Expression and preliminary functional analysis of Siglec-F on mouse macrophages

Feng, Yinhe; Mao, Hui

doi:10.1631/jzus.b1100218

Cited by 40 publications

(27 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Even though Siglec-F is also expressed by alveolar macrophages, 21 attenuation of St3gal3 had no effect on their numbers, which is consistent with a lack of biological effect seen through Siglec-F targeting on these cells compared with eosinophils. 22 The selective lung eosinophilia was not associated with any detectable alteration in levels of a panel of potentially relevant BALF cytokines or chemokines (see Fig E3). One possible explanation is that Siglec-F regulation of lung eosinophilia is upstream of these proinflammatory cytokines in allergen-induced responses.…”

Section: Discussionmentioning

confidence: 88%

Mice deficient in the St3gal3 gene product α2,3 sialyltransferase (ST3Gal-III) exhibit enhanced allergic eosinophilic airway inflammation

Kiwamoto

Brummet

et al. 2014

Journal of Allergy and Clinical Immunology

View full text Add to dashboard Cite

Background Sialic acid–binding immunoglobulin-like lectin (Siglec)-F is a proapoptotic receptor on mouse eosinophils, but little is known about its natural tissue ligand. Objective We previously reported that the St3gal3 gene product α2,3 sialyltransferase (ST3Gal-III) is required for constitutive Siglec-F lung ligand synthesis. We therefore hypothesized that attenuation of ST3Gal-III will decrease Siglec-F ligand levels and enhance allergic eosinophilic airway inflammation. Methods C57BL/6 wild-type mice and St3gal3 heterozygous or homozygous deficient (St3gal3+/− and St3gal3−/−) mice were used. Eosinophilic airway inflammation was induced through sensitization to ovalbumin (OVA) and repeated airway OVA challenge. Siglec-F human IgG1 fusion protein (Siglec-F-Fc) was used to detect Siglec-F ligands. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for inflammation, as well as various cytokines and chemokines. Serum was analyzed for allergen-specific immunoglobulin levels. Results Western blotting with Siglec-F-Fc detected approximately 500-kDa and approximately 200-kDa candidate Siglec-F ligands that were less abundant in St3gal3+/− lung extracts and nearly absent in St3gal3−/− lung extracts. After OVA sensitization and challenge, Siglec-F ligands were increased in wild-type mouse lungs but less so in St3gal3 mutants, whereas peribronchial and BALF eosinophil numbers were greater in the mutants, with the following rank order: St3gal3−/− ≥ St3gal3+/− > wild-type mice. Levels of various cytokines and chemokines in BALF were not significantly different among these 3 types of mice, although OVA-specific serum IgG1 levels were increased in St3gal3−/− mice. Conclusions After OVA sensitization and challenge, St3gal3+/− and St3gal3−/− mice have more intense allergic eosinophilic airway inflammation and less sialylated Siglec-F ligands in their airways. One possible explanation for these findings is that levels of sialylated airway ligands for Siglec-F might be diminished in mice with attenuated levels of ST3Gal-III, resulting in a reduction in a natural proapoptotic pathway for controlling airway eosinophilia.

show abstract

Section: Discussionmentioning

confidence: 88%

Mice deficient in the St3gal3 gene product α2,3 sialyltransferase (ST3Gal-III) exhibit enhanced allergic eosinophilic airway inflammation

Kiwamoto

Brummet

et al. 2014

Journal of Allergy and Clinical Immunology

View full text Add to dashboard Cite

show abstract

“…On eosinophils, Siglec F engagement modulates cell viability ex vivo , a feature that may limit allergic eosinophilia through induction of apoptosis [30, 31]. While the function of Siglec F on murine alveolar macrophages remains uncertain [32], the literature consensus is that it is one of the strong positive markers that define this resident population; in flow cytometric analyses, Siglec F is used in conjunction with CD11c or CD64 to distinguish AMs from Siglec-F + eosinophils [33 – 35]. Notably, cultures of MH-S cells in media supplemented with (10%) cell-free bronchoalveolar lavage fluid or clarified lung homogenate from naïve BALB/c mice had no impact on Siglec F expression (data not shown).…”

