monocytes

Circadian Regulation of Immune cells

Circadian Regulation of Immune cells

The reciprocal interplay between the circadian clock machinery and hypothalamus-pituitary-adrenal axis has been largely demonstrated: the circadian clock may control the physiological circadian endogenous glucocorticoid (GC) secretion and action; GCs, in turn, are potent regulators of the circadian clock and their inappropriate replacement has been associated with metabolic and immune impairment.

Monocyte absolute count as a preliminary tool to distinguish between SARS-CoV-2 and influenza A/B infections in patients requiring hospitalization

Since the most frequent symptoms of novel coronavi- rus 2019 disease (COVID-19) are common in influenza A/B (FLU), predictive models to distinguish between COVID-19 and FLU using standardized non-specif- ic laboratory indicators are needed. The aim of our study was to evaluate whether a recently dynamic nomogram, established in the Chinese population and based on age, lymphocyte percentage and monocyte absolute count, might apply to a different context. We collected data from 299 patients (243 with COVID-19 and 56 with FLU) at Policlinico Umberto I, Sapienza University of Rome.

Splenic Ly6Chi monocytes are critical players in dystrophic muscle injury and repair

Dystrophic muscle is characterised by chronic injury, and a steady recruitment of inflammatory Ly6Chi monocytes. Recent studies have identified the spleen as the dominant reservoir of these cells during chronic inflammation. Here we investigated the hitherto unexplored contribution of splenic Ly6Chi monocytes to dystrophic muscle pathology. Using the mdx mouse model of muscular dystrophy, we show that Ly6Chi monocytes accumulate in great numbers in the spleen over the course of the disease.

Insights into the phytochemistry of the cuban endemic medicinal plant phyllanthus orbicularis: fideloside, a novel bioactive 8-c-glycosyl 2,3-dihydroflavonol

Phyllanthus orbicularis (Phyllanthaceae) is an endemic evergreen tropical plant of Cuba that grows in the western part of the island and is used in traditional medicine as an infusion. The aqueous extract of this plant presents a wide range of pharmacological activitiessuch as antimutagenic, antioxidant and antiviral effects.

EBV up-regulates PD-L1 on the surface of primary monocytes by increasing ROS and activating TLR signaling and STAT3

Programmed death ligand 1 (PD-L1) (also called B7-H1) is a membrane immune-modulatory protein whose overexpression on the surface of tumor cells as well as APCs impairs T-cell-mediated killing. Viruses that establish chronic infections have developed a number of strategies to escape from immune recognition including the up-regulation of PD-L1. This study shows for the first time that the human oncovirus EBV infects human primary monocytes using HLA-DR and induced a strong up-regulation of PD-L1 expression on their surface.

HHV-6B reduces autophagy and induces ER stress in primary monocytes impairing their survival and differentiation into dendritic cells

HHV-6A and HHV-6B are ubiquitous human betaherpesviruses sharing more than 80% homology. HHV-6B is the most common cause of encephalitis in transplant patients and its primary infection may cause the exanthema subitum and febrile seizures in infants. HHV-6A and HHV-6B are able to infect several immune cell types such as T cells, monocytes and dendritic cells (DCs). In this study we found that HHV-6 B derived from patients affected by exanthema subitum impaired monocyte differentiation into DCs, as the infected cells acquired less CD1a DC marker and retained more CD14 monocyte marker.

EBV reduces autophagy, intracellular ROS and mitochondria to impair monocyte survival and differentiation

EBV has been reported to impair monocyte in vitro differentiation into dendritic cells (DCs) and reduce cell survival. In this study, we added another layer of knowledge to this topic and showed that these effects correlated with macroautophagy/autophagy, ROS and mitochondrial biogenesis reduction. Of note, autophagy and ROS, although strongly interconnected, have been separately reported to be induced by CSF2/GM-CSF (colony stimulating factor 2) and required for CSF2-IL4-driven monocyte in vitro differentiation into DCs.

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