A Role for B Cells to Transmit Hepatitis C Virus Infection

Hepatitis C virus (HCV) is highly variable and transmits through infected blood to establish a chronic liver infection in the majority of patients. Our knowledge on the infectivity of clinical HCV strains is hampered by the lack of in vitro cell culture systems that support efficient viral replication. We and others have reported that HCV can associate with and infect immune cells and may thereby evade host immune surveillance and elimination. To evaluate whether B cells play a role in HCV transmission, we assessed the ability of B cells and sera from recent (<2 years) or chronic (≥ 2 years) HCV patients to infect humanized liver chimeric mice. HCV was transmitted by B cells from chronic infected patients whereas the sera were non-infectious. In contrast, B cells from recently infected patients failed to transmit HCV to the mice, whereas all serum samples were infectious. We observed an association between circulating anti-glycoprotein E1E2 antibodies and B cell HCV transmission. Taken together, our studies provide evidence for HCV transmission by B cells, findings that have clinical implications for prophylactic and therapeutic antibody-based vaccine design.

Alzheimer’s Disease: Current Perspectives and Advances in Physiological Modeling

Though Alzheimer’s disease (AD) is the most common cause of dementia, complete disease-modifying treatments are yet to be fully attained. Until recently, transgenic mice constituted most in vitro model systems of AD used for preclinical drug screening; however, these models have so far failed to adequately replicate the disease’s pathophysiology. However, the generation of humanized APOE4 mouse models has led to key discoveries. Recent advances in stem cell differentiation techniques and the development of induced pluripotent stem cells (iPSCs) have facilitated the development of novel in vitro devices. These “microphysiological” systems—in vitro human cell culture systems designed to replicate in vivo physiology—employ varying levels of biomimicry and engineering control. Spheroid-based organoids, 3D cell culture systems, and microfluidic devices or a combination of these have the potential to replicate AD pathophysiology and pathogenesis in vitro and thus serve as both tools for testing therapeutics and models for experimental manipulation.

Hypoxia promotes a perinatal-like progenitor state in the adult murine epicardium

The epicardium is a reservoir of progenitors that give rise to coronary vasculature and stroma during development and mediates cardiac vascular repair in lower vertebrates. However, its role as a source of progenitors in the adult mammalian heart remains unclear due to lack of clear lineage markers and single-cell culture systems to elucidate epicardial progeny cell fate. We found that in vivo exposure of mice to physiological hypoxia induced adult epicardial cells to re-enter the cell cycle and to express a subset of developmental genes. Multiplex single cell transcriptional profiling revealed a lineage relationship between epicardial cells and smooth muscle, stromal, and endothelial fates, and that physiological hypoxia promoted an endothelial cell fate. In vitro clonal analyses of purified epicardial cells showed that cell growth and subsequent differentiation is dependent upon hypoxia, and that resident epicardial cells retain progenitor identity in the adult mammalian heart with self-renewal and multilineage differentiation potential. These results point to a source of progenitor cells in the adult heart that can promote heart revascularization, providing an invaluable in vitro model for further studies.

Cigarette Smoke Extract Produces Superoxide in Aqueous Media by Reacting with Bicarbonate

The toxicity of cigarette smoke (CS) is largely attributed to its ability to generate reactive oxygen species (ROS). Reportedly, CS generates superoxide in cell culture systems by stimulating the cells to produce superoxide and through direct chemical reactions with components of the culture media. In this study, we investigated CS-induced superoxide formation in biocompatible aqueous media and its characteristics. Cigarette smoke extract (CSE) and total particulate matter (TPM) were prepared from the mainstream smoke of 3R4F reference cigarettes. CSE and TPM generated superoxide in Hank’s balanced salt solution (HBSS), Dulbecco’s modified Eagle media (DMEM), and blood plasma, but not in distilled water and phosphate-buffered saline. Each constituent of HBSS in solution was tested, and bicarbonate was found to be responsible for the superoxide generation. More than half of the superoxide formation was abolished by pretreating CSE or TPM with peroxidase, indicating that the substrates of peroxidase, presumably peroxides and peroxy acids, mainly contributed to the superoxide production. In conclusion, the presence of bicarbonate in experimental conditions should be considered carefully in studies of the biological activity of CS. Furthermore, the local amount of bicarbonate in exposed tissues may be a determinant of tissue sensitivity to oxidative damage by CS.

