scholarly journals Novel Roles of the Picornaviral 3D Polymerase in Viral Pathogenesis

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Jason Kerkvliet ◽  
Ramakrishna Edukulla ◽  
Moses Rodriguez
Keyword(s):  
Immune Response ◽  
Antiviral Effect ◽  
Viral Pathogenesis ◽  
Structure And Function ◽  
Rna Dependent Rna Polymerase ◽  
Transgenic Expression ◽  
Antiviral Effects ◽  
Encephalomyelitis Virus ◽  
Picornavirus Infection ◽  
And Function

The RNA-dependent RNA-polymerase,3Dpol, is an essential component in the picornavirus genome for the replication of single stranded RNA. However, transgenic expression of3Dpolin mice has antiviral effects. Here, we discuss the structure and function of3Dpolduring picornavirus replication, we review the evidence and consequence of a host immune response to epitopes in3Dpolafter picornavirus infection, highlight data showing the antiviral effects of transgenic3Dpolfrom Theiler's murine encephalomyelitis virus (TMEV), and discuss potential mechanisms by which3Dpolis causing this antiviral effect in mice.

scholarly journals JNK pathway restricts DENV, ZIKV and CHIKV infection by activating complement and apoptosis in mosquito salivary glands

2020 ◽  
Author(s):  
Avisha Chowdhury ◽  
Cassandra M. Modahl ◽  
Siok Thing Tan ◽  
Benjamin Wong Wei Xiang ◽  
Dorothée Missé ◽  
...  
Keyword(s):  
Immune Response ◽  
Virus Infection ◽  
Salivary Glands ◽  
Antiviral Effect ◽  
Negative Regulator ◽  
Chikv Infection ◽  
Jnk Pathway ◽  
Antiviral Effects ◽  
Antiviral Function ◽  
Arbovirus Infection

AbstractArbovirus infection of Aedes aegypti salivary glands (SGs) determines transmission. However, there is a dearth of knowledge on SG immunity. Here, we characterized SG immune response to dengue, Zika and chikungunya viruses using high-throughput transcriptomics. The three viruses regulate components of Toll, IMD and JNK pathways. However, silencing of Toll and IMD components showed variable effects on SG infection by each virus. In contrast, regulation of JNK pathway produced consistent responses. Virus infection increased with depletion of component Kayak and decreased with depletion of negative regulator Puckered. Virus-induced JNK pathway regulates complement and apoptosis in SGs via TEP20 and Dronc, respectively. Individual and co-silencing of these genes demonstrate their antiviral effects and that both may function together. Co-silencing either TEP20 or Dronc with Puckered annihilates JNK pathway antiviral effect. We identified and characterized the broad antiviral function of JNK pathway in SGs, expanding the immune arsenal that blocks arbovirus transmission.

scholarly journals Correlating the structure and activity of Y. pestis Ail in a bacterial cell envelope

2020 ◽  
Author(s):  
J. E. Kent ◽  
L. M. Fujimoto ◽  
K. Shin ◽  
C. Singh ◽  
Y. Yao ◽  
...  
Keyword(s):  
Immune Response ◽  
Human Serum ◽  
Bacterial Cell ◽  
Model System ◽  
Structure And Function ◽  
Cell Surface Expression ◽  
Therapeutic Drug ◽  
E Coli ◽  
Cell Envelopes ◽  
And Function

ABSTRACTUnderstanding microbe-host interactions at the molecular level is a major goal of fundamental biology and therapeutic drug development. Structural biology strives to capture biomolecular structures in action, but the samples are often highly simplified versions of the complex native environment. Here we present an E. coli model system that allows us to probe the structure and function of Ail, the major surface protein of the deadly pathogen Yersinia pestis. We show that cell surface expression of Ail produces Y. pestis virulence phenotypes in E. coli, including resistance to human serum, co-sedimentation of human vitronectin and pellicle formation. Moreover, isolated bacterial cell envelopes, encompassing inner and outer membranes, yield high-resolution solid-state nuclear magnetic resonance (NMR) spectra that reflect the structure of Ail and reveal Ail sites that are sensitive to the bacterial membrane environment and involved in the interactions with human serum components. The data capture the structure and function of Ail in a bacterial outer membrane and set the stage for probing its interactions with the complex milieu of immune response proteins present in human serum.SIGNIFICANCEAil is a critical virulence factor of Y. pestis, and its interactions with human serum are central for promoting the immune resistance of bacteria to the human host defenses. Here we capture the action of Ail in a functional bacterial environment and set the stage for probing its interactions with the complex milieu of immune response proteins present in human serum. The development of an E. coli model system of Y. pestis for biophysical studies is new and biologically important. Finally, the work extends the range in-situ NMR spectroscopy to include models of microbial infection.

