scholarly journals Sequential Plasmodium chabaudi and Plasmodium berghei Infections Provide a Novel Model of Severe Malarial Anemia

2012 ◽  
Vol 80 (9) ◽  
pp. 2997-3007 ◽  
Author(s):  
Juliana V. Harris ◽  
Tiffany M. Bohr ◽  
Catherine Stracener ◽  
Mary E. Landmesser ◽  
Vladimir Torres ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Interleukin 10 ◽  
Red Cells ◽  
Second Phase ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Severe Malarial Anemia ◽  
Antibody Levels ◽  
Malarial Anemia

ABSTRACTLack of an adequate animal model ofPlasmodium falciparumsevere malarial anemia (SMA) has hampered the understanding of this highly lethal condition. We developed a model of SMA by infecting C57BL/6 mice withP. chabaudifollowed after recovery byP. bergheiinfection.P. chabaudi/P. berghei-infected mice had an initial 9- to 10-day phase of relatively low parasitemia and severe anemia, followed by a second phase of hyperparasitemia, more profound anemia, reticulocytosis, and death 14 to 21 days after infection.P. chabaudi/P. berghei-infected animals had more intense splenic hematopoiesis, higher interleukin-10 (IL-10)/tumor necrosis factor alpha and IL-12/gamma interferon (IFN-γ) ratios, and higher antibody levels againstP. bergheiandP. chabaudiantigens thanP. berghei-infected orP. chabaudi-recovered animals. Early treatment with chloroquine or artesunate did not prevent the anemia, suggesting that the bulk of red cell destruction was not due to the parasite. Red cells fromP. chabaudi/P. berghei-infected animals had increased surface IgG and C3 by flow cytometry. However, C3−/−mice still developed anemia. Tracking of red cells labeledex vivoandin vivoand analysis of frozen tissue sections by immunofluorescence microscopy showed that red cells fromP. chabaudi/P. berghei-infected animals were removed at an accelerated rate in the liver by erythrophagocytosis. This model is practical and reproducible, and its similarities withP. falciparumSMA in humans makes it an appealing system with which to study the pathogenesis of this condition and explore potential immunomodulatory interventions.

scholarly journals Cellular Microbiology of Mycoplasma canis

2016 ◽  
Vol 84 (6) ◽  
pp. 1785-1795 ◽  
Author(s):  
Dina L. Michaels ◽  
Jeffrey A. Leibowitz ◽  
Mohammed T. Azaiza ◽  
Pollob K. Shil ◽  
Suzanne M. Shama ◽  
...  
Keyword(s):  
Antigen Expression ◽  
Interleukin 10 ◽  
Factor H ◽  
Basic Knowledge ◽  
Complement Factor ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Dh82 Cells

Mycoplasma caniscan infect many mammalian hosts but is best known as a commensal or opportunistic pathogen of dogs. The unexpected presence ofM. canisin brains of dogs with idiopathic meningoencephalitis prompted newin vitrostudies to help fill the void of basic knowledge about the organism's candidate virulence factors, the host responses that it elicits, and its potential roles in pathogenesis. Secretion of reactive oxygen species and sialidase varied quantitatively (P< 0.01) among strains ofM. canisisolated from canine brain tissue or mucosal surfaces. All strains colonized the surface of canine MDCK epithelial and DH82 histiocyte cells and murine C8-D1A astrocytes. Transit through MDCK and DH82 cells was demonstrated by gentamicin protection assays and three-dimensional immunofluorescence imaging. Strains further varied (P< 0.01) in the extents to which they influenced the secretion of tumor necrosis factor alpha (TNF-α) and the neuroendocrine regulatory peptide endothelin-1 by DH82 cells. Inoculation withM. canisalso decreased major histocompatibility complex class II (MHC-II) antigen expression by DH82 cells (P< 0.01), while secretion of gamma interferon (IFN-γ), interleukin-6 (IL-6), interleukin-10 (IL-10), and complement factor H was unaffected. The basis for differences in the responses elicited by these strains was not obvious in their genome sequences. No acute cytopathic effects on any homogeneous cell line, or consistent patterns ofM. canispolyvalent antigen distribution in canine meningoencephalitis case brain tissues, were apparent. Thus, while it is not likely a primary neuropathogen,M. canishas the capacity to influence meningoencephalitis through complex interactions within the multicellular and neurochemicalin vivomilieu.

scholarly journals Acquisition of Hemozoin by Monocytes Down-Regulates Interleukin-12 p40 (IL-12p40) Transcripts and Circulating IL-12p70 through an IL-10-Dependent Mechanism: In Vivo and In Vitro Findings in Severe Malarial Anemia

