Multiplexed particle-based flow cytometric assays

Ultrasimple size encoded microfluidic chip for rapid simultaneous multiplex detection of DNA sequences

Simultaneous multiplexed analysis can provide comprehensive information for disease diagnosis. However, the current multiplex methods rely on sophisticated barcode technology, which hinders its wider application. In this study, an ultrasimple size encoding method is proposed for multiplex detection using a wedge-shaped microfluidic chip. Driving by negative pressure, microparticles are naturally arranged in distinct stripes based on their sizes within the chip. This size encoding method demonstrates a high level of precision, allowing for accuracy in distinguishing 3-5 sizes of microparticles with a remarkable accuracy rate of up to 99%, even the microparticles with a size difference as small as 0.5 μm. The entire size encoding process is completed in less than 5 min, making it ultrasimple, reliable, and easy to operate. To evaluate the function of this size encoding microfluidic chip, three commonly co-infectious viruses' nucleic acid sequences (including complementary DNA sequences of HIV and HCV, and DNA sequence of HBV) are employed for multiplex detection. Results indicate that all three DNA sequences can be sensitively detected without any cross-interference. This size-encoding microfluidic chip-based multiplex detection method is simple, rapid, and high-resolution, its successful application in serum samples renders it highly promising for potential clinical promotion.

Assessment of the systemic immune-inflammation index in type 2 diabetic patients with and without dry eye disease: A case-control study

Background

The inflammation plays a role in the pathophysiology of type-2 diabetes progression, and the mechanism remains unclear. The systemic immune-inflammation index (SII) is a novel inflammatory marker for type 2 diabetes patients and integrates multiple indicators in complete blood counts and routine blood tests.

Aim

Since there is no international diagnostic standard for dry eye disease (DED), this study uses low-cost inflammatory blood biomarkers to investigate the correlation between SII and DM2-DED and determine the diagnosis indices of other biomarkers in DM2-DED.

Methodology

A case-control retrospective analysis of totel patients n = 293 randomly selected and categorized into four groups: DED, DM2, DM2-DED, and healthy subjects. Demographic and blood biomarker variables were classified as categorical and continuous variables. The platelet-to-lymphocyte ratio (PLR), lymphocytes-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio (NLR), and SII were calculated platelet count multiply by NLR and analyzed for their correlation for all groups.

Results

Focusing on DM2-DED patients was more common in females, 59.6%, than in males, 40.2%. The mean ages were 60.7 ± 11.85 years, a statistically significant difference with all groups. In the study group DM2-DED, there was an increase in all blood markers compared to all remaining groups except PLR. Only neutrophil, hemoglobin A1c (HbA1c), and fasting blood sugar levels were statistically significant differences in DM2-DED patients (p > 0.001, p < 0.001, and p < 0.001, respectively) compared to all groups. There was a positive correlation between HbA1c and PLR, HbA1c and NLR, and HbA1c and SII (r = 0.037, p = 0.705; r = 0.031, p = 0.754; and r = 0.066, p < 0.501, respectively) in the DM2-DED group.

Conclusion

This study demonstrated that elevated SII values were linked to elevated HbA1c in DM2-DED patients. The potential of SII and HbA1c as early diagnostic indicators for ocular problems associated with diabetes mellitus is highlighted by their favorable connection in diagnosing DM2-DED.

Review of flow cytometry as a tool for cell and gene therapy

Quality control testing and analytics are critical for the development and manufacture of cell and gene therapies, and flow cytometry is a key quality control and analytical assay that is used extensively. However, the technical scope of characterization assays and safety assays must keep apace as the breadth of cell therapy products continues to expand beyond hematopoietic stem cell products into producing novel adoptive immune therapies and gene therapy products.  Flow cytometry services are uniquely positioned to support the evolving needs of cell therapy facilities, as access to flow cytometers, new antibody clones and improved fluorochrome reagents becomes more egalitarian. This report will outline the features, logistics, limitations and the current state of flow cytometry within the context of cellular therapy.

Omega-3 Fatty Acids and Markers of Thrombosis in Patients with Atrial Fibrillation

Omega-3 fatty acids (n-3 FAs) are associated with a lower risk of ischemic stroke in patients with atrial fibrillation (AF). Antithrombotic mechanisms may in part explain this observation. Therefore, we examined the association of n-3 FAs with D-dimer and beta-thromboglobulin (BTG), markers for activated coagulation and platelets, respectively. The n-3 FAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), docosapentaenoic acid (DPA) and alpha-linolenic acid (ALA) were determined via gas chromatography in the whole blood of 2373 patients with AF from the Swiss Atrial Fibrillation cohort study (ClinicalTrials.gov Identifier: NCT02105844). In a cross-sectional analysis, we examined the association of total n-3 FAs (EPA + DHA + DPA + ALA) and the association of individual fatty acids with D-dimer in patients with detectable D-dimer values (n = 1096) as well as with BTG (n = 2371) using multiple linear regression models adjusted for confounders. Median D-dimer and BTG levels were 0.340 ug/mL and 448 ng/mL, respectively. Higher total n-3 FAs correlated with lower D-dimer levels (coefficient 0.94, 95% confidence interval (Cl) 0.90-0.98, p = 0.004) and lower BTG levels (coefficient 0.97, Cl 0.95-0.99, p = 0.003). Likewise, the individual n-3 FAs EPA, DHA, DPA and ALA showed an inverse association with D-dimer. Higher levels of DHA, DPA and ALA correlated with lower BTG levels, whereas EPA showed a positive association with BTG. In patients with AF, higher levels of n-3 FAs were associated with lower levels of D-dimer and BTG, markers for activated coagulation and platelets, respectively. These findings suggest that n-3 FAs may exert antithrombotic properties in patients with AF.

A Human Whole Blood Culture System Reveals Detailed Cytokine Release Profiles of Implant Materials

Introduction

Common in vitro cell culture systems for testing implant material immune compatibility either rely on immortal human leukocyte cell lines or isolated primary cells. Compared to in vivo conditions, this generates an environment of substantially reduced complexity, often lacking important immune cell types, such as neutrophil granulocytes and others. The aim of this study was to establish a reliable test system for in vitro testing of implant materials under in vivo-like conditions.

Methods

Test materials were incubated in closed, CO2-independent, tube-based culture vessels containing a proprietary cell culture medium and human whole blood in either a static or occasionally rotating system. Multiplex cytokine analysis was used to analyze immune cell reactions.

Results

To demonstrate the applicability of the test system to implant materials, three commercially available barrier membranes (polytetrafluoroethylene (PTFE), polycaprolactone (PCL) and collagen) used for dental, trauma and maxillofacial surgery, were investigated for their potential interactions with immune cells. The results showed characteristic differences between the static and rotated incubation methods and in the overall activity profiles with very low immune cell responses to PTFE, intermediate ones to collagen and strong reactions to PCL.

Conclusion

This in vitro human whole blood model, using a complex organotypic matrix, is an excellent, easily standardized tool for categorizing immune cell responses to implant materials. Compared to in vitro cell culture systems used for materials research, this new assay system provides a far more detailed picture of response patterns the immune system can develop when interacting with different types of materials and surfaces.

Immune Markers Are Associated With Asymptomatic Intracranial Large Artery Stenosis and Future Vascular Events in NOMAS

BACKGROUND

Inflammation contributes to atherosclerosis but is incompletely characterized in intracranial large artery stenosis (ICAS). We hypothesized that immune markers would be associated with ICAS and modify the risk ICAS confers on future vascular events.

