scholarly journals Efficacy of Lysophosphatidylcholine in Combination with Antimicrobial Agents against Acinetobacter baumannii in Experimental Murine Peritoneal Sepsis and Pneumonia Models

2016 ◽  
Vol 60 (8) ◽  
pp. 4464-4470 ◽  
Author(s):  
R. Parra Millán ◽  
M. E. Jiménez Mejías ◽  
V. Sánchez Encinales ◽  
R. Ayerbe Algaba ◽  
A. Gutiérrez Valencia ◽  
...  

ABSTRACTImmune response stimulation to prevent infection progression may be an adjuvant to antimicrobial treatment. Lysophosphatidylcholine (LPC) is an immunomodulator involved in immune cell recruitment and activation. In this study, we aimed to evaluate the efficacy of LPC in combination with colistin, tigecycline, or imipenem in experimental murine models of peritoneal sepsis and pneumonia. We usedAcinetobacter baumanniistrain Ab9, which is susceptible to colistin, tigecycline, and imipenem, and multidrug-resistant strain Ab186, which is susceptible to colistin and resistant to tigecycline and imipenem. Pharmacokinetic and pharmacodynamic parameters for colistin, tigecycline, and imipenem and the 100% minimal lethal dose (MLD100) were determined for both strains. The therapeutic efficacies of LPC, colistin (60 mg/kg of body weight/day), tigecycline (10 mg/kg/day), and imipenem (180 mg/kg/day), alone or in combination, were assessed against Ab9 and Ab186 at the MLD100in murine peritoneal sepsis and pneumonia models. The levels of pro- and anti-inflammatory cytokines, i.e., tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10), were determined by enzyme-linked immunosorbent assay (ELISA) for the same experimental models after inoculating mice with the MLD of both strains. LPC in combination with colistin, tigecycline, or imipenem markedly enhanced the bacterial clearance of Ab9 and Ab186 from the spleen and lungs and reduced bacteremia and mouse mortality rates (P< 0.05) compared with those for colistin, tigecycline, and imipenem monotherapies. Moreover, at 4 h post-bacterial infection, Ab9 induced higher TNF-α and lower IL-10 levels than those with Ab186 (4 μg/ml versus 3 μg/ml [P< 0.05] and 2 μg/ml versus 3.4 μg/ml [P< 0.05], respectively). LPC treatment combined with colistin, tigecycline, or imipenem modestly reduced the severity of infection byA. baumanniistrains with different resistance phenotypes compared to LPC monotherapy in both experimental models.

2015 ◽  
Vol 59 (7) ◽  
pp. 3920-3924 ◽  
Author(s):  
Younes Smani ◽  
Juan Domínguez-Herrera ◽  
José Ibáñez-Martínez ◽  
Jerónimo Pachón

ABSTRACTDue to the significant increase in antimicrobial resistance ofAcinetobacter baumannii, immune system stimulation to block infection progression may be a therapeutic adjuvant to antimicrobial treatment. Lysophosphatidylcholine (LPC), a major component of phospholipids in eukaryotic cells, is involved in immune cell recruitment and modulation. The aim of this study was to show if LPC could be useful for treating infections caused byA. baumannii. A. baumanniiATCC 17978 was used in this study. Levels of serum LPC and levels of the inflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-1β, and IL-10 were determined by spectrophotometric assay and enzyme-linked immunosorbent assay (ELISA), respectively, using a murine peritoneal sepsis model in which mice were inoculated with 5.3 log CFU/ml ofA. baumannii. The therapeutic efficacy of LPC againstA. baumanniiin murine peritoneal sepsis and pneumonia models was assessed for 48 h after bacterial infection. At early time points in the murine model of peritoneal sepsis caused byA. baumannii, LPC was depleted and was associated with an increase of inflammatory cytokine release. Preemptive therapy with LPC in murine peritoneal sepsis and pneumonia models markedly enhanced spleen and lung bacterial clearance and reduced the numbers of positive blood cultures and the mouse mortality rates. Moreover, treatment with LPC reduced proinflammatory cytokine production. These data demonstrate that LPC is efficacious as a preemptive treatment in experimental models of peritoneal sepsis and pneumonia caused byA. baumannii.


