Luminex xMAP Research Articles

The development of a multiplex serological assay for avian influenza based on Luminex technology.

Avian influenza (AI) is an infectious disease in birds with enormous impact on the poultry sector. AI viruses are divided into different subtypes based on the antigenicity of their surface proteins haemagglutinin (HA) and neuraminidases (NA). In birds, 16 HA subtypes and 9 NA subtypes are detected in different combinations. Traditional serological methods for the subtyping of AI antibodies are labour-intensive and have to be performed for each HA and NA subtype separately. This study describes the development of a multiplex serological assay for subtyping AI antibodies in poultry sera using Luminex xMAP technology. This multiplex assay allows the detection of all AI serotypes in one single assay. For all HA and NA subtypes, recombinant proteins were purified and coupled to colour-coded magnetic bead sets. Using the Luminex MAGPIX device, binding of serum antibodies to the antigens on the bead sets is detected by fluorescent secondary antibodies, and the different bead sets are identified. The results of the multiplex assay were compared with that of the traditional singleplex assays. We show that serotyping using the novel multiplex serological assay is consistent with the results of the traditional assays in 97.8% of the reference sera and in 90.8% of the field sera. The assay has a higher sensitivity than the traditional assays, and requires a smaller sample volume. Therefore, the assay will allow complete AI-serotyping in small volumes of field sera, which will improve the monitoring of AI subtypes circulating in poultry significantly.

TRF2 positively regulates SULF2 expression increasing VEGF-A release and activity in tumor microenvironment

The telomeric protein TRF2 is overexpressed in several human malignancies and contributes to tumorigenesis even though the molecular mechanism is not completely understood. By using a high-throughput approach based on the multiplexed Luminex X-MAP technology, we demonstrated that TRF2 dramatically affects VEGF-A level in the secretome of cancer cells, promoting endothelial cell-differentiation and angiogenesis. The pro-angiogenic effect of TRF2 is independent from its role in telomere capping. Instead, TRF2 binding to a distal regulatory element promotes the expression of SULF2, an endoglucosamine-6-sulfatase that impairs the VEGF-A association to the plasma membrane by inducing post-synthetic modification of heparan sulfate proteoglycans (HSPGs). Finally, we addressed the clinical relevance of our findings showing that TRF2/SULF2 expression is a worse prognostic biomarker in colorectal cancer (CRC) patients.

A clinical, proteomics, and artificial intelligence-driven model to predict acute kidney injury in patients undergoing coronary angiography.

BackgroundStandard measures of kidney function are only modestly useful for accurate prediction of risk for acute kidney injury (AKI).HypothesisClinical and biomarker data can predict AKI more accurately.MethodsUsing Luminex xMAP technology, we measured 109 biomarkers in blood from 889 patients prior to undergoing coronary angiography. Procedural AKI was defined as an absolute increase in serum creatinine of ≥0.3 mg/dL, a percentage increase in serum creatinine of ≥50%, or a reduction in urine output (documented oliguria of <0.5 mL/kg per hour for >6 hours) within 7 days after contrast exposure. Clinical and biomarker predictors of AKI were identified using machine learning and a final prognostic model was developed with least absolute shrinkage and selection operator (LASSO).ResultsForty‐three (4.8%) patients developed procedural AKI. Six predictors were present in the final model: four (history of diabetes, blood urea nitrogen to creatinine ratio, C‐reactive protein, and osteopontin) had a positive association with AKI risk, while two (CD5 antigen‐like and Factor VII) had a negative association with AKI risk. The final model had a cross‐validated area under the receiver operating characteristic curve (AUC) of 0.79 for predicting procedural AKI, and an in‐sample AUC of 0.82 (P < 0.001). The optimal score cutoff had 77% sensitivity, 75% specificity, and a negative predictive value of 98% for procedural AKI. An elevated score was predictive of procedural AKI in all subjects (odds ratio = 9.87; P < 0.001).ConclusionsWe describe a clinical and proteomics‐supported biomarker model with high accuracy for predicting procedural AKI in patients undergoing coronary angiography.

