A Novel High Throughput Assay for Anthelmintic Drug Screening and Resistance Diagnosis by Real-Time Monitoring of Parasite Motility

Parasitic worms cause untold morbidity and mortality on billions of people and livestock. Drugs are available but resistance is problematic in livestock parasites and is a looming threat for human helminths. Currently, new drug discovery and resistance monitoring is hindered as drug efficacy is assessed by observing motility or development of parasites using laborious, subjective, low-throughput methods evaluated by eye using microscopy. Here we describe a novel application for a cell monitoring device (xCELLigence) that can simply and objectively assess real time anti-parasite efficacy of drugs on eggs, larvae and adults in a fully automated, label-free, high-throughput fashion. This technique overcomes the current low-throughput bottleneck in anthelmintic drug development and resistance detection pipelines. The widespread use of this device to screen for new therapeutics or emerging drug resistance will be an invaluable asset in the fight against human, animal and plant parasitic helminths and other pathogens that plague our planet

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

NK cell-mediated antibody-dependent cellular cytotoxicity is enhanced by tamoxifen in HER2/neu non-amplified, but not HER2/neu-amplified, breast cancer cells

Tumor-targeting antibodies have been successful in the treatment of various types of cancers. Antibodies engage the immune system with their Fc, stimulating immune cell effector function. In the clinic, FcγRIIIa polymorphisms with higher affinity for the Fc of antibodies were shown to improve response rates and overall survival. Efforts have been made to modify the Fc to enhance affinity to Fc receptors and thereby improve effector function. An alternative for improving immune effector function may be to increase the level of tumor antigen expression. In this study, tamoxifen was used to increase HER2/neu protein level to determine whether increased tumor antigen expression could enhance NK cell-mediated antibody-dependent cytotoxicity (ADCC). Tamoxifen was found to increase HER2/neu 1.5-fold to threefold in breast cancer cell lines that were HER2/neu non-amplified. Using flow cytometry to simultaneously evaluate NK cell degranulation and tumor cell death, the increase in HER2/neu enhanced NK cell-mediated ADCC. However, in cells that had HER2/neu gene amplification and estrogen receptor expression, tamoxifen elevated HER2/neu but failed to improve NK cell function. The quantity of HER2/neu on the tumor cell surface was approximately double that of the number of Fc receptors found on NK cells. This appears to reflect a ceiling at which increasing antigen expression fails to improve NK cell effector function. This has clinical implications as trying to increase antigen expression to enhance NK cell function may be useful for patients with antigen-low tumors, but not in those whose tumors have gene amplification or high levels of antigen expression

Differential regulation of human monocytes and NK cells by antibody-opsonized tumors

The monocyte network is important for therapeutic efficacy of antibody therapies against cancer. One mechanism which monocytes/macrophages use to kill cancer cells is phagocytosis. Using trastuzumab and human breast cancer cell lines as a model, we used flow cytometry to evaluate the importance of avidity, antigen density, Fcγ receptor (FcγR) expression, and FcγR polymorphisms in human monocyte phagocytosis. By increasing avidity for the tumor through the addition of pertuzumab to trastuzumab, there was a two-to-threefold increase in phagocytosis potency against the HCC1419 cell line compared to antibodies alone, while NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC) failed to increase tumor cell death. Consistent with increasing the avidity through multiple antibodies, antigen density significantly enhanced phagocytosis with breast cancer cell lines that were HER2 gene-amplified compared to non-amplified tumor cells. Confirmation that high antigen density enhanced phagocytosis was obtained when HER2 was overexpressed in HER2 non-amplified cell lines. In contrast, NK cell ADCC failed to distinguish differences in tumor cell death when comparing gene-amplified and non-amplified breast cancer cell lines. The level of phagocytosis was influenced by FcγRIIa and FcγRIIIa expression. Most monocytes are FcγRIIIa-, and the induction of the receptor significantly enhances antibody-dependent phagocytosis. Although both receptors are involved, when blocked FcγRIIIa had a greater influence on phagocytosis. Furthermore, the polymorphism FcγRIIIa 158V significantly enhanced phagocytosis; whereas FcγRIIa 131H polymorphism appeared to improve phagocytosis but was not statistically significant. Targeting of monocytes for enhanced phagocytosis may improve the effectiveness of therapeutic antibodies to improve clinical outcomes