scholarly journals Bacterial Lipopolysaccharide Activates Toll-Like Receptor 2 and Toll-Like Receptor 4 Gene Expression in PBMC of Vechur Cattle

2021 ◽  
Vol 12 (3) ◽  
pp. 186-191
Author(s):  
R. Lakshmi ◽  
◽  
K. K. Jayavardhanan ◽  
J. Thanislass ◽  
P. Visha ◽  
...  

Vechur cattle, an indigenous breed of Kerala and it is the smallest cattle breed in the world. They are highly disease resistant. The occurrence of mastitis is very Rare in this breed as compared to crossbred cattle. Rearing of these Vechur breed is more cost effective as they require less feed. Therefore, characterisation of factors involved in the immune system of these breeds might provide an insight into the mechanisms involved in the variation in disease resistance. Toll-like receptors (TLRs) are part of the innate immunity, can recognize the particular pathogens through Pathogen Associated Molecular pattern s (PAMPs) and play important roles in host defense. TLR2 and TLR4 important TLR mediate the responsiveness to bacterial lipopolysaccharide (LPS). Since Vechur cattle are less susceptible to mastitis, in vitro expression assay of TLRs were accessed by challenging the Peripheral Blood Mononuclear Cells (PBMC) with bacterial LPS. Treatment of PBMC with LPS, significantly increased TLR2 and TLR4 genes expression (p≤0.01) in Vechur cattle breed when compared with that of control and crossbred cattle. Among the two TLRs studied, the relative expression of mRNA in Vechur cattle was relatively higher for TLR2 (6.90) than TLR4 (4.24). The higher expression of TLR 2 and TLR 4might contribute maximum innate immune response against the mastitis bacteria in Vechur cattle.

2019 ◽  
Vol 17 (1) ◽  
pp. e0501 ◽  
Author(s):  
Sourabh Sulabh ◽  
Manjit Panigrahi ◽  
Satish Kumar ◽  
Rajat Varshney ◽  
Ankita Verma ◽  
...  

Mastitis is a complex disease responsible for huge economic losses to the dairy sector. The causal organisms include a wide variety of micro-organisms including several species of bacteria. Escherichia coli has been identified as one of the most common gram-negative bacteria causing clinical mastitis in cattle. The immune system, of different species and/or breeds, tries to combat these pathogens in an inconsistent manner with differential mode and intensity of immune response, eventually producing contradicting outcomes of this disease. Several reports suggest the existence of variability among different animal breeds/species, resulting in a dissimilar outcome of this disease among them. In order to evaluate the variation among different breeds/species, the present study was undertaken to examine the stimulant effect of E. coli lipopolysaccharide (LPS) on peripheral blood mononuclear cells (PBMCs). The PBMCs were harvested from blood samples of crossbred cattle, Tharparkar cattle and Murrah buffaloes. After 6 h of in vitro stimulation, qRT-PCR was employed to measure the relative mRNA expression levels of CCL5, IL-1β, IL-12β, IFN-γ and IL-10 genes in stimulated and unstimulated PBMCs. The selected genes revealed significant differences in the pattern of innate immune response among crossbred cattle, Tharparkar cattle and Murrah buffaloes. The results clearly indicate the presence of variation in the outcome of immune response even when the immunocytes were stimulated with the same dose of the antigen.


2014 ◽  
Vol 9 (6) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Uriel García-Hernández ◽  
Frank H. Robledo-Ávila ◽  
Violeta D. Álvarez-Jiménez ◽  
Octavio Rodríguez-Cortés ◽  
Isabel Wong-Baeza ◽  
...  