2006 ◽  
Vol 74 (9) ◽  
pp. 5249-5260 ◽  
Author(s):  
Christopher C. Keller ◽  
Ouma Yamo ◽  
Collins Ouma ◽  
John Michael Ong'echa ◽  
David Ounah ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Mononuclear Cells ◽  
Interleukin 12 ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Severe Malarial Anemia ◽  
Tnf Α ◽  
Malarial Anemia

ABSTRACT Severe malarial anemia (SMA) is a primary cause of morbidity and mortality in immune-naïve infants and young children residing in areas of holoendemic Plasmodium falciparum transmission. Although the immunopathogenesis of SMA is largely undefined, we have previously shown that systemic interleukin-12 (IL-12) production is suppressed during childhood blood-stage malaria. Since IL-10 and tumor necrosis factor alpha (TNF-α) are known to decrease IL-12 synthesis in a number of infectious diseases, altered transcriptional regulation of these inflammatory mediators was investigated as a potential mechanism for IL-12 down-regulation. Ingestion of naturally acquired malarial pigment (hemozoin [PfHz]) by monocytes promoted the overproduction of IL-10 and TNF-α relative to the production of IL-12, which correlated with an enhanced severity of malarial anemia. Experiments with cultured peripheral blood mononuclear cells (PBMC) and CD14+ cells from malaria-naïve donors revealed that physiological concentrations of PfHz suppressed IL-12 and augmented IL-10 and TNF-α by altering the transcriptional kinetics of IL-12p40, IL-10, and TNF-α, respectively. IL-10 neutralizing antibodies, but not TNF-α antibodies, restored PfHz-induced suppression of IL-12. Blockade of IL-10 and the addition of recombinant IL-10 to cultured PBMC from children with SMA confirmed that IL-10 was responsible for malaria-induced suppression of IL-12. Taken together, these results demonstrate that PfHz-induced up-regulation of IL-10 is responsible for the suppression of IL-12 during malaria.

scholarly journals Cytokine Profiles in Malawian Children Presenting with Uncomplicated Malaria, Severe Malarial Anemia, and Cerebral Malaria

2017 ◽  
Vol 24 (4) ◽  
Author(s):  
Wilson L. Mandala ◽  
Chisomo L. Msefula ◽  
Esther N. Gondwe ◽  
Mark T. Drayson ◽  
Malcolm E. Molyneux ◽  
...  
Keyword(s):  
Cerebral Malaria ◽  
Proinflammatory Cytokines ◽  
Uncomplicated Malaria ◽  
Acute Infection ◽  
Healthy Controls ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Severe Malarial Anemia ◽  
Tnf Α ◽  
Malarial Anemia

ABSTRACT Proinflammatory cytokines are involved in clearance of Plasmodium falciparum, and very high levels of these cytokines have been implicated in the pathogenesis of severe malaria. In order to determine how cytokines vary with disease severity and syndrome, we enrolled Malawian children presenting with cerebral malaria (CM), severe malarial anemia (SMA), and uncomplicated malaria (UCM) and healthy controls. We analyzed serum cytokine concentrations in acute infection and in convalescence. With the exception of interleukin 5 (IL-5), cytokine concentrations were highest in acute CM, followed by SMA, and were only mildly elevated in UCM. Cytokine concentrations had fallen to control levels when remeasured at 1 month of convalescence in all three clinical malaria groups. Ratios of IL-10 to tumor necrosis factor alpha (TNF-α) and of IL-10 to IL-6 followed a similar pattern. Children presenting with acute CM had significantly higher concentrations of TNF-α (P < 0.001), interferon gamma (IFN-γ) (P = 0.0019), IL-2 (P = 0.0004), IL-6 (P < 0.001), IL-8 (P < 0.001), and IL-10 (P < 0.001) in sera than healthy controls. Patients with acute CM had significantly higher concentrations of IL-6 (P < 0.001) and IL-10 (P = 0.0003) than those presenting with acute SMA. Our findings are consistent with the concept that high levels of proinflammatory cytokines, despite high levels of the anti-inflammatory cytokine IL-10, could contribute to the pathogenesis of CM.

scholarly journals Host-Pathogen Interaction and Signaling Molecule Secretion Are Modified in thedpp3Knockout Mutant of Candida lusitaniae

2013 ◽  
Vol 82 (1) ◽  
pp. 413-422 ◽  
Author(s):  
Ayman Sabra ◽  
Jean-Jacques Bessoule ◽  
Vessela Atanasova-Penichon ◽  
Thierry Noël ◽  
Karine Dementhon
Keyword(s):  
Interleukin 10 ◽  
Gene Inactivation ◽  
Physical Contact ◽  
Knockout Mutant ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Tnf Α ◽  
Candida Lusitaniae

