Reduced CD1d Expression And Function In Alveolar Macrophages From Asymptomatic HIV+ Persons

Alveolar macrophages (AMs) are tissue resident cells in the lungs derived from the fetal liver that maintain lung homeostasis and respond to inhaled stimuli. While the importance of AMs is undisputed, they remain refractory to standard experimental approaches and high-throughput functional genetics as they are challenging to isolate and rapidly lose AM properties in standard culture. This limitation hinders our understanding of key regulatory mechanisms that control AM maintenance and function. Here, we describe the development of a new model, fetal liver-derived alveolar-like macrophages (FLAMs), which maintains cellular morphologies, expression profiles, and functional mechanisms similar to murine AMs. FLAMs combine treatment with two key cytokines for AM maintenance, GM-CSF and TGFβ. We leveraged the long-term stability of FLAMs to develop functional genetic tools using CRISPR-Cas9-mediated gene editing. Targeted editing confirmed the role of AM-specific gene Marco and the IL-1 receptor Il1r1 in modulating the AM response to crystalline silica. Furthermore, a genome-wide knockout library using FLAMs identified novel genes required for surface expression of the AM marker Siglec-F, most notably those related to the peroxisome. Taken together, our results suggest that FLAMs are a stable, self-replicating model of AM function that enables previously impossible global genetic approaches to define the underlying mechanisms of AM maintenance and function.

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NF-κB Modulates TNF-α Production by Alveolar Macrophages in Asymptomatic HIV-Seropositive Individuals

The Journal of Immunology ◽

10.4049/jimmunol.164.3.1588 ◽

2000 ◽

Vol 164 (3) ◽

pp. 1588-1594 ◽

Cited By ~ 7

Author(s):

Jean-Marie Mathys ◽

Suzanne M. Melanson ◽

Deborah J. Schiffer-Alberts ◽

John P. A. Ioannidis ◽

Henry Koziel ◽

...

Keyword(s):

Alveolar Macrophages ◽

Tnf Α ◽

Hiv Seropositive ◽

Asymptomatic Hiv

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Differential Regulation of TLR4-Mediated TNF-a Release by Mammalian Target of Rapamycin and Glycogen Synthase Kinase-3 in Alveolar Macrophages from Asymptomatic HIV+ Persons.

10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a2292 ◽

2009 ◽

Author(s):

SD Tachado ◽

X Li ◽

M Bole ◽

A Anandaiah ◽

NR Patel ◽

...

Keyword(s):

Alveolar Macrophages ◽

Glycogen Synthase ◽

Mammalian Target Of Rapamycin ◽

Differential Regulation ◽

Glycogen Synthase Kinase ◽

Target Of Rapamycin ◽

Glycogen Synthase Kinase 3 ◽

Asymptomatic Hiv

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Proinflammatory Responses of Heme in Alveolar Macrophages: Repercussion in Lung Hemorrhagic Episodes

Mediators of Inflammation ◽

10.1155/2013/946878 ◽

2013 ◽

Vol 2013 ◽

pp. 1-11 ◽

Cited By ~ 9

Author(s):

Rafael L. Simões ◽

Maria Augusta Arruda ◽

Cláudio Canetti ◽

Carlos H. Serezani ◽

Iolanda M. Fierro ◽

...

Keyword(s):

Inflammatory Response ◽

Alveolar Macrophages ◽

Nuclear Translocation ◽

Tissue Injury ◽

Proinflammatory Responses ◽

Proinflammatory Molecule ◽

Free Heme ◽

Inflammatory Processes ◽

Lung Hemorrhage ◽

And Function

Clinical and experimental observations have supported the notion that free heme released during hemorrhagic and hemolytic episodes may have a major role in lung inflammation. With alveolar macrophages (AM) being the main line of defense in lung environments, the influence of free heme on AM activity and function was investigated. We observed that heme in a concentration range found during hemolytic episodes (3–30 μM) elicits AM to present a proinflammatory profile, stimulating reactive oxygen species (ROS) and nitric oxide (NO) generation and inducing IL-1β, IL-6, and IL-10 secretion. ROS production is NADPH oxidase-dependent, being inhibited by DPI and apocynin, and involves p47 subunit phosphorylation. Furthermore, heme induces NF-κB nuclear translocation, iNOS, and also HO-1 expression. Moreover, AM stimulated with free heme show enhanced phagocytic and bactericidal activities. Taken together, the data support a dual role for heme in the inflammatory response associated with lung hemorrhage, acting as a proinflammatory molecule that can either act as both an adjuvant of the innate immunity and as an amplifier of the inflammatory response, leading tissue injury. The understanding of heme effects on pulmonary inflammatory processes can lead to the development of new strategies to ameliorate tissue damage associated with hemorrhagic episodes.

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Suppression Of MTOR Activation Prolongs ERK1/2 MAP Kinase Phosphorylation And Augments TLR4-mediated TNF-± Release In Alveolar Macrophages From Asymptomatic HIV+ Persons In Vitro

10.1164/ajrccm-conference.2010.181.1_meetingabstracts.a5221 ◽

2010 ◽

Author(s):

Souvenir D. Tachado ◽

Xin Li ◽

Medhavi Bole ◽

Asha M. Anandaiah ◽

Benjamin A. Nelson ◽

...

Keyword(s):

Map Kinase ◽

Alveolar Macrophages ◽

Kinase Phosphorylation ◽

Asymptomatic Hiv

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Stimulatory Effects of Peroxisome Proliferator-Activated Receptor-γon FcγReceptor-Mediated Phagocytosis by Alveolar Macrophages

PPAR Research ◽

10.1155/2007/52546 ◽

2007 ◽

Vol 2007 ◽

pp. 1-8 ◽

Cited By ~ 13

Author(s):

David M. Aronoff ◽

Carlos H. Serezani ◽

Jennifer K. Carstens ◽

Teresa Marshall ◽

Srinivasa R. Gangireddy ◽

...

Keyword(s):

Alveolar Macrophages ◽

Peritoneal Macrophages ◽

Receptor Expression ◽

Cell Surface Receptor ◽

Peroxisome Proliferator ◽

Quiescent State ◽

Peroxisome Proliferator Activated Receptor ◽

Downstream Signaling ◽

Surface Receptor ◽

And Function

Alveolar macrophages abundantly express PPAR-γ, with both natural and synthetic agonists maintaining the cell in a quiescent state hyporesponsive to antigen stimulation. Conversely, agonists upregulate expression and function of the cell-surface receptor CD36, which mediates phagocytosis of lipids, apoptotic neutrophils, and other unopsonized materials. These effects led us to investigate the actions of PPAR-γagonists on the Fcγreceptor, which mediates phagocytosis of particles opsonized by binding of immunoglobulin G antibodies. We found that troglitazone, rosiglitazone, and 15-deoxy-Δ12,14-prostaglandinJ2increase the ability of alveolar, but not peritoneal, macrophages to carry out phagocytosis mediated by the Fcγreceptor. Receptor expression was not altered but activation of the downstream signaling proteins Syk, ERK-1, and ERK-2 was observed. Although it was previously known that PPAR-γligands stimulate phagocytosis of unopsonized materials, this is the first demonstration that they stimulate phagocytosis of opsonized materials as well.

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