Variations in T-Cell Response Among Cow’s Milk Allergy Children With Or Without Sensitization to Casein Protein

Objective: To explore the potential differences in allergen-specific T immunological responses among cow’s milk allergic(CMA) patients with or without casein sensitization. Methods: A total of 25 children with IgE-dependent CMA were recruited from outpatient clinic in Beijing Children’s Hospital from January to August of 2017, including 14 CMA patient with a positive sensitization to casein component, 11 CMA patient being sensitized to cow’s milk, but a negative sIgE for casein component, and another 10 atopic control subjects without CMA were also included as negative control group in this study. The expression level of T cell related transcription factor in PBMCs or total CD4+ cells were detected by quantitative PCR, and the release of T cell related cytokines in donor’s serum was determined by Luminex xMAP 200 System. Upon in-vitro stimulation with casein protein, the proliferation rates of PBMCs-derived T cells were assessed by flow cytometry, and T related cytokines production in culture supernatant was evaluated as well. Results: A significantly higher level of GATA3 expression transcripts in PBMCs or total CD4+ cells were detected in casein-sensitized CMA patients than those without casein sensitization. An increase in IL-4 (74.1±16.5pg/ml vs 64.9±12.8 pg/ml, P<0.05) and a decrease in IL-10 (3.1±2.4 pg/ml vs 4.9±2.8 pg/ml, P<0.05) production were found in casein-sensitized CMA patient’s plasma than patients without casein sensitization. Upon in-vitro stimulation with cow’s milk protein mixture, a significantly higher proliferation rate of casein-specific CD4+T cells (30.0±5.8% vs 20.7±5.5%, P<0.05) as well as increased productions of IL-4(4.1±13.6 vs 64.7±12.3pg/ml, P<0.05) and IL- 13(48.7±10.3 vs 38.7±9.4pg/ml, P<0.05) were found in casein-sensitized CMA patients compared those without casein sensitization. Conclusions: Our findings preliminarily revealed that a distinctive T cell mediated immune response among CMA patient with the different sensitized component.

The role of alpha-fetoprotein in regulation of the cytokine profile of activated T-helpers and their conversion in Th17 phenotype

We studied the effect of the native (non-recombinant) alpha-fetoprotein (AFP) on differentiation, proliferation, and cytokine profile of activated helper T cells 17 (Th17). The object of the study was a culture of isolated by immunomagnetic separation helper T cells (CD4+), induced into the Th17 phenotype by using TCR-activator and proinflammatory cytokines (IL-1β and IL-6). AFP had not significant effect on the frequency of Th17 cells (ROR-γτ+) in the helper T cell culture, and did not affect proliferation of these cells, as measured by Ki-67 expression. Evaluation of the cytokine profile of culture supernatants by using the Luminex xMAP technology, revealed that AFP did not affect the levels of IL-4, IL-5, IL-7, IL-8, IL-10, IL-17, IFN-γ and TNF-α, but at concentrations of 50 IU/ml and 100 IU/ml it increased IL-2 production by activated helper T cells. At the same time, AFP suppressed the synthesis of G-CSF and GM-CSF (10 IU/ml), but stimulated the production of CCL4/MIP-1β (100 IU/ml) and CCL2/MCP-1 chemokines (10 IU/ml and 50 IU/ml).

943: Effect of simvastatin on MAPK signaling in fetal brain in a LPS induced preterm inflammation

We have previously shown that maternal administration of simvastatin prevents inflammatory responses in fetal brain in a well-established murine model of lipopolysaccharide (LPS) – induced preterm inflammation. The objective of this study was test the hypothesis that these beneficial effects are mediated through the mitogen- activated protein kinases (MAPK) signaling pathway. Pregnant CD-1 mice on day 15 of gestation were randomly injected intraperitoneally with either saline or simvastatin (10 mg/g of body weight in saline). After 2 hours, mice were injected with either LPS (250 mg/saline) or saline in order to end-up in saline + saline (CTR, n=8), saline + LPS (LPS, n=9) and simvastatin + LPS (Simv + LPS, n=7) groups. The simvastatin+saline group was not included because we do not anticipate the use of simvastatin alone. Six hours after the last injection, all mice were euthanized, pups quickly dissected and tissues collected. Fetal brains from each litter were pooled together. Tissues were homogenized and equal amounts of total protein were assayed using Luminex xMAP method for the phosphorylated p53, cJUN, JNK, STAT1, ATF2, p38, MEK1, HSP27, ERK, and MSK1. The median fluorescence intensity (MFI) was normalized to GAPDH control for each protein. One-Way or Kruskal-Wallis ANOVA with Holm-Sidak or Dunn’s post-hoc tests as appropriate was used for analysis (statistical significance P<.05). Exposure to LPS lowered the protein expression of pATF2, pERK, pp53, pMEK1, pMSK, pSTAT1 and pc-Jun with pJNK reaching statistical significance (Figure). Simv rescued the levels of pATF2, pJNK and pc-Jun, but the results were not statistically significant. Prenatal exposure to LPS downregulates some proteins involved in MAPK signaling in fetal brain, indicating an effect on cellular proliferation, differentiation, survival, and death. Simvastatin partially prevented the LPS effect on these proteins. Further studies are needed to determine the mechanisms of the reported beneficial effects of statinsin the setting of preterm inflammation.

