scholarly journals Flagellin Is an Effective Adjuvant for Immunization against Lethal Respiratory Challenge with Yersinia pestis

2006 ◽  
Vol 74 (2) ◽  
pp. 1113-1120 ◽  
Author(s):  
Anna N. Honko ◽  
Nammalwar Sriranganathan ◽  
Cynthia J. Lees ◽  
Steven B. Mizel
Keyword(s):  
Yersinia Pestis ◽  
Neutrophil Infiltration ◽  
Specific Ige ◽  
Innate Immune ◽  
Igg Antibody ◽  
Adjuvant Activity ◽  
Necrosis Factor Alpha ◽  
Potent Inducer ◽  
Cytokines And Chemokines ◽  
F1 Antigen

ABSTRACT Gram-negative flagellin, a Toll-like receptor 5 (TLR5) agonist, is a potent inducer of innate immune effectors such as cytokines and nitric oxide. In the lung, flagellin induces a localized and transient innate immune response characterized by neutrophil infiltration and the production of cytokines and chemokines. In view of the extraordinary potency of flagellin as an inducer of innate immunity and the contribution of innate responses to the development of adaptive immunity, we evaluated the efficacy of recombinant Salmonella flagellin as an adjuvant in an acellular plague vaccine. Mice immunized intranasally or intratracheally with the F1 antigen of Yersinia pestis and flagellin exhibited dramatic increases in anti-F1 plasma immunoglobulin G (IgG) titers that remained stable over time. In contrast, control mice had low or undetectable antibody responses. The IgG1/IgG2a ratio of antibody titers against F1 in immunized mice is consistent with a Th2 bias. However, no significant antigen-specific IgE production was detected. Interferons, tumor necrosis factor alpha, and interleukin-6 were not essential for the adjuvant effects of flagellin. Preexisting antiflagellin antibodies had no significant effect on the adjuvant activity of flagellin. Importantly, intranasal immunization with flagellin and the F1 antigen was protective against intranasal challenge with virulent Y. pestis CO92, with 93 to 100% survival of immunized mice. Lastly, vaccination of cynomolgus monkeys with flagellin and a fusion of the F1 and V antigens of Y. pestis induced a robust antigen-specific IgG antibody response.

scholarly journals Induction of Cytokines and Chemokines in Human Monocytes by Mycoplasma fermentans-Derived Lipoprotein MALP-2

1999 ◽  
Vol 67 (12) ◽  
pp. 6303-6308 ◽  
Author(s):  
A. Kaufmann ◽  
P. F. Mühlradt ◽  
D. Gemsa ◽  
H. Sprenger
Keyword(s):  
Cell Wall ◽  
Bacterial Infections ◽  
Cytokine Gene Expression ◽  
Mononuclear Leukocytes ◽  
Human Monocytes ◽  
Necrosis Factor Alpha ◽  
Potent Inducer ◽  
Mycoplasma Fermentans ◽  
Inflammatory Reactions ◽  
Cytokines And Chemokines

ABSTRACT Bacterial infections are characterized by strong inflammatory reactions. The responsible mediators are often bacterially derived cell wall molecules, such as lipopolysaccharide or lipoteichoic acids, which typically stimulate monocytes and macrophages to release a wide variety of inflammatory cytokines and chemokines. Mycoplasmas, which lack a cell wall, may also stimulate monocytes very efficiently. This study was performed to identify mycoplasma-induced mediators. We investigated the induction of cytokines and chemokines in human monocytes exposed to the Mycoplasma fermentans-derived membrane component MALP-2 (macrophage-activating lipopeptide 2) by dose response and kinetic analysis. We found a rapid and strong MALP-2-inducible chemokine and cytokine gene expression which was followed by the release of chemokines and cytokines with peak levels after 12 to 20 h. MALP-2 induced the neutrophil-attracting CXC chemokines interleukin-8 (IL-8) and GRO-α as well as the mononuclear leukocyte-attracting CC chemokines MCP-1, MIP-1α, and MIP-1β. Production of the proinflammatory cytokines tumor necrosis factor alpha and IL-6 started at the same time as chemokine release but required 10- to 100-fold-higher MALP-2 doses. The data show that the mycoplasma-derived lipopeptide MALP-2 represents a potent inducer of chemokines and cytokines which may, by the attraction and activation of neutrophils and mononuclear leukocytes, significantly contribute to the inflammatory response during mycoplasma infection.

