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 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 Mesenchymal Stem Cells Attenuate Acute Lung Injury in Mice Partly by Suppressing Alveolar Macrophage Activation in a PGE2-dependent Manner

2021 ◽  
Author(s):  
Gaojian Wang ◽  
Yaping Zhang ◽  
Nianqiang Hu ◽  
Qinxue Liu ◽  
Fengjie Ma ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Macrophage Activation ◽  
Rna Seq ◽  
Ep4 Receptor ◽  
Pge2 Receptor ◽  
Cox2 Inhibitor

Abstract Background: Mesenchymal stem cell have shown therapeutic effect on acute lung injury, MSC could be activated when added to inflammatory environment and in turn suppress inflammation, yet the mechanism is complex and not understood. Methods: To determine the effect of MSC on ALI and alveolar macrophage activation, MSCs were administered to ALI mice and co-cultured with activated MH-S cells (alveolar macrophage cell line). To find the genes critical for MSC’s immunosuppressive effects, rest and activated MSCs induced by inflammatory MH-S cells were harvested for RNA-seq. To prove that PGE2 participates in the immunosuppressive effects of MSC, COX2 inhibitor and PGE2 receptor antagonist were added to the co-culture system and administrated to ALI mice. Results: The intratracheal administration of MSCs attenuated ALI and suppressed alveolar macrophages activation in vivo, the activation of MH-S cells was also significantly reduced after co-culturing with MSCs in vitro. The RNA-seq data of rest and activated MSCs suggested that the Ptgs2 gene may play an important role in MSC exerting immunosuppressive effects. Correspondingly, we found that the COX2 protein and PGE2 released by activated MSCs were increased dramatically after co-culturing with MH-S. The use of COX2 inhibitor NS-398 restrained the secretion of PGE2 and reversed the suppressive effect on macrophages activation of MSCs in vitro. Furthermore, GW627368X, a selective antagonist of PGE2 receptor (EP4 receptor), also reversed the inhibitory effects of MSCs on alveolar macrophages and their protective effects on ALI mice.Conclusions: MSC attenuate ALI partly through suppressing alveolar macrophage activation via PGE2 binding to EP4 receptor.

scholarly journals Alveolar Macrophage–mediated Killing of Pneumocystis carinii f. sp. muris Involves Molecular Recognition by the Dectin-1 β-Glucan Receptor

2003 ◽  
Vol 198 (11) ◽  
pp. 1677-1688 ◽  
Author(s):  
Chad Steele ◽  
Luis Marrero ◽  
Steve Swain ◽  
Allen G. Harmsen ◽  
Mingquan Zheng ◽  
...  
Keyword(s):  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Pneumocystis Carinii ◽  
Innate Immune ◽  
Chain Reaction ◽  
Raw 264.7 Macrophages ◽  
Inflammatory Protein ◽  
Polymerase Chain ◽  
High Concentrations ◽  
Macrophage Inflammatory Protein

Innate immune mechanisms against Pneumocystis carinii, a frequent cause of pneumonia in immunocompromised individuals, are not well understood. Using both real time polymerase chain reaction as a measure of organism viability and fluorescent deconvolution microscopy, we show that nonopsonic phagocytosis of P. carinii by alveolar macrophages is mediated by the Dectin-1 β-glucan receptor and that the subsequent generation of hydrogen peroxide is involved in alveolar macrophage–mediated killing of P. carinii. The macrophage Dectin-1 β-glucan receptor colocalized with the P. carinii cyst wall. However, blockage of Dectin-1 with high concentrations of anti–Dectin-1 antibody inhibited binding and concomitant killing of P. carinii by alveolar macrophages. Furthermore, RAW 264.7 macrophages overexpressing Dectin-1 bound P. carinii at a higher level than control RAW cells. In the presence of Dectin-1 blockage, killing of opsonized P. carinii could be restored through FcγRII/III receptors. Opsonized P. carinii could also be efficiently killed in the presence of FcγRII/III receptor blockage through Dectin-1–mediated phagocytosis. We further show that Dectin-1 is required for P. carinii–induced macrophage inflammatory protein 2 production by alveolar macrophages. Taken together, these results show that nonopsonic phagocytosis and subsequent killing of P. carinii by alveolar macrophages is dependent upon recognition by the Dectin-1 β-glucan receptor.