Compartment syndrome-induced muscle injury is diminished by the neutralization of pro-inflammatory cytokines.

Objectives:Compartment syndrome (CS) is one of the most devastating consequences of musculoskeletal trauma. The pathophysiology of CS includes elevation of intracompartmental pressure (ICP), causing damage to the microcirculation, decreased oxygen delivery, tissue anoxia, and cell death. CS is a combined ischemic and inflammatory condition that induces the systemic inflammatory cascade. In complete ischemia, within the first hour of reperfusion, a peak in the pro-inflammatory cytokine, tumor necrosis factor alpha (TNF-α) has been previously reported. The purpose of this study was to examine the suspected systemic inflammatory cytokine/chemokine release in response to CS, and to evaluate the microvascular dysfunction, tissue injury, and inflammatory response following the neutralization of pro-inflammatory cytokines TNF-α and/or interleukin-1 beta (IL-1β).Methods:Twenty-eight male Wistar rats were randomly assigned into 5 groups: Sham (no CS), CS (with isotype control), CS+TNF-α neutralizing antibody (NA), CS+IL-1β NA, CS+Combo (both TNF-α and IL-1β NA). CS was induced by elevation of ICP above 30 mm Hg through an infusion of isotonic saline into the anterior compartment of the hind limb for 2 hours; NA were administered just prior to fasciotomy. Microvascular perfusion, cellular tissue injury, and inflammatory response within the extensor digitorum longus muscle were assessed using intravital video microscopy for 45 minutes after fasciotomy. Systemic levels of 24 different cytokines/chemokines were also measured, using the xMAP Luminex technology.Results:Of the 24 cytokines/chemokines sampled, 6 were significantly elevated from their baseline levels, and included the pro-inflammatory cytokines TNF-α, IL-1β, growth-related oncogene/keratinocyte chemoattractant (GRO/KC), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1 alpha (MIP-1α), and the anti-inflammatory cytokine IL-10. CS resulted in a significant decrease in microvascular perfusion, from 75 ± 2% continuously perfused capillaries in the sham to 31 ± 4% in CS (P < .001), a significant increase in tissue injury (0.33 ± 0.4 versus 0.04 ± 0.01 in sham) and leukocyte activation (14 ± 2 adherent leukocytes/1000 μm2 versus 2 ± 1 adherent leukocytes/100 μm2 in sham, P < .001). CS-associated tissue injury was significantly decreased with TNF-α neutralization (P < .05), both when administered alone or in combination with IL-1β (P < .05). Additionally, TNF-α neutralization blocked CS-associated leukocyte activation (P < .05); IL-1β neutralization also diminished leukocyte adhesion (P < .05). Perfusion remained virtually unchanged in CS animals treated with NA (36 ± 4%, 32 ± 3% and 30 ± 2% in CS+TNF-α, CS+IL-1β and CS+Combo groups, respectively).Conclusion:The results of this study indicate that CS induces a systemic inflammation, as evidenced by upregulation of inflammatory cytokines/chemokines in circulation. Neutralization of TNF-α led to a significant reduction in tissue injury; however, it had no effect on the CS-induced microvascular dysfunction. This suggests a distinct role of TNF-α in the pathophysiology of muscle injury in CS.

Elevated IL-1Ra Levels in the Stem Cell Product Is Associated with the Development of Engraftment Syndrome Following Autologous Stem Cell Transplantation for the Treatment of Multiple Myeloma and Lymphoma

