The microRNA days: The COVID-19 pandemic from the point of view of short RNAs

MicroRNA ◽  
2021 ◽  
Vol 11 ◽  
Author(s):  
Alberto Izzotti

Abstract: Despite their biological simplicity, microRNA-based organisms, such as RNA viruses, are currently shown to be unexpected threats to mammals, including humans. This situation is exemplified by the COVID-19 pandemic triggered by the spread of SARS-CoV-2. RNA viruses are older than DNA viruses. Indeed, from an evolutionary standpoint, RNA is an older molecule than DNA. The strength of RNA viruses, compared to DNA viruses, resides in their simplicity and instability. The instability of RNA viruses, such as human immunodeficiency virus (HIV) and flu viruses, generates mutants to escape the host’s defense mechanisms. A formidable combination of lethality and infectivity was recently achieved by SARS-CoV-2. Complex DNAbased defense systems use Toll-like receptors to intercept viral RNA inside a cell. Activation of Toll-like receptors triggers inflammation and activates lymphocytes and monocytes, causing thromboxane release. In the case of SARS-CoV-2 infection, this process results in cytokine storms and lung thromboembolism. The ongoing pandemic can be envisioned as a struggle between highly evolved complex DNA organisms, i.e., humans, and poorly evolved simple RNA organisms, i.e., SARS-CoV-2 virus. Quite surprisingly, the complex organism has a serious problem defeating the simplistic organism. However, humans are finally developing a new effective weapon in fighting the SARS-CoV-2 virus, paradoxically, RNA-based vaccines. These considerations underscore the relevance of microRNAs as powerful tools in therapeutic and preventive medicine.

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 958
Author(s):  
Kaitlyn Speckhart ◽  
Jeffrey M. Williams ◽  
Billy Tsai

To initiate infection, a virus enters a host cell typically via receptor-dependent endocytosis. It then penetrates a subcellular membrane, reaching a destination that supports transcription, translation, and replication of the viral genome. These steps lead to assembly and morphogenesis of the new viral progeny. The mature virus finally exits the host cell to begin the next infection cycle. Strikingly, viruses hijack host molecular chaperones to accomplish these distinct entry steps. Here we highlight how DNA viruses, including polyomavirus and the human papillomavirus, exploit soluble and membrane-associated chaperones to enter a cell, penetrating and escaping an intracellular membrane en route for infection. We also describe the mechanism by which RNA viruses—including flavivirus and coronavirus—co-opt cytosolic and organelle-selective chaperones to promote viral endocytosis, protein biosynthesis, replication, and assembly. These examples underscore the importance of host chaperones during virus infection, potentially revealing novel antiviral strategies to combat virus-induced diseases.


2016 ◽  
Vol 4 (9) ◽  
pp. 1672-1685 ◽  
Author(s):  
Abhinav P. Acharya ◽  
Matthew R. Carstens ◽  
Jamal S. Lewis ◽  
Natalia Dolgova ◽  
C. Q. Xia ◽  
...  

Experimental vaccine adjuvants are being designed to target specific toll-like receptors (TLRs) alone or in combination, expressed by antigen presenting cells, notably dendritic cells (DCs).


Author(s):  
A. E. Vatter ◽  
J. Zambernard

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.


2020 ◽  
Vol 16 (34) ◽  
pp. 2853-2861
Author(s):  
Yanli Li ◽  
Rui Yang ◽  
Limo Chen ◽  
Sufang Wu

CD38 is a transmembrane glycoprotein that is widely expressed in a variety of human tissues and cells, especially those in the immune system. CD38 protein was previously considered as a cell activation marker, and today monoclonal antibodies targeting CD38 have witnessed great achievements in multiple myeloma and promoted researchers to conduct research on other tumors. In this review, we provide a wide-ranging review of the biology and function of the human molecule outside the field of myeloma. We focus mainly on current research findings to summarize and update the findings gathered from diverse areas of study. Based on these findings, we attempt to extend the role of CD38 in the context of therapy of solid tumors and expand the role of the molecule from a simple marker to an immunomodulator.


2020 ◽  
Vol 222 (11) ◽  
pp. 1837-1842 ◽  
Author(s):  
Nikolaus Jilg ◽  
Pilar Garcia-Broncano ◽  
Michael Peluso ◽  
Florencia P Segal ◽  
Ronald J Bosch ◽  
...  

