Replication protein Rep provides selective advantage to viruses in the presence of CRISPR-Cas immunity

Prokaryotic viruses express anti-CRISPR (Acr) proteins to inhibit the host adaptive immune system, CRISPR-Cas. While the virus infection biology was shown to be strongly dependent on the relative strengths of the host CRISPR-Cas and viral Acrs, little is known about the role of the core processes of viral life cycle (replication, packaging etc) in defence/anti-defence arms race. Here, we demonstrate the selective advantage provided by a replication initiator, Rep, in the context of CRISPR-Acr interactions. First, we developed a two-host based CRISPR-Cas genome editing tool for the deletion of highly conserved and thus potentially important viral genes. Using this strategy, we deleted a highly conserved Rep-coding gene, gp16, from the genome of Sulfolobus islandicus rod-shaped virus 2 (SIRV2). The knockout mutant (?gp16) produced around 4 fold less virus in a CRISPR-null host, suggesting that Rep is the major contributor to replication initiation in Rudiviridae. Indeed, DNA sequencing revealed Rep-dependent replication initiation from the viral genome termini, in addition to Rep-independent replication initiation from non-terminal sites. Intriguingly, the lack of Rep showed a profound effect on virus propagation in a host carrying CRISPR-Cas immunity. Accordingly, the co-infecting parental virus (rep-containing) outcompeted the Δgp16 mutant much more quickly in CRISPR-containing host than in CRISPR-null host, demonstrating a selective advantage provided by Rep in the presence of host CRISPR-Cas immunity. Despite the non-essentiality, rep is carried by all known members of Rudiviridae, which is likely an evolutionary outcome driven by the ubiquitous presence of CRISPR-Cas in Sulfolobales.

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Concomitant autoimmunity may be a predictor of more severe stages of endometriosis

Scientific Reports ◽

10.1038/s41598-021-94877-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Vanni Valeria Stella ◽

Villanacci Roberta ◽

Salmeri Noemi ◽

Papaleo Enrico ◽

Delprato Diana ◽

...

Keyword(s):

Autoimmune Disease ◽

Adaptive Immune System ◽

Stage Iv ◽

Multivariate Logistic Regression Model ◽

Medical Patients ◽

Laparoscopic Procedures ◽

Logistic Analysis ◽

Increased Risk ◽

History Of

AbstractPathogenesis of endometriosis is still unclear and a role of both innate and adaptive immune system has been postulated. Some recent findings have revealed an increased risk to have concomitant autoimmune disease in women with endometriosis, but no study so far has investigated whether this association could affect endometriosis severity and stage. We retrospectively reviewed medical patients’ notes of women with a confirmed diagnosis of endometriosis who referred to our endometriosis outpatient clinic between January 2015 and December 2019. Cases (endometriosis and an autoimmune disease) were matched in a 1:3 ratio by age and study period with controls (endometriosis without history of autoimmunity). At univariate logistic analysis, concomitant autoimmunity (OR 2.63, 95% CI 1.64–4.21, p < 0.001) and the number of laparoscopic procedures performed (OR 2.81, 95% CI 1.45–5.43, p = 0.002) emerged as factors significantly associated with the likelihood of stage IV endometriosis. In the multivariate logistic regression model, concomitant autoimmunity remained a significant predictor of stage IV endometriosis (OR 2.54, 95% CI 1.57–4.10, p = 0.004), whereas the association between the number of laparoscopic procedures performed and stage IV endometriosis was found to be of borderline-significance (OR 2.70, 95% 1.37–5.30, p = 0.050). Our findings suggest that endometriosis is more severe in patients who are also affected by autoimmune disturbances after controlling for relevant confounders.

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The role of interleukin-17 in the pathogenesis of systemic sclerosis: Pro-fibrotic or anti-fibrotic?

Journal of Scleroderma and Related Disorders ◽

10.1177/23971983211039421 ◽

2021 ◽

pp. 239719832110394

Author(s):

Silvia Bellando-Randone ◽

Emanuel Della-Torre ◽

Andra Balanescu

Keyword(s):

Systemic Sclerosis ◽

Therapeutic Target ◽

Inflammatory Diseases ◽

Adaptive Immune System ◽

Disease Stage ◽

Target Cells ◽

Interleukin 17 ◽

T Helper 17 ◽

Attractive Therapeutic Target

Systemic sclerosis is characterized by widespread fibrosis of the skin and internal organs, vascular impairment, and dysregulation of innate and adaptive immune system. Growing evidence indicates that T-cell proliferation and cytokine secretion play a major role in the initiation of systemic sclerosis, but the role of T helper 17 cells and of interleukin-17 cytokines in the development and progression of the disease remains controversial. In particular, an equally distributed body of literature supports both pro-fibrotic and anti-fibrotic effects of interleukin-17, suggesting a complex and nuanced role of this cytokine in systemic sclerosis pathogenesis that may vary depending on disease stage, target cells in affected organs, and inflammatory milieu. Although interleukin-17 already represents an established therapeutic target for several immune-mediated inflammatory diseases, more robust experimental evidence is required to clarify whether it may become an attractive therapeutic target for systemic sclerosis as well.