scholarly journals The mRNA-LNP platform’s lipid nanoparticle component used in preclinical vaccine studies is highly inflammatory

2021 ◽  
Author(s):  
Sonia Ndeupen ◽  
Zhen Qin ◽  
Sonya Jacobsen ◽  
Henri Estanbouli ◽  
Aurélie Bouteau ◽  
...  
Keyword(s):  
Side Effects ◽  
Immune Responses ◽  
Inflammatory Responses ◽  
Neutrophil Infiltration ◽  
Intradermal Injection ◽  
Preclinical Studies ◽  
Adjuvant Activity ◽  
Adaptive Immune ◽  
Cytokines And Chemokines ◽  
Very High

ABSTRACTVaccines based on mRNA-containing lipid nanoparticles (LNPs) are a promising new platform used by two leading vaccines against coronavirus disease in 2019 (COVID-19). Clinical trials and ongoing vaccinations present with very high protection levels and varying degrees of side effects. However, the nature of the reported side effects remains poorly defined. Here we present evidence that LNPs used in many preclinical studies are highly inflammatory in mice. Intradermal injection of these LNPs led to rapid and robust inflammatory responses, characterized by massive neutrophil infiltration, activation of diverse inflammatory pathways, and production of various inflammatory cytokines and chemokines. The same dose of LNP delivered intranasally led to similar inflammatory responses in the lung and resulted in a high mortality rate.In summary, here we show that the LNPs used for many preclinical studies are highly inflammatory. Thus, their potent adjuvant activity and reported superiority comparing to other adjuvants in supporting the induction of adaptive immune responses could stem from their inflammatory nature. Furthermore, the preclinical LNPs are similar to the ones used for human vaccines, which could also explain the observed side effects in humans using this platform.

scholarly journals Modulation of Innate Immune Toxicity by Silver Nanoparticle Exposure and the Preventive Effects of Pterostilbene

2021 ◽  
Vol 22 (5) ◽  
pp. 2536
Author(s):  
Rong-Jane Chen ◽  
Chiao-Ching Huang ◽  
Rosita Pranata ◽  
Yu-Hsuan Lee ◽  
Yu-Ying Chen ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Good Alternative ◽  
Innate Immune ◽  
Toxic Effects ◽  
Transgenic Zebrafish ◽  
Zebrafish Model ◽  
Cytokines And Chemokines ◽  
Living Organisms ◽  
And Function ◽  
Immune Toxicity

Silver nanoparticles pose a potential risk to ecosystems and living organisms due to their widespread use in various fields and subsequent gradual release into the environment. Only a few studies have investigated the effects of silver nanoparticles (AgNPs) toxicity on immunological functions. Furthermore, these toxic effects have not been fully explored. Recent studies have indicated that zebrafish are considered a good alternative model for testing toxicity and for evaluating immunological toxicity. Therefore, the purpose of this study was to investigate the toxicity effects of AgNPs on innate immunity using a zebrafish model and to investigate whether the natural compound pterostilbene (PTE) could provide protection against AgNPs-induced immunotoxicity. Wild type and neutrophil- and macrophage-transgenic zebrafish lines were used in the experiments. The results indicated that the exposure to AgNPs induced toxic effects including death, malformation and the innate immune toxicity of zebrafish. In addition, AgNPs affect the number and function of neutrophils and macrophages. The expression of immune-related cytokines and chemokines was also affected. Notably, the addition of PTE could activate immune cells and promote their accumulation in injured areas in zebrafish, thereby reducing the damage caused by AgNPs. In conclusion, AgNPs may induce innate immune toxicity and PTE could ameliorate this toxicity.

scholarly journals Intestinal Permeability Is a Mechanical Rheostat in the Pathogenesis of Liver Cirrhosis

2021 ◽  
Vol 22 (13) ◽  
pp. 6921
Author(s):  
Norihisa Nishimura ◽  
Kosuke Kaji ◽  
Koh Kitagawa ◽  
Yasuhiko Sawada ◽  
Masanori Furukawa ◽  
...  
Keyword(s):  
Liver Disease ◽  
Gut Microbiota ◽  
Intestinal Permeability ◽  
Proinflammatory Cytokines ◽  
Liver Diseases ◽  
Pathogenic Bacteria ◽  
Necrosis Factor Alpha ◽  
Cytokines And Chemokines ◽  
Liver Disease Progression ◽  
Cirrhotic Patients