METHODS

This study included a subsample of stroke-free participants in the prospective NOMAS (Northern Manhattan Study), who had blood samples analyzed with a 60-plex immunoassay (collected from 1993 to 2001) and ICAS assessment with time-of-flight magnetic resonance angiography (obtained from 2003 to 2008). We dichotomized ICAS as either ≥50% stenosis or not (including no ICAS). We ascertained post-magnetic resonance imaging vascular events. We used least absolute shrinkage and selection operator procedures to select immune markers independently associated with ICAS. Then, we grouped selected immune markers into a derived composite Z score. Using proportional odds regression, we quantified the association of the composite immune marker Z score, ICAS, and risk of vascular events.

RESULTS

Among 1211 participants (mean age, 71±9 years; 59% women; 65% Hispanic participants), 8% had ≥50% ICAS. Using least absolute shrinkage and selection operator regression, we identified CXCL9 (C-X-C motif chemokine ligand 9), HGF (hepatocyte growth factor), resistin, SCF (stem cell factor), and VEGF-A(vascular endothelial growth factor A) to have the strongest positive relationships with ≥50% ICAS in fully adjusted models. Selected markers were used to derive a composite immune marker Z score. Over an average follow-up of 12 years, we found that each unit increase in immune marker Z scores was associated with an 8% (95% CI, 1.05-1.11), 11% (95% CI, 1.06-1.16), and 5% (95% CI, 1.01-1.09) increased hazard of death, vascular death, and any vascular event, respectively, in adjusted models. We did not find a significant interaction between immune marker Z scores and ICAS in their relationship with any longitudinal outcome.

CONCLUSIONS

Among a diverse stroke-free population, selected serum immune markers were associated with ICAS and future vascular events. Further study is needed to better understand their role in the pathogenesis of ICAS and as a potential therapeutic target in stroke prevention.

Photonic-Plasmonic Coupling Enhanced Fluorescence Enabling Digital-Resolution Ultrasensitive Protein Detection

Assays utilizing fluorophores are common throughout life science research and diagnostics, although detection limits are generally limited by weak emission intensity, thus requiring many labeled target molecules to combine their output to achieve higher signal-to-noise. We describe how the synergistic coupling of plasmonic and photonic modes can significantly boost the emission from fluorophores. By optimally matching the resonant modes of a plasmonic fluor (PF) nanoparticle and a photonic crystal (PC) with the absorption and emission spectrum of the fluorescent dye, a 52-fold improvement in signal intensity is observed, enabling individual PFs to be observed and digitally counted, where one PF tag represents one detected target molecule. The amplification can be attributed to the strong near-field enhancement due to the cavity-induced activation of the PF, PC band structure-mediated improvement in collection efficiency, and increased rate of spontaneous emission. The applicability of the method by dose-response characterization of a sandwich immunoassay for human interleukin-6, a biomarker used to assist diagnosis of cancer, inflammation, sepsis, and autoimmune disease is demonstrated. A limit of detection of 10 fg mL-1 and 100 fg mL-1 in buffer and human plasma respectively, is achieved, representing a capability nearly three orders of magnitude lower than standard immunoassays.

Redefining serological diagnostics with immunoaffinity proteomics

Serological diagnostics is generally defined as the detection of specific human immunoglobulins developed against viral, bacterial, or parasitic diseases. Serological tests facilitate the detection of past infections, evaluate immune status, and provide prognostic information. Serological assays were traditionally implemented as indirect immunoassays, and their design has not changed for decades. The advantages of straightforward setup and manufacturing, analytical sensitivity and specificity, affordability, and high-throughput measurements were accompanied by limitations such as semi-quantitative measurements, lack of universal reference standards, potential cross-reactivity, and challenges with multiplexing the complete panel of human immunoglobulin isotypes and subclasses. Redesign of conventional serological tests to include multiplex quantification of immunoglobulin isotypes and subclasses, utilize universal reference standards, and minimize cross-reactivity and non-specific binding will facilitate the development of assays with higher diagnostic specificity. Improved serological assays with higher diagnostic specificity will enable screenings of asymptomatic populations and may provide earlier detection of infectious diseases, autoimmune disorders, and cancer. In this review, we present the major clinical needs for serological diagnostics, overview conventional immunoassay detection techniques, present the emerging immunoassay detection technologies, and discuss in detail the advantages and limitations of mass spectrometry and immunoaffinity proteomics for serological diagnostics. Finally, we explore the design of novel immunoaffinity-proteomic assays to evaluate cell-mediated immunity and advance the sequencing of clinically relevant immunoglobulins.

Comparative analysis of tear cytokines in patients with glaucoma, ocular hypertension, and healthy controls

PURPOSE

To investigate the ocular surface inflammation in patients with primary open angle glaucoma and ocular hypertension by analyzing tears and to compare findings with healthy controls.

METHODS

Observational case-control study. Tear samples were collected by 5 µl microcapillary tube from 24 patients with glaucoma treated by antiglaucoma drops, 9 non-treated patients with ocular hypertension and 45 healthy controls. Tears were analyzed from right eye by multiplex Bio-Plex system for the presence of 6 cytokines: IL1β, IL10, IL4, IFNγ, MIF and VEGF.

RESULTS

Significantly higher concentrations of IL1β and IL10 (glaucoma or ocular hypertension vs. healthy controls, p < 0.0001), VEGF (glaucoma vs. ocular hypertension, p < 0.05; ocular hypertension vs. healthy controls, p < 0.02) and MIF (glaucoma vs. healthy controls, p < 0.03) were detected in patients' tears. Both patient groups have activated to a significantly lower extent the Th1 pathway represented by IFNγ than Th2 pathway represented by IL10 (p < 0.001) and, at the same time, the IFNγ/IL4 ratio was significantly increased in healthy controls (p < 0.001) and patients with ocular hypertension (p < 0.02) compared to glaucoma individuals.

CONCLUSION

This study shows that secretion of inflammation-related cytokines by conjunctival cells is increased in both, glaucoma and ocular hypertension patients and can be detected in their tears. Nevertheless, data indicates stronger ocular surface inflammation in non-treated follow-up patients diagnosed with ocular hypertension than in glaucoma subjects treated by antiglaucoma drops.

Scope of Onsite, Portable Prevention Diagnostic Strategies for Alternaria Infections in Medicinal Plants

Medicinal plants are constantly challenged by different biotic inconveniences, which not only cause yield and economic losses but also affect the quality of products derived from them. Among them, Alternaria pathogens are one of the harmful fungal pathogens in medicinal plants across the globe. Therefore, a fast and accurate detection method in the early stage is needed to avoid significant economic losses. Although traditional methods are available to detect Alternaria, they are more time-consuming and costly and need good expertise. Nevertheless, numerous biochemical- and molecular-based techniques are available for the detection of plant diseases, but their efficacy is constrained by differences in their accuracy, specificity, sensitivity, dependability, and speed in addition to being unsuitable for direct on-field studies. Considering the effect of Alternaria on medicinal plants, the development of novel and early detection measures is required to detect causal Alternaria species accurately, sensitively, and rapidly that can be further applied in fields to speed up the advancement process in detection strategies. In this regard, nanotechnology can be employed to develop portable biosensors suitable for early and correct pathogenic disease detection on the field. It also provides an efficient future scope to convert innovative nanoparticle-derived fabricated biomolecules and biosensor approaches in the diagnostics of disease-causing pathogens in important medicinal plants. In this review, we summarize the traditional methods, including immunological and molecular methods, utilized in plant-disease diagnostics. We also brief advanced automobile and efficient sensing technologies for diagnostics. Here we are proposing an idea with a focus on the development of electrochemical and/or colorimetric properties-based nano-biosensors that could be useful in the early detection of Alternaria and other plant pathogens in important medicinal plants. In addition, we discuss challenges faced during the fabrication of biosensors and new capabilities of the technology that provide information regarding disease management strategies.