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Dynamic Association of the Replication Initiator and Transcription Factor DnaA with the Bacillus subtilis Chromosome during Replication Stress

Journal of Bacteriology ◽

10.1128/jb.01294-08 ◽

2008 ◽

Vol 191 (2) ◽

pp. 486-493 ◽

Cited By ~ 22

Author(s):

Adam M. Breier ◽

Alan D. Grossman

Keyword(s):

Transcription Factor ◽

Chromatin Immunoprecipitation ◽

Binding Sites ◽

Replication Fork ◽

Replication Stress ◽

Replication Initiation ◽

Pass Through ◽

Bacillus Subtilis Chromosome ◽

Rapid Signaling ◽

Replication Initiator

ABSTRACT DnaA functions as both a transcription factor and the replication initiator in bacteria. We characterized the DNA binding dynamics of DnaA on a genomic level. Based on cross-linking and chromatin immunoprecipitation data, DnaA binds at least 17 loci, 15 of which are regulated transcriptionally in response to inhibition of replication (replication stress). Six loci, each of which has a cluster of at least nine potential DnaA binding sites, had significant increases in binding by DnaA when replication was inhibited, indicating that the association of DnaA with at least some of its target sites is altered after replication stress. When replication resumed from oriC after inhibition of replication initiation, these high levels of binding decreased rapidly at origin-proximal and origin-distal regions, well before a replication fork could pass through each of the regulated regions. These findings indicate that there is rapid signaling to decrease activation of DnaA during replication and that interaction between DnaA bound at each site and the replication machinery is not required for regulation of DnaA activity in response to replication stress.

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The Periplasmic α-Carbonic Anhydrase Activity of Helicobacter pylori Is Essential for Acid Acclimation

Journal of Bacteriology ◽

10.1128/jb.187.2.729-738.2005 ◽

2005 ◽

Vol 187 (2) ◽

pp. 729-738 ◽

Cited By ~ 124

Author(s):

Elizabeth A. Marcus ◽

Amiel P. Moshfegh ◽

George Sachs ◽

David R. Scott

Keyword(s):

Helicobacter Pylori ◽

Membrane Potential ◽

Carbonic Anhydrase ◽

Membrane Integrity ◽

Carbonic Anhydrase Activity ◽

Knockout Mutant ◽

Inner Membrane ◽

Acid Acclimation

ABSTRACT The role of the periplasmic α-carbonic anhydrase (α-CA) (HP1186) in acid acclimation of Helicobacter pylori was investigated. Urease and urea influx through UreI have been shown to be essential for gastric colonization and for acid survival in vitro. Intrabacterial urease generation of NH3 has a major role in regulation of periplasmic pH and inner membrane potential under acidic conditions, allowing adequate bioenergetics for survival and growth. Since α-CA catalyzes the conversion of CO2 to HCO3 −, the role of CO2 in periplasmic buffering was studied using an α-CA deletion mutant and the CA inhibitor acetazolamide. Western analysis confirmed that α-CA was bound to the inner membrane. Immunoblots and PCR confirmed the absence of the enzyme and the gene in the α-CA knockout. In the mutant or in the presence of acetazolamide, there was an ∼3 log10 decrease in acid survival. In acid, absence of α-CA activity decreased membrane integrity, as observed using membrane-permeant and -impermeant fluorescent DNA dyes. The increase in membrane potential and cytoplasmic buffering following urea addition to wild-type organisms in acid was absent in the α-CA knockout mutant and in the presence of acetazolamide, although UreI and urease remained fully functional. At low pH, the elevation of cytoplasmic and periplasmic pH with urea was abolished in the absence of α-CA activity. Hence, buffering of the periplasm to a pH consistent with viability depends not only on NH3 efflux from the cytoplasm but also on the conversion of CO2, produced by urease, to HCO3 − by the periplasmic α-CA.