Dialyzable leukocyte extracts (DLE) transfer specific cell-mediated immune responses from sensitized donors to non-immune recipients. In addition, DLE have several immunomodulatory effects and are used for the treatment of several infectious and non-infectious diseases. Previous studies showed that human DLE obtained from virus-infected leukocytes and bovine DLE decrease the production of the pro-inflammatory cytokine TNF-α in response to bacterial lipopolysaccharide, in vitro and in vivo. In the present work, we inquire as to whether DLE from uninfected human leukocytes have the ability to regulate cytokine production in peripheral blood mononuclear cells (PBMC) in vitro. We observed that PBMC from healthy individuals were able to produce TNF-α, IL-12 and IL-10 after stimulation with DLE. Moreover, we identified monocytes as the main cell population that produced TNF-α after DLE stimulation. Interestingly, we found that DLE contain unidentified ligands that activate Toll-like receptor (TLR)-2. Finally, we observed that DLE directly activated monocytes through TLR-2. These results reveal a new biological activity of DLE, and suggest that part of the immunomodulatory properties of DLE could be attributed to TLR-2 activation on monocytes and to the induction of a pro-inflammatory environment that is crucial for control of infectious diseases.


2007 ◽  
Vol 85 (7) ◽  
pp. 739-746 ◽  
Author(s):  
Yuriy Lissitsyn ◽  
Allan B. Becker ◽  
Anita L. Kozyrskyj ◽  
Kent T. HayGlass

Toll-like receptor (TLR) agonists, ubiquitously present in the environment, are key players in activating synthesis of cytokines and chemokines that control normal and pathophysiological processes, including multiple inflammatory diseases. TLR2 and TLR4 respond to bacterial cell wall products. We examined the impact of TLR activation on human immune capacity using stimuli ranging from the low levels seen in most environments to the high concentrations widely used for in vitro studies. Peripheral blood mononuclear cells from 117 healthy children were activated with lipopolysaccharide (TLR4 ligand) or peptidoglycan (TLR2 ligand) over a million-fold range of concentrations. Resulting interleukin-6, CCL2, and CCL22 production were quantified by ELISA. The intensity of cytokine production elicited was linearly related to the intensity of the stimulus up to maximal responses. In marked contrast, chemokine production was not linearly related to agonist concentration. Responses rose with increasing stimulation, and then were markedly reduced (40%–100%, p < 0.0001) in response to the high levels of TLR stimulation most commonly cited. Thus, the levels of TLR4 and TLR2 agonists typically used for in vitro interrogation of immune capacity yield results clearly distinct from those obtained using commonly occurring environmental levels of TLR ligands. These findings demonstrate the importance of utilizing TLR ligands at concentrations more closely mimicking environmental levels when assessing immune capacity.


2008 ◽  
Vol 28 (14) ◽  
pp. 4507-4519 ◽  
Author(s):  
C. T. Ranjith-Kumar ◽  
K. E. Duffy ◽  
J. L. Jordan ◽  
A. Eaton-Bassiri ◽  
Robert Vaughan ◽  
...  

ABSTRACT Toll-like receptor 3 (TLR3) can signal the production of a suite of cytokines and chemokines in response to double-stranded RNA (dsRNA) ligands or the dsRNA mimic poly(I-C). Using a human embryonic kidney 293T cell line to express human TLR3, we determined that poly(I-C)-induced signal could be significantly inhibited by single-stranded DNAs (ssDNAs), but not ssRNA or dsDNA. The ssDNA molecules that down-modulated TLR3 signaling did not affect TLR4 and do not require the hypomethylated CpG motif found in TLR9 ligands. The degree of modulation can be altered by the length, base sequence, and modification state of the ssDNAs. An inhibitory ssDNA was found to colocalize with TLR3 in transfected cells and in a cell line that naturally expresses TLR3. The inhibitory ssDNAs can compete efficiently with dsRNA for binding purified TLR3 ectodomains in vitro, while noninhibitory nucleic acids do not. The ssDNAs also decrease the levels of several cytokines produced by the human bronchial epithelial cell line BEAS-2B and by human peripheral blood mononuclear cells in response to poly(I-C) stimulation of native TLR3. These activities indicate that ssDNAs could be used to regulate the inflammatory response through TLR3.


2020 ◽  
Vol 12 (543) ◽  
pp. eaay8924 ◽  
Author(s):  
Gemma Moncunill ◽  
Anja Scholzen ◽  
Maximillian Mpina ◽  
Augusto Nhabomba ◽  
Aurore Bouyoukou Hounkpatin ◽  
...  

