Immune-checkpoint inhibitors from cancer to COVID‑19: A promising avenue for the treatment of patients with COVID‑19

The severe acute respiratory syndrome associated coronavirus‑2 (SARS‑CoV‑2) poses a threat to human life worldwide. Since early March, 2020, coronavirus disease 2019 (COVID‑19), characterized by an acute and often severe form of pneumonia, has been declared a pandemic. This has led to a boom in biomedical research studies at all stages of the pipeline, from the in vitro to the clinical phase. In line with this global effort, known drugs, currently used for the treatment of other pathologies, including antivirals, immunomodulating compounds and antibodies, are currently used off‑label for the treatment of COVID‑19, in association with the supportive standard care. Yet, no effective treatments have been identified. A new hope stems from medical oncology and relies on the use of immune‑checkpoint inhibitors (ICIs). In particular, amongst the ICIs, antibodies able to block the programmed death‑1 (PD‑1)/PD ligand-1 (PD‑L1) pathway have revealed a hidden potential. In fact, patients with severe and critical COVID‑19, even prior to the appearance of acute respiratory distress syndrome, exhibit lymphocytopenia and suffer from T‑cell exhaustion, which may lead to viral sepsis and an increased mortality rate. It has been observed that cancer patients, who usually are immunocompromised, may restore their anti‑tumoral immune response when treated with ICIs. Moreover, viral-infected mice and humans, exhibit a T‑cell exhaustion, which is also observed following SARS‑CoV‑2 infection. Importantly, when treated with anti‑PD‑1 and anti‑PD‑L1 antibodies, they restore their T‑cell competence and efficiently counteract the viral infection. Based on these observations, four clinical trials are currently open, to examine the efficacy of anti‑PD‑1 antibody administration to both cancer and non‑cancer individuals affected by COVID‑19. The results may prove the hypothesis that restoring exhausted T‑cells may be a winning strategy to beat SARS‑CoV‑2 infection

Effect of insulin-like growth factor I on HIV type 1 long terminal repeat-driven chloramphenicol acetyltransferase expression

In this study, we have investigated the ability of insulin-like growth factor I (IGF-I) to inhibit HIV long terminal repeat (LTR)-driven gene expression. Using COS 7 cells cotransfected with tat and an HIV LTR linked to a chloramphenicol acetyltransferase (CAT) reporter, we observed that physiological levels of IGF-I (10-9 M) significantly inhibited CAT expression in a concentration- and time-dependent manner. IGF-I did not inhibit C AT expression in COS 7 cells transfected with pSVCAT, and did not affect CAT expression in the absence of cotransfection with tat . Transfection of HIV-1 proviral DNA into COS 7 cells +/- IGF-I resulted in a significant decrease ( p 0.05) in infectious virion production. Both IGF-I and Ro24-7429 inhibited LTR-driven C AT expression, while TNF- alpha -enhanced CAT expression was not affected by IGF-I. On the other hand, a plasmid encoding parathyroid hormone-related peptide exhibited dramatic additivity of inhibition of CAT expression in COS 7 cells. Finally, we show that in Jurkat or U937 cells cotransfected with HIVLTRCAT/tat, IGF-I significantly inhibited CAT expression. Further, interleukin 4 showed in U937 cells inhibition of CAT expression that was not additive to IGF-I induced inhibition. Our data demonstrate that IGF-I can specifically inhibit HIVLTRCAT expression. This inhibition may occur at the level of the tat /TAR interaction. Finally, this IGF-I effect is seen in target cell lines and similar paths of inhibition may be involved in the various cell types employed. <br /

Neuropilin‑1 as a new potential SARS‑CoV‑2 infection mediator implicated in the neurologic features and central nervous system involvement of COVID‑19

Availability of data and materials: All data generated or analysed during this study are included in this published article.Copyright © 2020 Davies et al. Infection by the severe acute respiratory syndrome (SARS) coronavirus‑2 (SARS‑CoV‑2) is the cause of the new viral infectious disease (coronavirus disease 2019; COVID‑19). Emerging evidence indicates that COVID‑19 may be associated with a wide spectrum of neurological symptoms and complications with central nervous system (CNS) involvement. It is now well‑established that entry of SARS‑CoV‑2 into host cells is facilitated by its spike proteins mainly through binding to the angiotensin‑converting enzyme 2 (ACE‑2). Preclinical studies have suggested that neuropilin‑1 (NRP1), which is a transmembrane receptor that lacks a cytosolic protein kinase domain and exhibits high expression in the respiratory and olfactory epithelium, may also be implicated in COVID‑19 by enhancing the entry of SARS‑CoV‑2 into the brain through the olfactory epithelium. In the present study, we expand on these findings and demonstrate that the NRP1 is also expressed in the CNS, including olfactory‑related regions such as the olfactory tubercles and paraolfactory gyri. This furthers supports the potential role of NRP1 as an additional SARS‑CoV‑2 infection mediator implicated in the neurologic manifestations of COVID‑19. Accordingly, the neurotropism of SARS‑CoV‑2 via NRP1‑expressing cells in the CNS merits further investigation.No funding was received

The dose response principle from philosophy to modern toxicology: The impact of ancient philosophy and medicine in modern toxicology science

Since ancient times the concept of dose response, from a toxicological perspective, has been a matter of concern. Already by the 8th century BC and over the years, many enlightened people have attempted to interpret this phenomenon, observing and coming across its results and practical implementation through exposure to chemical substances, either from natural or synthetic sources. Nowadays, the environmental exposure of human populations to chemicals in terms of quantity and quality might differ. Nevertheless, dose response still remains an issue joining hands with scientific and technological progress. The aim of the present review is not only to briefly recount the history of the dose response concept, from ancient time theories to novel approaches, but also to draw the outline of challenges and requirements toxicology science needs to fulfill

COVID-19 pandemic and its impact on mental health of healthcare professionals.

In light of the unprecedented public health crisis of the COVID-19 pandemic, it is highly important to acknowledge the psychological impact of this mounting threat on healthcare professionals. Previous experience from smaller scale epidemics and emerging literature around COVID-19 show that the unparalleled amount of stress that healthcare workers are dealing with, is associated with increased psychological morbidities. We have depicted the psychological burden that the COVID-19 pandemic has posed on healthcare professionals in Greece and have reviewed the literature around the effect of previous epidemics on frontline healthcare staff. Moreover, we discuss potential triggers and the need for measures to minimise the psychological pressure on those at the frontline against this biothreat