Engraftment syndrome (ES) is a frequently occurring complication in patients receiving autologous stem cell transplantation (ASCT) for the treatment of multiple myeloma and various types of non-Hodgkin lymphomas. This clinical entity presents as skin rashes, diarrhea, non-infectious fevers and capillary leak syndrome in the peri-engraftment period coinciding with neutrophil recovery. The etiology and risk factors contributing to the development of ES remain unclear. The goal of the present study was to analyze the cytokine composition of the grafted mobilized peripheral blood stem cell product as well as serum cytokine levels in patients undergoing ASCT for the treatment of multiple myeloma and lymphoma. Cytokines were analyzed in the apheresis stem cell product, as well as patient plasma 1-2 days pre-transplant, 12 days post-transplant, and 2-4 months post-transplant using the Luminex xMAP multiplex cytokine platform. The concentrations of 29 cytokines from 38 patients were analyzed. Seventeen of these patients were diagnosed with engraftment syndrome using the Spitzer criteria. Patients who developed ES were shown to have significantly elevated levels of IL-1 receptor antagonist (IL-1Ra) in the apheresis product as compared to patients that did not develop ES (31,033 vs. 6015 pg/ml; p=0.028). IL-1Ra levels were not significantly different at other time points. IL-1Ra competes with IL-1α and IL-1β for binding to the IL-1 receptor thus acting as an antagonist to this proinflammatory cytokine. The gene encoding IL-1Ra has a tandem repeat sequence resulting in polymorphic alleles in the population with varying number of repeats. The allele containing 2 repeats, IL1RN*2, has been associated with various inflammatory diseases including Sjogren's syndrome, ulcerative colitis, Crohn disease, psoriasis, multiple sclerosis, and SLE. We performed PCR on the DNA isolated from the PBMCs of these patients to determine if patients with elevated IL-1Ra possessed the IL1RN*2 allele. Results did not find any correlation between IL-1RN*2 allele and elevated IL-1Ra levels in the apheresis samples. In addition, levels of the chemokine IFN-gamma-induced protein 10 (IP-10/CXCL10) were found to be significantly higher in patients diagnosed with ES at both the day 12 post-transplant (1089 vs. 689 pg/ml; p=0.022) and 2-4 month post-transplant time points (1768 vs. 922 pg/ml; p<0.01), and trending higher in the apheresis product (6132 vs. 2655 pg/ml; p=0.126). IP-10, which plays a role in leukocyte homing to inflamed tissues, has been identified as a major biological marker of disease severity in several inflammatory conditions. The only other cytokine that exhibited a significant difference at any time point was the increased level of IL-12p40 in the apheresis product of those developing ES (412 vs. 74 pg/ml; p=0.026). Characterizing these and other differences in graft product composition and changes that occur during hematopoietic reconstitution may aid in prediction or early identification of ES and may lead to early intervention treatment for this common and potentially serious complication of ASCT. DisclosuresSiegel:Takeda: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Speakers Bureau; Merck: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria. Biran:Takeda: Consultancy, Speakers Bureau; Merck: Research Funding; Amgen: Consultancy, Speakers Bureau; Celgene: Consultancy, Honoraria, Speakers Bureau; BMS: Research Funding. Vesole:Amgen: Speakers Bureau; Takeda: Speakers Bureau. Feldman:Janssen: Speakers Bureau; Pharmacyclics: Speakers Bureau; Celgene: Speakers Bureau; Johnson and Johnson: Speakers Bureau; Seattle Genetics: Research Funding, Speakers Bureau; KITE: Speakers Bureau; Portola: Research Funding. Skarbnik:Novartis: Honoraria, Speakers Bureau; Seattle Genetics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Gilead Sciences: Honoraria, Speakers Bureau; Genentech: Honoraria, Speakers Bureau; Jazz Pharmaceuticals: Honoraria, Speakers Bureau; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Pharmacyclics: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

Plasma cytokines as potential biomarkers of kidney damage in patients with systemic lupus erythematosus.

Systemic lupus erythematosus is a heterogeneous chronic inflammatory autoimmune disorder characterized by an exacerbated expression of cytokines and chemokines in different tissues and organs. Renal involvement is a significant contributor to the morbidity and mortality of systemic lupus erythematosus, and its diagnosis is based on renal biopsy, an invasive procedure with a high risk of complications. Therefore, the development of alternative, non-invasive diagnostic tests for kidney disease in patients with systemic lupus erythematosus is a priority. To evaluate the plasma levels of a panel of cytokines and chemokines using multiplex xMAP technology in a cohort of Colombian patients with active and inactive systemic lupus erythematosus, and to evaluate their potential as biomarkers of renal involvement. Plasma from 40 systemic lupus erythematosus non-nephritis patients and 80 lupus nephritis patients with different levels of renal involvement were analyzed for 39 cytokines using Luminex xMAP technology. Lupus nephritis patients had significantly increased plasma eotaxin, TNF-α, interleukin-17-α, interleukin-10, and interleukin-15 as compared to the systemic lupus erythematosus non-nephritis group. Macrophage-derived chemokine, growth regulated oncogene alpha, and epidermal growth factor were significantly elevated in systemic lupus erythematosus non-nephritis patients when compared to lupus nephritis individuals. Plasma eotaxin levels allowed a discrimination between systemic lupus erythematosus non-nephritis and lupus nephritis patients, for which we performed a receiver operating characteristic curve to confirm. We observed a correlation of eotaxin levels with active nephritis (Systemic Lupus Erythematosus Disease Activity Index). Our data indicate that circulating cytokines and chemokines could be considered good predictors of renal involvement in individuals with systemic lupus erythematosus.

