scholarly journals Exogenous Heat-Killed Escherichia coli Improves Alveolar Macrophage Activity and Reduces Pneumocystis carinii Lung Burden in Infant Mice

2007 ◽  
Vol 75 (7) ◽  
pp. 3382-3393 ◽  
Author(s):  
Kerry M. Empey ◽  
Melissa Hollifield ◽  
Beth A. Garvy
Keyword(s):  
Escherichia Coli ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Cytokine Production ◽  
Pneumocystis Carinii ◽  
Effector Cells ◽  
Macrophage Activity ◽  
Adult Mice

ABSTRACT Pneumocystis carinii is an opportunistic fungal pathogen that causes life-threatening pneumonia in immunocompromised individuals. Infants appear to be particularly susceptible to Pneumocystis pulmonary infections. We have previously demonstrated that there is approximately a 3-week delay in the clearance of Pneumocystis organisms from pup mouse lungs compared to that in adults. We have further shown that there is approximately a 1-week delay in alveolar macrophage activation in pups versus adult mice. Alveolar macrophages are the primary effector cells responsible for the killing and clearance of Pneumocystis, suggesting that pup alveolar macrophages may be involved in the delayed clearance of this organism. Alveolar macrophages cultured in vitro with Pneumocystis alone demonstrate little to no activation, as indicated by a lack of cytokine production. However, when cultured with lipopolysaccharide (LPS) or zymosan, cytokine production was markedly increased, suggesting that pup alveolar macrophages are specifically unresponsive to Pneumocystis organisms rather than being intrinsically unable to become activated. Furthermore, pup mice treated with aerosolized, heat-killed Escherichia coli in vivo were able to clear Pneumocystis more efficiently than were control mice. Together, these data suggest that while pup alveolar macrophages are unresponsive to P. carinii f. sp. muris organisms, they are capable of activation by heat-killed E. coli in vivo, as well as LPS and zymosan in vitro. The lack of response of pup mice to P. carinii f. sp. muris may reflect protective mechanisms specific to the developing pup lung, but ultimately it results in insufficient clearance of Pneumocystis organisms.

scholarly journals Passive Immunization of Neonatal Mice against Pneumocystis carinii f. sp. muris Enhances Control of Infection without Stimulating Inflammation

2004 ◽  
Vol 72 (11) ◽  
pp. 6211-6220 ◽  
Author(s):  
Kerry M. Empey ◽  
Melissa Hollifield ◽  
Kevin Schuer ◽  
Francis Gigliotti ◽  
Beth A. Garvy
Keyword(s):  
Alveolar Macrophage ◽  
Specific Antibody ◽  
Alveolar Macrophages ◽  
Macrophage Activation ◽  
Pneumocystis Carinii ◽  
Passive Immunization ◽  
Activation Markers ◽  
Effector Cells ◽  
Macrophage Activity ◽  
Neonatal Mice

ABSTRACT Pneumocystis carinii is an opportunistic fungal pathogen that causes life-threatening pneumonia in immunocompromised individuals. Infants appear to be particularly susceptible to infection with Pneumocystis. We have previously shown that there is a significant delay in clearance of the organisms from the lungs of neonatal mice compared to adults. Since alveolar macrophages are the effector cells responsible for killing and clearance of Pneumocystis, we have examined alveolar macrophage activity in neonatal mice. We found that alveolar macrophage activation is delayed about 1 week in Pneumocystis-infected neonates compared to adults. Opsonization of the organism by Pneumocystis-specific antibody resulted in increased clearance of the organism in neonatal mice; however, there was decreased expression of activation markers on neonatal alveolar macrophages and reduced levels of cytokines associated with macrophage activation. Mice born to immunized dams had significant amounts of Pneumocystis-specific immunoglobulin G in their lungs and serum at day 7 postinfection, whereas mice born to naïve dams had merely detectable levels. This difference correlated with enhanced Pneumocystis clearance in mice born to immunized dams. The increase in specific antibody, however, did not result in significant inflammation in the lungs, as no differences in numbers of activated CD4+ cells were observed. Furthermore, there was no difference in cytokine or chemokine concentrations in the lungs of pups born to immune compared to naïve dams. These findings indicate that specific antibody plays an important role in Pneumocystis clearance from lungs of infected neonates; moreover, this process occurs without inducing inflammation in the lungs.

