scholarly journals Toxoplasma gondii GRA28 is required for specific induction of the regulatory chemokine CCL22 in human and mouse cells

2020 ◽  
Author(s):  
Elizabeth N. Rudzki ◽  
Stephanie E. Ander ◽  
Rachel S. Coombs ◽  
Hisham I. Alrubaye ◽  
Leah F. Cabo ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Tolerance ◽  
Inflammatory Responses ◽  
Severe Disease ◽  
Transcriptional Level ◽  
Placental Cells ◽  
Host Signaling ◽  
Mouse Cells ◽  
Protozoan Pathogen ◽  
The Impact

ABSTRACTToxoplasma gondii is an intracellular protozoan pathogen of humans that causes severe disease in immunocompromised patients and in the developing fetus. T. gondii specifically alters production of the immunomodulatory chemokine CCL22 in human placental cells during infection. Using a combination of bioinformatics and molecular genetics, we have now identified T. gondii GRA28 as the gene product required for CCL22 induction. GRA28 is strongly co-regulated at the transcriptional level along with other known secreted effectors and their chaperones. GRA28 is secreted into the host cell where it localizes to the nucleus, and deletion of this gene results in reduced CCL22 secretion from human monocytes and second trimester placental explants. The impact of GRA28 on CCL22 is also conserved in mouse immune and placental cells and the deletion of GRA28 results in increased inflammatory responses and reduced CNS burden during mouse infectionsAUTHOR SUMMARYToxoplasma gondii is a globally ubiquitous pathogen that can cause severe disease in HIV/AIDS patients and can also cross the placenta and infect the developing fetus. We have found that placental and immune cells infected with T. gondii secrete signfiicant amounts of a chemokine (called “CCL22”) that is critical for immune tolerance during pregnancy. In order to better understand whether this is a response by the host or a process that is driven by the parasite, we have identified a T. gondii gene that is absolutely required to induce CCL22 production in human cells, indicating that CCL22 production is a process driven almost entirely by the parasite rather than the host. Consistent with its role in immune tolerance, we also found that T. gondii parasites lacking this gene are less able to proliferate and disseminate throughout the host. Taken together these data illustrate a direct relationship between CCL22 levels in the infected host and a key parasite effector, and provide an interesting example of how T. gondii can directly modulate host signaling pathways in order to facilitate its growth and dissemination.

scholarly journals Toxoplasma gondii GRA28 Is Required for Placenta-Specific Induction of the Regulatory Chemokine CCL22 in Human and Mouse

mBio ◽  
2021 ◽  
Author(s):  
Elizabeth N. Rudzki ◽  
Stephanie E. Ander ◽  
Rachel S. Coombs ◽  
Hisham S. Alrubaye ◽  
Leah F. Cabo ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Immune Tolerance ◽  
Immune Cells ◽  
Severe Disease ◽  
Aids Patients ◽  
Content Type ◽  
Specific Induction ◽  
Human And Mouse ◽  
Hiv Aids

Toxoplasma gondii is a globally ubiquitous pathogen that can cause severe disease in HIV/AIDS patients and can also cross the placenta and infect the developing fetus. We have found that placental and immune cells infected with T. gondii secrete significant amounts of a chemokine (called CCL22) that is critical for immune tolerance during pregnancy.

scholarly journals AMPK activates Parkin independent autophagy and improves post sepsis immune defense against secondary bacterial lung infections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nathaniel B. Bone ◽  
Eugene J. Becker ◽  
Maroof Husain ◽  
Shaoning Jiang ◽  
Anna A. Zmijewska ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Inflammatory Responses ◽  
Abdominal Sepsis ◽  
Immune Defense ◽  
Bacterial Killing ◽  
Lung Infections ◽  
Sepsis Survivors ◽  
The Impact