Human Organoid and Supporting Technologies for Cancer and Toxicological Research

Recent progress in the field of organoid-based cell culture systems has enabled the use of patient-derived cells in conditions that resemble those in cancer tissue, which are better than two-dimensional (2D) cultured cell lines. In particular, organoids allow human cancer cells to be handled in conditions that resemble those in cancer tissue, resulting in more efficient establishment of cells compared with 2D cultured cell lines, thus enabling the use of multiple patient-derived cells with cells from different genetic background, in keeping with the heterogeneity of the cells. One of the most valuable points of using organoids is that human cells from either healthy or cancerous tissue can be used. Using genome editing technology such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein, organoid genomes can be modified to, for example, cancer-prone genomes. The normal, cancer, or genome-modified organoids can be used to evaluate whether chemicals have genotoxic or non-genotoxic carcinogenic activity by evaluating the cancer incidence, cancer progression, and cancer metastasis. In this review, the organoid technology and the accompanying technologies were summarized and the advantages of organoid-based toxicology and its application to pancreatic cancer study were discussed.

Cell Culture Systems for Assessing Toxicity and Chemotherapeutic Potential of Phytochemical Antioxidants

This review article seeks to provide relevant information about the applicability of cell-based assays in assessing cytotoxicity of phytochemicals in light of several traditional methods available. Phenolic compounds and other phytochemicals are significant resources for drug discovery and development, thus underlining the enormous potentials of plant-derived natural products for the prevention and management of oxidative stress associated with cancer and other diseases. These effects have been linked to the content of phytochemicals such as phenolic compounds and their antioxidant properties. The abundance and complexity of these bio-constituents highlight the need for well-defined methods for the in vitro characterization and quantification of extracts and/or preparations that can translate to in vivo effects. Cell culture systems provide a useful model for basic research and a wide range of clinical in vitro studies and physiological processes as well as assessing the toxicity and therapeutic potential of compounds including plant extracts with potential medicinal benefits. Their use in cancer research provide a useful insight into possible therapeutic properties of phytochemicals at the cellular level. This approach has been instrumental in the initial stages of developing chemotherapeutic agents where human cancer cell lines are used as experimental models. These models have continued to contribute to elucidating specific requirements for certain biochemical events associated with proliferation, metabolism, loss of cell viability/apoptosis. Cell culture systems remain a promising tool in natural product development.

Primary Lung Cancer Organoids for Personalized Medicine—Are They Ready for Clinical Use?

Despite many developments in recent years, non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related death worldwide. Therefore, additional research, aiming to further elucidate the underlying molecular mechanisms of malignant transformation and development of therapy resistance, as well as the identification of additional novel therapeutic avenues, is crucial. For this purpose, reliable in vitro models are indispensable, as they allow for quick identification of suspected oncogenic drivers or evaluation of novel therapeutic strategies in a timely and cost-effective fashion. However, standard two-dimensional cell culture systems, the most frequently used in vitro model, are usually not truly representative of the situation in a patient as these models lack the tumor heterogeneity, the surrounding tumor microenvironment and the three-dimensional complexity of a tumor in vitro. For this reason, 3D cell culture systems, in particular organoids generated from normal non-malignant cells or tumor cell-based organoids (tumoroids), have in recent years gained much attention as alternative in vitro model systems that more closely resemble the actual primary tumor. In this review, we provide an overview of the available literature in the field of NSCLC organoids, which might still be in its infancy, but is gaining momentum.