scholarly journals Wnt/β-catenin signaling regulates lipopolysaccharide-altered polarizations of RAW264.7 cells and alveolar macrophages in mouse lungs

2021 ◽  
Vol 19 ◽  
pp. 205873922110593
Author(s):  
Jiali Yang ◽  
Ying Wang ◽  
Dandan Yang ◽  
Jia Ma ◽  
Shuang Wu ◽  
...  
Keyword(s):  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Macrophage Polarization ◽  
Raw264.7 Cells ◽  
M1 Polarization ◽  
Inflammatory Phenotype ◽  
Inflammatory State ◽  
Anti Inflammatory

Introduction Macrophages are capable of exerting both proinflammatory and anti-inflammatory functions in response to distinct environmental stimuli, by polarizing into classically inflammatory state (M1) and anti-inflammatory phenotype (M2), respectively. The Wnt/β-catenin signaling plays an important role in the tissue homeostasis and immune regulations, including the macrophage polarizations. However, the molecular mechanism of Wnt/β-catenin signaling in regulating alveolar macrophage polarization in an inflammatory state remains unclear. Methods The Wnt/β-catenin signaling-altered phenotypes of murine macrophage-like RAW264.7 cells in vitro and alveolar macrophage in vivo in both of naïve and lipopolysaccharide-induced inflammation states were accessed by immunoblotting and immunostaining assays. Results The activation of Wnt/β-catenin signaling inhibited macrophage M1 polarization, but promoted alternative M2 polarization in murine RAW264.7 cells under a naïve state. Interestingly, in an LPS-induced inflammation condition, the enhanced Wnt/β-catenin activity suppressed both M1 and M2 polarizations in RAW264.7 cells in vitro, and primary alveolar macrophages of LPS-challenged mice in vivo. Molecular analysis further demonstrated an involvement of Stat signing in regulating Wnt/β-catenin signaling-altered polarizations in mouse alveolar macrophages. Conclusion These results suggest a mechanism by which Wnt/β-catenin signaling modulates macrophage polarization in an inflammation state by regulating the Stat signaling pathway.

scholarly journals In Vitro and In Vivo Bacteriolytic Activities of Escherichia coli Phages: Implications for Phage Therapy

2004 ◽  
Vol 48 (7) ◽  
pp. 2558-2569 ◽  
Author(s):  
Sandra Chibani-Chennoufi ◽  
Josette Sidoti ◽  
Anne Bruttin ◽  
Elizabeth Kutter ◽  
Shafiq Sarker ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Environmental Water ◽  
Gut Flora ◽  
E Coli ◽  
Adult Mice ◽  
Fecal Recovery ◽  
Gut Mucosa

ABSTRACT Four T4-like coliphages with broad host ranges for diarrhea-associated Escherichia coli serotypes were isolated from stool specimens from pediatric diarrhea patients and from environmental water samples. All four phages showed a highly efficient gastrointestinal passage in adult mice when added to drinking water. Viable phages were recovered from the feces in a dose-dependent way. The minimal oral dose for consistent fecal recovery was as low as 103 PFU of phage per ml of drinking water. In conventional mice, the orally applied phage remained restricted to the gut lumen, and as expected for a noninvasive phage, no histopathological changes of the gut mucosa were detected in the phage-exposed animals. E. coli strains recently introduced into the intestines of conventional mice and traced as ampicillin-resistant colonies were efficiently lysed in vivo by phage added to the drinking water. Likewise, an in vitro phage-susceptible E. coli strain freshly inoculated into axenic mice was lysed in vivo by an orally applied phage, while an in vitro-resistant E. coli strain was not lysed. In contrast, the normal E. coli gut flora of conventional mice was only minimally affected by oral phage application despite the fact that in vitro the majority of the murine intestinal E. coli colonies were susceptible to the given phage cocktail. Apparently, the resident E. coli gut flora is physically or physiologically protected against phage infection.

scholarly journals Scavenger Receptor A Dampens Induction of Inflammation in Response to the Fungal Pathogen Pneumocystis carinii