AbstractMetabolic and bioenergetic plasticity of immune cells is essential for optimal responses to bacterial infections. AMPK and Parkin ubiquitin ligase are known to regulate mitochondrial quality control mitophagy that prevents unwanted inflammatory responses. However, it is not known if this evolutionarily conserved mechanism has been coopted by the host immune defense to eradicate bacterial pathogens and influence post-sepsis immunosuppression. Parkin, AMPK levels, and the effects of AMPK activators were investigated in human leukocytes from sepsis survivors as well as wild type and Park2−/− murine macrophages. In vivo, the impact of AMPK and Parkin was determined in mice subjected to polymicrobial intra-abdominal sepsis and secondary lung bacterial infections. Mice were treated with metformin during established immunosuppression. We showed that bacteria and mitochondria share mechanisms of autophagic killing/clearance triggered by sentinel events that involve depolarization of mitochondria and recruitment of Parkin in macrophages. Parkin-deficient mice/macrophages fail to form phagolysosomes and kill bacteria. This impairment of host defense is seen in the context of sepsis-induced immunosuppression with decreased levels of Parkin. AMPK activators, including metformin, stimulate Parkin-independent autophagy and bacterial killing in leukocytes from post-shock patients and in lungs of sepsis-immunosuppressed mice. Our results support a dual role of Parkin and AMPK in the clearance of dysfunctional mitochondria and killing of pathogenic bacteria, and explain the immunosuppressive phenotype associated Parkin and AMPK deficiency. AMPK activation appeared to be a crucial therapeutic target for the macrophage immunosuppressive phenotype and to reduce severity of secondary bacterial lung infections and respiratory failure.

scholarly journals Pattern of inflammatory immune response determines the clinical course and outcome of COVID-19: unbiased clustering analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eunyoung Emily Lee ◽  
Kyoung-Ho Song ◽  
Woochang Hwang ◽  
Sin Young Ham ◽  
Hyeonju Jeong ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Clustering Analysis ◽  
Validation Cohort ◽  
Inflammatory Responses ◽  
Clinical Course ◽  
Severe Disease ◽  
Outcome Data ◽  
Inflammatory Immune Response ◽  
Cluster 2

AbstractThe objective of the study was to identify distinct patterns in inflammatory immune responses of COVID-19 patients and to investigate their association with clinical course and outcome. Data from hospitalized COVID-19 patients were retrieved from electronic medical record. Supervised k-means clustering of serial C-reactive protein levels (CRP), absolute neutrophil counts (ANC), and absolute lymphocyte counts (ALC) was used to assign immune responses to one of three groups. Then, relationships between patterns of inflammatory responses and clinical course and outcome of COVID-19 were assessed in a discovery and validation cohort. Unbiased clustering analysis grouped 105 patients of a discovery cohort into three distinct clusters. Cluster 1 (hyper-inflammatory immune response) was characterized by high CRP levels, high ANC, and low ALC, whereas Cluster 3 (hypo-inflammatory immune response) was associated with low CRP levels and normal ANC and ALC. Cluster 2 showed an intermediate pattern. All patients in Cluster 1 required oxygen support whilst 61% patients in Cluster 2 and no patient in Cluster 3 required supplementary oxygen. Two (13.3%) patients in Cluster 1 died, whereas no patient in Clusters 2 and 3 died. The results were confirmed in an independent validation cohort of 116 patients. We identified three different patterns of inflammatory immune response to COVID-19. Hyper-inflammatory immune responses with elevated CRP, neutrophilia, and lymphopenia are associated with a severe disease and a worse outcome. Therefore, targeting the hyper-inflammatory response might improve the clinical outcome of COVID-19.

scholarly journals Transcriptomic Analysis of Inbred Chicken Lines Reveals Infectious Bursal Disease Severity Is Associated with Greater Bursal Inflammation In Vivo and More Rapid Induction of Pro-Inflammatory Responses in Primary Bursal Cells Stimulated Ex Vivo

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 933
Author(s):  
Amin S. Asfor ◽  
Salik Nazki ◽  
Vishwanatha R.A.P. Reddy ◽  
Elle Campbell ◽  
Katherine L. Dulwich ◽  
...  
Keyword(s):  
Rho Gtpases ◽  
Inflammatory Responses ◽  
Ex Vivo ◽  
Severe Disease ◽  
Infectious Bursal Disease ◽  
Rna Seq ◽  
Rapid Induction ◽  
Cytoskeletal Regulation ◽  
Bursal Disease