Section: 0 Results and Discussionmentioning

confidence: 99%

Immortalized MH-S cells lack defining features of primary alveolar macrophages and do not support mouse pneumovirus replication

et al. 2016

View full text Add to dashboard Cite

The SV-40-transformed MH-S cell line maintains some, but not all, features of primary alveolar macrophages (AMs) from BALB/c mice. We show here that MH-S cells produce inflammatory cytokines IL-6 and CXCL10 in response to challenge with Gram-positive Lactobacillus reuteri, and to TLR2 and NOD2 ligands Pam3CSK4 and MDP, respectively. In contrast, although wild-type AMs are infected in vivo by pneumonia virus of mice (PVM), no virus replication was detected in MH-S cells. Interestingly, the surface immunophenotype of MH-S cells (CD11c+Siglec F−) differs from that of wild-type AMs (CD11c+ Siglec F+) and is similar to that of immature AMs isolated from granulocyte macrophage-colony stimulating factor (GM-CSF) gene-deleted mice; AMs from GM-CSF−/− mice also support PVM replication. However, MH-S cells do not express the GM-CSF receptor alpha chain (CD116) and do not respond to GM-CSF. Due to these unusual features, MH-S cells should be used with caution as experimental models of AMs.

show abstract

“…7 Unlike mouse eosinophils, alveolar macrophages do not appear to undergo apoptosis when Siglec-F is engaged. 46 And while human eosinophils express the closest functional paralog of Siglec-F, namely Siglec-8, human alveolar macrophages do not. 7 Based on these observations, we propose that constitutive and inducible mucins derived from airway epithelium and glands play a previously unappreciated role in dampening eosinophilic inflammation via siglec-sialoside interactions.…”

Section: Discussionmentioning

confidence: 99%

Endogenous airway mucins carry glycans that bind Siglec-F and induce eosinophil apoptosis

Kiwamoto

Katoh

Evans

et al. 2015

Journal of Allergy and Clinical Immunology

View full text Add to dashboard Cite

Background Siglec-F is a glycan binding protein selectively expressed on mouse eosinophils. Its engagement induces apoptosis, suggesting a pathway for ameliorating eosinophilia in asthma and other eosinophil-associated diseases. Siglec-F recognizes sialylated, sulfated glycans in glycan binding assays, but the identities of endogenous sialoside ligands and their glycoprotein carriers in vivo are unknown. Methods Lungs from normal and mucin-deficient mice, as well as mouse tracheal epithelial cells from mice, were interrogated in vitro and in vivo for the expression of Siglec-F ligands. Western blotting and immunocytochemistry used Siglec-F-Fc as a probe for directed purification, followed by liquid chromatography-tandem mass spectrometric analysis of recognized glycoproteins. Purified components were tested in mouse eosinophil binding assays and flow cytometry-based cell death assays. Results We detected mouse lung glycoproteins that bound to Siglec-F; binding was sialic-acid dependent. Proteomic analysis of Siglec-F binding material identified Muc5b and Muc4. Cross-affinity enrichment and histochemical analysis of lungs from mucin-deficient mice assigned and validated the identity of Muc5b as one glycoprotein ligand for Siglec-F. Purified mucin preparations carried sialylated and sulfated glycans, bound to eosinophils and induced their death in vitro. Mice conditionally deficient in Muc5b displayed exaggerated eosinophilic inflammation in response to intratracheal installation of IL-13. Conclusions These data identify a previously unrecognized endogenous anti-inflammatory property of airway mucins by which their glycans can control lung eosinophilia through engagement of Siglec-F.

show abstract

Expression and preliminary functional analysis of Siglec-F on mouse macrophages

Abstract: Sialic acid-binding immunoglobulin-like lectin (Siglec

Cited by 40 publications

References 34 publications

Mice deficient in the St3gal3 gene product α2,3 sialyltransferase (ST3Gal-III) exhibit enhanced allergic eosinophilic airway inflammation

Mice deficient in the St3gal3 gene product α2,3 sialyltransferase (ST3Gal-III) exhibit enhanced allergic eosinophilic airway inflammation

Immortalized MH-S cells lack defining features of primary alveolar macrophages and do not support mouse pneumovirus replication

Endogenous airway mucins carry glycans that bind Siglec-F and induce eosinophil apoptosis

Contact Info

Product

Resources

About