustained at 12 months (81 and 183) and 18 months (80 and 182 respectively). Females had lower HRQoL than males post-op at 6 (SF36 p = 0.012; IBDQ p = 0.007) and 12 months (SF36 p = 0.001, IBDQ p = 0.006). Smokers had poorer HRQoL compared to non-smokers at both 12 and 18 months: SF36 at 12 month p = 0.002, and IBDQ at 12 and 18 months (p = 0.046, p = 0.047 respectively). Persistent endoscopic remission, thiopurine or adalimumab therapy and treatment step up were not associated with changes in HRQoL. There was a significant inverse correlation between CDAI and both SF-36 and IBDQ at 6, 12 and 18 months. HRQoL did not correlate with endoscopic remission, CRP or FC. Conclusions: Intestinal resection of all macroscopic Crohn’s disease, with a focus on maintaining remission, is associated with significant and sustained improvement in general and disease-specific HRQoL. The lower HRQoL in female patients and smokers may reflect partly their lower QoL in the healthy and IBD populations, but this requires further investigation. A higher clinical disease activity index, but not direct measures of active disease or type of drug therapy, is associated with a lower HRQoL, suggesting that symptoms reflect subjective personal factors and not active mucosal disease or drug effects.E.K. Wright ... J.M. Andrews ... P.A. Bampton ... et al

Efficacy of thiopurines and adalimumab in preventing Crohn's disease recurrence in high-risk patients - a POCER study analysis

Background: Crohn's disease recurs in the majority of patients after intestinal resection. Aim: To compare the relative efficacy of thiopurines and anti-TNF therapy in patients at high risk of disease recurrence. Methods: As part of a larger study comparing post-operative management strategies, patients at high risk of recurrence (smoker, perforating disease, ≥2nd operation) were treated after resection of all macroscopic disease with 3 months metronidazole together with either azathioprine 2 mg/kg/day or mercaptopurine 1.5 mg/kg/day. Thiopurine-intolerant patients received adalimumab induction then 40 mg fortnightly. Patients underwent colonoscopy at 6 months with endoscopic recurrence assessed blind to treatment. Results: A total of 101 patients [50% male; median (IQR) age 36 (25–46) years] were included. There were no differences in disease history between thiopurine- and adalimumab-treated patients. Fifteen patients withdrew prior to 6 months, five due to symptom recurrence (of whom four were colonoscoped). Endoscopic recurrence (Rutgeerts score i2–i4) occurred in 33 of 73 (45%) thiopurine vs. 6 of 28 (21%) adalimumab-treated patients [intention-to-treat (ITT); P = 0.028] or 24 of 62 (39%) vs. 3 of 24 (13%) respectively [per-protocol analysis (PPA); P = 0.020]. Complete mucosal endoscopic normality (Rutgeerts i0) occurred in 17/73 (23%) vs. 15/28 (54%) (ITT; P = 0.003) and in 27% vs. 63% (PPA; P = 0.002). The most advanced disease (Rutgeerts i3 and i4) occurred in 8% vs. 4% (thiopurine vs. adalimumab). Conclusions: In Crohn's disease patients at high risk of post-operative recurrence adalimumab is superior to thiopurines in preventing early disease recurrence.P. De Cruz ... J. M. Andrews ... et al