In order to better understand differences in the outcome of infectious bursal disease virus (IBDV) infection, we inoculated a very virulent (vv) strain into White Leghorn chickens of inbred line W that was previously reported to experience over 24% flock mortality, and three inbred lines (15I, C.B4 and 0) that were previously reported to display no mortality. Within each experimental group, some individuals experienced more severe disease than others but line 15I birds experienced milder disease based on average clinical scores, percentage of birds with gross pathology, average bursal lesion scores and average peak bursal virus titre. RNA-Seq analysis revealed that more severe disease in line W was associated with significant up-regulation of pathways involved in inflammation, cytoskeletal regulation by Rho GTPases, nicotinic acetylcholine receptor signaling, and Wnt signaling in the bursa compared to line 15I. Primary bursal cell populations isolated from uninfected line W birds contained a significantly greater percentage of KUL01+ macrophages than cells isolated from line 15I birds (p < 0.01) and, when stimulated ex vivo with LPS, showed more rapid up-regulation of pro-inflammatory gene expression than those from line 15I birds. We hypothesize that a more rapid induction of pro-inflammatory cytokine responses in bursal cells following IBDV infection leads to more severe disease in line W birds than in line 15I.

scholarly journals Splanchnic Vein Thrombosis in Acute Pancreatitis and Its Consequences

2021 ◽  
Vol 27 ◽  
pp. 107602962110102
Author(s):  
Łukasz Nawacki ◽  
Jarosław Matykiewicz ◽  
Ewa Stochmal ◽  
Stanisław Głuszek
Keyword(s):  
Acute Pancreatitis ◽  
Severe Disease ◽  
Vascular Complication ◽  
Strong Positive Correlation ◽  
Splanchnic Vein Thrombosis ◽  
Vein Thrombosis ◽  
Computed Tomography Scans ◽  
Negative Effect ◽  
Medical Histories ◽  
The Impact

Splanchnic vein thrombosis (SVT) is a serious vascular complication that can occur in patients with acute pancreatitis. We assessed the incidence of SVT and its relationship with acute pancreatitis (AP) and associated complications. We carried out a retrospective analysis of medical histories from patients hospitalized with AP in a single surgical center. Histories were acquired from patients with abdominal and pelvic computed tomography scans performed between the 2nd and 3rd day of hospitalization. We assessed the impact and extent of thrombosis over the disease course. We found a strong positive correlation (Cramer’s V coefficient = 0.34) between SVT and disease severity. Mortality in the study group was 7.2% (8 patients) of which 5 patients (62.5%) were diagnosed with SVT. We observed an increased incidence of death among patients with thrombosis, with results approaching significance ( P = 0.056). In our study, we found that SVT has a negative effect on the course of AP and is associated with more severe disease and increased mortality.

scholarly journals Parenteral Fish-Oil Containing Lipid Emulsions Limit Initial Lipopolysaccharide-Induced Host Immune Responses in Preterm Pigs

Nutrients ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 205
Author(s):  
William Yakah ◽  
David Ramiro-Cortijo ◽  
Pratibha Singh ◽  
Joanne Brown ◽  
Barbara Stoll ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fish Oil ◽  
Soybean Oil ◽  
Inflammatory Responses ◽  
Postnatal Period ◽  
Lipid Emulsions ◽  
Omega 3 ◽  
Oil Emulsion ◽  
Mixed Oil ◽  
The Impact