Identifying immune correlates of protection and mechanisms of immunity accelerates and streamlines the development of vaccines. RTS,S/AS01E, the most clinically advanced malaria vaccine, has moderate efficacy in African children. In contrast, immunization with sporozoites under antimalarial chemoprophylaxis (CPS immunization) can provide 100% sterile protection in naïve adults. We used systems biology approaches to identifying correlates of vaccine-induced immunity based on transcriptomes of peripheral blood mononuclear cells from individuals immunized with RTS,S/AS01E or chemoattenuated sporozoites stimulated with parasite antigens in vitro. Specifically, we used samples of individuals from two age cohorts and three African countries participating in an RTS,S/AS01E pediatric phase 3 trial and malaria-naïve individuals participating in a CPS trial. We identified both preimmunization and postimmunization transcriptomic signatures correlating with protection. Signatures were validated in independent children and infants from the RTS,S/AS01E phase 3 trial and individuals from an independent CPS trial with high accuracies (>70%). Transcription modules revealed interferon, NF-κB, Toll-like receptor (TLR), and monocyte-related signatures associated with protection. Preimmunization signatures suggest that priming the immune system before vaccination could potentially improve vaccine immunogenicity and efficacy. Last, signatures of protection could be useful to determine efficacy in clinical trials, accelerating vaccine candidate testing. Nevertheless, signatures should be tested more extensively across multiple cohorts and trials to demonstrate their universal predictive capacity.


2020 ◽  
Author(s):  
Hacer Kuzu Okur ◽  
Koray Yalcin ◽  
Cihan Tastan ◽  
Sevda Demir ◽  
Bulut Yurtsever ◽  
...  

UNSTRUCTURED Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). Coronavirus disease 2019 (COVID-19) pandemic affected more than two million people over the world, resulting in unprecedented health, social and economic crises. The COVID-19, viral pneumonia that progresses to ARDS and even multiple organ failure, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High blood neutrophil levels are an early indicator of SARS-CoV-2 infection and predict severe respiratory diseases. A similar mucus structure is detected in COVID-19 patients due to the accumulation of excessive NET in the lungs. Here, we show our preliminary results with dornase alfa that may have an in-vitro anti-viral effect against SARS-CoV-2 infection in a bovine kidney cell line, MDBK without drug toxicity on healthy adult peripheral blood mononuclear cells. In this preliminary study, we also showed that dornase alfa can promote clearance of NET formation in both an in-vitro and three COVID-19 cases who showed clinical improvement in radiological analysis (2-of-3 cases), oxygen saturation (SpO2), respiratory rate, disappearing of dyspnea and coughing.


Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1037
Author(s):  
Patricia Ruiz-Limon ◽  
Maria L. Ladehesa-Pineda ◽  
Clementina Lopez-Medina ◽  
Chary Lopez-Pedrera ◽  
Maria C. Abalos-Aguilera ◽  
...  

Endothelial dysfunction (ED) is well known as a process that can lead to atherosclerosis and is frequently presented in radiographic axial spondyloarthritis (r-axSpA) patients. Here, we investigated cellular and molecular mechanisms underlying r-axSpA-related ED, and analyzed the potential effect of peripheral blood mononuclear cells (PBMCs) in promoting endothelial injury in r-axSpA. A total of 30 r-axSpA patients and 32 healthy donors (HDs) were evaluated. The endothelial function, inflammatory and atherogenic profile, and oxidative stress were quantified. In vitro studies were designed to evaluate the effect of PBMCs from r-axSpA patients on aberrant endothelial activation. Compared to HDs, our study found that, associated with ED and the plasma proatherogenic profile present in r-axSpA, PBMCs from these patients displayed a pro-oxidative, proinflammatory, and proatherogenic phenotype, with most molecular changes noticed in lymphocytes. Correlation studies revealed the relationship between this phenotype and the microvascular function. Additional in vitro studies confirmed that PBMCs from r-axSpA patients promoted endothelial injury. Altogether, this study suggests the relevance of r-axSpA itself as a strong and independent cardiovascular risk factor, contributing to a dysfunctional endothelium and atherogenic status by aberrant activation of PBMCs. Lymphocytes could be the main contributors in the development of ED and subsequent atherosclerosis in this pathology.


Sign in / Sign up

Export Citation Format

Share Document