Clinical Validation of Newly Developed Multiplex Kit Using Luminex xMAP Technology for Detecting Simultaneous RAS and BRAF Mutations in Colorectal Cancer: Results of the RASKET-B Study

Detection of RAS and BRAF mutations is essential to determine the optimal treatment strategy for metastatic colorectal cancer (CRC). We prospectively evaluated the MEBGEN RASKET-B KIT (RASKET-B), a novel multiplex kit, simultaneously detecting 48 types of RAS mutations and the BRAF V600E mutation using Luminex xMAP technology. The aim was to obtain market approval for RASKET-B as an in vitro diagnostic (IVD) option in Japan. Genomic DNA was extracted from 302 formalin-fixed paraffin-embedded tissues obtained from CRC patients. The primary endpoints were the concordance rate (CR) between the results from RASKET-B and the previously approved IVD kit (RASKET) for RAS mutations, and CR between the results from RASKET-B and direct sequencing (DS) for BRAF mutations. The secondary endpoints included the CR between RASKET-B and DS for RAS mutations and between RASKET-B and the pyrosequencing (PYRO) for the BRAF V600E mutation. Among the 302 samples, 142 RAS mutations (47%) and 18 BRAF V600E mutations (6.0%) were detected by RASKET-B. All mutations detected in the recruited patients were mutually exclusive. Both RAS and BRAF mutation rates were statistically higher in right-sided than left-sided CRC. The CR between RASKET-B and RASKET for RAS gene and RASKET-B and DS for BRAF V600E mutation was 100% for both (95% CI: 99%-100%). The results from RASKET-B were also highly concordant with DS for RAS (97.4%) and with PYRO for the BRAF (V600E) gene (99.7%). RASKET-B thus provides rapid, precise, and simultaneous detection of RAS and BRAF mutations in CRC.

Melamine and cyanuric acid exposure and kidney injury in US children

BackgroundMelamine and cyanuric acid, which are currently used in a variety of common consumer products and present in foods, have been implicated in the development of urolithiasis and acute kidney injury in Chinese children. To determine whether US children have measurable concentrations of these chemicals in their bodies and whether they are at greater risk of acute kidney injury, we measured melamine and cyanuric acid exposure in a cohort of US children and determined their relationship with markers of kidney injury. MethodsWe measured urinary melamine and cyanuric acid in a convenience sample of 109 children (4 months – 8 years) from Seattle, WA and New York City, NY using liquid chromatography with tandem mass spectrometry. We measured several urinary markers of kidney injury: fatty acid binding protein 3 (FABP3), kidney injury molecule 1 (KIM1), neutrophil gelatinase-associated lipocalin (NGAL) using Luminex xMAP methods, and urine urea was measured using standard laboratory methods. We described urinary melamine and cyanuric acid concentrations and assessed predictors of the exposures. We used multivariable linear regression to assess relationships between melamine/cyanuric acid and kidney injury markers in unadjusted and adjusted (creatinine, age, sex) analyses. ResultsMelamine and cyanuric acid were above the limit of detection (LOD) in 78% and 95% of all samples, respectively. The mean concentrations (SD) for melamine and cyanuric acid were 27.4 ng/ml (141.9 ng/ml) and 35.3 ng/ml (42.4 ng/ml). In unadjusted analyses, we observed statistically significant increases in the percentages of FABP3 and KIM1 in relation to a one log unit change in melamine and cyanuric acid, respectively. In adjusted analyses, we observed a 55% (95% CI 0, 141) increase in KIM1 in relation to a one log unit increase in cyanuric acid. ConclusionsUS children have detectable concentrations of melamine and cyanuric acid in urine, and these concentrations are higher than those reported in children from other countries. This is a novel finding that improves upon previous exposure estimates using questionnaires only and suggests widespread exposure in the population. Cyanuric acid is associated with increased KIM 1 concentrations, suggesting kidney injury. Given the potential widespread exposure, future analyses should examine melamine and cyanuric acid in relation to chronic kidney disease and markers of kidney injury in a larger cohort that is representative of the general population.

