Evaluation of SARS-CoV-2 entry, inflammation and new therapeutics in human lung tissue cells.

The development of physiological models that reproduce SARS-CoV-2 infection in primary human cells will be instrumental to identify host-pathogen interactions and potential therapeutics. Here, using cell suspensions directly from primary human lung tissues (HLT), we have developed a rapid platform for the identification of viral targets and the expression of viral entry factors, as well as for the screening of viral entry inhibitors and anti-inflammatory compounds. The direct use of HLT cells, without long-term cell culture and in vitro differentiation approaches, preserves main immune and structural cell populations, including the most susceptible cell targets for SARS-CoV-2; alveolar type II (AT-II) cells, while maintaining the expression of proteins involved in viral infection, such as ACE2, TMPRSS2, CD147 and AXL. Further, antiviral testing of 39 drug candidates reveals a highly reproducible method, suitable for different SARS-CoV-2 variants, and provides the identification of new compounds missed by conventional systems, such as VeroE6. Using this method, we also show that interferons do not modulate ACE2 expression, and that stimulation of local inflammatory responses can be modulated by different compounds with antiviral activity. Overall, we present a relevant and rapid method for the study of SARS-CoV-2.

Intraepithelial CD15 infiltration identifies high-grade anal dysplasia in people with HIV.

Men who have sex with men (MSM) with HIV are at high risk for squamous intraepithelial lesion (SIL) and anal cancer. Identifying local immunological mechanisms involved in the development of anal dysplasia could aid treatment and diagnostics. Here, we studied 111 anal biopsies obtained from 101 MSM with HIV, who participated in an anal screening program. We first assessed multiple immune subsets by flow cytometry, in addition to histological examination, in a discovery cohort. Selected molecules were further evaluated by immunohistochemistry in a validation cohort. Pathological samples were characterized by the presence of resident memory T cells with low expression of CD103 and by changes in natural killer cell subsets, affecting residency and activation. Furthermore, potentially immunosuppressive subsets, including CD15+CD16+ mature neutrophils, gradually increased as the anal lesion progressed. Immunohistochemistry verified the association between the presence of CD15 in the epithelium and SIL diagnosis for the correlation with high-grade SIL. A complex immunological environment with imbalanced proportions of resident effectors and immune-suppressive subsets characterized pathological samples. Neutrophil infiltration, determined by CD15 staining, may represent a valuable pathological marker associated with the grade of dysplasia.

Peripheral and lung resident memory T cell responses against SARS-CoV-2.

Resident memory T cells (TRM) positioned within the respiratory tract are probably required to limit SARS-CoV-2 spread and COVID-19. Importantly, TRM are mostly non-recirculating, which reduces the window of opportunity to examine these cells in the blood as they move to the lung parenchyma. Here, we identify circulating virus-specific T cell responses during acute infection with functional, migratory and apoptotic patterns modulated by viral proteins and associated with clinical outcome. Disease severity is associated predominantly with IFNγ and IL-4 responses, increased responses against S peptides and apoptosis, whereas non-hospitalized patients have increased IL-12p70 levels, degranulation in response to N peptides and SARS-CoV-2-specific CCR7+ T cells secreting IL-10. In convalescent patients, lung-TRM are frequently detected even 10 months after initial infection, in which contemporaneous blood does not reflect tissue-resident profiles. Our study highlights a balanced anti-inflammatory antiviral response associated with a better outcome and persisting TRM cells as important for future protection against SARS-CoV-2 infection.

Beyond the Scavenging of Reactive Oxygen Species (ROS): Direct Effect of Cerium Oxide Nanoparticles in Reducing Fatty Acids Content in an In Vitro Model of Hepatocellular Steatosis.

Nonalcoholic fatty liver disease (NAFLD) is characterized by hepatic accumulation of lipids. Antisteatotic effects of cerium oxide nanoparticles (CeO2NPs) have recently been shown in animal models of liver disease. However, it is unclear whether the activity of CeO2NPs is related solely to the decrease in oxidative stress or, in addition, they directly decrease liver fatty acid accumulation. To address this question, in this work, we used an in vitro model of hepatocellular steatosis, exposing HepG2 cells to oleic and palmitic acid. Cell uptake of CeO2NPs and their effect on oxidative stress and viability of hepatic cells cultured with H2O2 were also evaluated. Results show that CeO2NPs were uptaken by HepG2 cells and reduced oxidative stress and improved cell viability. Treatment with oleic and palmitic acid increased lipogenesis and the content of different fatty acids. CeO2NPs reduced palmitic and stearic acid and most fatty acids consisting of more than 18 carbon atoms. These effects were associated with significant changes in elongase and desaturase activity. In conclusion, CeO2NPs directly protected HepG2 cells from cell injury in oxidative stress conditions and reduced fatty acid content in steatotic conditions by inducing specific changes in fatty acid metabolism, thus showing potential in the treatment of NAFLD.

Validation of a routine gas chromatography mass spectrometry method for 2-hydroxyglutarate quantification in human serum as a screening tool for detection of idh mutations.

High circulating levels of 2-hydroxyglutarate (2HG) have been reported in patients with determinate isocitrate dehydrogenase (IDH) mutated tumors. Recent studies indicate that in malignancies such as acute myeloid leukemia (AML), measurements of 2HG in serum provide useful diagnostic and prognostic information and improve patient selection and monitoring of IDH-targeted treatments. In the current study, we validated a sensitive and specific gas chromatography mass spectrometry (GC-MS) method specifically intended to quantify serum levels of 2HG in routine clinical laboratories. Extraction was liquid-liquid with ethyl acetate, and derivatization was reduced to 3 min of microwave irradiation. The analytical method was linear over a wide dynamic range, presenting acceptable intraday and day-to-day precision and accuracy. The limit of quantification was 10 ng/mL, process efficiency ranged between 38% and 49%, and recovery of added 2HG was 99-105%. 2HG was found to be stable in serum for up to 48 h at both 4 °C and at ambient temperature, and after three freeze-thaw cycles. Microwave derivatizated extracts in the autosampler were found to be stable for up to 120 h. In summary, the present method is useful for quantification of 2HG serum levels in patients with IDH mutated malignancies in clinical laboratories.