scholarly journals MHC structure and function – antigen presentation. Part 1

2015 ◽  
Vol 13 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Anna Carla Goldberg ◽  
Luiz Vicente Rizzo
Keyword(s):  
Immune Response ◽  
T Cell Receptors ◽  
Adaptive Immune Response ◽  
Structure And Function ◽  
Cell Surfaces ◽  
Vast Array ◽  
Innate Defense ◽  
Adaptive Immune ◽  
And Function ◽  
Antigen Presenting

The setting for the occurrence of an immune response is that of the need to cope with a vast array of different antigens from both pathogenic and non-pathogenic sources. When the first barriers against infection and innate defense fail, adaptive immune response enters the stage for recognition of the antigens by means of extremely variable molecules, namely immunoglobulins and T-cell receptors. The latter recognize the antigen exposed on cell surfaces, in the form of peptides presented by the HLA molecule. The first part of this review details the central role played by these molecules, establishing the close connection existing between their structure and their antigen presenting function.

Connective tissue and inflammation

2014 ◽  
Vol 155 (12) ◽  
pp. 453-460 ◽  
Author(s):  
Lajos Jakab
Keyword(s):  
Immune Response ◽  
Connective Tissue ◽  
Adaptive Immune Response ◽  
Sialic Acids ◽  
Structure And Function ◽  
Psychological State ◽  
Connective Tissues ◽  
Cellular Events ◽  
Inflammatory Processes ◽  
And Function

The author summarizes the structure of the connective tissues, the increasing motion of the constituents, which determine the role in establishing the structure and function of that. The structure and function of the connective tissue are related to each other in the resting as well as inflammatory states. It is emphasized that cellular events in the connective tissue are part of the defence of the organism, the localisation of the damage and, if possible, the maintenance of restitutio ad integrum. The organism responds to damage with inflammation, the non specific immune response, as well as specific, adaptive immunity. These processes are located in the connective tissue. Sterile and pathogenic inflammation are relatively similar processes, but inevitable differences are present, too. Sialic acids and glycoproteins containing sialic acids have important roles, and the role of Siglecs is also highlighted. Also, similarities and differences in damages caused by pathogens and sterile agents are briefly summarized. In addition, the roles of adhesion molecules linked to each other, and the whole event of inflammatory processes are presented. When considering practical consequences it is stressed that the structure (building up) of the organism and the defending function of inflammation both have fundamental importance. Inflammation has a crucial role in maintaining the integrity and the unimpaired somato-psychological state of the organism. Thus, inflammation serves as a tool of organism identical with the natural immune response, inseparably connected with the specific, adaptive immune response. The main events of the inflammatory processes take place in the connective tissue. Orv. Hetil., 2014, 155(12), 453–460.

scholarly journals MHC structure and function − antigen presentation. Part 2

2015 ◽  
Vol 13 (1) ◽  
pp. 157-162 ◽  
Author(s):  
Anna Carla Goldberg ◽  
Luiz Vicente Rizzo
Keyword(s):  
Immune Response ◽  
T Cells ◽  
T Cell ◽  
Antigen Presentation ◽  
T Cell Receptor ◽  
Cell Receptor ◽  
Structure And Function ◽  
Alternative Sources ◽  
And Function ◽  
Significant Class

The second part of this review deals with the molecules and processes involved in the processing and presentation of the antigenic fragments to the T-cell receptor. Though the nature of the antigens presented varies, the most significant class of antigens is proteins, processed within the cell to be then recognized in the form of peptides, a mechanism that confers an extraordinary degree of precision to this mode of immune response. The efficiency and accuracy of this system is also the result of the myriad of mechanisms involved in the processing of proteins and production of peptides, in addition to the capture and recycling of alternative sources aiming to generate further diversity in the presentation to T-cells.

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