Alveolar macrophages contribute to alveolar barrier dysfunction in ventilator-induced lung injury

2006 ◽  
Vol 291 (6) ◽  
pp. L1191-L1198 ◽  
Author(s):  
James A. Frank ◽  
Charlie M. Wray ◽  
Danny F. McAuley ◽  
Reto Schwendener ◽  
Michael A. Matthay
Keyword(s):  
Mechanical Ventilation ◽  
Epithelial Cell ◽  
Lung Injury ◽  
Tidal Volume ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Macrophage Activation ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial ◽  
Ventilator Induced Lung Injury

In patients requiring mechanical ventilation for acute lung injury or acute respiratory distress syndrome (ARDS), tidal volume reduction decreases mortality, but the mechanisms of the protective effect have not been fully explored. To test the hypothesis that alveolar macrophage activation is an early and critical event in the initiation of ventilator-induced lung injury (VILI), rats were ventilated with high tidal volume (HVT) for 10 min to 4 h. Alveolar macrophage counts in bronchoalveolar lavage (BAL) fluid decreased 45% by 20 min of HVT( P < 0.05) consistent with activation-associated adhesion. Depletion of alveolar macrophages in vivo with liposomal clodronate significantly decreased permeability and pulmonary edema following 4 h of HVT( P < 0.05). BAL fluid from rats exposed to 20 min of HVTincreased nitric oxide synthase activity nearly threefold in naïve primary alveolar macrophages ( P < 0.05) indicating that soluble factors present in the air spaces contribute to macrophage activation in VILI. Media from cocultures of alveolar epithelial cell monolayers and alveolar macrophages exposed to 30 min of stretch in vitro also significantly increased nitrite production in naïve macrophages ( P < 0.05), but media from stretched alveolar epithelial cells or primary alveolar macrophages alone did not, suggesting alveolar epithelial cell-macrophage interaction was required for the subsequent macrophage activation observed. These data demonstrate that injurious mechanical ventilation rapidly activates alveolar macrophages and that alveolar macrophages play an important role in the initial pathogenesis of VILI.

scholarly journals Correlation of Organism Burden and Alveolar Macrophage Counts during Infection with Pneumocystis carinii and Recovery

2003 ◽  
Vol 10 (2) ◽  
pp. 293-302 ◽  
Author(s):  
Mark E. Lasbury ◽  
Pamela J. Durant ◽  
Marilyn S. Bartlett ◽  
James W. Smith ◽  
Chao-Hung Lee
Keyword(s):  
Animal Model ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Pneumocystis Carinii ◽  
Pneumocystis Pneumonia ◽  
Rapid Decrease ◽  
Immune State ◽  
Phosphate Buffered Saline ◽  
Time Point

ABSTRACT Changes in the number of alveolar macrophages were correlated with organism burden during Pneumocystis carinii infection. The lungs of healthy, dexamethasone-treated, and dexamethasone-treated and P. carinii-infected rats were lavaged with phosphate-buffered saline. Counting of alveolar macrophages in the lavage fluids revealed that P. carinii infection caused a 58% decrease in the number of alveolar macrophages and that higher P. carinii organism burdens caused a more rapid decrease in alveolar macrophage number. As a control, healthy rats were challenged with the same number of organisms as that normally used to generate P. carinii infections in dexamethasone-treated rats. Thirteen days after challenge, these rats had a profound (54%) increase in alveolar macrophage number in response to the challenge, while the number of alveolar macrophages in immunosuppressed and P. carinii-infected rats had decreased significantly by this time point. These experiments created the first animal model to mimic human pneumocystis pneumonia in alveolar macrophage number alterations. Reduction of P. carinii organism numbers by treatment of rats with trimethoprim and sulfamethoxazole brought a slow rebound in alveolar macrophage number, while recovery from P. carinii infection by cessation of immunosuppression brought a rapid rebound in alveolar macrophage number. These results suggest that both the immune state of the host and P. carinii burden affect alveolar macrophage number.

Adherence and morphology of guinea pig alveolar macrophages: effect of N-formyl methionyl peptides

1980 ◽  
Vol 29 (3) ◽  
pp. 1185-1189
Author(s):  
M D Rossman ◽  
A M Cassizzi ◽  
R P Daniele
Keyword(s):  
Guinea Pig ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Macrophage Activation ◽  
Morphological Changes

N-Formyl methionyl phenylalanine increased alveolar macrophage adherence and diameter and induced morphological changes associated with activation. N-Formyl methionyl phenylalanine may be useful in understanding macrophage activation and bacteriolytic function.

