Proteomics show antigen presentation processes in human immune cells after AS03-H5N1 vaccination.

Adjuvants enhance immunity elicited by vaccines through mechanisms that are poorly understood. Using a systems biology approach, we investigated temporal protein expression changes in five primary human immune cell populations: neutrophils, monocytes, natural killer cells, T cells, and B cells after administration of either an Adjuvant System 03 adjuvanted or unadjuvanted split-virus H5N1 influenza vaccine. Monocytes demonstrated the strongest differential signal between vaccine groups. On day 3 post-vaccination, several antigen presentation-related pathways, including MHC class I-mediated antigen processing and presentation, were enriched in monocytes and neutrophils and expression of HLA class I proteins was increased in the Adjuvant System 03 group. We identified several protein families whose proteomic responses predicted seroprotective antibody responses (>1:40 hemagglutination inhibition titer), including inflammation and oxidative stress proteins at day 1 as well as immunoproteasome subunit (PSME1 and PSME2) and HLA class I proteins at day 3 in monocytes. While comparison between temporal proteomic and transcriptomic results showed little overlap overall, enrichment of the MHC class I antigen processing and presentation pathway in monocytes and neutrophils was confirmed by both approaches.

Cell-Based Systems Biology Analysis of Human AS03-Adjuvanted H5N1 Avian Influenza Vaccine Responses: A Phase I Randomized Controlled Trial.

BACKGROUND: Vaccine development for influenza A/H5N1 is an important public health priority, but H5N1 vaccines are less immunogenic than seasonal influenza vaccines. Adjuvant System 03 (AS03) markedly enhances immune responses to H5N1 vaccine antigens, but the underlying molecular mechanisms are incompletely understood. OBJECTIVE AND METHODS: We compared the safety (primary endpoint), immunogenicity (secondary), gene expression (tertiary) and cytokine responses (exploratory) between AS03-adjuvanted and unadjuvanted inactivated split-virus H5N1 influenza vaccines. In a double-blinded clinical trial, we randomized twenty adults aged 18-49 to receive two doses of either AS03-adjuvanted (n = 10) or unadjuvanted (n = 10) H5N1 vaccine 28 days apart. We used a systems biology approach to characterize and correlate changes in serum cytokines, antibody titers, and gene expression levels in six immune cell types at 1, 3, 7, and 28 days after the first vaccination. RESULTS: Both vaccines were well-tolerated. Nine of 10 subjects in the adjuvanted group and 0/10 in the unadjuvanted group exhibited seroprotection (hemagglutination inhibition antibody titer > 1:40) at day 56. Within 24 hours of AS03-adjuvanted vaccination, increased serum levels of IL-6 and IP-10 were noted. Interferon signaling and antigen processing and presentation-related gene responses were induced in dendritic cells, monocytes, and neutrophils. Upregulation of MHC class II antigen presentation-related genes was seen in neutrophils. Three days after AS03-adjuvanted vaccine, upregulation of genes involved in cell cycle and division was detected in NK cells and correlated with serum levels of IP-10. Early upregulation of interferon signaling-related genes was also found to predict seroprotection 56 days after first vaccination. CONCLUSIONS: Using this cell-based systems approach, novel mechanisms of action for AS03-adjuvanted pandemic influenza vaccination were observed. TRIAL REGISTRATION: ClinicalTrials.gov NCT01573312.

A cell-based systems biology assessment of human blood to monitor immune responses after influenza vaccination.

Systems biology is an approach to comprehensively study complex interactions within a biological system. Most published systems vaccinology studies have utilized whole blood or peripheral blood mononuclear cells (PBMC) to monitor the immune response after vaccination. Because human blood is comprised of multiple hematopoietic cell types, the potential for masking responses of under-represented cell populations is increased when analyzing whole blood or PBMC. To investigate the contribution of individual cell types to the immune response after vaccination, we established a rapid and efficient method to purify human T and B cells, natural killer (NK) cells, myeloid dendritic cells (mDC), monocytes, and neutrophils from fresh venous blood. Purified cells were fractionated and processed in a single day. RNA-Seq and quantitative shotgun proteomics were performed to determine expression profiles for each cell type prior to and after inactivated seasonal influenza vaccination. Our results show that transcriptomic and proteomic profiles generated from purified immune cells differ significantly from PBMC. Differential expression analysis for each immune cell type also shows unique transcriptomic and proteomic expression profiles as well as changing biological networks at early time points after vaccination. This cell type-specific information provides a more comprehensive approach to monitor vaccine responses.

Multi-organ inflammation after hepatic cryoablation in BALB/c mice.