ABSTRACTCandida lusitaniaeis an emerging opportunistic yeast and an attractive model to discover new virulence factors inCandidaspecies by reverse genetics. Our goal was to create adpp3Δ knockout mutant and to characterize the effects of this gene inactivation on yeastin vitroandin vivointeraction with the host. The secretion of two signaling molecules inCandidaspecies, phenethyl alcohol (PEA) and tyrosol, but not of farnesol was surprisingly altered in thedpp3Δ knockout mutant. NO and reactive oxygen species (ROS) production as well as tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10) secretion were also modified in macrophages infected with this mutant. Interestingly, we found that the wild-type (WT) strain induced an increase in IL-10 secretion by zymosan-activated macrophages without the need for physical contact, whereas thedpp3Δ knockout mutant lost this ability. We further showed a striking role of PEA and tyrosol in this modulation. Last, theDPP3gene was found to be an essential contributor to virulence in mice models, leading to an increase in TNF-α secretion and brain colonization. Although reinsertion of a WTDPP3copy in thedpp3Δ knockout mutant was not sufficient to restore the WT phenotypesin vitro, it allowed a restoration of those observedin vivo. These data support the hypothesis that some of the phenotypes observed followingDPP3gene inactivation may be directly dependent onDPP3, while others may be the indirect consequence of another genetic modification that systematically arises when theDPP3gene is inactivated.

scholarly journals Distinct Effects of Integrins αXβ2 and αMβ2 on Leukocyte Subpopulations during Inflammation and Antimicrobial Responses

2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Samir Jawhara ◽  
Elzbieta Pluskota ◽  
Wei Cao ◽  
Edward F. Plow ◽  
Dmitry A. Soloviev
Keyword(s):  
Fungal Pathogens ◽  
Opportunistic Infections ◽  
Ex Vivo ◽  
Polymorphonuclear Neutrophils ◽  
Primary Role ◽  
Immune Functions ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Anti Inflammatory

ABSTRACTIntegrins αMβ2and αXβ2are homologous adhesive receptors that are expressed on many of the same leukocyte populations and bind many of the same ligands. Although αMβ2was extensively characterized and implicated in leukocyte inflammatory and immune functions, the roles of αXβ2remain largely obscure. Here, we tested the ability of mice deficient in integrin αMβ2or αXβ2to deal with opportunistic infections and the capacity of cells derived from these animals to execute inflammatory functions. The absence of αMβ2affected the recruitment of polymorphonuclear neutrophils (PMN) to bacterial and fungal pathogens as well as to model inflammatory stimuli, and αMβ2-deficient PMN displayed defective inflammatory functions. In contrast, deficiency of αXβ2abrogated intraperitoneal recruitment and adhesive functions of monocytes and macrophages (Mϕ) and the ability of these cells to kill/phagocytoseCandida albicansorEscherichia colicells bothex vivoandin vivo. During systemic candidiasis, the absence of αXβ2resulted in the loss of antifungal activity by tissue Mϕ and inhibited the production of tumor necrosis factor alpha (TNF-α)/interleukin-6 (IL-6) in infected kidneys. Deficiency of αMβ2suppressed Mϕ egress from the peritoneal cavity, decreased the production of anti-inflammatory IL-10, and stimulated the secretion of IL-6. The absence of αXβ2, but not of αMβ2, increased survival against a septic challenge with lipopolysaccharide (LPS) by 2-fold. Together, these results suggest that αMβ2plays a primary role in PMN inflammatory functions and regulates the anti-inflammatory functions of Mϕ, whereas αXβ2is central in the regulation of inflammatory functions of recruited and tissue-resident Mϕ.

scholarly journals Alveolar Macrophage Deactivation in Murine Septic Peritonitis: Role of Interleukin 10

2001 ◽  
Vol 69 (3) ◽  
pp. 1394-1401 ◽  
Author(s):  
Raju C. Reddy ◽  
Gina H. Chen ◽  
Michael W. Newstead ◽  
Tom Moore ◽  
Xianying Zeng ◽  
...  
Keyword(s):  
Proinflammatory Cytokines ◽  
Phagocytic Activity ◽  
Cell Function ◽  
Ex Vivo ◽  
Cecal Ligation ◽  
Interleukin 10 ◽  
Sepsis Syndrome ◽  
Sham Operation ◽  
Necrosis Factor Alpha