Conventional and State-of-the-Art Detection Methods of Bovine Spongiform Encephalopathy (BSE)

Bovine spongiform encephalopathy (BSE) is a fatal neurodegenerative disease that belongs to a group of diseases known as transmissible spongiform encephalopathies (TSEs). It is believed that the infectious agent responsible for prion diseases is abnormally folded prion protein (PrP^Sc), which derives from a normal cellular protein (PrP^C), which is a cell surface glycoprotein predominantly expressed in neurons. There are three different types of BSE, the classical BSE (C-type) strain and two atypical strains (H-type and L-type). BSE is primarily a disease of cattle; however, sheep and goats also can be infected with BSE strains and develop a disease clinically and pathogenically indistinguishable from scrapie. Therefore, TSE cases in cattle and small ruminants require discriminatory testing to determine whether the TSE is BSE or scrapie and to discriminate classical BSE from the atypical H- or L-type strains. Many methods have been developed for the detection of BSE and have been reported in numerous studies. Detection of BSE is mainly based on the identification of characteristic lesions or detection of the PrP^Sc in the brain, often by use of their partial proteinase K resistance properties. The objective of this paper was to summarize the currently available methods, highlight their diagnostic performance, and emphasize the advantages and drawbacks of the application of individual tests.

A digital nanoplasmonic microarray immunosensor for multiplexed cytokine monitoring during CAR T-cell therapy from a leukemia tumor microenvironment model

The release of cytokines by chimeric antigen receptor (CAR) T-cells and tumor resident immune cells defines a significant part of CAR T-cell functional activity and patient immune responses during CAR T-cell therapy. However, few studies have so far precisely characterized the cytokine secretion dynamics in the tumor niche during CAR T-cell therapy, which requires multiplexed, and timely biosensing platforms and integration with biomimetic tumor microenvironment. Herein, we implemented a digital nanoplasmonic microarray immunosensor with a microfluidic biomimetic Leukemia-on-a-Chip model to monitor cytokine secretion dynamics during CD19 CAR T-cell therapy against precursor B-cell acute lymphocytic leukemia (B-ALL). The integrated nanoplasmonic biosensors achieved precise multiplexed cytokine measurements with low operating sample volume, short assay time, heightened sensitivity, and negligible sensor crosstalk. Using the digital nanoplasmonic biosensing approach, we measured the concentrations of six cytokines (TNF-α, IFN-γ, MCP-1, GM-CSF, IL-1β, and IL-6) during first 5 days of CAR T-cell treatment in the microfluidic Leukemia-on-a-Chip model. Our results revealed a heterogeneous secretion profile of various cytokines during CAR T-cell therapy and confirmed a correlation between the cytokine secretion profile and the CAR T-cell cytotoxic activity. The capability to monitor immune cell cytokine secretion dynamics in a biomimetic tumor microenvironment could further help in study of cytokine release syndrome during CAR T-cell therapy and in development of more efficient and safer immunotherapies.

Serum short chain fatty acids mediate hippocampal BDNF and correlate with decreasing neuroinflammation following high pectin fiber diet in mice

Introduction

Dietary components, such as prebiotic fiber, are known to impact brain chemistry via the gut-brain axis. In particular, short chain fatty acids (SCFAs) generated from excessive soluble fiber consumption are thought to impact neuroimmune signaling and brain function through increased production of neurotropic factors. Given reports that high dietary fiber intake is associated with increased mental health and improved quality of life scores, we set out to identify whether changes in SCFA levels as a result of a high soluble fiber diet mediate hippocampal neuroinflammation and brain derived neurotrophic factor (BDNF) in mice.

Methods

Adult male and female C57BL/6 mice were fed a 1-month high pectin fiber or cellulose-based control diet. Following 1 month of excessive pectin consumption, serum SCFAs were measured using gas chromatography-mass spectrometry (GC-MS) and hippocampal cytokines and BDNF were assessed via multiplex magnetic bead immunoassay.

Results

Pectin-based fiber diet increased circulating acetic acid in both sexes, with no effect on propionic or butyric acid. In the hippocampus, a high fiber diet decreased TNFa, IL-1ß, IL-6, and IFNγ and increased BDNF levels. Furthermore, increased SCFA levels were inversely correlated with neuroinflammation in the hippocampus, with acetic acid revealed as a strong mediator of increased BDNF production.

Conclusion

Collectively, these findings highlight the beneficial effects of fiber-induced molecular changes in a brain region known to influence mood- and cognition-related behaviors. Dietary composition should be considered when developing mental health management plans for men and women with an emphasis on increasing soluble fiber intake.

Biophysical and biochemical insights in the design of immunoassays

BACKGROUND

Rapid antigen assays have been attractive for decentralized, point of care diagnostics because of their low cost, robustness, and ease of use. The development of a diagnostic assay for a newly emerging infectious disease needs to take into account the progression of a disease, whether there is human to human transmission, and patient biomarker levels with time, and these all impact the choice of antigen targets and affinity agents.

SCOPE OF REVIEW

The factors involved in the biophysical design of rapid antigen immunoassays are discussed, focusing on antigen selection and designing for cross-reactivity. State of the art in the biophysical characterization of protein-ligand or antigen-antibody interactions, the different types of affinity agents used in immunoassays, and biochemical conjugation strategies are described.

MAJOR CONCLUSIONS

Antigen choice is a critical factor in immunoassay diagnostic development, and should account for the properties of the virion, virus, and disease progression. Biophysical and biochemical aspects of immunoassays are critical for performance.

GENERAL SIGNIFICANCE

This review can serve as an instructive guide to aid in diagnostic development for future emerging diseases.

Development of Multiplexed Bead-Based Immunoassays for Profiling Soluble Cytokines and CD163 Using Mass Cytometry

Bead-based immunoassays are multiparametric analysis allowing for the simultaneous quantification of a large number of biomarkers within a single sample. Mass cytometry is an emerging cytometric technique that offers a high multiplexing capacity in a high-throughput setting but has not yet been applied to bead-based assays. In this study, we developed a multiplex bead-based immunoassay of cytokines and CD163 designed for mass cytometry (MC). A set of 11 types of lanthanide-encoded microbeads were synthesized by two-stage dispersion polymerization as classifier candidates for the assay. These beads were then decorated with different Abs on the surface to capture the target cytokines in solution. Gold nanoparticles were employed as reporters to identify the binding of target cytokines on the classifier surface. As a proof-of-concept study, we first developed four-plex and nine-plex assays of mixtures of cytokines in standard solutions. The MC signal intensities of these immunoassays were responsive to the concentration differences in the standard solutions with high detection sensitivities at low analyte concentrations. Finally, we examined a sample of peripheral blood mononuclear cells (PBMCs) with the nine-plex assay, comparing an unstimulated sample with a sample stimulated to promote cytokine secretion.

Advanced density-based methods for the characterization of materials, binding events, and kinetics

Investigations of the densities of chemicals and materials bring valuable insights into the fundamental understanding of matter and processes. Recently, advanced density-based methods have been developed with wide measurement ranges (i.e. 0-23 g cm^-3), high resolutions (i.e. 10^-6 g cm^-3), compatibility with different types of samples and the requirement of extremely low volumes of sample (as low as a single cell). Certain methods, such as magnetic levitation, are inexpensive, portable and user-friendly. Advanced density-based methods are, therefore, beneficially used to obtain absolute density values, composition of mixtures, characteristics of binding events, and kinetics of chemical and biological processes. Herein, the principles and applications of magnetic levitation, acoustic levitation, electrodynamic balance, aqueous multiphase systems, and suspended microchannel resonators for materials science are discussed.