2013 ◽  
Vol 82 (1) ◽  
pp. 62-71 ◽  
Author(s):  
Musa Mulongo ◽  
Tracy Prysliak ◽  
Erin Scruten ◽  
Scott Napper ◽  
Jose Perez-Casal

ABSTRACTMycoplasma bovisis one of the major causative pathogens of bovine respiratory complex disease (BRD), which is characterized by enzootic pneumonia, mastitis, pleuritis, and polyarthritis.M. bovisenters and colonizes bovine respiratory epithelial cells through inhalation of aerosol from contaminated air. The nature of the interaction betweenM. bovisand the bovine innate immune system is not well understood. We hypothesized thatM. bovisinvades blood monocytes and regulates cellular function to support its persistence and systemic dissemination. We used bovine-specific peptide kinome arrays to identify cellular signaling pathways that could be relevant toM. bovis-monocyte interactionsin vitro. We validated these pathways using functional, protein, and gene expression assays. Here, we show that infection of bovine blood monocytes withM. bovisdelays spontaneous or tumor necrosis factor alpha (TNF-α)/staurosporine-driven apoptosis, activates the NF-κB p65 subunit, and inhibits caspase-9 activity. We also report thatM. bovis-infected bovine monocytes do not produce gamma interferon (IFN-γ) and TNF-α, although the level of production of interleukin-10 (IL-10) is elevated. Our findings suggest thatM. bovistakes over the cellular machinery of bovine monocytes to prolong bacterial survival and to possibly facilitate subsequent systemic distribution.


2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Deepak Kumar Deep ◽  
Ruchi Singh ◽  
Arpita Kulshrestha ◽  
Saima Wajid ◽  
Poonam Salotra

ABSTRACT The oral drug miltefosine (MIL) was introduced in the Indian subcontinent in the year 2002 for the treatment of visceral leishmaniasis (VL). However, recent reports on its declining efficacy and increasing relapse rates pose a serious concern. An understanding of the factors contributing to MIL tolerance in Leishmania parasites is critical. In the present study, we assessed the role of the lipase precursor-like protein (Lip) in conferring tolerance to miltefosine by episomally overexpressing Lip in Leishmania donovani (LdLip++). We observed a significant increase (∼3-fold) in the MIL 50% inhibitory concentration (IC50) at both the promastigote (3.90 ± 0.68 µM; P < 0.05) and intracellular amastigote (9.10 ± 0.60 µM; P < 0.05) stages compared to the wild-type counterpart (LdNeo) (MIL IC50s of 1.49 ± 0.20 µM at the promastigote stage and 3.95 ± 0.45 µM at the amastigote stage). LdLip++ parasites exhibited significantly (P < 0.05) increased infectivity to host macrophages and increased metacyclogenesis and tolerance to MIL-induced oxidative stress. The susceptibility of LdLip++ to other antileishmanial drugs (sodium antimony gluconate and amphotericin B) remained unchanged. In comparison to LdNeo, the LdLip++ parasites elicited high host interleukin-10 (IL-10) cytokine expression levels (1.6-fold; P < 0.05) with reduced expression of the cytokine tumor necrosis factor alpha (TNF-α) (1.5-fold; P < 0.05), leading to a significantly (P < 0.01) increased ratio of IL-10/TNF-α. The above-described findings suggest a role of lipase precursor-like protein in conferring tolerance to the oral antileishmanial drug MIL in L. donovani parasites.


2012 ◽  
Vol 80 (6) ◽  
pp. 2231-2239 ◽  
Author(s):  
Mariángeles Noto Llana ◽  
Sebastián Hernán Sarnacki ◽  
María Victoria Vázquez ◽  
Alejandra Sonia Gartner ◽  
Mónica Nancy Giacomodonato ◽  
...  

ABSTRACTIn developing countries, one-third of reactive arthritis (ReA) cases are associated withSalmonellaenterocolitis; nevertheless, there is no animal model for studying this pathology. Here we induced a self-limitingSalmonella entericaserovar Enteritidis enterocolitis in mice to analyze the onset of ReA. BALB/c mice received orally 20 μg of streptomycin 24 h before intragastric inoculation of a low dose (3 × 103to 4 × 103CFU) ofS. Enteritidis. In response toSalmonellainfection, a 30-fold increase in the expression of interleukin-17 (IL-17), measured by quantitative PCR, was observed in mesenteric lymph nodes 5 days postinfection. At this time synovitis was already evident, and concomitantly, a significant increase in joint tumor necrosis factor alpha (TNF-α) was detected by enzyme-linked immunosorbent assay (ELISA). The early development of joint lesions was accompanied by an increased expression of IL-17 in inguinal and popliteal lymph nodes. Infection with 107CFU of an isogenic ΔinvGmutant bearing a defective type III secretion system ofSalmonellaencoded in the pathogenicity island 1 apparatus (TTSS-1) induced enterocolitis histologically similar to that triggered by the wild-type strain. Interestingly, despite the higher infective dose used, the mutant did not trigger intestinal IL-17. Moreover, no synovitis was observed in mice suffering ΔinvGenterocolitis. Neutralization of IL-17 in mice infected withS. Enteritidis prevented both synovitis and the increment of TNF-α in the joints, suggesting that IL-17 participates in the generation ofSalmonella-induced ReA through the induction of TNF-α in the joints.