MODULATION OF IMMUNE RESPONSE UPON EXPOSURE TO HIV

Introduction IL-17 and IL-23 serve as pro-inflammatory cytokines that counteract HIV by regenerating Th-17 cells, while interferon gamma (IFN-γ) enhances the replication rate of HIV-1. We examined how the levels of these cytokines vary across the course of a week based on how recently the patient was exposed to HIV. Methods In accordance with the Helsinki Declaration, PBMCs were isolated from two volunteers with a 5-year difference in time of diagnosis with HIV. Samples were stimulated with Lipopolysacharide (LPS), Staphylococcal Enterotoxin B (SEB) and analyzed by quantitative immunoassay (Luminex xMAP). The association between cytokine concentration and time were evaluated by linear and logistic regression. Results The difference between the net increase of IL-17 for the recently infected vs. previously infected samples were 1.2 pg/mL (unstimulated), 10.34 pg/mL (LPS), and 625.45 pg/mL (SEB). For IL-23, differences were -10.56 pg/mL, -1597 pg/mL, and -8.64 pg/mL. IFN-γ had differences of 46.44 pg/mL, 1,029 pg/mL, and 426 pg/mL. Conclusions IL-17, IL-23, and IFN-γ increased across all conditions. However, to our knowledge, this is the first experiment to show that IL-17 and IFN-γ increases more rapidly when less time has elapsed since exposure to HIV. IL-23 increased more rapidly when more time had elapsed since initial exposure. IL-23 differentiates T-Cells, which produce IL-17 and IFN-γ and are destroyed by HIV. Therefore, when the infection is initially developing in the body, IL-23 is unable to consistently accumulate. Even though further research is necessary, this data could show that HIV treatment must be adapted over time to achieve the most effective results.

Impact of Positive Selection on Incidence of Different Viruses During Multiple Generations of Potato Seed Tubers in Uganda

Smallholder farmers in Uganda commonly use seed potato tubers from the informal sector, especially by seed recycling over several generations. Therefore, seed tubers are highly degenerated with viruses and other pathogens, resulting in poor yield and quality of the produce. Over one cycle of multiplication, degeneration management by positive seed selection was found to be efficient in reducing virus diseases compared with the farmers’ method of selection. The objective of this study was to assess to what extent positive selection over several seasons can reduce six different virus incidences in seed lots of different starting quality in southwestern Uganda. Multi-seasonal trials were carried out in three locations, with five seed lots from four sources and three cultivars. Detection of viruses was based on DAS-ELISA and Luminex xMAP technology. Analysis was carried out with analysis of variance (ANOVA) on angular-transformed percentages of virus incidence. Results showed fluctuations in some viruses over seasons with lower Potato leafroll virus (PLRV) and Potato virus X (PVX) incidences in lots from positive selection compared with lots from farmers’ selection. In contrast, some seed lots were initially highly infected with Potato virus S (PVS) and Potato virus M (PVM) and showed no reduction in virus incidence through positive selection. In general, little infection with Potato virus Y (PVY) and Potato virus A (PVA) was found. Based on these results, it is recommended that smallholder farmers are trained in positive selection to opt for less virus-infected plants and tubers, thus increasing potato production.

The association between selected mid-trimester amniotic fluid candidate proteins and spontaneous preterm delivery

Objective: The aim of this study was to explore inflammatory response and identify early potential biomarkers in mid-trimester amniotic fluid associated with subsequent spontaneous preterm delivery (PTD).Methods: A cohort study was performed at Sahlgrenska University Hospital/Östra, Gothenburg, Sweden, between 2008 and 2010. Amniotic fluid was collected from consecutive women undergoing mid-trimester transabdominal genetic amniocentesis at 14–19 gestational weeks. Clinical data and delivery outcome variables were obtained from medical records. The analysis included 19 women with spontaneous PTD and 118 women who delivered at term. A panel of 26 candidate proteins was analyzed using Luminex xMAP technology. Candidate protein concentrations were analyzed with ANCOVA and adjusted for plate effects.Results: The median gestational age at delivery was 35 + 3 weeks in women with spontaneous PTD and 40 + 0 weeks in women who delivered at term. Nominally significantly lower amniotic fluid levels of adiponectin (PTD: median 130,695 pg/mL (IQR 71,852–199,414) vs term: median 185,329 pg/mL (IQR (135,815–290,532)), granulocyte-macrophage colony stimulating factor (PTD: median 137 pg/mL (IQR 74–156) vs term: median 176 pg/mL (IQR 111–262)), and macrophage migration inhibitory factor (PTD: median 3025 pg/mL (IQR 1885–3891) vs term: median 3400 pg/mL (IQR 2181–5231)) were observed in the spontaneous PTD group, compared with the term delivery group, after adjusting for plate effects. No significant differences remained after Bonferroni correction for multiple comparisons.Conclusions: Our results are important in the process of determining the etiology behind spontaneous PTD but due to the non-significance after Bonferroni correction, the results should be interpreted with caution. Further analyses of larger sample size will be required to determine whether these results are cogent and to examine whether microbial invasion of the amniotic cavity or intra-amniotic inflammation occurs in asymptomatic women in the mid-trimester with subsequent spontaneous PTD.