Serum Phytosterols Are Not Associated with Inflammatory Markers in Two Cross-Sectional, Swiss Population-Based Studies (The CoLaus|PsyCoLaus Study)

Background: The association between inflammation and dietary sterols remains poorly assessed at the population level. Aims: To assess the possible association between serum levels of various phytosterols (PS) and inflammatory markers. Methods: Serum levels of six PS (campesterol, campestanol, stigmasterol, sitosterol, sitostanol, brassicasterol), four cholesterol synthesis markers (lathosterol, lanosterol, desmosterol, dihydroxylanosterol) and one cholesterol absorption marker (cholestanol) were measured together with levels of CRP, IL-6 and TNF-α in two cross-sectional surveys of a population-based, prospective study. Results: CRP levels were negatively associated with levels of cholestanol and of sterols of plant origin, although some associations were not statistically significant. CRP levels were positively associated with cholesterol synthesis markers in the first but not in the second follow-up. IL-6 levels were negatively associated with cholestanol in both follow-ups. No associations between IL-6 levels and PS were found in the first follow-up, while significant negative associations with campesterol, sitosterol, brassicasterol, sitostanol and campesterol:TC ratio were found in the second follow-up. TNF-α levels were negatively associated with cholestanol in both follow-ups. These associations did not withstand adjusting for sex, age, BMI and statin administration. Conclusions: In a population-based study, PS serum levels were not significantly associated with inflammatory markers.

A low-cost flow cell for flow cytometry

Flow cytometry is an essential analytical technique used in biomedical diagnostics to measure properties of cells, micro-organisms, and particles. Laser light is scattered from particles focused in a flow cell and collected by light sensors, where the intensity of the scattered light is a function of the scattering angle, the refractive index of the particle and surrounding medium, the wavelength of light, and the size and the shape of the particle. One of the critical parts of the cytometer is the flow cell where the particle stream is constrained into a tight region within 10-30 μm using hydrodynamic focusing. The conventional flow cells use thick quartz flow cells, which are expensive and therefore not suitable for instruments targeted for resource-constrained settings. We demonstrate a compact, economical, bio-compatible flow cell assembly design that incorporates inexpensive and easily available capillaries attached to sturdy polymer fixtures in a simple manner that performs the focusing of a sample stream of particles. The flow cell has been tested by studying the relation between sample core diameter, and sample and sheath flow rates. Small-angle scattering (forward scatter) and wide-angle scattering (side scatter) have been captured for the enumeration and characterization of particles. We show excellent agreement between the size distribution obtained via direct imaging and that obtained from light scattering. The flow cell was also used to successfully size white blood cells in human blood samples.

Acupuncture and its effect on cytokine and chemokine profiles in seasonal allergic rhinitis: a preliminary three-armed, randomized, controlled trial

Purpose

Numerous studies have demonstrated effectiveness for acupuncture in the treatment of seasonal allergic rhinitis (SAR). However, the underlying mechanism remains still unclear.

Methods

29 SAR patients were recruited from a large randomized, controlled trial investigating the efficacy of acupuncture in SAR. 16 patients were treated by acupuncture plus rescue medication (RM, cetirizine), 6 patients received sham acupuncture plus RM and 8 patients RM alone over 8 weeks. Patients were blinded to the allocation to real or sham acupuncture. At baseline and different time-points during intervention, plasma and nasal concentration of mediators of various biological functions were determined in addition to validated disease-specific questionnaires.

Results

The concentration of biomarkers related to the Th1-, Th2-, and Treg-cluster was not changed in patients who received acupuncture, in neither plasma nor nasal fluid. However, with respect to eotaxin and some unspecific pro-inflammatory cytokines (IL-1b, IL-8, IP-10, MIP-1b, MCP-1), acupuncture led to a, partially significantly, lower nasal concentration than sham acupuncture or RM. Furthermore, the nasal symptom score was significantly reduced in patients only after real acupuncture.

Conclusion

In SAR, acupuncture reduces the intranasal unspecific inflammation, but does not seem to act immunologically on the Th1–Th2-imbalance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00405-022-07335-5.

Maternal mid-gestational and child cord blood immune signatures are strongly associated with offspring risk of ASD

Epidemiological studies and work in animal models indicate that immune activation may be a risk factor for autism spectrum disorders (ASDs). We measured levels of 60 cytokines and growth factors in 869 maternal mid-gestational (MMG) and 807 child cord blood (CB) plasma samples from 457 ASD (385 boys, 72 girls) and 497 control children (418 boys, 79 girls) from the Norwegian Autism Birth Cohort. We analyzed associations first using sex-stratified unadjusted and adjusted logistic regression models, and then employed machine learning strategies (LASSO + interactions, Random Forests, XGBoost classifiers) with cross-validation and randomly sampled test set evaluation to assess the utility of immune signatures as ASD biomarkers. We found prominent case-control differences in both boys and girls with alterations in a wide range of analytes in MMG and CB plasma including but not limited to IL1RA, TNFα, Serpin E1, VCAM1, VEGFD, EGF, CSF1, and CSF2. MMG findings were most striking, with particularly strong effect sizes in girls. Models did not change appreciably upon adjustment for maternal conditions, medication use, or emotional distress ratings. Findings were corroborated using machine learning approaches, with area under the receiver operating characteristic curve values in the test sets ranging from 0.771 to 0.965. Our results are consistent with gestational immunopathology in ASD, may provide insights into sex-specific differences, and have the potential to lead to biomarkers for early diagnosis.

Development of a microsphere-based immunoassay for the serological diagnosis of equine trypanosomosis

Trypanozoon infections in equids are caused by three parasite species in the Trypanozoon subgenus: Trypanosoma equiperdum, T. brucei and T. evansi. They are respectively responsible for infectious diseases dourine, nagana and surra. Due to the threat that Trypanozoon infection represents for international horse trading, accurate diagnostic tests are crucial. Current tests suffer from poor sensitivity and specificity, due in the first case to the transient presence of parasites in the blood and in the second, to antigenic cross-reactivity among Trypanozoon subspecies. This study was designed to develop a microsphere‐based immunoassay for diagnosing equine trypanosomosis. We tested beads coated with eight Trypanosoma spp. recombinant antigens: enolase, GM6, PFR1, PFR2, ISG65, VSGat, RoTat1.2 and JN2118HU. Of these, GM6 was identified as the best candidate for the serological diagnosis of Trypanozoon infections in equids. Using a receiver operating characteristic (ROC) analysis on 349 equine sera, anti-GM6 antibodies were detected with an AUC value of 0.994 offering a sensitivity of 97.9% and a specificity of 96.0%. Our findings show that the GM6 antigen is a good target for diagnosing equine trypanosomosis using a microsphere‐based immunoassay. This promising assay could be a useful alternative to the official diagnostic tool for equine trypanosomosis.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.

Compact Quantum-Dot Microbeads with Sub-Nanometer Emission Linewidth

Fluorescent microbeads are widely used for applications in life sciences and medical diagnosis. The spectral contrast and sharpness of photoluminescence are critical in the utilities of microbeads for imaging and multiplexing. Here, we demonstrate microbeads capable of generating single-peak laser emission with a sub-nanometer linewidth. The microbeads are made of quantum dots that are tightly packed and crosslinked via ligand exchange for high optical gain and refractive index as well as material stability. Bright single-mode lasing with no photobleaching is achieved with particle diameters as small as 1.5 μm in the air. Sub-nm lasing emission is maintained even inside high-index surroundings, such as organic solvents and biological tissues. Feasibility of intracellular tagging and multi-color imaging in vivo is demonstrated.

Current state of technologies and recognition of anti-SSA/Ro antibodies in China: A multi-center study

Background

Previous studies have demonstrated that Ro60 and Ro52 have different clinical implications, and anti‐Ro52 antibodies are an independent serum marker of systemic autoimmune diseases, including Sjögren's syndrome. Many different assays have been adopted to detect anti‐Sjögren's syndrome antigen A (SSA)/Ro antibodies, while to date no specific approach has been recommended as optimal for anti‐SSA/Ro antibody testing. Herein, we performed a multi‐center study to explore the current clinical utility of different strategies for anti‐SSA/Ro antibody testing in China.

