The severe acute respiratory syndrome caused by Coronavirus 2 (SARS-CoV-2) that appeared in December 2019 has precipitated the global pandemic Coronavirus Disease 2019 (COVID-19). However, in many parts of Africa fewer than expected cases of COVID-19, with lower rates of mortality, have been reported. Individual human leukocyte antigen (HLA) alleles can affect both the susceptibility and the severity of viral infections. In the case of COVID-19 such an analysis may contribute to identifying individuals at higher risk of the disease and the epidemiological level to understanding the differences between countries in the epidemic patterns. It is also recognized that first antigen exposure influences the consequence of subsequent exposure. We thus propose a theory incorporating HLA antigens, the “original antigenic sin (OAS)” effect, and presentation of viral peptides which could explain with differential susceptibility or resistance to SARS-CoV-2 infections.
Non–small‐lung cancer (NSCLC) is the leading cause of cancer death. Early detection of NSCLC could pave the way for effective therapies. Analysis of molecular genetic biomarkers in biological fluids has been proposed as a useful tool for cancer diagnosis. Here, we aimed to develop a panel of noncoding RNAs (ncRNAs) in sputum for NSCLC early detection. Expression of 11 ncRNAs were analyzed by real–time polymerase chain reaction in sputum samples of 30 NSCLC patients and 30 sex‐ and age‐matched cancer‐free controls. Stability of endogenous microRNAs (miRNAs) in sputum was evaluated after 3 and 6 days at 4°C, 6 months, and 1 year at −80°C. Nine ncRNAs showed significant differences of their expression in sputum between NSCLC patients and controls. A logistic regression model with the best prediction was built based on miR‐145, miR‐126, and miR‐7. The composite of the three miRNAs produced 90% sensitivity and specificity in distinguishing NSCLC patients from the controls. Results indicate that miRNAs could be useful biomarkers based on their stability under various storage conditions and maintain differential changes between cancer and control groups. Moreover, measurement of miRNAs in sputum could be a noninvasive approach for detection of lung cancer.
Umbelliprenin (UMB) has shown various pharmacological properties in vitro. We investigated the antineoplastic and immunostimulatory effects of UMB in 4T1 mammary-tumor-bearing mice. Two-hundred microliter of UMB (12.5 mg/ml) was intraperitoneally administrated to healthy and tumor-bearing female Balb/c mice for a period of 18 days. Data was analyzed using GraphPad Prism 5 software for Windows (version 5, La Jolla, CA). UMB caused a significant decrease in tumor size (P < 0.01). Serum interferon gamma (IFNγ) was augmented in both healthy and tumor-bearing animals (P < 0.01), and IL-4 declined in healthy animals (P < 0.01) treated with UMB. Expressions of Ki-67, VEGF, CD31, MMP2, MMP9, VCAM1, and NF-κB were significantly decreased in tumors from UMB-treated animals (P < 0.001), whereas E-Cadherin and TNFR1 expressions were markedly increased (P < 0.001). The rates of liver and lung metastases in UMB-administrated animals were smaller compared to the control. UMB can potently inhibit tumor growth, angiogenesis, metastasis, and inflammation and potentiate an antitumor immune response in vivo. However, further investigations are required to evaluate the UMB mechanisms of action in cancerous cells.
Exosomes are small extracellular vesicles that pass genetic material between various cells to modulate
or alter their biological function. The role of exosomes is to communicate with the target cell for cell-to-cell
communication. Their inherent characteristics of exosomes, such as adhesion molecules, allow targeting specifically
to the receiving cell. Exosomes are involved in cell to cell communication in the immune system including
antigen presentation, natural killer cells (NK cells) and T cell activation/polarisation, immune suppression and
various anti-inflammatory processes. In this review, we have described various functions of exosomes secreted by
the immune cells in initiating, activating and modulating immune responses; and highlight the distinct roles of
exosomal surface proteins and exosomal cargo. Potential applications of exosomes such as distribution vehicles
for immunotherapy are also discussed.
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