Multicomponent lipid emulsions are available for critical care of preterm infants. We sought to determine the impact of different lipid emulsions on early priming of the host and its response to an acute stimulus. Pigs delivered 7d preterm (n = 59) were randomized to receive different lipid emulsions for 11 days: 100% soybean oil (SO), mixed oil emulsion (SO, medium chain olive oil and fish oil) including 15% fish oil (MO15), or 100% fish oil (FO100). On day 11, pigs received an 8-h continuous intravenous infusion of either lipopolysaccharide (LPS—lyophilized Escherichia coli) or saline. Plasma was collected for fatty acid, oxylipin, metabolomic, and cytokine analyses. At day 11, plasma omega-3 fatty acid levels in the FO100 groups showed the highest increase in eicosapentaenoic acid, EPA (0.1 ± 0.0 to 9.7 ± 1.9, p < 0.001), docosahexaenoic acid, DHA (day 0 = 2.5 ± 0.7 to 13.6 ± 2.9, p < 0.001), EPA and DHA-derived oxylipins, and sphingomyelin metabolites. In the SO group, levels of cytokine IL1β increased at the first hour of LPS infusion (296.6 ± 308 pg/mL) but was undetectable in MO15, FO100, or in the animals receiving saline instead of LPS. Pigs in the SO group showed a significant increase in arachidonic acid (AA)-derived prostaglandins and thromboxanes in the first hour (p < 0.05). No significant changes in oxylipins were observed with either fish-oil containing group during LPS infusion. Host priming with soybean oil in the early postnatal period preserves a higher AA:DHA ratio and the ability to acutely respond to an external stimulus. In contrast, fish-oil containing lipid emulsions increase DHA, exacerbate a deficit in AA, and limit the initial LPS-induced inflammatory responses in preterm pigs.

Pathologic and immunohistochemical findings in an outbreak of systemic toxoplasmosis in a mob of red kangaroos

2021 ◽  
pp. 104063872110018
Author(s):  
Mariano Carossino ◽  
Rudy Bauer ◽  
Mark A. Mitchell ◽  
Charles O. Cummings ◽  
Anke C. Stöhr ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Sudden Death ◽  
Domestic Cat ◽  
High Morbidity ◽  
Severe Condition ◽  
Multiple Organs ◽  
Macropus Rufus ◽  
Pulmonary Parenchyma ◽  
Protozoan Pathogen ◽  
Clinical Conditions

Toxoplasma gondii is a zoonotic protozoan pathogen that infects many endothermic vertebrates, including humans; the domestic cat and other felids serve as the definitive host. Macropodids are considered highly susceptible to toxoplasmosis. Here, we describe the clinical, pathologic, and immunohistochemical findings of an outbreak of systemic toxoplasmosis in a mob of 11 red kangaroos ( Macropus rufus), with high morbidity (73%) and mortality (100%) rates. Affected animals had either severe and rapidly deteriorating clinical conditions or sudden death, which was correlated with widespread necrotizing lesions in multiple organs and intralesional T. gondii organisms identified via MIC3-specific immunohistochemistry and confirmed by REP529-specific rtPCR. Quantification of parasites demonstrated the highest parasite density in pulmonary parenchyma compared with other tissues. Our study highlights the continued importance of this severe condition in Australian marsupials.

scholarly journals A sand fly salivary protein acts as a neutrophil chemoattractant

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anderson B. Guimaraes-Costa ◽  
John P. Shannon ◽  
Ingrid Waclawiak ◽  
Jullyanna Oliveira ◽  
Claudio Meneses ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Calcium Influx ◽  
Parasite Burden ◽  
Salivary Protein ◽  
Sand Fly ◽  
Human Neutrophils ◽  
Chemotactic Protein ◽  
The Impact

AbstractApart from bacterial formyl peptides or viral chemokine mimicry, a non-vertebrate or insect protein that directly attracts mammalian innate cells such as neutrophils has not been molecularly characterized. Here, we show that members of sand fly yellow salivary proteins induce in vitro chemotaxis of mouse, canine and human neutrophils in transwell migration or EZ-TAXIScan assays. We demonstrate murine neutrophil recruitment in vivo using flow cytometry and two-photon intravital microscopy in Lysozyme-M-eGFP transgenic mice. We establish that the structure of this ~ 45 kDa neutrophil chemotactic protein does not resemble that of known chemokines. This chemoattractant acts through a G-protein-coupled receptor and is dependent on calcium influx. Of significance, this chemoattractant protein enhances lesion pathology (P < 0.0001) and increases parasite burden (P < 0.001) in mice upon co-injection with Leishmania parasites, underlining the impact of the sand fly salivary yellow proteins on disease outcome. These findings show that some arthropod vector-derived factors, such as this chemotactic salivary protein, activate rather than inhibit the host innate immune response, and that pathogens take advantage of these inflammatory responses to establish in the host.