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Adipocytes, Innate Immunity and Obesity: A Mini-Review

Frontiers in Immunology ◽

10.3389/fimmu.2021.650768 ◽

2021 ◽

Vol 12 ◽

Author(s):

Alecia M. Blaszczak ◽

Anahita Jalilvand ◽

Willa A. Hsueh

Keyword(s):

Adipose Tissue ◽

Immune System ◽

Immune Cells ◽

Adaptive Immune System ◽

Innate Immune ◽

Lymphoid Cells ◽

Innate Immune Cells ◽

Adaptive Immune

The role of adipose tissue (AT) inflammation in obesity and its multiple related-complications is a rapidly expanding area of scientific interest. Within the last 30 years, the role of the adipocyte as an endocrine and immunologic cell has been progressively established. Like the macrophage, the adipocyte is capable of linking the innate and adaptive immune system through the secretion of adipokines and cytokines; exosome release of lipids, hormones, and microRNAs; and contact interaction with other immune cells. Key innate immune cells in AT include adipocytes, macrophages, neutrophils, and innate lymphoid cells type 2 (ILC2s). The role of the innate immune system in promoting adipose tissue inflammation in obesity will be highlighted in this review. T cells and B cells also play important roles in contributing to AT inflammation and are discussed in this series in the chapter on adaptive immunity.

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The AC4 Protein of a Cassava Geminivirus Is Required for Virus Infection

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-12-18-0354-r ◽

2019 ◽

Vol 32 (7) ◽

pp. 865-875 ◽

Cited By ~ 8

Author(s):

Kegui Chen ◽

Behnam Khatabi ◽

Vincent N. Fondong

Keyword(s):

Plant Viruses ◽

Wild Type Virus ◽

Virus Infectivity ◽

Type Virus ◽

Wild Type ◽

Knockout Mutant ◽

East African ◽

Reading Frame ◽

Cell Membrane Binding

Geminiviruses (family Geminiviridae) are among the most devastating plant viruses worldwide, causing severe damage in crops of economic and subsistence importance. These viruses have very compact genomes and many of the encoded proteins are multifunctional. Here, we investigated the role of the East African cassava mosaic Cameroon virus (EACMCV) AC4 on virus infectivity in Nicotiana benthamiana. Results showed that plants inoculated with EACMCV containing a knockout mutation in an AC4 open reading frame displayed symptoms 2 to 3 days later than plants inoculated with wild-type virus, and these plants recovered from infection, whereas plants inoculated with the wild-type virus did not. Curiously, when an additional mutation was made in the knockout mutant, the resulting double mutant virus completely failed to cause any apparent symptoms. Interestingly, the role of AC4 on virus infectivity appeared to be dependent on an encoded N-myristoylation motif that mediates cell membrane binding. We previously showed that EACMCV containing the AC4T38I mutant produced virus progeny characterized by second-site mutations and reversion to wild-type virus. These results were confirmed in this study using additional mutations. Together, these results show involvement of EACMCV AC4 in virus infectivity; they also suggest a role for the combined action of mutation and selection, under prevailing environmental conditions, on begomovirus genetic variation and diversity.

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A Role of Inflammation and Immunity in Essential Hypertension—Modeled and Analyzed Using Petri Nets

International Journal of Molecular Sciences ◽

10.3390/ijms21093348 ◽

2020 ◽

Vol 21 (9) ◽

pp. 3348

Author(s):

Dorota Formanowicz ◽

Agnieszka Rybarczyk ◽

Marcin Radom ◽

Piotr Formanowicz

Keyword(s):

Essential Hypertension ◽

Adaptive Immune System ◽

Low Grade ◽

Kinin System ◽

Reactive Protein ◽

Adaptive Immune ◽

Key Enzyme ◽

Kallikrein Kinin System ◽

Low Grade Inflammation

Recent studies have shown that the innate and adaptive immune system, together with low-grade inflammation, may play an important role in essential hypertension. In this work, to verify the importance of selected factors for the development of essential hypertension, we created a Petri net-based model and analyzed it. The analysis was based mainly on t-invariants, knockouts of selected fragments of the net and its simulations. The blockade of the renin-angiotensin (RAA) system revealed that the most significant effect on the emergence of essential hypertension has RAA activation. This blockade affects: (1) the formation of angiotensin II, (2) inflammatory process (by influencing C-reactive protein (CRP)), (3) the initiation of blood coagulation, (4) bradykinin generation via the kallikrein-kinin system, (5) activation of lymphocytes in hypertension, (6) the participation of TNF alpha in the activation of the acute phase response, and (7) activation of NADPH oxidase—a key enzyme of oxidative stress. On the other hand, we found that the blockade of the activation of the RAA system may not eliminate hypertension that can occur due to disturbances associated with the osmotically independent binding of Na in the interstitium. Moreover, we revealed that inflammation alone is not enough to trigger primary hypertension, but it can coexist with it. We believe that our research may contribute to a better understanding of the pathology of hypertension. It can help identify potential subprocesses, which blocking will allow better control of essential hypertension.

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