Methods

Twenty‐one tertiary care centers were included in this questionnaire‐based study. The self‐administered questionnaire mainly includes testing methods for anti‐SSA/Ro antibodies, reporting system of results, and interpretation of results by clinicians.

Results

Six different methods were applied to detect anti‐SSA/Ro antibodies in the 21 centers. Line immunoassay (eight different commercial kits) was the most frequently adopted method (21/21, 100%), with different cutoff values and strategies for intensity stratification. There were two reporting systems: One was reported as “anti‐SSA antibodies” and “anti‐Ro52 antibodies” (12/21, 57%), while the other was “anti‐SSA/Ro60 antibodies” and “anti‐SSA/Ro52 antibodies” (9/21, 43%). Notably, six centers (29%) considered either positive anti‐Ro60 or anti‐Ro52 antibodies as positive anti‐SSA antibodies, all of which adopted the latter reporting system.

Conclusion

Significant variabilities existed among anti‐SSA/Ro assays. Nearly 30% of centers misinterpreted the definition of positive anti‐SSA antibodies, which may be attributed to the confusing reporting systems of line immunoassay. Therefore, we advocate standardization of the nomenclature of anti‐SSA/Ro antibodies, changing the “anti‐SSA/Ro52” label in favor of the “anti‐Ro52” antibodies for a clear designation.

Effect of a Fiber D-Limonene-Enriched Food Supplement on Intestinal Microbiota and Metabolic Parameters of Mice on a High-Fat Diet

Several studies showed that D-Limonene can improve metabolic parameters of obese mice via various mechanisms, including intestinal microbiota modulation. Nevertheless, its effective doses often overcome the acceptable daily intake, rising concerns about toxicity. In this study we administered to C57BL/6 mice for 84 days a food supplement based on D-Limonene, adsorbed on dietary fibers (FLS), not able to reach the bloodstream, to counteract the metabolic effects of a high-fat diet (HFD). Results showed that daily administration of D-Limonene (30 and 60 mg/kg body weight) for 84 days decreased the weight gain of HFD mice. After 84 days we observed a statistically significant difference in weight gain in the group of mice receiving the higher dose of FLS compared to HFD mice (35.24 ± 4.56 g vs. 40.79 ± 3.28 g, p < 0.05). Moreover, FLS at both doses tested was capable of lowering triglyceridemia and also fasting glycemia at the higher dose. Some insights on the relevant fatty acid changes in hepatic tissues were obtained, highlighting the increased polyunsaturated fatty acid (PUFA) levels even at the lowest dose. FLS was also able to positively modulate the gut microbiota and prevent HFD-associated liver steatosis in a dose-dependent manner. These results demonstrate that FLS at these doses can be considered non-toxic and could be an effective tool to counteract diet-induced obesity and ameliorate metabolic profile in mice.

Multiplex protein analysis for the study of glaucoma

INTRODUCTION

Glaucoma, a leading cause of irreversible blindness in the world, is a chronic neurodegenerative disease of multifactorial origin. Extensive research is ongoing to better understand, prevent, and treat progressive degeneration of retinal ganglion cells in glaucoma. While experimental models of glaucoma and postmortem tissues of human donors are analyzed for pathophysiological comprehension and improved treatment of this blinding disease, clinical samples of intraocular biofluids and blood collected from glaucoma patients are analyzed to identify predictive, diagnostic, and prognostic biomarkers. Multiplexing techniques for protein analysis offer a valuable approach for translational glaucoma research.

AREAS COVERED

This review provides an overview of the increasing applications of multiplex protein analysis for glaucoma research and also highlights current research challenges in the field and expected solutions from emerging technological advances.

EXPERT OPINION

Analytical techniques for multiplex analysis of proteins can help uncover neurodegenerative processes for enhanced treatment of glaucoma and can help identify molecular biomarkers for improved clinical testing and monitoring of this complex disease. This evolving field and continuously growing availability of new technologies are expected to broaden the comprehension of this complex neurodegenerative disease and speed up the progress toward new therapeutics and personalized patient care to prevent blindness from glaucoma.

Immune markers are associated with cognitive performance in a multiethnic cohort: The Northern Manhattan Study

OBJECTIVE

To determine whether immune protein panels add significant information to correlates of cognition.

BACKGROUND

Immune mechanisms in vascular cognitive aging are incompletely characterized.

DESIGN/METHODS

A subsample of the prospective Northern Manhattan Study underwent detailed neuropsychological testing. Cognitive scores were converted into Z-scores and categorized into four domains (memory, language, processing speed, and executive function) based on factor analysis. Blood samples were analyzed using a 60-plex immunoassay. We used least absolute shrinkage and selection operator (LASSO) procedures to select markers and their interactions independently associated with cognitive scores. Linear regression models assessed cross-sectional associations of known correlates of cognition with cognitive scores, and assessed model fit before and after addition of LASSO-selected immune markers.

RESULTS

Among 1179 participants (mean age 70 ± 8.9 years, 60% women, 68% Hispanic), inclusion of LASSO-selected immune markers improved model fit above age, education, and other risk factors (p for likelihood ratio test < 0.005 for all domains). C-C Motif Chemokine Ligand 11 (CCL 11, eotaxin), C-X-C Motif Chemokine Ligand 9 (CXCL9), hepatocyte growth factor (HGF), and serpin E1 (plasminogen activator inhibitor-1) were associated with each of the domains and with overall cognitive function. Immune marker effects were comparable to conventional risk factors: for executive function, each standard deviation (SD) increase in CCL11 was associated with an effect equivalent to aging three years; for memory, HGF had twice the effect of aging.

CONCLUSIONS

Immune markers associate with cognitive function in a multi-ethnic cohort. Further work is needed to validate these findings and determine optimal treatment targets.

Uncovering the Depths of the Human Proteome: Antibody-based Technologies for Ultrasensitive Multiplexed Protein Detection and Quantification

Probing the human proteome in tissues and biofluids such as plasma is attractive for biomarker and drug target discovery. Recent breakthroughs in multiplex, antibody-based, proteomics technologies now enable the simultaneous quantification of thousands of proteins at as low as sub fg/ml concentrations with remarkable dynamic ranges of up to 10-log. We herein provide a comprehensive guide to the methodologies, performance, technical comparisons, advantages, and disadvantages of established and emerging technologies for the multiplexed ultrasensitive measurement of proteins. Gaining holistic knowledge on these innovations is crucial for choosing the right multiplexed proteomics tool for applications at hand to critically complement traditional proteomics methods. This can bring researchers closer than ever before to elucidating the intricate inner workings and cross talk that spans multitude of proteins in disease mechanisms.

Laboratory Approaches to Test the Function of Antiphospholipid Antibodies

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder caused by the presence of aPLs (antiphospholipid antibodies, i.e., anti-β₂-glycoprotein I and anti-cardiolipin). Everyday practice in terms of laboratory diagnostics of APS includes determination of aPLs and well-known functional assays assessing for lupus anticoagulant (LA), in turn using various tests. According to recent guidelines, the recommended method for LA identification or exclusion is based on the Russell Viper Venom test and a sensitive activated partial thromboplastin time assay. Despite the fact that LA can be quantified in laboratory practice in this way, LA is still used as a binary parameter that is just one of the risk factors of thrombosis in APS. As of today, there are no other functional assays to routinely assess the risk of thrombosis in APS. It is well-known that APS patients display a wide range of clinical outcomes although they may express very similar laboratory findings. One way to solve this dilemma, could be if antibodies could be further delineated using more advanced functional tests. Therefore, we review the diagnostic approaches to test the function of aPLs. We further discuss how thrombin generation assays, and rotational thromboelastometry tests can be influenced by LA, and how experimental methods, such as flow cytometric platelet activation, surface plasmon resonance, or nano differential scanning fluorimetry can bring us closer to the puzzling interaction of aPLs with platelets as well as with their soluble protein ligand. These novel approaches may eventually enable better characterization of aPL, and also provide a better linkage to APS pathophysiology.