Recent studies have suggested that an alteration in the gut microbiota and their products, particularly endotoxins derived from Gram-negative bacteria, may play a major role in the pathogenesis of liver diseases. Gut dysbiosis caused by a high-fat diet and alcohol consumption induces increased intestinal permeability, which means higher translocation of bacteria and their products and components, including endotoxins, the so-called “leaky gut”. Clinical studies have found that plasma endotoxin levels are elevated in patients with chronic liver diseases, including alcoholic liver disease and nonalcoholic liver disease. A decrease in commensal nonpathogenic bacteria including Ruminococaceae and Lactobacillus and an overgrowth of pathogenic bacteria such as Bacteroidaceae and Enterobacteriaceae are observed in cirrhotic patients. The decreased diversity of the gut microbiota in cirrhotic patients before liver transplantation is also related to a higher incidence of post-transplant infections and cognitive impairment. The exposure to endotoxins activates macrophages via Toll-like receptor 4 (TLR4), leading to a greater production of proinflammatory cytokines and chemokines including tumor necrosis factor-alpha, interleukin (IL)-6, and IL-8, which play key roles in the progression of liver diseases. TLR4 is a major receptor activated by the binding of endotoxins in macrophages, and its downstream signal induces proinflammatory cytokines. The expression of TLR4 is also observed in nonimmune cells in the liver, such as hepatic stellate cells, which play a crucial role in the progression of liver fibrosis that develops into hepatocarcinogenesis, suggesting the importance of the interaction between endotoxemia and TLR4 signaling as a target for preventing liver disease progression. In this review, we summarize the findings for the role of gut-derived endotoxemia underlying the progression of liver pathogenesis.

scholarly journals Human Immunodeficiency Virus Infection Alters Tumor Necrosis Factor Alpha Production via Toll-Like Receptor-Dependent Pathways in Alveolar Macrophages and U1 Cells

2008 ◽  
Vol 82 (16) ◽  
pp. 7790-7798 ◽  
Author(s):  
Marlynne Q. Nicol ◽  
Jean-Marie Mathys ◽  
Albertina Pereira ◽  
Kevin Ollington ◽  
Michael H. Ieong ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Innate Immune ◽  
Hiv Positive ◽  
Toll Like Receptor ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Immunodeficiency Virus ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Human immunodeficiency virus (HIV)-positive persons are predisposed to pulmonary infections, even after receiving effective highly active antiretroviral therapy. The reasons for this are unclear but may involve changes in innate immune function. HIV type 1 infection of macrophages impairs effector functions, including cytokine production. We observed decreased constitutive tumor necrosis factor alpha (TNF-α) concentrations and increased soluble tumor necrosis factor receptor type II (sTNFRII) in bronchoalveolar lavage fluid samples from HIV-positive subjects compared to healthy controls. Moreover, net proinflammatory TNF-α activity, as measured by the TNF-α/sTNFRII ratio, decreased as HIV-related disease progressed, as manifested by decreasing CD4 cell count and increasing HIV RNA (viral load). Since TNF-α is an important component of the innate immune system and is produced upon activation of Toll-like receptor (TLR) pathways, we hypothesized that the mechanism associated with deficient TNF-α production in the lung involved altered TLR expression or a deficit in the TLR signaling cascade. We found decreased Toll-like receptor 1 (TLR1) and TLR4 surface expression in HIV-infected U1 monocytic cells compared to the uninfected parental U937 cell line and decreased TLR message in alveolar macrophages (AMs) from HIV-positive subjects. In addition, stimulation with TLR1/2 ligand (Pam3Cys) or TLR4 ligand (lipopolysaccharide) resulted in decreased intracellular phosphorylated extracellular signal-regulated kinase and subsequent decreased transcription and expression of TNF-α in U1 cells compared to U937 cells. AMs from HIV-positive subjects also showed decreased TNF-α production in response to these TLR2 and TLR4 ligands. We postulate that HIV infection alters expression of TLRs with subsequent changes in mitogen-activated protein kinase signaling and cytokine production that ultimately leads to deficiencies of innate immune responses that predispose HIV-positive subjects to infection.