2007 ◽  
Vol 75 (8) ◽  
pp. 3999-4005 ◽  
Author(s):  
Melissa Hollifield ◽  
Elsa Bou Ghanem ◽  
Willem J. S. de Villiers ◽  
Beth A. Garvy
Keyword(s):  
Alveolar Macrophages ◽  
Pneumocystis Carinii ◽  
Scavenger Receptor ◽  
Interleukin 12 ◽  
Wild Type ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Scavenger Receptor A

ABSTRACT Alveolar macrophages are the effector cells largely responsible for clearance of Pneumocystis carinii from the lungs. Binding of organisms to β-glucan and mannose receptors has been shown to stimulate phagocytosis of the organisms. To further define the mechanisms used by alveolar macrophages for clearance of P. carinii, mice deficient in the expression of scavenger receptor A (SRA) were infected with P. carinii, and clearance of organisms was monitored over time. SRA-deficient (SRAKO) mice consistently cleared P. carinii faster than did wild-type control mice. Expedited clearance corresponded to elevated numbers of activated CD4+ T cells in the alveolar spaces of SRAKO mice compared to wild-type mice. Alveolar macrophages from SRAKO mice had increased expression of CD11b on their surfaces, consistent with an activated phenotype. However, they were not more phagocytic than macrophages expressing SRA, as measured by an in vivo phagocytosis assay. SRAKO alveolar macrophages produced significantly more tumor necrosis factor alpha (TNF-α) than wild-type macrophages when stimulated with lipopolysaccharide in vitro but less TNF-α in response to P. carinii in vitro. However, upon in vivo stimulation, SRAKO mice produced significantly more TNF-α, interleukin 12 (IL-12), and IL-18 in response to P. carinii infection than did wild-type mice. Together, these data indicate that SRA controls inflammatory cytokines produced by alveolar macrophages in the context of P. carinii infection.

Effect of recombinant Panton–Valentine leukocidin in vitro on apoptosis and cytokine production of human alveolar macrophages

2010 ◽  
Vol 56 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Benquan Wu ◽  
Wenxian Zhang ◽  
Jing Huang ◽  
Hui Liu ◽  
Tiantuo Zhang
Keyword(s):  
Alveolar Macrophages ◽  
Cytokine Production ◽  
Lavage Fluid ◽  
Effector Cells ◽  
Tnf Α ◽  
Human Alveolar Macrophages ◽  
The Impact ◽  
Panton Valentine Leukocidin ◽  
Valentine Leukocidin

Panton–Valentine leukocidin (PVL) is associated with rare cases of necrotizing pneumonia that occur in otherwise healthy individuals. Human alveolar macrophages (HAMs) are major effector cells in host defense against infections. However, the impact of PVL on HAMs is uncertain. We evaluated the role of PVL in cytotoxicity and production of inflammatory cytokines secreted by HAMs. HAMs were purified from bronchoalveolar lavage fluid. Recombinant PVL (rPVL) was used in the study to interfere with HAM apoptosis and cytokine production in vitro. Hoechst 33342 fluorescence staining, transmission electron microscopy examination, and flow cytometry indicated that rPVL (10 nmol/L) treatment resulted in HAMs with markedly apoptotic characteristics, and HAMs treated with rPVL at 100 nmol/L showed clear indication of necrosis. A treatment of rPVL at 10 nmol/L elicited the secretion of IL-10 by HAMs relative to untreated control cells, but there was a slight decrease in the constitutive secretion of tumor necrosis factor (TNF)-α. Our results indicate that PVL-treated samples decreased HAM viability, leading to apoptosis at low concentrations and necrosis at high concentrations. In addition, PVL-treated cells released increased amounts of IL-10 and decreased amounts of TNF-α under apoptosis-inducing concentrations. Therefore, we speculated that PVL could play a negative role in HAM function at lower concentrations.

scholarly journals Noncapsulated Klebsiella pneumoniae Bearing Mannose-Containing O Antigens Is Rapidly Eradicated from Mouse Lung and Triggers Cytokine Production by Macrophages following Opsonization with Surfactant Protein D

2005 ◽  
Vol 73 (12) ◽  
pp. 8282-8290 ◽  
Author(s):  
Elena Kostina ◽  
Itzhak Ofek ◽  
Erika Crouch ◽  
Rotem Friedman ◽  
Lea Sirota ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Alveolar Macrophages ◽  
Cytokine Production ◽  
Human Monocyte ◽  
Surfactant Protein ◽  
Mouse Lung ◽  
Surfactant Protein D ◽  
O Antigens