Tumor-Induced Inflammatory Cytokines and the Emerging Diagnostic Devices for Cancer Detection and Prognosis

Chronic inflammation generated by the tumor microenvironment is known to drive cancer initiation, proliferation, progression, metastasis, and therapeutic resistance. The tumor microenvironment promotes the secretion of diverse cytokines, in different types and stages of cancers. These cytokines may inhibit tumor development but alternatively may contribute to chronic inflammation that supports tumor growth in both autocrine and paracrine manners and have been linked to poor cancer outcomes. Such distinct sets of cytokines from the tumor microenvironment can be detected in the circulation and are thus potentially useful as biomarkers to detect cancers, predict disease outcomes and manage therapeutic choices. Indeed, analyses of circulating cytokines in combination with cancer-specific biomarkers have been proposed to simplify and improve cancer detection and prognosis, especially from minimally-invasive liquid biopsies, such as blood. Additionally, the cytokine signaling signatures of the peripheral immune cells, even from patients with localized tumors, are recently found altered in cancer, and may also prove applicable as cancer biomarkers. Here we review cytokines induced by the tumor microenvironment, their roles in various stages of cancer development, and their potential use in diagnostics and prognostics. We further discuss the established and emerging diagnostic approaches that can be used to detect cancers from liquid biopsies, and additionally the technological advancement required for their use in clinical settings.

Analytical validation and reference intervals for a commercial multiplex assay to measure five novel biomarkers for acute kidney injury in canine urine

Novel urinary biomarkers are increasingly utilized for the diagnosis of acute kidney injury (AKI) in dogs. Magnetic-bead based immunoassays for the simultaneous measurement of multiple biomarkers represent a potentially efficient and cost effective tool for investigators; however there is limited data to support their reliable use in dogs. Analytical validation of a commercial multiplex assay for the measurement of five AKI biomarkers: clusterin, cystatin C, kidney-injury molecule 1 (KIM-1), monocyte chemoattractant protein 1 and neutrophil gelatinase-associated lipocalin (NGAL) in canine urine was performed. The effect of pre-analytical factors including potential interfering substances and sample storage methods were investigated. Urine from 110 healthy dogs was used to determine reference intervals for each biomarker measured, according to American Society of Veterinary Clinical Pathology guidelines. Additionally, urine from 21 dogs with pyuria was used to evaluate the impact of pyuria on biomarker concentration. The assay performed with acceptable accuracy and precision for the measurement of NGAL only. Clinically relevant urine concentrations of bilirubin, haemoglobin, and synthetic colloid solutions led to interference (mean percentage difference > +/- 15% compared to control) with measurement of all or some of the biomarkers. All biomarkers were stable in urine stored at 20-22 °C for 2 h, 4 °C for 12 h, or -20 °C for 6 months. Reference intervals could not be established for KIM-1 due to unacceptable measurement imprecision (intra- and inter assay coefficient of variation 45% and 20% respectively). Urine NGAL concentration was significantly elevated in pyuria (P < 0.001).

The impact of cytokine levels in young South African children with and without HIV-associated acute lower respiratory infections

Altered host immune responses are considered to play a key role in the pathogenesis of acute lower respiratory infections (ALRI). The existing literature on cytokine responses in ALRI is largely focussed on adults from developed countries and there are few reports describing the role of cytokines in childhood ALRI, particularly in African or human immunodeficiency virus (HIV)-infected populations. To measure systemic cytokine levels in blood plasma from young South African children with and without ALRI and with and without HIV to determine associations between cytokine responses and disease status and respiratory viral identification. Blood plasma samples were collected from 106 hospitalized ALRI cases and 54 non-ALRI controls less than 2 years of age. HIV status was determined. Blood plasma concentrations of 19 cytokines, 7 chemokines, and 4 growth factors (epidermal growth factor, fibroblast growth factor-basic, hepatocyte growth factor, and vascular endothelial) were measured using The Human Cytokine 30-Plex Panel. Common respiratory viruses were identified by PCR. Mean cytokine concentrations for G-CSF, interferon (IFN)-γ, interleukin (IL)-5, and MCP-1 were significantly higher in ALRI cases than in nonrespiratory controls. Within the ALRI cases, several cytokines were higher in children with a virus compared with children without a virus. Mean cytokine concentrations for IFN-α, IFN-γ, IL-4, IL-5, IL-13, tumour necrosis factor-α, and MIP-1α were significantly lower in HIV-infected cases than in HIV-uninfected cases, while IP-10 and monokine induced by interferon-γ were significantly higher in HIV-infected cases than in HIV-uninfected cases. Certain cytokines are likely to play an important role in the host immune response to ALRI. HIV-infected children have impaired inflammatory responses to respiratory infections compared with HIV-uninfected children.

Ethanol Extract of Orostachys japonicus A. Berger (Crassulaceae) Protects Against Type 2 Diabetes by Reducing Insulin Resistance and Hepatic Inflammation in Mice

Type 2 diabetes (T2D) is a threaten human health problem, and accompanied by hyperglycemia and disorder of insulin secretion, is a major cause of abnormalities in maintaining blood glucose homeostasis. Also, low-grade inflammation, as well as insulin resistance (IR), is a common feature in patients with T2D. Numerous causes of the outbreak of T2D have been suggested by researchers, who indicate that genetic background and epigenetic predisposition, such as overnutrition and deficient physical activity, hasten the promotion of T2D milieu. Orostachys japonicus A. Berger (O. japonicus) is a herbal and remedial plant whose various activities include hemostatic, antidotal, febrile, and anti-inflammatory. Hence, we designed to evaluate the antidiabetic efficacy of ethanol extracts of O. japonicus (OJE). Six-week-old C57BL/Ksj-db/db (db/db) mice were used. The results showed that mice given various concentrations of OJE (0, 50, 100, and 200 mg/kg per day) for 8 weeks showed significantly reduced hyperglycemia, IR, and liver injury, confirmed by measuring diabetic parameters, serum, and hepatic biochemicals. Furthermore, the treatment of OJE markedly decreased the mRNA levels of proinflammatory cytokines, lipid accumulation, and gluconeogenesis-related genes. Consistently, western blot analysis indicated that mice treated with OJE showed increased levels of phospho-c-Jun N-terminal kinase, phospho-Akt, glucose transporters 2 and 4 (GLUT2 and GLUT4) in T2D mice. Likewise, much the same results were obtained in in vitro experiments. Taken together, OJE had hopeful advantage in sustaining the glucose homeostasis and diminishing IR, and could be a safe alternative remedy for treating T2D.

Development and Validation of a Multiplex Microsphere Immunoassay Using Dried Blood Spots for SARS-CoV-2 Seroprevalence: Application in First Responders in Colorado, USA

Serological testing of large representative populations for antibodies to SARS-CoV-2 is needed to estimate seroprevalence, transmission dynamics, and the duration of antibody responses from natural infection and vaccination. In this study, a high-throughput SARS-CoV-2 multiplex microsphere immunoassay (MMIA) was developed for the receptor binding domain (RBD) and nucleocapsid (N) that was more sensitive than enzyme-linked immunosorbent assay (ELISA) (98% versus 87%). The MMIA was then applied and validated in 264 first responders in Colorado using serum and dried blood spot (DBS) eluates, compared to ELISA, and evaluated for neutralizing antibodies. Four percent (11/264) of first responders were seropositive in July to August 2020. Serum and DBS were highly correlated for anti-RBD and anti-N antibodies (R = 0.83, P < 0.0001 and R = 0.87, P < 0.0001, respectively) by MMIA. The MMIA accurately predicted SARS-CoV-2 neutralizing antibodies using DBS (R = 0.76, P = 0.037). On repeat antibody testing 3 months later, anti-RBD IgG decreased less rapidly than anti-N IgG measured by MMIA, with a median change in geometric median fluorescence intensity of 62% versus 79% (P < 0.01) for anti-RBD and anti-N IgG, respectively. This novel MMIA using DBS could be scalable for rapid and affordable SARS-CoV-2 serosurveillance in the United States and globally.