scholarly journals The interplay between environmental exposures and COVID-19 risks in the health of children

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Peter D. Sly ◽  
Brittany A. Trottier ◽  
Catherine M. Bulka ◽  
Stephania A. Cormier ◽  
Julius Fobil ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Disease Severity ◽  
Research Effort ◽  
Severe Disease ◽  
Environmental Exposures ◽  
Research Strategy ◽  
Lessons Learned ◽  
Research Questions ◽  
The Impact

Abstract Background An unusual feature of SARS-Cov-2 infection and the COVID-19 pandemic is that children are less severely affected than adults. This is especially paradoxical given the epidemiological links between poor air quality and increased COVID-19 severity in adults and that children are generally more vulnerable than adults to the adverse consequences of air pollution. Objectives To identify gaps in knowledge about the factors that protect children from severe SARS-Cov-2 infection even in the face of air pollution, and to develop a transdisciplinary research strategy to address these gaps. Methods An international group of researchers interested in children’s environmental health was invited to identify knowledge gaps and to develop research questions to close these gaps. Discussion Key research questions identified include: what are the effects of SAR-Cov-2 infection during pregnancy on the developing fetus and child; what is the impact of age at infection and genetic susceptibility on disease severity; why do some children with COVID-19 infection develop toxic shock and Kawasaki-like symptoms; what are the impacts of toxic environmental exposures including poor air quality, chemical and metal exposures on innate immunity, especially in the respiratory epithelium; what is the possible role of a “dirty” environment in conveying protection – an example of the “hygiene hypothesis”; and what are the long term health effects of SARS-Cov-2 infection in early life. Conclusion A concerted research effort by a multidisciplinary team of scientists is needed to understand the links between environmental exposures, especially air pollution and COVID-19. We call for specific research funding to encourage basic and clinical research to understand if/why exposure to environmental factors is associated with more severe disease, why children appear to be protected, and how innate immune responses may be involved. Lessons learned about SARS-Cov-2 infection in our children will help us to understand and reduce disease severity in adults, the opposite of the usual scenario.

scholarly journals The impact of COVID-19 on emergency surgical presentations in a university teaching hospital

2021 ◽  
Author(s):  
Ahmed M. Kamil ◽  
Matthew G. Davey ◽  
Fadi Marzouk ◽  
Rish Sehgal ◽  
Amy L. Fowler ◽  
...  
Keyword(s):  
Acute Appendicitis ◽  
Teaching Hospital ◽  
Historical Data ◽  
Severe Disease ◽  
University Teaching ◽  
Readmission Rates ◽  
Descriptive Data ◽  
Operative Complications ◽  
Hospital Patients ◽  
The Impact

Abstract Introduction The Coronavirus-19 (COVID-19) pandemic has led to a 50–70% reduction in acute non-COVID-19 presentations to emergency departments globally. Aim To determine the impact of COVID-19 on incidence, severity, and outcomes of acute surgical admissions in an Irish University teaching hospital. Methods Descriptive data concerning patients presenting with acute appendicitis, diverticulitis, and cholecystitis were analysed and compared from March–May 2020 to March–May 2019. Results Acute surgical admissions decreased in March from 191 (2020) to 55 (2019) (55%), before increasing by 28% in April (2019: 119, 2020: 153). Admissions due to acute cholecystitis reduced by 33% (2019: 33, 2020: 22), with increased severity at presentation (P = 0.079) and higher 30-day readmission rates (P = 0.056) reported. Acute appendicitis presentations decreased by 44% (2019: 78, 2020: 43, P = 0.019), with an increase in severity (P < 0.001), conservative management (P < 0.001), and post-operative complications (P = 0.029) in 2020 compared to the same period in 2019. Conclusion COVID-19 has potentiated a significant reduction in acute surgical presentations to our hospital. Patients presenting with acute appendicitis during the pandemic had more severe disease, were more likely to have complications, and were significantly more likely to be managed conservatively when compared to historical data.

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