he coronavirus disease-19 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first reported in Wuhan, China in December 2019. Since then, it has spread globally, already infecting millions of people worldwide. As of 30 June 2020, 213 countries have reported COVID-19 cases, with a total number that reached above 10.3 million, the most being in the USA (2.6 million), Brazil (1.4 million), Russia (640 thousand), India (548 thousand) and UK (314 thousand). USA has the highest number of deaths (126 thousand) followed by Brazil (58 thousand), UK (44 thousand) and Italy (35 thousand). The worldwide case fatality rate across all communities is 4.9%. Coronaviruses (CoVs) are enveloped viruses entrapping non-segmented, positive-sense and single-stranded ribonucleic acid (ssRNA). Their genome size ranges from 26 to 32 kb, being the largest known RNA virus. SARS-CoV-2 3' terminus encodes structural proteins, including spike (S) glycoproteins 1,2 , membrane (M) glycoproteins 3 , as well as envelope (E) 4 and nucleocapsid (N) proteins 2,5 (Fig. 1). In addition to the genes encoding structural proteins, there are specific genomic regions encoding for viral proteins required for replication 6 , in addition to other non-structural proteins, such as the papain-like protease (PLpro) 7 and coronavirus main protease (3CLpro) 8. According to the Center for Disease Control and Prevention (CDC), the incubation period following infection is 2-14 days, with an estimated median of 5.1 days 9,10. However, cases with longer incubation of 24 days have been reported 11. The long incubation period is the primary reason for the massive infection, as it is mostly asymptomatic yet contagious 10. Although the estimated patients' age average is ~70, all age groups are susceptible to this virus. However, the elder population (>60) and people with comorbidities are more likely to develop severe symptoms upon infection 12. Much like previous CoVs, severe acute respiratory syndrome (SARS) and Middle East respiratory ryndrome (MERS), SARS-CoV-2 is predominantly infecting the lower airways, ranging from mild respiratory illness to severe acute respiratory syndrome and septic shock in advanced stages 6. The most commonly reported symptoms are fever, dry cough, dyspnea, fatigue and myalgia, which are early characteristics of the most frequent manifestation of SARS-CoV-2 infection, pneumonia 13-15. Physicians and pathologists
Ibrutinib sensitizes melanoma to immune checkpoint modulators following immunization with nano-vaccines by relieving immune-suppressing microenvironment One Sentence Summary: Combination of dendritic cell-targeted nano-vaccines with a myeloid-derived suppressor cell inhibitor and immune checkpoint modulators expands the host antitumor immune cells, restricts tumour growth and prolongs survival in an orthotopic melanoma model.
Lipid nanoparticles are used widely as anticancer drug and gene delivery systems. Internalizing into the target cell is a prerequisite for the proper activity of many nanoparticulate drugs. We show here, that the lipid composition of a nanoparticle affects its ability to internalize into triplenegative breast cancer cells. The lipid headgroup had the greatest effect on enhancing cellular uptake compared to other segments of the molecule. Having a receptor-targeted headgroup induced the greatest increase in cellular uptake, followed by cationic amine headgroups, both being superior to neutral (zwitterion) phosphatidylcholine or to negatively-charged headgroups. The lipid tails also affected the magnitude of cellular uptake. Longer acyl chains facilitated greater liposomal cellular uptake compared to shorter tails, 18:0>16:0>14:0. When having the same lipid tail length, unsaturated lipids were superior to saturated ones, 18:1>18:0. Interestingly, liposomes composed of phospholipids having 14:0 or 12:0-carbon-long-tails, such as DMPC and DLPC, decreased cell viability in a concertation dependent manner, due to a destabilizing effect these lipids had on the cancer cell membrane. Contrarily, liposomes composed of phospholipids having longer carbon tails (16:0 and 18:0), such as DPPC and HSPC, enhanced cancer cell proliferation. This effect is attributed to the integration of the exogenous liposomal lipids into the cancer-cell membrane, supporting the proliferation process. Cholesterol is a common lipid additive in nanoscale formulations, rigidifying the membrane and stabilizing its structure. Liposomes composed of DMPC (14:0) showed increased cellular uptake when enriched with cholesterol, both by endocytosis and by fusion. Contrarily, the effect of cholesterol on HSPC (18:0) liposomal uptake was minimal. Furthermore, the concentration of nanoparticles in solution affected their cellular uptake. The higher the concentration of nanoparticles the greater the absolute number of nanoparticles taken up per cell. However, the efficiency of nanoparticle uptake, i.e. the percent of nanoparticles taken up by cells, decreased as the concentration of nanoparticles increased. This
Glioblastoma (GB) is a highly invasive type of brain cancer exhibiting poor prognosis. As such, its microenvironment plays a crucial role in its progression. Among the brain stromal cells, the microglia were shown to facilitate GB invasion and immunosuppression. However, the reciprocal mechanisms by which GB cells alter microglia/macrophages behavior are not fully understood. We propose that these mechanisms involve adhesion molecules such as the Selectins family. These proteins are involved in immune modulation and cancer immunity. We show that P-selectin mediates microglia-enhanced GB proliferation and invasion by altering microglia/macrophages activation state. We demonstrate these findings by pharmacological and molecular inhibition of P-selectin which leads to reduced tumor growth and increased survival in GB mouse models. Our work sheds light on tumor-associated microglia/macrophage function and the mechanisms by which GB cells suppress the immune system and invade the brain, paving the way to exploit P-selectin as a target for GB therapy.
Glioblastoma (GB) is the most lethal type of primary tumor in the central nervous system. Current treatments include surgical resection followed by chemotherapy and radiotherapy. With this therapeutic regimen, the median survival is less than two years. However, these treatments do not much improve the overall survival of GB patients. GBs are highly angiogenic and invasive tumors and often acquire resistance to therapy. The invasive nature of the disease limits the ability to achieve complete resection of the tumor and the majority of GB patients will experience disease relapse. Moreover, GB is highly heterogeneous, harboring different mutations and presenting different phenotypes. As the brain is considered to be an immune‐privileged tissue, GB is defined as a cold tumor for which current immunotherapies have not yet been demonstrated to improve survival. On top of these challenges, the blood brain barrier (BBB) restricts the uptake of drugs by the brain, thus limiting the therapeutic options. Therefore, enormous efforts are being dedicated to the development of novel nanomedicines, which will be able to cross the BBB and specifically target the cancer cells. Here, the current achievements in drug delivery and novel therapeutic approaches for GB therapy are discussed.
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