BACKGROUND: There is increasing evidence that injury to the liver can precipitate or exaggerate lung injury. We have previously shown that hepatic cryoablation (cryo) causes activation of nuclear factor (NF)-kappaB, cytokinemia (tumor necrosis factor-alpha, Mouse Macrophage Inflammatory Protein-2 [MIP-2]), and lung inflammation in transgenic HLL (5'HIV-LTR-Luciferase gene) mice and in Sprague-Dawley rats. It has been reported that BALB/c mice are susceptible to traumatic injury and are active immune responders. We tested whether activation of NF-kappaB and the development of multiple-organ inflammation in response to hepatic injury from 35% cryo were demonstrable in the BALB/c mouse. METHODS: BALB/c mice (n = 9) were anesthetized, and midline laparotomy was performed. Cryoablation was performed with careful isolation of adjacent structures to avoid inadvertent organ injury to the gastrointestinal tract. A freeze-thaw cycle of the left lobe of the liver was induced, encompassing approximately 35% (by weight). Animals were sacrificed at 1, 2, 4, and 24 h after cryoablation. Serum was collected via IVC puncture and liver, lungs, and kidneys were harvested and freeze-clamped. Two animals were sacrificed without undergoing cryo surgery to serve as a baseline control. NF-kappaB activity was monitored by electrophoretic mobility shift assays. MIP-2 levels and Mouse KC levels from tissue and serum were measured using enzyme-linked immunosorbent assay. Organs were submitted for histological review. We characterized lung inflammation induced by cryosurgery by measuring total and differential cell counts in lung lavage fluid 4 h after hepatic cryoablation. RESULTS: After cryo, NF-kappaB activation was demonstrated in the 1, 2, and 4-h time points by electrophoretic mobility shift assay in the liver and lungs. Mouse KC and MIP-2 levels increased from baseline, peaked at the 4-h time point, and returned to baseline after 24 h in both liver and lung. Lung lavage 4 h after cryoablation showed increased total cells and neutrophilic lung inflammation. CONCLUSIONS: BALB/c mice demonstrate evidence of multi-organ inflammation in response to 35% hepatic cryo. These data demonstrate that this model provides for assessment of liver-mediated multi-system inflammation after direct liver injury.

Biliary reconstruction is enhanced with a collagen-polyethylene glycol sealant.

Bile leaks occur in up to 27 per cent of liver transplant patients after biliary reconstruction. Synthetic sealants have not been investigated for these biliary procedures. We performed a randomized controlled study to evaluate a novel absorbable polyethylene glycol/collagen biopolymer sealant (CT3 Surgical Sealant) after incomplete end-to-end choledochocholedochostomy (CDCD) in pigs. Pigs (n = 18) underwent transection of the common bile duct and incomplete CDCD over a T-tube, leaving a one-sixth circumferential defect anteriorly. Animals were randomly assigned to treatment (CDCD with sealant, n = 9) or control (no sealant, n = 9). Drains were used to monitor leak volume and bilirubin (bili) concentration. Cholangiography was performed on postoperative day 3. Leaks were defined as drain bili/serum bill > 3, total drain output > 10 mL/kg, and/or extravasation on cholangiography. Animals sacrificed at 3 and 8 weeks (n = 4 and n = 5 from each group, respectively) underwent pathologic examination of the CDCD site. Statistical methods included Student's t test, chi2, linear regression, and analysis of variance procedures. The control group had a higher drain output rate over the first 4 postoperative days than the treatment group (P < 0.05, analysis of variance). Five of nine (56%) control and one of nine (11%) treatment animals had a bile leak (P < 0.05, chi2). There was no major inflammatory response to the sealant versus controls. We conclude that CT3 is effective in decreasing biliary leaks in an incomplete CDCD porcine model with no major adverse pathologic changes. This sealant should be considered for trials for biliary reconstruction in humans.

Prevention of gallstone formation in morbidly obese patients undergoing rapid weight loss: results of a randomized controlled pilot study.

INTRODUCTION: An increased risk of gallstone (GS) formation has been linked to obesity and to episodes of rapid and significant weight loss. Previous reports have suggested that bile salt therapy (ursodeoxycholic acid) or prostaglandin inhibition (ibuprofen) may prevent gallstone formation in this high-risk group. The purpose of this study was to investigate GS prevention following bariatric surgery. DESIGN: Randomized double blind controlled trial. METHODS: Sixty patients without gallstones preoperatively (gender, 9 male, 51 female; average preop wt, 349.6 lb; mean age, 38 years) were randomly assigned to receive urso (600 mg/day, n = 20), ibuprofen (600 mg/d, n = 20), or placebo (n = 20). At the time of standard open gastric bypass, intraoperative ultrasonography confirmed the absence of stones or microcalculi, and bile samples were collected via puncture of the gallbladder for bile lipid analysis. Following recovery and resumption of a bariatric diet, study medication was prescribed for the first 6 months postop. Gallbladder emptying and GS formation were assessed using ultrasonograms preop and at 3, 6, 9, and 12 months postop (gallbladder emptying following a high-fat liquid test meal was assessed preop, and at 3 and 6 months postop). RESULTS: Forty-one (68.3%, 8 male, 33 female) of the original 60 patients completed all phases of the study (15 urso, 15 ibuprofen, 11 placebo). The average weight loss was 98.5 +/- 7.2 lb over the 12-month period following bariatric surgery. Twenty-nine (71%) of 41 patients who completed the study developed GS. Of those who formed stones, 12 (41%) developed symptomatic GS and 8/12 (67%) underwent cholecystectomy (4 refused operation). Preoperative gallbladder emptying studies showed no differences in emptying between groups (urso 29%, ibuprofen 32%, and placebo 30%). There was no correlation found between the cholesterol saturation index (CSI mean 205.15, range 67-360) and the incidence of GS. There was a statistical difference (P < 0.01) between the ursodeoxycholic acid group and the ibuprofen group with respect to the incidence of stone formation. There was correlation between weight loss (mean 99 lb, range 21-278 lb) and GS formation, in that patients who lost more weight had a greater tendency to form gallstones. Complete medical compliance was achieved in only 17/60 (28%) of patients originally enrolled. CONCLUSIONS: This pilot study confirms the high incidence of gallstone formation (71% of assessed patients) associated with rapid weight loss in patients undergoing gastric bypass. Despite active enrollment in a supervised prevention trial, the two therapies investigated to reduce gallstone formation were not efficacious, likely because compliance with medical therapy was poor. These findings highlight the significant risk of gallstone formation in this patient cohort even when prevention strategies are utilized.