Optimization of a Multiplex RNA-based Expression Assay Using Breast Cancer Archival Material

Nucleic acid degradation in archival tissue, tumor heterogeneity, and a lack of fresh frozen tissue specimens can negatively impact cancer diagnostic services in pathology laboratories worldwide. Gene amplification and expression diagnostic testing using archival material or material that requires transportation to servicing laboratories, needs a more robust and accurate test adapted to current clinical workflows. Our research team optimized the use of Invitrogen™ QuantiGene™ Plex Assay (Thermo Fisher Scientific) to quantify RNA in archival material using branched-DNA (bDNA) technology on Luminex xMAP® magnetic beads. The gene expression assay described in this manuscript is a novel, quick, and multiplex method that can accurately classify breast cancer into the different molecular subtypes, omitting the subjectivity of interpretation inherent in imaging techniques. In addition, due to the low input of material required, heterogeneous tumors can be laser microdissected using Hematoxylin and Eosin (H&E) stained sections. This method has a wide range of possible applications including tumor classification with diagnostic potential and measurement of biomarkers in liquid biopsies, which would allow better patient management and disease monitoring. In addition, the quantitative measurement of biomarkers in archival material is useful in oncology research with access to libraries of clinically-annotated material, in which retrospective studies can validate potential biomarkers and their clinical outcome correlation.

Optimization of a Multiplex RNA-based Expression Assay Using Breast Cancer Archival Material.

Nucleic acid degradation in archival tissue, tumor heterogeneity, and a lack of fresh frozen tissue specimens can negatively impact cancer diagnostic services in pathology laboratories worldwide. Gene amplification and expression diagnostic testing using archival material or material that requires transportation to servicing laboratories, needs a more robust and accurate test adapted to current clinical workflows. Our research team optimized the use of Invitrogen™ QuantiGene™ Plex Assay (Thermo Fisher Scientific) to quantify RNA in archival material using branched-DNA (bDNA) technology on Luminex xMAP® magnetic beads. The gene expression assay described in this manuscript is a novel, quick, and multiplex method that can accurately classify breast cancer into the different molecular subtypes, omitting the subjectivity of interpretation inherent in imaging techniques. In addition, due to the low input of material required, heterogeneous tumors can be laser microdissected using Hematoxylin and Eosin (H&E) stained sections. This method has a wide range of possible applications including tumor classification with diagnostic potential and measurement of biomarkers in liquid biopsies, which would allow better patient management and disease monitoring. In addition, the quantitative measurement of biomarkers in archival material is useful in oncology research with access to libraries of clinically-annotated material, in which retrospective studies can validate potential biomarkers and their clinical outcome correlation.

Establishment and optimization of a liquid bead array for the simultaneous detection of ten insect-borne pathogens

BackgroundInsect-borne diseases could induce severe symptoms in human and clinical signs in animals, such as febrility, erythra, arthralgia and hemorrhagic fever, and cause significant economic losses and pose public health threat all over the world. The significant advantages of Luminex xMAP technology are high-throughput, high parallel and automation. This study aimed to establish a liquid bead array based on Luminex xMAP technology that was able to simultaneously detect multiple insect-borne pathogens.MethodsSpecific probes and primers to detect the nucleic acid of 10 insect-borne pathogens were designed. Probes were coupled with fluorescent carboxylated microspheres. The parameters of the system were optimized, including ratio of forward/reverse primers (1:2), hybridization temperature (50 °C) and duration (30 min) and quantity of PCR product (2 μl). The sensitivity and specificity of the system were also evaluated. Moreover mixed nucleic acid of 10 insect-borne pathogens, including Bluetongue virus, Epizootic hemorrhagic disease virus of deer, Coxiella burnetii, African swine fever virus, West Nile fever virus, Borrelia burgdorferi, vesicular stomatitis virus, Rift Valley fever virus, Ebola virus and Schmalenberg’s disease virus, and 3000 clinical samples were tested for practicability.ResultsThe optimized detection system showed high sensitivity, specificity and reproducibility. Each probe showed specific fluorescence signal intensity without any cross-hybridization for the other insect-borne pathogens tested, which included dengue virus, tick-borne encephalitis virus, Japanese encephalitis virus, Xinjiang hemorrhagic fever virus, spotted fever group rickettsiae, ehrlichiae and chikungunya virus. The limit of detection was 10 copies of target gene. Insect-borne pathogens were successfully detected among the 3000 clinical samples, and the results were consistent with those obtained using gold-standard assays or commercial nucleic acid detection kits.ConclusionsThis optimized liquid array detection system was high-throughput and highly specific and sensitive in screening of the insect-borne pathogens. It was promising in detection of these pathogens for molecular epidemiological studies.

Autoreactive T cells to citrullinated HSP90 are associated with interstitial lung disease in rheumatoid arthritis.