ABSTRACT To better understand the relationship between the surface polysaccharides of pulmonary pathogens and components of the lung innate immune system, we employed selected serotypes of Klebsiella pneumoniae expressing distinct capsular polysaccharides and/or O antigen in a murine model of K. pneumoniae infection. In addition, we examined the effect of surfactant protein D (SP-D) on the cytokine response of human monocyte-derived macrophages to these serotypes in vitro. Noncapsulated mannose-containing O3 serotypes (K50/n and K55/n), which react efficiently with SP-D in vitro, triggered high levels of interleukin-1β (IL-1β) and IL-6 production. In vivo, they were more efficiently cleared from the lungs of mice but not from macrophage-depleted mice. They also were more efficiently internalized by alveolar macrophages in vivo. In contrast, galactose-containing O1 serotypes (K2/n and K21a/n), which interact poorly with SP-D, exhibited significantly lower cytokine production and less efficient pulmonary clearance and were ineffectively internalized by alveolar macrophages. These findings are consistent with in vitro results showing that production of IL-1β and IL-6 mRNA and IL-6 protein by human macrophages exposed to mannose-bearing Klebsiella O serotypes is significantly increased by SP-D. Thus, survival of inhaled bacteria in the lung depends partially on the lipopolysaccharide structure of the bacteria and their interactions with innate immunity components. We speculate that an imbalance of host SP-D and therefore cytokine levels may result in high susceptibility of the host to the pathogen.

scholarly journals SYNERGISTIC IMMUNOMODULATORY ACTIVITY OF PROBIOTICS BIFIDOBACTERIUM ANIMALIS AND LACTOBACILLUS CASEI IN ENTEROAGGREGATIVE ESCHERICHIA COLI (EAEC)-INFECTED CACO-2 CELLS

2021 ◽  
Vol 58 (4) ◽  
pp. 433-438
Author(s):  
Andréa Fonseca FERREIRA ◽  
Ricardo Luís Lopes BRAGA ◽  
Maysa Ferreira ANDRADE ◽  
Ana Claudia de Paula ROSA ◽  
Wânia Ferraz PEREIRA-MANFRO
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Casei ◽  
Cytokine Production ◽  
In Vitro Models ◽  
Enzyme Linked Immunosorbent Assay ◽  
Immunomodulatory Activity ◽  
Bifidobacterium Animalis ◽  
Tnf Α

ABSTRACT BACKGROUND: Enteroaggregative Escherichia coli (EAEC) is an E. coli pathotype that presents aggregative adhesion patterns on in vitro cultivated cells, mainly related to persistent diarrhea cases in children. EAEC virulence factors are important for host colonization and pathogenicity. Intestinal epithelial cells (IECs) recognize pathogen-associated molecular patterns (PAMPs) and initiate an immune response. Several studies using in vivo and in vitro models emphasize the probiotic activity and immunomodulatory capacity of Lactobacillus and Bifidobacterium species. OBJECTIVE To evaluate the modulation of cytokine production by probiotics Bifidobacterium animalis and Lactobacillus casei in human intestinal Caco-2 cells exposed to different strains of EAEC. METHODS: Caco-2 cells were incubated with EAEC strains in the presence or absence of probiotics. The production of cytokines IL-8, TNF-α, IL-1β and IL-10 was evaluated in the supernatants by a sandwich enzyme-linked immunosorbent assay (ELISA). RESULTS: Cytokine production did not change when uninfected and EAEC-infected Caco-2 cells were exposed to probiotics separately. All EAEC induced a significant increase in IL-8 production by Caco-2 cells, but the probiotics, even together, could not reduce its production. On the other hand, the synergic activity of probiotic strains significantly increased TNF-α production but decreased the basal production of IL-1ß. Also, probiotics induced a significant increase in the production of the anti-inflammatory cytokine IL-10 during EAEC infection. CONCLUSION: Our results reinforce the synergistic immunomodulatory activity of probiotics during EAEC infection.

scholarly journals Aerosol 1,25-dihydroxyvitamin D3 supplementation: A strategy to boost anti-tumor innate immune activity

