scholarly journals Proteomics of Brucella

Proteomes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 8 ◽  
Author(s):  
Ansgar Poetsch ◽  
María Inés Marchesini

Brucella spp. are Gram negative intracellular bacteria responsible for brucellosis, a worldwide distributed zoonosis. A prominent aspect of the Brucella life cycle is its ability to invade, survive and multiply within host cells. Comprehensive approaches, such as proteomics, have aided in unravelling the molecular mechanisms underlying Brucella pathogenesis. Technological and methodological advancements such as increased instrument performance and multiplexed quantification have broadened the range of proteome studies, enabling new and improved analyses, providing deeper and more accurate proteome coverage. Indeed, proteomics has demonstrated its contribution to key research questions in Brucella biology, i.e., immunodominant proteins, host-cell interaction, stress response, antibiotic targets and resistance, protein secretion. Here, we review the proteomics of Brucella with a focus on more recent works and novel findings, ranging from reconfiguration of the intracellular bacterial proteome and studies on proteomic profiles of Brucella infected tissues, to the identification of Brucella extracellular proteins with putative roles in cell signaling and pathogenesis. In conclusion, proteomics has yielded copious new candidates and hypotheses that require future verification. It is expected that proteomics will continue to be an invaluable tool for Brucella and applications will further extend to the currently ill-explored aspects including, among others, protein processing and post-translational modification.

2015 ◽  
Vol 81 (12) ◽  
pp. 4090-4097 ◽  
Author(s):  
Ofelia C. Romero-Maraccini ◽  
Joanna L. Shisler ◽  
Thanh H. Nguyen

ABSTRACTRotavirus, the leading cause of diarrheal diseases in children under the age of five, is often resistant to conventional wastewater treatment and thus can remain infectious once released into the aquatic environment. Solar and heat treatments can inactivate rotavirus, but it is unknown how these treatments inactivate the virus on a molecular level. To answer this question, our approach was to correlate rotavirus inactivation with the inhibition of portions of the virus life cycle as a means to identify the mechanisms of solar or heat inactivation. Specifically, the integrity of the rotavirus NSP3 gene, virus-host cell interaction, and viral RNA synthesis were examined after heat (57°C) or solar treatment of rotavirus. Only the inhibition of viral RNA synthesis positively correlated with a loss of rotavirus infectivity; 57°C treatment of rotavirus resulted in a decrease of rotavirus RNA synthesis at the same rate as rotavirus infectivity. These data suggest that heat treatment neutralized rotaviruses primarily by targeting viral transcription functions. In contrast, when using solar disinfection, the decrease in RNA synthesis was responsible for approximately one-half of the decrease in infectivity, suggesting that other mechanisms, including posttranslational, contribute to inactivation. Nevertheless, both solar and heat inactivation of rotaviruses disrupted viral RNA synthesis as a mechanism for inactivation.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Alex Steimle ◽  
Julia-Stefanie Frick

How does the host manage to tolerate its own intestinal microbiota? A simple question leading to complicated answers. In order to maintain balanced immune responses in the intestine, the host immune system must tolerate commensal bacteria in the gut while it has to simultaneously keep the ability to fight pathogens and to clear infections. If this tender equilibrium is disturbed, severe chronic inflammatory reactions can result. Tolerogenic intestinal dendritic cells fulfil a crucial role in balancing immune responses and therefore creating homeostatic conditions and preventing from uncontrolled inflammation. Although several dendritic cell subsets have already been characterized to play a pivotal role in this process, less is known about definite molecular mechanisms of how intestinal dendritic cells are converted into tolerogenic ones. Here we review how gut commensal bacteria interact with intestinal dendritic cells and why this bacteria-host cell interaction is crucial for induction of dendritic cell tolerance in the intestine. Hereby, different commensal bacteria can have distinct effects on the phenotype of intestinal dendritic cells and these effects are mainly mediated by impacting toll-like receptor signalling in dendritic cells.


2016 ◽  
Vol 91 (4) ◽  
Author(s):  
Giulia Torriani ◽  
Clara Galan-Navarro ◽  
Stefan Kunz

ABSTRACT Viral entry represents the first step of every viral infection and is a determinant for the host range and disease potential of a virus. Here, we review the latest developments on cell entry of the highly pathogenic Old World arenavirus Lassa virus, providing novel insights into the complex virus-host cell interaction of this important human pathogen. We will cover new discoveries on the molecular mechanisms of receptor recognition, endocytosis, and the use of late endosomal entry factors.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Caroline Maria Marcos ◽  
Gabrielle Tamer ◽  
Haroldo Cesar de Oliveira ◽  
Patricia Akemi Assato ◽  
Liliana Scorzoni ◽  
...  

AbstractThe genus Paracoccidioides consist of dimorphic fungi geographically limited to the subtropical regions of Latin America, which are responsible for causing deep systemic mycosis in humans. However, the molecular mechanisms by which Paracoccidioides spp. causes the disease remain poorly understood. Paracoccidioides spp. harbor genes that encode proteins involved in host cell interaction and mitochondrial function, which together are required for pathogenicity and mediate virulence. Previously, we identified TufM (previously known as EF-Tu) in Paracoccidioides brasiliensis (PbTufM) and suggested that it may be involved in the pathogenicity of this fungus. In this study, we examined the effects of downregulating PbTUFM using a silenced strain with a 55% reduction in PbTUFM expression obtained by antisense-RNA (aRNA) technology. Silencing PbTUFM yielded phenotypic differences, such as altered translation elongation, respiratory defects, increased sensitivity of yeast cells to reactive oxygen stress, survival after macrophage phagocytosis, and reduced interaction with pneumocytes. These results were associated with reduced virulence in Galleria mellonella and murine infection models, emphasizing the importance of PbTufM in the full virulence of P. brasiliensis and its potential as a target for antifungal agents against paracoccidioidomycosis.