2013 ◽  
Vol 82 (1) ◽  
pp. 413-422 ◽  
Author(s):  
Ayman Sabra ◽  
Jean-Jacques Bessoule ◽  
Vessela Atanasova-Penichon ◽  
Thierry Noël ◽  
Karine Dementhon

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.


2016 ◽  
Vol 85 (1) ◽  
Author(s):  
Barbara Misme-Aucouturier ◽  
Marjorie Albassier ◽  
Nidia Alvarez-Rueda ◽  
Patrice Le Pape

ABSTRACT A delayed type of multicellular process could be crucial during chronic candidiasis in determining the course of infection. This reaction, consisting of organized immune cells surrounding the pathogen, initiates an inflammatory response to avoid fungal dissemination. The goal of the present study was to examine, at an in vitro cellular scale, Candida and human immune cell interaction dynamics during a long-term period. By challenging human peripheral blood immune cells from 10 healthy donors with 32 Candida albicans and non-albicans (C. glabrata, C. tropicalis, C. parapsilosis, C. dubliniensis, C. lusitaniae, C. krusei, and C. kefyr) clinical isolates, we showed that Candida spp. induced the formation of granuloma-like structures within 6 days after challenge, but their sizes and the respective fungal burdens differed according to the Candida species. These two parameters are positively correlated. Phenotypic characteristics, such as hypha formation and higher axenic growth rate, seem to contribute to yeast persistence within granuloma-like structures. We showed an interindividual variability of the human response against Candida spp. Higher proportions of neutrophils and elevated CD4+/CD8+ T cell ratios during the first days after challenge were correlated with early production of gamma interferon (IFN-γ) and associated with controlled infection. In contrast, the persistence of Candida could result from upregulation of proinflammatory cytokines such as interleukin-6 (IL-6), IFN-γ, and tumor necrosis factor alpha (TNF-α) and a poor anti-inflammatory negative feedback (IL-10). Importantly, regulatory subsets of NK cells and CD4lo CD8hi doubly positive (DP) lymphocytes at late stage infiltrate granuloma-like structures and could correlate with the IL-10 and TNF-α production. These data offer a base frame to explain cellular events that guide infection control or fungal persistence.


2012 ◽  
Vol 81 (3) ◽  
pp. 684-689 ◽  
Author(s):  
Jennifer H. Moffatt ◽  
Marina Harper ◽  
Ashley Mansell ◽  
Bethany Crane ◽  
Timothy C. Fitzsimons ◽  
...  

ABSTRACTInfections caused by multidrug-resistantAcinetobacter baumanniihave emerged as a serious global health problem. We have shown previously thatA. baumanniican become resistant to the last-line antibiotic colistin via the loss of lipopolysaccharide (LPS), including the lipid A anchor, from the outer membrane (J. H. Moffatt, M. Harper, P. Harrison, J. D. Hale, E. Vinogradov, T. Seemann, R. Henry, B. Crane, F. St. Michael, A. D. Cox, B. Adler, R. L. Nation, J. Li, and J. D. Boyce, Antimicrob. Agents Chemother.54:4971–4977, 2010). Here, we show how these LPS-deficient bacteria interact with components of the host innate immune system. LPS-deficientA. baumanniistimulated 2- to 4-fold lower levels of NF-κB activation and tumor necrosis factor alpha (TNF-α) secretion from immortalized murine macrophages, but it still elicited low levels of TNF-α secretion via a Toll-like receptor 2-dependent mechanism. Furthermore, we show that while LPS-deficientA. baumanniiwas not altered in its resistance to human serum, it showed increased susceptibility to the human antimicrobial peptide LL-37. Thus, LPS-deficient, colistin-resistantA. baumanniishows significantly altered activation of the host innate immune inflammatory response.


2011 ◽  
Vol 79 (12) ◽  
pp. 4876-4892 ◽  
Author(s):  
Aarti Gautam ◽  
Saurabh Dixit ◽  
Mario T. Philipp ◽  
Shree R. Singh ◽  
Lisa A. Morici ◽  
...  