Modernization of Control of Pathogenic Micro-Organisms in the Food-Chain Requires a Durable Role for Immunoaffinity-Based Detection Methodology-A Review

Food microbiology is deluged by a vastly growing plethora of analytical methods. This review endeavors to color the context into which methodology has to fit and underlines the importance of sampling and sample treatment. The context is that the highest risk of food contamination is through the animal and human fecal route with a majority of foodborne infections originating from sources in mass and domestic kitchens at the end of the food-chain. Containment requires easy-to-use, failsafe, single-use tests giving an overall risk score in situ. Conversely, progressive food-safety systems are relying increasingly on early assessment of batches and groups involving risk-based sampling, monitoring environment and herd/flock health status, and (historic) food-chain information. Accordingly, responsible field laboratories prefer specificity, multi-analyte, and high-throughput procedures. Under certain etiological and epidemiological circumstances, indirect antigen immunoaffinity assays outperform the diagnostic sensitivity and diagnostic specificity of e.g., nucleic acid sequence-based assays. The current bulk of testing involves therefore ante- and post-mortem probing of humoral response to several pathogens. In this review, the inclusion of immunoglobulins against additional invasive micro-organisms indicating the level of hygiene and ergo public health risks in tests is advocated. Immunomagnetic separation, immunochromatography, immunosensor, microsphere array, lab-on-a-chip/disc platforms increasingly in combination with nanotechnologies, are discussed. The heuristic development of portable and ambulant microfluidic devices is intriguing and promising. Tant pis, many new platforms seem unattainable as the industry standard. Comparability of results with those of reference methods hinders the implementation of new technologies. Whatever the scientific and technological excellence and incentives, the decision-maker determines this implementation after weighing mainly costs and business risks.

Impact of prenatal maternal cytokine exposure on sex differences in brain circuitry regulating stress in offspring 45 years later

Stress is associated with numerous chronic diseases, beginning in fetal development with in utero exposures (prenatal stress) impacting offspring's risk for disorders later in life. In previous studies, we demonstrated adverse maternal in utero immune activity on sex differences in offspring neurodevelopment at age seven and adult risk for major depression and psychoses. Here, we hypothesized that in utero exposure to maternal proinflammatory cytokines has sex-dependent effects on specific brain circuitry regulating stress and immune function in the offspring that are retained across the lifespan. Using a unique prenatal cohort, we tested this hypothesis in 80 adult offspring, equally divided by sex, followed from in utero development to midlife. Functional MRI results showed that exposure to proinflammatory cytokines in utero was significantly associated with sex differences in brain activity and connectivity during response to negative stressful stimuli 45 y later. Lower maternal TNF-α levels were significantly associated with higher hypothalamic activity in both sexes and higher functional connectivity between hypothalamus and anterior cingulate only in men. Higher prenatal levels of IL-6 were significantly associated with higher hippocampal activity in women alone. When examined in relation to the anti-inflammatory effects of IL-10, the ratio TNF-α:IL-10 was associated with sex-dependent effects on hippocampal activity and functional connectivity with the hypothalamus. Collectively, results suggested that adverse levels of maternal in utero proinflammatory cytokines and the balance of pro- to anti-inflammatory cytokines impact brain development of offspring in a sexually dimorphic manner that persists across the lifespan.

Brain damage caused by neonatal hypoxia-ischemia and the effects of hypothermia in severe combined immunodeficient (SCID) mice

Neonatal hypoxic-ischemic encephalopathy (HIE) is a major cause of brain damage in newborns. Although therapeutic hypothermia has been shown to be neuroprotective against neonatal HIE in clinical trials, its effect is not satisfactory. Cell-based therapies have attracted much attention as novel treatments for HIE. Preclinical studies on a variety of human cell transplantation methods have been performed in immunodeficient/immunosuppressed animals, such as severe combined immunodeficient (SCID) mice, which lack functional T and B lymphocytes. The detailed characteristics of neonatal HIE in SCID mice, however, have not been delineated. In preclinical studies, novel therapies for neonatal HIE should be evaluated in combination with hypothermia, which has become a standard treatment for neonatal HIE. However, the effects of hypothermia in SCID mice have not been delineated. In the present study, we compared neonatal hypoxic-ischemic (HI) brain damage in SCID mice and wild-type mice treated with or without hypothermia. Male and female mouse pups were subjected to HI insult induced by unilateral common carotid artery ligation combined with systemic hypoxia on postnatal day 12. In the first 4 h after HI insult, body temperature was maintained at 36 °C for the normothermia groups or 32 °C for the hypothermia groups. The severity of brain damage in SCID mice did not differ from that in wild-type mice based on most evaluations, i.e., cerebral blood flow, hemiparesis, muscle strength, spontaneous activity, cerebral hemispheric volume, neuropathological injury, and serum cytokine levels, although spleen weight, brain weight, leukocyte counts and the levels of some cytokines in the peripheral blood were different between genotypes. The effects of hypothermia in SCID mice were comparable to those in wild-type mice based on most evaluations. Taken together, these findings indicate that SCID mice can be used as an appropriate preclinical model for cell therapies for neonatal HIE.

Distinct host-immune response toward species related intracellular mycobacterial killing: A transcriptomic study

The comparison of the host immune response when challenged with pathogenic and nonpathogenic species of mycobacteria can provide answers to the unresolved question of how pathogens subvert or inhibit an effective response. We infected human monocyte derived macrophages (hMDMs) with different species of mycobacteria, in increasing order of pathogenicity, i.e. M. smegmatis, M. bovis BCG, and M. tuberculosis R179 that had been cultured in the absence of detergents. RNA was isolated post-infection and transcriptomic analysis using amplicons (Ampliseq) revealed 274 differentially expressed genes (DEGs) across three species, out of which we selected 19 DEGs for further validation. We used qRT-PCR to confirm the differential expression of 19 DEGs. We studied biological network through Ingenuity Pathway Analysis® (IPA) which revealed up-regulated pathways of the interferon and interleukin family related to the killing of M. smegmatis. Apart from interferon and interleukin family, we found one up-regulated (EIF2AK2) and two down-regulated (MT1A and TRIB3) genes as unique potential targets found by Ampliseq and qRT-PCR which may be involved in the intracellular mycobacterial killing. The roles of these genes have not previously been described in tuberculosis. Multiplex ELISA of culture supernatants showed increased host immune response toward M. smegmatis as compared to M. bovis BCG and M.tb R179. These results enhance our understanding of host immune response against M.tb infection.

Evidence for an enhanced procoagulant state in remitted major depression

OBJECTIVES

Hypercoagulability is one mechanism to explain the increased risk of incident atherothrombotic disease in patients with major depressive disorder (MDD). We examined whether patients with remitted MDD show an enhanced procoagulant state.

METHODS

63 individuals (median age 35 years, 59% women), 40 with a DSM-IV diagnosis of remitted MDD, made by a clinical interview, and 23 healthy controls provided blood samples for the measurement of fibrinogen, D-dimer, von Willebrand factor, and plasminogen activator inhibitor-1. Standardised z-scores of plasma levels of these haemostatic factors were added to form a procoagulant index (PCI) as the primary outcome variable. Self-ratings of residual depressive symptoms and trait anxiety were also obtained.