Effects of methylene blue, indigo carmine solution and autologous erythrocyte suspension on formation of adhesions after injection into rats

Reproduction ◽  
2000 ◽  
pp. 225-229 ◽  
Author(s):  
A Gul ◽  
C Kotan ◽  
I Dilek ◽  
T Gul ◽  
A Tas ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Macrophage Activation ◽  
Indigo Carmine ◽  
Adhesion Formation ◽  
Albino Rats ◽  
Erythrocyte Suspension ◽  
Peritoneal Adhesions ◽  
Tubal Patency ◽  
Macrophage Activity ◽  
Group Score

The aim of this study was to determine whether autologous erythrocyte suspension can be used as a dye for evaluation of tubal patency and whether it has any advantages over methylene blue or indigo carmine solutions. Reproductively healthy female nulliparous Wistar Albino rats (n = 30), aged 6 months, mass 165-195 g, were assigned randomly to three groups. Rats received a 1 ml i.p. injection of 5% (w/v) methylene blue solution (methylene blue group: n = 10), 5% (w/v) indigo carmine solution (indigo carmine group: n = 10) or 5% (v/v) fresh autologous erythrocyte suspension (autologous erythrocyte group: n = 10). At 4 weeks after injection, a small sterile opening was made in the peritoneal cavity of each rat. The cavity was rinsed once with TCM-199 to collect macrophages. The rinsed peritoneal contents were cultured overnight to evaluate macrophage activation. The peritoneal opening was expanded for evaluation of adhesion formation. Only one rat from the autologous erythrocyte group had intra-peritoneal adhesions (score 2), whereas all rats in the methylene blue group (score 1: n = 1; score 2: n = 4; score 3: n = 4; and score 4: n = 1) and seven rats in the indigo carmine group (score 1: n = 1; score 2: n = 2; score 3: n = 3; and score 4: n = 1) had intra-abdominal adhesions. Macrophage activity was observed in the cultured peritoneal contents collected from the methylene blue and indigo carmine groups but not from the autologous erythrocyte group. Adhesion formation could be due to macrophage activation caused by methylene blue and indigo carmine solutions. These results indicate that tubal patency can be observed by laparoscopy using autologous erythrocyte suspension. The results of this study are believed to be the first to indicate that a patient's own erythrocyte suspension could be used during observation of tubal patency by laparoscopy. However, further studies are required.

HIV Impairs Alveolar Macrophage Mannose Receptor Function Against Pneumocystis carinii

CHEST Journal ◽  
1993 ◽  
Vol 103 (2) ◽  
pp. 111S-112S ◽  
Author(s):  
Henry Koziel ◽  
B.A. Kruskal ◽  
R.A.B Ezekowitz ◽  
R.M Rose
Keyword(s):  
Alveolar Macrophage ◽  
Pneumocystis Carinii ◽  
Mannose Receptor ◽  
Receptor Function ◽  
Macrophage Mannose Receptor

scholarly journals A novel procedure for the rapid isolation of surfactant protein A with retention of its alveolar-macrophage-stimulating properties

1995 ◽  
Vol 309 (2) ◽  
pp. 551-555 ◽  
Author(s):  
J F van Iwaarden ◽  
F Teding van Berkhout ◽  
J A Whitsett ◽  
R S Oosting ◽  
L M G van Golde
Keyword(s):  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Protein A ◽  
Surfactant Protein ◽  
Surfactant Protein A ◽  
Normal Rat ◽  
Normal Human ◽  
Novel Method ◽  
Alveolar Proteinosis ◽  
Simplex Virus

Previous studies have shown that surfactant protein A (SP-A) derived from alveolar-proteinosis patients activates rat alveolar macrophages. However, it is not known if normal rat, dog and human SP-A can also stimulate alveolar macrophages. As alveolar-proteinosis SP-A has a slightly different structure from ordinary SP-A, it would be possible that the ascribed alveolar-macrophage-stimulating properties of SP-A are restricted to alveolar-proteinosis SP-A. To clarify this issue, we isolated SP-A from normal rat and dog pulmonary surfactants, using the same isolation technique commonly used for the isolation of alveolar-proteinosis SP-A, i.e. by butanol precipitation. In contrast with human alveolar-proteinosis SP-A, rat and dog SP-A obtained thus could not activate rat alveolar macrophages to produce oxygen radicals or enhance the phagocytosis of fluorescein isothiocyanate-labelled herpes simplex virus. However, rat, dog and normal human SP-A isolated by a novel method, involving extraction from pulmonary surfactant by using n-octyl beta-D-glucopyranoside and subsequent purification by cation-exchange chromatography, were able to elicit an oxidative burst in rat as well as normal human alveolar macrophages. In addition, dog and rat SP-A obtained thus stimulated the phagocytosis of herpes simplex virus by rat alveolar macrophages. These findings indicate that normal human, rat and dog SP-A have the same alveolar-macrophage-stimulating properties as human alveolar proteinosis SP-A. Dog and rat SP-A isolated by this novel method had the same Ca(2+)-dependent self-aggregation and lipid-aggregation properties as SP-A isolated by butanol precipitation. The new and milder isolation procedure yielded SP-A of high purity, as judged by SDS/PAGE and ELISA.

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