ABSTRACT Sepsis predisposes the host to a number of infectious sequelae, particularly the development of nosocomial pneumonia. Mechanisms by which sepsis results in impairment of lung antibacterial host defense have not been well defined. Alveolar macrophages (AM) represent important immune effector cells of the lung airspace. In this study, we examined the effects of cecal ligation and puncture (CLP) on murine AM function ex vivo, including the expression of proinflammatory cytokines and AM phagocytic activity. AM were harvested from mice subjected to a sham operation and CLP 24 h after laparotomy, adherence purified, and challenged with lipopolysaccharide (LPS) or left unstimulated. Both unstimulated and LPS-stimulated AM from mice subjected to CLP (CLP mice) produced significantly smaller amounts of proinflammatory cytokines tumor necrosis factor alpha and interleukin (IL-12) and C-X-C chemokines KC and macrophage inflammatory protein 2 than similarly treated AM from animals subjected to a sham operation. Furthermore, AM isolated from CLP mice displayed a marked impairment in phagocytic activity, as determined by flow cytometry, with this defect persisting to 48 h post-CLP. Induction of peritoneal sepsis syndrome resulted in a time-dependent increase in IL-10 in plasma and peritoneal fluid. Interestingly, the impairment in AM proinflammatory-cytokine production and phagocytic activity observed in AM from CLP mice was partially reversed by the in vivo neutralization of IL-10 prior to AM harvest. These observations suggest that abdominal sepsis syndrome results in significant impairment in AM effector cell function, which is mediated, in part, by sepsis-induced expression of IL-10.

scholarly journals Ex VivoMaturation Assay for Testing Antimalarial Sensitivity of Rodent Malaria Parasites

2016 ◽  
Vol 60 (11) ◽  
pp. 6859-6866 ◽  
Author(s):  
Zi Wei Chang ◽  
Benoit Malleret ◽  
Bruce Russell ◽  
Laurent Rénia ◽  
Carla Claser
Keyword(s):  
Ex Vivo ◽  
Single Step ◽  
Parasite Development ◽  
Ring Stage ◽  
Malaria Parasites ◽  
Rodent Malaria ◽  
Content Type ◽  
Parasite Biology

ABSTRACTEx vivoassay systems provide a powerful approach to studying human malaria parasite biology and to testing antimalarials. For rodent malaria parasites, short-termin vitroculture andex vivoantimalarial susceptibility assays are relatively cumbersome, relying onin vivopassage for synchronization, since ring-stage parasites are an essential starting material. Here, we describe a new approach based on the enrichment of ring-stagePlasmodium berghei,P. yoelii, andP. vinckei vinckeiusing a single-step Percoll gradient. Importantly, we demonstrate that the enriched ring-stage parasites develop synchronously regardless of the parasite strain or species used. Using a flow cytometry assay with Hoechst and ethidium or MitoTracker dye, we show that parasite development is easily and rapidly monitored. Finally, we demonstrate that this approach can be used to screen antimalarial drugs.

scholarly journals Changes in the Molecular and Functional Phenotype of Bovine Monocytes during Theileria parva Infection

2019 ◽  
Vol 87 (12) ◽  
Author(s):  
Reginaldo G. Bastos ◽  
Kelly Sears ◽  
Kelcey D. Dinkel ◽  
Donald P. Knowles ◽  
Lindsay M. Fry
Keyword(s):  
Ex Vivo ◽  
Interleukin 1 ◽  
T Cell Response ◽  
Sub Saharan Africa ◽  
Cytotoxic T Cell ◽  
Theileria Parva ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Lethal Infection ◽  
Infected Cells

ABSTRACT Theileria parva is the causative agent of East Coast fever (ECF), a tick-borne disease that kills over a million cattle each year in sub-Saharan Africa. Immune protection against T. parva involves a CD8+ cytotoxic T cell response to parasite-infected cells. However, there is currently a paucity of knowledge regarding the role played by innate immune cells in ECF pathogenesis and T. parva control. Here, we demonstrate an increase in intermediate monocytes (CD14++ CD16+) with a concomitant decrease in the classical (CD14++ CD16−) and nonclassical (CD14+ CD16+) subsets at 12 days postinfection (dpi) during lethal infection but not during nonlethal T. parva infection. Ex vivo analyses of monocytes demonstrated upregulation of interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) mRNA and increased nitric oxide production during T. parva lethal infection compared to nonlethal infection at 10 dpi. Interestingly, no significant differences in peripheral blood parasite loads were observed between lethally and nonlethally infected animals at 12 dpi. In vitro stimulation with T. parva schizont-infected cells or Escherichia coli lipopolysaccharide (LPS) resulted in significant upregulation of IL-1β production by monocytes from lethally infected cattle compared to those from nonlethally infected animals. Strikingly, monocytes from lethally infected animals produced significant amounts of IL-10 mRNA after stimulation with T. parva schizont-infected cells. In conclusion, we demonstrate that T. parva infection leads to alterations in the molecular and functional phenotypes of bovine monocytes. Importantly, since these changes primarily occur in lethal infection, they can serve as biomarkers for ECF progression and severity, thereby aiding in the standardization of protection assessment for T. parva candidate vaccines.