ABSTRACTInterleukin-10 (IL-10) modulates inflammatory responses elicitedin vitroandin vivobyBorrelia burgdorferi, the Lyme disease spirochete. How IL-10 modulates these inflammatory responses still remains elusive. We hypothesize that IL-10 inhibits effector functions of multiple genes induced byB. burgdorferiin macrophages to control concomitantly elicited inflammation. Because macrophages are essential in the initiation of inflammation, we used mouse J774 macrophages and liveB. burgdorferispirochetes as the model target cell and stimulant, respectively. First, we employed transcriptome profiling to identify genes that were induced by stimulation of cells with live spirochetes and that were perturbed by addition of IL-10 to spirochete cultures. Spirochetes significantly induced upregulation of 347 genes at both the 4-h and 24-h time points. IL-10 inhibited the expression levels, respectively, of 53 and 65 of the 4-h and 24-h genes, and potentiated, respectively, at 4 h and 24 h, 65 and 50 genes. Prominent among the novel identified IL-10-inhibited genes also validated by quantitative real-time PCR (qRT-PCR) were Toll-like receptor 1 (TLR1), TLR2, IRAK3, TRAF1, IRG1, PTGS2, MMP9, IFI44, IFIT1, and CD40. Proteome analysis using a multiplex enzyme-linked immunosorbent assay (ELISA) revealed the IL-10 modulation/and or potentiation of RANTES/CCL5, macrophage inflammatory protein 2 (MIP-2)/CXCL2, IP-10/CXCL10, MIP-1α/CCL3, granulocyte colony-stimulating factor (G-CSF)/CSF3, CXCL1, CXCL5, CCL2, CCL4, IL-6, tumor necrosis factor alpha (TNF-α), IL-1α, IL-1β, gamma interferon (IFN-γ), and IL-9. Similar results were obtained using sonicated spirochetes or lipoprotein as stimulants. Our data show that IL-10 alters effectors induced byB. burgdorferiin macrophages to control concomitantly elicited inflammatory responses. Moreover, for the first time, this study provides global insight into potential mechanisms used by IL-10 to control Lyme disease inflammation.


2015 ◽  
Vol 59 (12) ◽  
pp. 7367-7373 ◽  
Author(s):  
P. Tsirigotis ◽  
N. Papanikolaou ◽  
A. Elefanti ◽  
P. Konstantinou ◽  
K. Gkirkas ◽  
...  

ABSTRACTJanus kinases (JAK) are intracellular tyrosine kinases that transduce cytokine-mediated signals to the nucleus, promoting gene expression. Cytokines play a major role in microbial sepsis, which is often associated with uncontrolled inflammation leading to death. JAK inhibitors have been used for the treatment of several autoimmune diseases by modulating immune response, but they have never been tested against microbial sepsis. Ruxolitinib is a small-molecule inhibitor of JAK1/2 proteins, which are involved in the downstream signaling pathway of the vast majority of proinflammatory and anti-inflammatory cytokines. We therefore studied the effect of ruxolitinib in a mouse model of sepsis due toCandida albicans. When ruxolitinib therapy (50 mg/kg [of body weight]/day) was started 1 day before infection, the median survival time was reduced by 3 days, the fungal loads in all organs were higher, the inflammation was significantly less, and serum tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10) levels and IL-10/TNF-α ratios were higher than in controls. When ruxolitinib therapy (50 to 1.5 mg/kg/day) was started 1 day after infection, an inverted-U relationship was found, with 6.25 mg/kg/day prolonging median survival time by 6 days, resulting in similar fungal loads, less inflammation, and similar cytokine levels but higher IL-10/TNF-α ratios than the controls. The optimal dose of ruxolitinib controlled infection and prolonged survival with less inflammation than in control animals. Administration of JAK inhibitors may be a promising therapeutic adjunct that needs further investigation.


2014 ◽  
Vol 82 (9) ◽  
pp. 3775-3782 ◽  
Author(s):  
Lyticia A. Ochola ◽  
Cyrus Ayieko ◽  
Lily Kisia ◽  
Ng'wena G. Magak ◽  
Estela Shabani ◽  
...  

ABSTRACTIndividuals naturally exposed toPlasmodium falciparumlose clinical immunity after a prolonged lack of exposure.P. falciparumantigen-specific cytokine responses have been associated with protection from clinical malaria, but the longevity ofP. falciparumantigen-specific cytokine responses in the absence of exposure is not well characterized. A highland area of Kenya with low and unstable malaria transmission provided an opportunity to study this question. The levels of antigen-specific cytokines and chemokines associated in previous studies with protection from clinical malaria (gamma interferon [IFN-γ], interleukin-10 [IL-10], and tumor necrosis factor alpha [TNF-α]), with increased risk of clinical malaria (IL-6), or with pathogenesis of severe disease in malaria (IL-5 and RANTES) were assessed by cytometric bead assay in April 2008, October 2008, and April 2009 in 100 children and adults. During the 1-year study period, none had an episode of clinicalP. falciparummalaria. Two patterns of cytokine responses emerged, with some variation by antigen: a decrease at 6 months (IFN-γ and IL-5) or at both 6 and 12 months (IL-10 and TNF-α) or no change over time (IL-6 and RANTES). These findings document thatP. falciparumantigen-specific cytokine responses associated in prior studies with protection from malaria (IFN-γ, TNF-α, and IL-10) decrease significantly in the absence ofP. falciparumexposure, whereas those associated with increased risk of malaria (IL-6) do not. The study findings provide a strong rationale for future studies of antigen-specific IFN-γ, TNF-α, and IL-10 responses as biomarkers of increased population-level susceptibility to malaria after prolonged lack ofP. falciparumexposure.


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