Previous analysis of comparative anti-citrullinated heat shock protein 90 (citHSP90) antibody profiles between bronchoalveolar lavage fluid and serum indicates that the lung plays a direct role in shaping the immune repertoire of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). To address the contribution of citHSP90β-specific T cells in this process, we evaluated invitro cytokine responses to citHSP90β in RA patients with different stages of ILD as well as in controls with non-RA connective tissue disease-associated ILD (CTD-ILD). Cultures derived from whole blood were individually stimulated with HSP90β, citHSP90β, citrullinated BSA, or no antigen. The concentrations of 13 cytokines and chemokines in the plasma supernatant were then measured using Luminex xMAP technology. CitHSP90β induced significantly higher levels of interferon-γ (IFN-γ) levels in RA-ILD (interstitial lung abnormalities=2+3) groups compared to the RA-no ILD group (P=0.01), but did not stimulate the production of other cytokines (P>0.05). Furthermore, citHSP90β did not stimulate the production of IFN-γ or other cytokines in those individuals with non-RA CTD-ILD. Overall, the production of IFN-γ by T cells stimulated with citHSP90β demonstrates a bias toward TH1 immune responses that are likely involved in the pathogenesis of RA-ILD.

Dynamics of Immune Responses during Experimental Mycobacterium kansasii Infection of Cynomolgus Monkeys (Macaca fascicularis).

To profile the dynamic changes of immune responses for M. kansasii infection, 3 cynomolgus monkeys were experimentally infected with M. kansasii by intratracheal inhalation of 1 × 106 CFU bacteria per monkey. Every 2 to 4 weeks, tuberculin skin testings (TSTs) were performed and blood samples were collected for immunoassay. Multiple cytokines in a single sample were measured by Luminex xMAP technologies. IgM and IgA were detected by double-antibody sandwich ELISA. IgG against PPD and 11 M. tuberculosis proteins were detected by using of indirect ELISA. At week 16, all animals were euthanized for necropsy and histological analysis. Positivities of TSTs emerged from week 2 to 6 postinfection. Leukocyte counts and T lymphocyte subsets experienced moderate increases. Among 44 kinds of cytokines, 36 kinds of them showed increases of different dynamic types and 8 kinds of them showed no specific changes. Total IgM and IgA showed a transient increase at an early infection stage. Positivities of M. tuberculosis specific IgM and IgA emerged as early as week 2 postinfection. All animals showed positive IgG against PPD and negative IgG responses to 38 kDa, MPT64L, TB16.3, 16 kDa, U1, and MTB81 antigens during the infection period. IgG against ESAT-6, CFP10, CFP10-ESAT-6, Ag85b, and 14 kDa antigens reached positive levels. The IgG avidities of PPD, ESAT-6, CFP10-ESAT-6, and Ag85b were all above 50 percent. In conclusion, the data indicate that M. kansasii infection in monkeys can induce positivities of TSTs, increases of multiple cytokines, and cross-reactive antibody responses to M. tuberculosis antigens.

Subsite heterogeneity in the profiles of circulating cytokines in colorectal cancer

Colorectal cancers (CRCs) are treated as one entity but are in fact a heterogeneous group of diseases. If not addressed, subsite-associated variability may interfere with mechanism-targeted therapies and accuracy of potential CRC biomarkers. Little is known about the contribution of systemic inflammatory and immune mediators to subsite heterogeneity in CRC. Our purpose was to compare the profiles of key cytokines between right and left colonic and rectal CRCs. Using Luminex xMAP® technology, serum concentrations of eotaxin, IL-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-9, IL-10, IL-12(p70), IL-13, IL-15, IL-17, IFNγ, IP-10, FGF-2, G-CSF, GM-CSF, MCP-1, MIP-1α and β, PDGF-BB, RANTES, TNFα, and VEGF-A were determined in 104 CRC patients. We found the concentrations of IL-12(p70), IL-10, IL-1ra, IL-4, IL-6, IL-7, IL-8, G-CSF and TNFα to be significantly higher in right-sided and GM-CSF in left-sided than rectal CRCs. The concentrations of IFNγ and MIP-1α were significantly higher in right-sided CRCs as compared to cancers of other locations combined. In turn, MIP-1β was higher in rectal CRCs as compared to colon cancers. Taken together, our results show subsite heterogeneity of CRC cancers in terms of systemic inflammatory and immune responses that ought to be taken into account when attempting immunotherapy or developing biomarkers. Additionally, more pronounced TH2 response accompanied by TH1 immunity and more prominent tumor-promoting inflammation in CRC patients with primary tumors originating from right-sided colon may constitute a molecular background of unfavorable prognosis associated with this location.