scholarly journals The Recognition of and Reactions to Nucleic Acid Nanoparticles by Human Immune Cells

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4231
Author(s):  
Dominika Bila ◽  
Yasmine Radwan ◽  
Marina A. Dobrovolskaia ◽  
Martin Panigaj ◽  
Kirill A. Afonin

The relatively straightforward methods of designing and assembling various functional nucleic acids into nanoparticles offer advantages for applications in diverse diagnostic and therapeutic approaches. However, due to the novelty of this approach, nucleic acid nanoparticles (NANPs) are not yet used in the clinic. The immune recognition of NANPs is among the areas of preclinical investigation aimed at enabling the translation of these novel materials into clinical settings. NANPs’ interactions with the complement system, coagulation systems, and immune cells are essential components of their preclinical safety portfolio. It has been established that NANPs’ physicochemical properties—composition, shape, and size—determine their interactions with immune cells (primarily blood plasmacytoid dendritic cells and monocytes), enable recognition by pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs) and RIG-I-like receptors (RLRs), and mediate the subsequent cytokine response. However, unlike traditional therapeutic nucleic acids (e.g., CpG oligonucleotides), NANPs do not trigger a cytokine response unless they are delivered into the cells using a carrier. Recently, it was discovered that the type of carrier provides an additional tool for regulating both the spectrum and the magnitude of the cytokine response to NANPs. Herein, we review the current knowledge of NANPs’ interactions with various components of the immune system to emphasize the unique properties of these nanomaterials and highlight opportunities for their use in vaccines and immunotherapy.

2018 ◽  
Vol 72 (1) ◽  
pp. 447-478 ◽  
Author(s):  
Xiaojun Tan ◽  
Lijun Sun ◽  
Jueqi Chen ◽  
Zhijian J. Chen

Microbial infections are recognized by the innate immune system through germline-encoded pattern recognition receptors (PRRs). As most microbial pathogens contain DNA and/or RNA during their life cycle, nucleic acid sensing has evolved as an essential strategy for host innate immune defense. Pathogen-derived nucleic acids with distinct features are recognized by specific host PRRs localized in endolysosomes and the cytosol. Activation of these PRRs triggers signaling cascades that culminate in the production of type I interferons and proinflammatory cytokines, leading to induction of an antimicrobial state, activation of adaptive immunity, and eventual clearance of the infection. Here, we review recent progress in innate immune recognition of nucleic acids upon microbial infection, including pathways involving endosomal Toll-like receptors, cytosolic RNA sensors, and cytosolic DNA sensors. We also discuss the mechanisms by which infectious microbes counteract host nucleic acid sensing to evade immune surveillance.


2020 ◽  
Vol 48 (20) ◽  
pp. 11785-11798
Author(s):  
Morgan Brittany Johnson ◽  
Justin R Halman ◽  
Daniel K Miller ◽  
Joseph S Cooper ◽  
Emil F Khisamutdinov ◽  
...  

Abstract Nucleic acid nanoparticles (NANPs) have become powerful new platforms as therapeutic and diagnostic tools due to the innate biological ability of nucleic acids to identify target molecules or silence genes involved in disease pathways. However, the clinical application of NANPs has been limited by factors such as chemical instability, inefficient intracellular delivery, and the triggering of detrimental inflammatory responses following innate immune recognition of nucleic acids. Here, we have studied the effects of altering the chemical composition of a circumscribed panel of NANPs that share the same connectivity, shape, size, charge and sequences. We show that replacing RNA strands with either DNA or chemical analogs increases the enzymatic and thermodynamic stability of NANPs. Furthermore, we have found that such composition changes affect delivery efficiency and determine subcellular localization, effects that could permit the targeted delivery of NANP-based therapeutics and diagnostics. Importantly, we have determined that altering NANP composition can dictate the degree and mechanisms by which cell immune responses are initiated. While RNA NANPs trigger both TLR7 and RIG-I mediated cytokine and interferon production, DNA NANPs stimulate minimal immune activation. Importantly, incorporation of 2′F modifications abrogates RNA NANP activation of TLR7 but permits RIG-I dependent immune responses. Furthermore, 2′F modifications of DNA NANPs significantly enhances RIG-I mediated production of both proinflammatory cytokines and interferons. Collectively this indicates that off-target effects may be reduced and/or desirable immune responses evoked based upon NANPs modifications. Together, our studies show that NANP composition provides a simple way of controlling the immunostimulatory potential, and physicochemical and delivery characteristics, of such platforms.


2021 ◽  
Vol 22 (2) ◽  
pp. 922
Author(s):  
Martin Bartas ◽  
Jiří Červeň ◽  
Simona Guziurová ◽  
Kristyna Slychko ◽  
Petr Pečinka

Nucleic acid-binding proteins are traditionally divided into two categories: With the ability to bind DNA or RNA. In the light of new knowledge, such categorizing should be overcome because a large proportion of proteins can bind both DNA and RNA. Another even more important features of nucleic acid-binding proteins are so-called sequence or structure specificities. Proteins able to bind nucleic acids in a sequence-specific manner usually contain one or more of the well-defined structural motifs (zinc-fingers, leucine zipper, helix-turn-helix, or helix-loop-helix). In contrast, many proteins do not recognize nucleic acid sequence but rather local DNA or RNA structures (G-quadruplexes, i-motifs, triplexes, cruciforms, left-handed DNA/RNA form, and others). Finally, there are also proteins recognizing both sequence and local structural properties of nucleic acids (e.g., famous tumor suppressor p53). In this mini-review, we aim to summarize current knowledge about the amino acid composition of various types of nucleic acid-binding proteins with a special focus on significant enrichment and/or depletion in each category.