scholarly journals Pannexin-1 Channels as Mediators of Neuroinflammation

2021 ◽  
Vol 22 (10) ◽  
pp. 5189
Author(s):  
Joon Ho Seo ◽  
Miloni S. Dalal ◽  
Jorge E. Contreras
Keyword(s):  
Immune Cells ◽  
Neurological Diseases ◽  
Atp Release ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Damage Site ◽  
Pannexin 1 ◽  
Cytokines And Chemokines ◽  
Secondary Damage ◽  
Dying Cells

Neuroinflammation is a major component of central nervous system (CNS) injuries and neurological diseases, including Alzheimer’s disease, multiple sclerosis, neuropathic pain, and brain trauma. The activation of innate immune cells at the damage site causes the release of pro-inflammatory cytokines and chemokines, which alter the functionality of nearby tissues and might mediate the recruitment of leukocytes to the injury site. If this process persists or is exacerbated, it prevents the adequate resolution of the inflammation, and ultimately enhances secondary damage. Adenosine 5′ triphosphate (ATP) is among the molecules released that trigger an inflammatory response, and it serves as a chemotactic and endogenous danger signal. Extracellular ATP activates multiple purinergic receptors (P2X and P2Y) that have been shown to promote neuroinflammation in a variety of CNS diseases. Recent studies have shown that Pannexin-1 (Panx1) channels are the principal conduits of ATP release from dying cells and innate immune cells in the brain. Herein, we review the emerging evidence that directly implicates Panx-1 channels in the neuroinflammatory response in the CNS.

Specific IgE and IgG antibody responses in children to timothy pollen components during immunotherapy

Allergy ◽  
1989 ◽  
Vol 44 (6) ◽  
pp. 380-384 ◽  
Author(s):  
S. L. NORDVALL ◽  
B. RENCK ◽  
R. EINARSSON
Keyword(s):  
Specific Ige ◽  
Antibody Responses ◽  
Igg Antibody

scholarly journals Relation of Endothelial Dysfunction and Adipokines Levels to Insulin Resistance in Metabolic Syndrome Patients

2009 ◽  
Vol 63 (4-5) ◽  
pp. 222-227
Author(s):  
Pēteris Tretjakovs ◽  
Antra Jurka ◽  
Inga Bormane ◽  
Indra Miķelsone ◽  
Dace Reihmane ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Metabolic Syndrome ◽  
Endothelial Dysfunction ◽  
Doppler Imaging ◽  
Necrosis Factor Alpha ◽  
Monocyte Chemoattractant Protein 1 ◽  
Cytokines And Chemokines ◽  
Tnf Α ◽  
Artery Disease ◽  
D 20

Relation of Endothelial Dysfunction and Adipokines Levels to Insulin Resistance in Metabolic Syndrome Patients Obese metabolic syndrome (MS) patients were categorised into three groups: 44 with type 2 diabetes mellitus (T2DM)(D); 20 with T2DM and coronary artery disease (CAD) (DC), and 26 with MS alone (M). Eighteen healthy subjects were selected as controls (C). Insulin resistance (IR) was assessed by HOMA-IR. Adiponectin, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and interleukin-8 (IL-8) concentrations were measured by xMAP technology. Endothelin-1 (ET-1) was determined by ELISA. We used laser Doppler imaging for evaluating cutaneous endothelium-dependent vasodilatation in the hand. D and DC groups had significantly elevated IR compared with M or C group (P < 0.01). TNF-α, IL-6, IL-8, MCP-1 and ET-1 levels in DC were significantly elevated compared with other groups (P < 0.001). IL-6, IL-8, MCP-1 and ET-1 in D group were higher than those in C group (P < 0.05). TNF-α, IL-6, IL-8, MCP-1 and ET-1 concentrations were correlated with HOMA-IR indexes and adiponectin levels. All patients had lower adiponectin concentrations than controls (P < 0.001), but there were no differences between the patient groups. Only D and DC groups demonstrated a significant and similar decrease in LDI-Ach marker compared to C group (P < 0.001). LDI-Ach values were significantly correlated with HOMA-IR indexes and adiponectin levels (P < 0.001). Our findings show that obese MS patients have significantly increased HOMA-IR, TNF-α, IL-6, MCP-1 and IL-8 levels, decreased adiponectin concentration, and endothelial dysfunction, but the presence of T2DM and CAD in these patients is associated with more pronounced endothelial dysfunction and increased production of inflammatory cytokines and chemokines.