Abstract AIDS Clinical Trials Group study A5308 found reduced T-cell activation and exhaustion in human immunodeficiency virus (HIV) controllers start antiretroviral therapy (ART). We further assessed HIV-specific T-cell responses and post-ART viral loads. Before ART, the 31% of participants with persistently undetectable viremia had more robust HIV-specific T-cell responses. During ART, significant decreases were observed in a broad range of T-cell responses. Eight controllers in A5308 and the Study of the Consequences of the Protease Inhibitor Era (SCOPE) cohort showed no viremia above the level of quantification in the first 12 weeks after ART discontinuation. ART significantly reduced HIV-specific T-cell responses in HIV controllers but did not adversely affect controller status after ART discontinuation.


Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 320 ◽  
Author(s):  
Alexandra P. M. Cloherty ◽  
Anusca G. Rader ◽  
Brandon Compeer ◽  
Carla M. S. Ribeiro

Human immunodeficiency virus-1 (HIV-1) persists as a global health concern, with an incidence rate of approximately 2 million, and estimated global prevalence of over 35 million. Combination antiretroviral treatment is highly effective, but HIV-1 patients that have been treated still suffer from chronic inflammation and residual viral replication. It is therefore paramount to identify therapeutically efficacious strategies to eradicate viral reservoirs and ultimately develop a cure for HIV-1. It has been long accepted that the restriction factor tripartite motif protein 5 isoform alpha (TRIM5α) restricts HIV-1 infection in a species-specific manner, with rhesus macaque TRIM5α strongly restricting HIV-1, and human TRIM5α having a minimal restriction capacity. However, several recent studies underscore human TRIM5α as a cell-dependent HIV-1 restriction factor. Here, we present an overview of the latest research on human TRIM5α and propose a novel conceptualization of TRIM5α as a restriction factor with a varied portfolio of antiviral functions, including mediating HIV-1 degradation through autophagy- and proteasome-mediated mechanisms, and acting as a viral sensor and effector of antiviral signaling. We have also expanded on the protective antiviral roles of autophagy and outline the therapeutic potential of autophagy modulation to intervene in chronic HIV-1 infection.


Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 446
Author(s):  
Kevin M. Rose ◽  
Stephanie J. Spada ◽  
Rebecca Broeckel ◽  
Kristin L. McNally ◽  
Vanessa M. Hirsch ◽  
...  

An evolutionary arms race has been ongoing between retroviruses and their primate hosts for millions of years. Within the last century, a zoonotic transmission introduced the Human Immunodeficiency Virus (HIV-1), a retrovirus, to the human population that has claimed the lives of millions of individuals and is still infecting over a million people every year. To counteract retroviruses such as this, primates including humans have evolved an innate immune sensor for the retroviral capsid lattice known as TRIM5α. Although the molecular basis for its ability to restrict retroviruses is debated, it is currently accepted that TRIM5α forms higher-order assemblies around the incoming retroviral capsid that are not only disruptive for the virus lifecycle, but also trigger the activation of an antiviral state. More recently, it was discovered that TRIM5α restriction is broader than previously thought because it restricts not only the human retroelement LINE-1, but also the tick-borne flaviviruses, an emergent group of RNA viruses that have vastly different strategies for replication compared to retroviruses. This review focuses on the underlying mechanisms of TRIM5α-mediated restriction of retroelements and flaviviruses and how they differ from the more widely known ability of TRIM5α to restrict retroviruses.


Viruses ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1086
Author(s):  
Francois Helle ◽  
Lynda Handala ◽  
Marine Bentz ◽  
Gilles Duverlie ◽  
Etienne Brochot

Extracellular vesicles have recently emerged as a novel mode of viral transmission exploited by naked viruses to exit host cells through a nonlytic pathway. Extracellular vesicles can allow multiple viral particles to collectively traffic in and out of cells, thus enhancing the viral fitness and diversifying the transmission routes while evading the immune system. This has been shown for several RNA viruses that belong to the Picornaviridae, Hepeviridae, Reoviridae, and Caliciviridae families; however, recent studies also demonstrated that the BK and JC viruses, two DNA viruses that belong to the Polyomaviridae family, use a similar strategy. In this review, we provide an update on recent advances in understanding the mechanisms used by naked viruses to hijack extracellular vesicles, and we discuss the implications for the biology of polyomaviruses.


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