Author(s):  
Dimitrij Lang

The success of the protein monolayer technique for electron microscopy of individual DNA molecules is based on the prevention of aggregation and orientation of the molecules during drying on specimen grids. DNA adsorbs first to a surface-denatured, insoluble cytochrome c monolayer which is then transferred to grids, without major distortion, by touching. Fig. 1 shows three basic procedures which, modified or not, permit the study of various important properties of nucleic acids, either in concert with other methods or exclusively:1) Molecular weights relative to DNA standards as well as number distributions of molecular weights can be obtained from contour length measurements with a sample standard deviation between 1 and 4%.


Author(s):  
Stephen D. Jett

The electrophoresis gel mobility shift assay is a popular method for the study of protein-nucleic acid interactions. The binding of proteins to DNA is characterized by a reduction in the electrophoretic mobility of the nucleic acid. Binding affinity, stoichiometry, and kinetics can be obtained from such assays; however, it is often desirable to image the various species in the gel bands using TEM. Present methods for isolation of nucleoproteins from gel bands are inefficient and often destroy the native structure of the complexes. We have developed a technique, called “snapshot blotting,” by which nucleic acids and nucleoprotein complexes in electrophoresis gels can be electrophoretically transferred directly onto carbon-coated grids for TEM imaging.


2021 ◽  
Vol 23 (1) ◽  
pp. 219-228
Author(s):  
Nabanita Saikia ◽  
Mohamed Taha ◽  
Ravindra Pandey

The rational design of self-assembled nanobio-molecular hybrids of peptide nucleic acids with single-wall nanotubes rely on understanding how biomolecules recognize and mediate intermolecular interactions with the nanomaterial's surface.


2020 ◽  
Author(s):  
K Jamal Jameel ◽  
S Yanik ◽  
E Bülthoff ◽  
F Yusuf ◽  
B Struck ◽  
...  

2019 ◽  
Vol 20 (8) ◽  
pp. 799-816 ◽  
Author(s):  
Yue Qiu ◽  
Guo-wei Tu ◽  
Min-jie Ju ◽  
Cheng Yang ◽  
Zhe Luo

Sepsis, which is a highly heterogeneous syndrome, can result in death as a consequence of a systemic inflammatory response syndrome. The activation and regulation of the immune system play a key role in the initiation, development and prognosis of sepsis. Due to the different periods of sepsis when the objects investigated were incorporated, clinical trials often exhibit negative or even contrary results. Thus, in this review we aim to sort out the current knowledge in how immune cells play a role during sepsis.


2021 ◽  
Vol 22 (3) ◽  
pp. 1448
Author(s):  
Jessica Aijia Liu ◽  
Jing Yu ◽  
Chi Wai Cheung

Pain can be induced by tissue injuries, diseases and infections. The interactions between the peripheral nervous system (PNS) and immune system are primary actions in pain sensitizations. In response to stimuli, nociceptors release various mediators from their terminals that potently activate and recruit immune cells, whereas infiltrated immune cells further promote sensitization of nociceptors and the transition from acute to chronic pain by producing cytokines, chemokines, lipid mediators and growth factors. Immune cells not only play roles in pain production but also contribute to PNS repair and pain resolution by secreting anti-inflammatory or analgesic effectors. Here, we discuss the distinct roles of four major types of immune cells (monocyte/macrophage, neutrophil, mast cell, and T cell) acting on the PNS during pain process. Integration of this current knowledge will enhance our understanding of cellular changes and molecular mechanisms underlying pain pathogenies, providing insights for developing new therapeutic strategies.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii114-ii114
Author(s):  
Adam Grippin ◽  
Brandon Wummer ◽  
Hector Mendez-Gomez ◽  
Tyler Wildes ◽  
Kyle Dyson ◽  
...  

Abstract BACKGROUND Brain tumors are notoriously difficult to treat in part due to their isolation behind the blood brain barrier and their power to suppress antitumor immune responses. We have previously reported cationic liposome formulations capable of delivering immune modulatory nucleic acids to immune cells in various peripheral organs, but there is currently no reliable method to deliver nucleic acids into brain tumors without direct injection into the tumor site. OBJECTIVE Here, we report the development of a customized lipid nanoparticle to deliver immune modulatory nucleic acids to immune cells in brain tumors. APPROACH Cationic liposomes composed of varying lipid combinations were evaluated for their ability to deliver functional mRNA and siRNA to innate immune cells in vitro and in intracranial tumor models. Nucleic acids were labelled with Cy3 to monitor particle distribution in vivo. RESULTS Lipids composed of DOTAP and cholesterol selectively delivered mRNA and siRNA to intracranial GL261 and KR158b tumors. Interestingly, these particles selectively delivered these nucleic acids to CD45+ white blood cells with minimal delivery to CD45- tumor cells or normal brain tissue. Encapsulation of siRNA blocking programmed death ligand 1 (PDL1) significantly reduced PDL1 expression on innate immune cells in brain tumors, with the greatest effects on tumor-associated macrophages. Co-administration of systemic checkpoint blockade with intravenous administration of these lipid nanoparticles bearing PDL1 siRNA enabled systemic and intratumoral checkpoint blockade, leading to 37% long term survivorship in an otherwise fatal intracranial tumor model. CONCLUSIONS Our customized lipid nanoparticles enable potent intratumoral immune modulation via delivery of nucleic acids to immune cells in brain tumors.


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