scholarly journals Enhancement of Methacholine-Evoked Tracheal Contraction Induced by Bacterial Lipopolysaccharides Depends on Epithelium and Tumor Necrosis Factor

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
T. Secher ◽  
F. Rodrigues Coelho ◽  
N. Noulin ◽  
A. Lino dos Santos Franco ◽  
V. Quesniaux ◽  
...  
Keyword(s):  
Contractile Response ◽  
Ex Vivo ◽  
Adaptor Protein ◽  
Respiratory Pattern ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Bacterial Lipopolysaccharides ◽  
Necrosis Factor

Inhaled bacterial lipopolysaccharides (LPSs) induce an acute tumour necrosis factor-alpha (TNF-α-) dependent inflammatory response in the murine airways mediated by Toll-like receptor 4 (TLR4) via the myeloid differentiation MyD88 adaptor protein pathway. However, the contractile response of the bronchial smooth muscle and the role of endogenous TNFα in this process have been elusive. We determined the in vivo respiratory pattern of C57BL/6 mice after intranasal LPS administration with or without the presence of increasing doses of methacholine (MCh). We found that LPS administration altered the basal and MCh-evoked respiratory pattern that peaked at 90 min and decreased thereafter in the next 48 h, reaching basal levels 7 days later. We investigated in controlled ex vivo condition the isometric contraction of isolated tracheal rings in response to MCh cholinergic stimulation. We observed that preincubation of the tracheal rings with LPS for 90 min enhanced the subsequent MCh-induced contractile response (hyperreactivity), which was prevented by prior neutralization of TNFα with a specific antibody. Furthermore, hyperreactivity induced by LPS depended on an intact epithelium, whereas hyperreactivity induced by TNFα was well maintained in the absence of epithelium. Finally, the enhanced contractile response to MCh induced by LPS when compared with control mice was not observed in tracheal rings from TLR4- or TNF- or TNF-receptor-deficient mice. We conclude that bacterial endotoxin-mediated hyperreactivity of isolated tracheal rings to MCh depends upon TLR4 integrity that signals the activation of epithelium, which release endogenous TNFα.

scholarly journals Eyedrop Inoculation Causes Sublethal Leptospirosis in Mice

2017 ◽  
Vol 85 (4) ◽  
Author(s):  
Joseph Pierce Sullivan ◽  
Nisha Nair ◽  
Hari-Hara Potula ◽  
Maria Gomes-Solecki
Keyword(s):  
Periodic Acid ◽  
Interleukin 10 ◽  
Periodic Acid Schiff ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Infectious Dose ◽  
Inflammatory Protein ◽  
Mucosal Surfaces ◽  
Infected Urine ◽  
Mononuclear Cell Infiltrates

ABSTRACT Leptospirosis is potentially a fatal zoonosis acquired by contact of skin and mucosal surfaces with soil and water contaminated with infected urine. We analyzed the outcome of infection of C3H/HeJ mice with Leptospira interrogans serovar Copenhageni using an enzootic mode of transmission, the conjunctival route. Infection led to weight loss and L. interrogans dissemination from blood to urine, and spirochetes were detected in blood and urine simultaneously. The infectious dose that led to consistent dissemination to kidney after conjunctival infection was ∼108 leptospires. Interestingly, a lower number of spirochetes appeared to colonize the kidney, given that we quantified ∼105 and ∼10 leptospires per μl of urine and per μg of kidney, respectively. Leptospira-specific IgM and IgG were detected at 15 days postinfection, and isotyping of the Ig subclass showed that the total IgG response switched from an IgG1 response to an IgG3 response after infection with L. interrogans. Histological periodic acid-Schiff D staining of infected kidney showed interstitial nephritis, mononuclear cell infiltrates, and reduced size of glomeruli. Quantification of proinflammatory immunomediators in kidney showed that keratinocyte-derived chemokine, macrophage inflammatory protein 2, RANTES, tumor necrosis factor alpha, gamma interferon, and interleukin-10 were upregulated in infected mice. We show that the kinetics of disease progression after infection via the ocular conjunctiva is delayed compared with infection via the standard intraperitoneal route. Differences may be related to the number of L. interrogans spirochetes that succeed in overcoming the natural defenses of the ocular conjunctiva and transit through tissue.

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