RESULTS

Compared with controls, remitted MDD patients had higher PCI (p = 0.013, Cohen's d = 0.69) and fibrinogen (p = 0.001, d = 0.91), controlling for age, sex, body mass index, smoking and C-reactive protein. There were no significant associations of the PCI and individual haemostatic molecules with age of MDD onset, time since the last MDD episode, the number of previous MDD episodes and residual depressive symptoms. Additional adjustment for anxiety symptoms did not change these results.

CONCLUSIONS

Remitted MDD is associated with an enhanced procoagulant state. Hypercoagulability seems more a trait than a state characteristic of depression.

Ability of different assay platforms to measure renal biomarker concentrations during ischaemia-reperfusion acute kidney injury in dogs

Several protein biomarkers have been shown to be useful for the early diagnosis of acute kidney injury (AKI) in animals and people. Multiplex assays for measurement of a panel of renal biomarkers in canine samples have recently become available. This study compared the use of two such assays, versus previously validated ELISAs, to measure five biomarkers in canine samples during ischaemia-reperfusion (IR) AKI. Blood and urine was collected from six male anaesthetised greyhounds that underwent 1-h of renal ischaemia (severe hypotension induced by acute haemorrhage) and 2-h of reperfusion (intravenous fluid resuscitation). Histology confirmed presence of acute tubular injury at 2 h of reperfusion. Concentrations of clusterin, cystatin C, kidney-injury molecule 1 (KIM-1), monocyte chemoattractant protein 1, and neutrophil gelatinase-associated lipocalin (NGAL) at baseline and following IR, measured by two different multiplex assays and previously-validated single analyte immunoassays, were compared. Only NGAL was significantly elevated following IR with all assays investigated. Whether concentrations of the other four biomarkers were significantly increased following IR depended on the assay used. Concentrations of cystatin C and KIM-1 measured with the multiplex assays were of a vast magnitude lower than those measured with the corresponding single analyte ELISAs. We conclude that further validation is required before these assays can reliably be used to measure AKI biomarkers in canine samples.

Maternal Immune activity during pregnancy and socioeconomic disparities in children's self-regulation

Maternal immune activity during pregnancy has been associated with risk for psychiatric disorders in offspring, but less is known about its implications for children's emotional and behavioral development. This study examined whether concentrations of five cytokines assayed from prenatal serum were associated with socioeconomic status (SES) and racial disparities in their offspring's self-regulation abilities. Participants included 1628 women in the Collaborative Perinatal Project (CPP). Seven behavioral items conceptually related to self-regulation were rated by CPP psychologists when children were 4 years old. Concentrations of interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, and IL-10 were assessed. Covariates included child sex and mother's age, psychiatric disorders, and medical conditions during pregnancy. There were significant SES differences in child self-regulation, with higher SES children scoring higher on self-regulation (β = 0.18, 95% CI [0.11, 0.25]), but no racial differences. The concentration of IL-8 in maternal serum was associated with higher child self-regulation, β = 0.09, 95% CI [0.02, 0.16]. In mediation analyses, variation in maternal IL-8 contributed to the association between family SES and child self-regulation (β = 0.02, 95% CI [0.003, 0.030]), explaining about one-tenth of the SES disparities. This study suggests pregnancy as an early sensitive period and maternal immune activity as an important context for child development.

Microglia in Prion Diseases: Angels or Demons?

Prion diseases are rare transmissible neurodegenerative disorders caused by the accumulation of a misfolded isoform (PrP^Sc) of the cellular prion protein (PrP^C) in the central nervous system (CNS). Neuropathological hallmarks of prion diseases are neuronal loss, astrogliosis, and enhanced microglial proliferation and activation. As immune cells of the CNS, microglia participate both in the maintenance of the normal brain physiology and in driving the neuroinflammatory response to acute or chronic (e.g., neurodegenerative disorders) insults. Microglia involvement in prion diseases, however, is far from being clearly understood. During this review, we summarize and discuss controversial findings, both in patient and animal models, suggesting a neuroprotective role of microglia in prion disease pathogenesis and progression, or—conversely—a microglia-mediated exacerbation of neurotoxicity in later stages of disease. We also will consider the active participation of PrP^C in microglial functions, by discussing previous reports, but also by presenting unpublished results that support a role for PrP^C in cytokine secretion by activated primary microglia.

Importance of the Use of Oxidative Stress Biomarkers and Inflammatory Profile in Aqueous and Vitreous Humor in Diabetic Retinopathy

Diabetic retinopathy is one of the leading causes of visual impairment and morbidity worldwide, being the number one cause of blindness in people between 27 and 75 years old. It is estimated that ~191 million people will be diagnosed with this microvascular complication by 2030. Its pathogenesis is due to alterations in the retinal microvasculature as a result of a high concentration of glucose in the blood for a long time which generates numerous molecular changes like oxidative stress. Therefore, this narrative review aims to approach various biomarkers associated with the development of diabetic retinopathy. Focusing on the molecules showing promise as detection tools, among them we consider markers of oxidative stress (TAC, LPO, MDA, 4-HNE, SOD, GPx, and catalase), inflammation (IL-6, IL-1ß, IL-8, IL-10, IL-17A, TNF-α, and MMPs), apoptosis (NF-kB, cyt-c, and caspases), and recently those that have to do with epigenetic modifications, their measurement in different biological matrices obtained from the eye, including importance, obtaining process, handling, and storage of these matrices in order to have the ability to detect the disease in its early stages.

Magnetic Levitation in Chemistry, Materials Science, and Biochemistry

All matter has density. The recorded uses of density to characterize matter date back to as early as ca. 250 BC, when Archimedes was believed to have solved "The Puzzle of The King's Crown" using density.^[1] Today, measurements of density are used to separate and characterize a range of materials (including cells and organisms), and their chemical and/or physical changes in time and space. This Review describes a density-based technique-magnetic levitation (which we call "MagLev" for simplicity)-developed and used to solve problems in the fields of chemistry, materials science, and biochemistry. MagLev has two principal characteristics-simplicity, and applicability to a wide range of materials-that make it useful for a number of applications (for example, characterization of materials, quality control of manufactured plastic parts, self-assembly of objects in 3D, separation of different types of biological cells, and bioanalyses). Its simplicity and breadth of applications also enable its use in low-resource settings (for example-in economically developing regions-in evaluating water/food quality, and in diagnosing disease).

Profound Functional Suppression of Tumor-Infiltrating T-Cells in Ovarian Cancer Patients Can Be Reversed Using PD-1-Blocking Antibodies or DARPin® Proteins

PD-1/PD-L1 blockade has revolutionized the field of immunooncology. Despite the relative success, the response rate to anti-PD-1 therapy requires further improvements. Our aim was to explore the enhancement of T-cell function by using novel PD-1-blocking proteins and compare with clinically approved monoclonal antibodies (mAbs). We isolated T-cells from the ascites and tumor of 17 patients with advanced epithelial ovarian cancer (EOC) and analyzed the effects using the mAbs nivolumab and pembrolizumab and two novel engineered ankyrin repeat proteins (DARPin® proteins). PD-1 blockade with either mAb or DARPin® molecule significantly increased the release of IFN-γ, granzyme B, IL-2, and TNF-α, demonstrating successful reinvigoration. The monovalent DARPin® protein was less effective compared to its bivalent equivalent, demonstrating that bivalency brings an additional benefit to PD-1 blockade. Overall, we found a higher fold increase of lymphokine secretion in response to the PD-1 blockade by tumor-derived T-cells; however, the absolute amounts were significantly lower compared to the release from ascites-derived T-cells. Our results demonstrate that PD-1 blockade can only partially reinvigorate functionally suppressed T-cells from EOC patients. This warrants further investigation preferably in combination with other therapeutics. The study provides an early pilot proof-of-concept for the potential use of DARPin® proteins as eligible alternative scaffold proteins to block PD-1.