2010 ◽  
Vol 2010 ◽  
pp. 1-18 ◽  
Author(s):  
Wanderley de Souza ◽  
Tecia Maria Ulisses de Carvalho ◽  
Emile Santos Barrias

Trypanosoma cruzi, the causative agent of Chagas' disease, which affects a large number of individuals in Central and South America, is transmitted to vertebrate hosts by blood-sucking insects. This protozoan is an obligate intracellular parasite. The infective forms of the parasite are metacyclic and bloodstream trypomastigote and amastigote. Metacyclic trypomastigotes are released with the feces of the insect while amastigotes and bloodstream trypomastigotes are released from the infected host cells of the vertebrate host after a complex intracellular life cycle. The recognition between parasite and mammalian host cell involves numerous molecules present in both cell types. Here, we present a brief review of the interaction betweenTrypanosoma cruziand its host cells, mainly emphasizing the mechanisms and molecules that participate in theT. cruziinvasion process of the mammalian cells.


Author(s):  
A. E. Ritchie

The cause of bluecomb disease in turkeys is unknown. Filtration of infective intestinal contents suggests a viral origin. To date, it has not been possible to isolate the etiologic agent in various cell cultures. The purpose of this work was to characterize as many virus-like entities as were recognizable in intestines of both healthy and bluecomb-infected turkeys. By a comparison of the viral populations it was hoped that some insight might be gained into the cause of this disease. Studies of turkey hemorraghic enteritis by Gross and Moore (Avian Dis. 11: 296-307, 1967) have suggested that a bacteriophage-host cell interaction may bear some causal relationship to that disease.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Plinio S. Vieira ◽  
Isabela M. Bonfim ◽  
Evandro A. Araujo ◽  
Ricardo R. Melo ◽  
Augusto R. Lima ◽  
...  

AbstractXyloglucans are highly substituted and recalcitrant polysaccharides found in the primary cell walls of vascular plants, acting as a barrier against pathogens. Here, we reveal that the diverse and economically relevant Xanthomonas bacteria are endowed with a xyloglucan depolymerization machinery that is linked to pathogenesis. Using the citrus canker pathogen as a model organism, we show that this system encompasses distinctive glycoside hydrolases, a modular xyloglucan acetylesterase and specific membrane transporters, demonstrating that plant-associated bacteria employ distinct molecular strategies from commensal gut bacteria to cope with xyloglucans. Notably, the sugars released by this system elicit the expression of several key virulence factors, including the type III secretion system, a membrane-embedded apparatus to deliver effector proteins into the host cells. Together, these findings shed light on the molecular mechanisms underpinning the intricate enzymatic machinery of Xanthomonas to depolymerize xyloglucans and uncover a role for this system in signaling pathways driving pathogenesis.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 380
Author(s):  
Ales Macela ◽  
Klara Kubelkova

SARS-CoV-2 infection induces the production of autoantibodies, which is significantly associated with complications during hospitalization and a more severe prognosis in COVID-19 patients. Such a response of the patient’s immune system may reflect (1) the dysregulation of the immune response or (2) it may be an attempt to regulate itself in situations where the non-infectious self poses a greater threat than the infectious non-self. Of significance may be the primary virus-host cell interaction where the surface-bound ACE2 ectoenzyme plays a critical role. Here, we present a brief analysis of recent findings concerning the immune recognition of SARS-CoV-2, which, we believe, favors the second possibility as the underlying reason for the production of autoantibodies during COVID-19.


2021 ◽  
Vol 22 (7) ◽  
pp. 3463
Author(s):  
Chia-Hung Lin ◽  
Chen-Chung Liao ◽  
Mei-Yu Chen ◽  
Teh-Ying Chou

Protein O-GlcNAcylation is a dynamic post-translational modification involving the attachment of N-acetylglucosamine (GlcNAc) to the hydroxyl groups of Ser/Thr residues on numerous nucleocytoplasmic proteins. Two enzymes are responsible for O-GlcNAc cycling on substrate proteins: O-GlcNAc transferase (OGT) catalyzes the addition while O-GlcNAcase (OGA) helps the removal of GlcNAc. O-GlcNAcylation modifies protein functions; therefore, dysregulation of O-GlcNAcylation affects cell physiology and contributes to pathogenesis. To maintain homeostasis of cellular O-GlcNAcylation, there exists feedback regulation of OGT and OGA expression responding to fluctuations of O-GlcNAc levels; yet, little is known about the molecular mechanisms involved. In this study, we investigated the O-GlcNAc-feedback regulation of OGT and OGA expression in lung cancer cells. Results suggest that, upon alterations in O-GlcNAcylation, the regulation of OGA expression occurs at the mRNA level and likely involves epigenetic mechanisms, while modulation of OGT expression is through translation control. Further analyses revealed that the eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1) contributes to the downregulation of OGT induced by hyper-O-GlcNAcylation; the S5A/S6A O-GlcNAcylation-site mutant of 4E-BP1 cannot support this regulation, suggesting an important role of O-GlcNAcylation. The results provide additional insight into the molecular mechanisms through which cells may fine-tune intracellular O-GlcNAc levels to maintain homeostasis.


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