scholarly journals High-Affinity Interaction between Gram-Negative Flagellin and a Cell Surface Polypeptide Results in Human Monocyte Activation

2000 ◽  
Vol 68 (10) ◽  
pp. 5525-5529 ◽  
Author(s):  
Patrick F. McDermott ◽  
Federica Ciacci-Woolwine ◽  
James A. Snipes ◽  
Steven B. Mizel
Keyword(s):  
Cell Surface ◽  
Mutational Analysis ◽  
Hypervariable Region ◽  
Gram Negative Bacteria ◽  
Human Monocytes ◽  
Necrosis Factor Alpha ◽  
Potent Inducer ◽  
Gram Negative ◽  
High Affinity ◽  
Tnf Α

ABSTRACT Flagella from diverse gram-negative bacteria induce tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β) synthesis by human monocytes (F. Ciacci-Woolwine, P. F. McDermott, and S. B. Mizel, Infect. Immun. 67:5176–5185, 1999). In this study, we establish that purified flagellin (FliC or FljB), the major filament protein from Salmonella enterica serovar Enteritidis,S. enterica serovar Typhimurium, and Pseudomonas aeruginosa, is an extremely potent inducer of TNF-α production by human monocytes and THP-1 myelomonocytic cells. Fifty percent of maximal TNF-α production (EC50) was obtained with 1.5 × 10−11 M flagellin (0.75 ng/ml). Mutagenesis studies revealed that the central hypervariable region of flagellin is essential for the TNF-α-inducing activity of the protein. Although less active than the wild-type protein, a Salmonellaflagellin mutant composed of only the central hypervariable region retained substantial TNF-α-inducing activity at nanomolar concentrations. In contrast, the conserved amino- and carboxy-terminal regions are inactive. Mutational analysis of the hypervariable region revealed that it contains two equally active TNF-α-inducing domains. The ability of THP-1 cells to respond to purified flagellins is dramatically reduced by mild trypsin treatment of the cells. Taken together, our results demonstrate that the cytokine-inducing activity of flagellins from gram-negative bacteria results from the interaction of these proteins with high-affinity cell surface polypeptide receptors on monocytes.

Modulation by dexamethasone of phospholipase A2 activities in endotoxemic guinea pigs

1995 ◽  
Vol 79 (4) ◽  
pp. 1271-1277 ◽  
Author(s):  
C. M. De Castro ◽  
M. F. Bureau ◽  
M. A. Nahori ◽  
C. H. Dumarey ◽  
B. B. Vargaftig ◽  
...  
Keyword(s):  
Bronchoalveolar Lavage ◽  
Phospholipase A2 ◽  
Alveolar Macrophages ◽  
Guinea Pigs ◽  
Ex Vivo ◽  
Neutrophil Infiltration ◽  
Tnf Alpha ◽  
Necrosis Factor Alpha ◽  
Intracellular Enzyme ◽  
Lps Challenge

One hour after lipopolysaccharide (LPS) administration (intravenous) in guinea pigs, alveolar macrophages are primed for an ex vivo increased secretion of arachidonic acid metabolites from the cyclooxygenase and the lipoxygenase pathways, with challenge by a second stimulus. At the same time, maximal levels of tumor necrosis factor-alpha (TNF-alpha) are observed in the circulation and in the bronchoalveolar lavage fluid. An extracellular form of phospholipase A2, corresponding probably to the low-molecular-mass type II enzyme, known to accumulate in inflammatory exudates, appears later in the serum of guinea pigs, to reach maximal levels 6 h after the LPS. Unlike the intracellular enzyme, extracellular phospholipase A2 is not increased by LPS in alveolar macrophages or in bronchoalveolar lavage fluids. After 24 h, at the time when neither TNF-alpha nor extracellular phospholipase A2 is present and priming of macrophages is over, maximal neutrophil infiltration is observed in the alveolar space of LPS-treated guinea pigs. Dexamethasone administered repeatedly during 3 days (subcutaneous) before the LPS challenge prevented both early events such as the macrophage priming and the TNF-alpha appearance and later events such as extracellular phospholipase A2 release and neutrophil recruitment.

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