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248789
Author(s):  
Francesca Bianchi ◽  
Michele Sommariva ◽  
Valentino Le Noci ◽  
Simone Camelliti ◽  
Nicoletta Gagliano ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Alveolar Macrophages ◽  
Nk Cell ◽  
Lung Metastases ◽  
Local Immunity ◽  
Dihydroxyvitamin D3 ◽  
Effector Cells ◽  
1,25 Dihydroxyvitamin D3

Background 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] plays a role in calcium homeostasis but can also exert immunomodulatory effects. In lungs, characterized by a particular immunosuppressive environment primarily due to the presence of alveolar macrophages (AM), 1,25(OH)2D3 has been shown to favor the immune response against pathogens. Here, we explored the ability of aerosolized 1,25(OH)2D3 to locally promote an anti-tumor phenotype in alveolar macrophages (AM) in the treatment of lung metastases. Methods Cytotoxicity assay has been used to assess the capability of AM, in vitro treated of not with 1,25(OH)2D3, to stimulate NK cells. Sulforhodamine B (SRB) assay has been used to assess the effect of 1,25(OH)2D3 on MC-38 and B16 tumor cells in vitro growth. 1,25(OH)2D3 was aerosolized in immunocompetent mouse models to evaluate the effect of local administration of 1,25(OH)2D3 on in vivo growth of MC-38 and B16 tumor cells within lungs and on infiltrating immune cells. Results In vitro incubation of naïve AM with 1,25(OH)2D3 improved their ability to stimulate NK cell cytotoxicity. In vivo aerosolized 1,25(OH)2D3 significantly reduced the metastatic growth of MC-38 colon carcinoma, a tumor histotype that frequently metastasizes to lung in human. Immune infiltrate obtained from digested lungs of 1,25(OH)2D3-treated mice bearing MC-38 metastases revealed an increased expression of MHCII and CD80 on AM and an up-modulation of CD69 expression on effector cells that paralleled a strong increased ability of these cells to kill MC-38 tumor in vitro. Conclusions Together, these data show that aerosol delivery can represent a feasible and novel approach to supplement 1,25(OH)2D3 directly to the lungs promoting the activation of local immunity against cancer.

Безопасность соединений из группы терпенов ментанового ряда in vitro и in vivo

2020 ◽  
Vol 83 (4) ◽  
pp. 24-30
Author(s):  
Ирина Владимировна Акулина ◽  
Светлана Ивановна Павлова ◽  
Ирина Семеновна Степаненко ◽  
Назира Сунагатовна Карамова ◽  
Александр Владиславович Сергеев ◽  
...  
Keyword(s):  
Escherichia Coli

Проведено токсикологическое исследование соединений с антибактериальными свойствами из группы терпенов ментанового ряда в условиях in vitro и in vivo: лимонена (B34), его производного (+)-1,2-оксида лимонена (B60) и серосодержащего монотерпенового соединения 2-(1’-гидрокси-4’-изопренил-1’-метилциклогексил-2’-тио)метилэтаноата (B65). В условиях in vitro (культура опухолевых клеток HeLa) изучаемые монотерпены в диапазоне концентраций 2 – 200 мкг/мл обладали цитотоксичностью. Ингибирующая концентрация (ИК50) для B34 составила 231 (167 – 295) мкг/мл, для B60 – 181 (105 – 257) мкг/мл, ИК50 B65 – 229 (150 – 308) мкг/мл. Исследование генотоксичности показало, что B34 и B65 в диапазоне концентраций 50 – 1000 мкг/мл не индуцируют SOS мутагенез в клетках Escherichia coli PQ37, тогда как B60 в концентрациях 500 и 1000 мкг/мл проявляет генотоксичность. In vivo в остром эксперименте на беспородных мышах установлена низкая токсичность B34 и его производных при различных путях введения. Наименьший показатель острой токсичности имеет B65, в связи с чем дополнительно на крысах проведено изучение его хронической токсичности. Ежедневное внутрижелудочное введение B65 в разовых дозах, составляющих 1/10 и 1/20 ЛД50 (1000 мг/кг и 500 мг/кг), в течение 1 мес не вызывало гибели животных, значимых нарушений общего состояния, изменения динамики массы тела, морфопатологических изменений. Внутрижелудочное введение B65 крысам в высокой токсической дозе 2000 мг/кг (1/5 ЛД50) в течение месяца вызывает патоморфологические изменения структуры печени.

Sign in / Sign up

Export Citation Format

Share Document