Protein kinase C and a calcium-independent phospholipase are required for IgG-mediated phagocytosis by Mono-Mac-6 cells
Abstract
Mono-Mac-6 (MM6) human monocytes ingest IgG-opsonized particles better than other human cell lines. We compared the phagocytic signaling pathway in MM6 with human monocytes. MM6 expressed FcgammaRI at levels similar to monocytes, whereas FcRgammaII expression was approximately double. MM6 ingested IgG-opsonized erythrocytes (EIgG) in a calcium-independent manner. Incubation of MM6 with bromoenol lactone, an inhibitor of the phagocytic phospholipase (pPL), coordinately decreased phagocytosis and pPL activity. This inhibition was overcome by exogenous arachidonic acid, suggesting that phagocytosis requires pPL activation and arachidonic acid release. MM6 phagocytosis was inhibited with staurosporine and activated with diacylglycerol, supporting a role for protein kinase C (PKC) in this process. The pPL activators mastoparan and melittin restored phagocytosis to PKC-inhibited cells, suggesting that pPL lies downstream from PKC. These results suggest that the MM6 signal transduction pathway for IgG-mediated phagocytosis is similar to that of monocytes (PKC-->pPL-->arachidonic acid-->phagocytosis). The results are discussed in the context of the finding that MM6 exhibit low phagocytosis relative to monocytes and thus may represent an attractive cell line for molecular manipulation in "recovery of function" studies.
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Addition of exogenous DAG or its analogues augments phagocytosis, an effect attributed to PKC isoforms.
“Accordingly, addition of exogenous DAG or its analogues augments phagocytosis (Karimi et al. 1999), an effect that has been attributed to PKC isoforms.”
From Localized Biphasic Changes in Phosphatidylinositol-4,5-Bisphosphate at Sites of Phagocytosis (2000) · cites this paper as Karimi et al. 1999
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Localized Biphasic Changes in Phosphatidylinositol-4,5-Bisphosphate at Sites of Phagocytosis
Botelho, R. J., Teruel, M., Dierckman, R., Anderson, R., Wells, A., York, J. D., Meyer, T., & Grinstein, S. (2000) · The Journal of Cell Biology · doi:10.1083/jcb.151.7.1353 · Cited by 539 · see citing works
“Accordingly, addition of exogenous DAG or its analogues augments phagocytosis (Karimi et al., 1999), an effect that has been attributed to PKC isoforms.”
BackgroundMcNally, A. K., & Anderson, J. M. (2005) · Experimental and Molecular Pathology · doi:10.1016/j.yexmp.2005.06.008 · Cited by 80 · see citing works
- Authors
- Karimi, K., Gemmill, T. R., & Lennartz, M. R.
- Affiliations
- Albany Medical College (US)
- Corresponding author
- Lennartz, Michelle R
- ORCID
- Lennartz, Michelle R
- Venue
- Journal of Leukocyte Biology
- Publisher
- Oxford University Press (OUP)
- Published
- 1999-06-01
- Volume
- 65
- Issue
- 6
- Pages
- 854-862
- ISSN
- 0741-5400 (ISSN-L)
- 1938-3673
- OpenAlex
- W1856761497
- Cited by
- 37
- References
- 0
- Citations by year
- 2026: 1 · 2023: 2 · 2022: 1 · 2021: 1 · 2020: 2 · 2019: 1 · 2017: 1 · 2015: 1 · 2014: 3 · 2013: 2 · 2012: 1
- FWCI
- 1.25
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- Journal of Leukocyte Biology (publishedVersion)
- PubMed (publishedVersion)
- Funders
- National Institutes of Health (5r29gm045983-06)
- National Institute of General Medical Sciences (GM45983)
- Topics
- Life Sciences › Immunology and Microbiology › Immunology › Phagocytosis and Immune Regulation
- Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Protein Kinase Regulation and GTPase Signaling
- Life Sciences › Immunology and Microbiology › Immunology › Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Keywords
- protein kinase C, phospholipase, Mono Mac 6 cells, human monocytes, Fc gamma receptor I, Fc gamma receptor II, arachidonic acid, diacylglycerol, staurosporine, mastoparan, melittin, opsonized erythrocytes, functional recovery
- MeSH terms
- Arachidonic Acids, Cell Line, Enzyme Activation, Enzyme Inhibitors, Flow Cytometry, Humans, Immunoglobulin G, Macrophages, Melitten, Monocytes, Opsonin Proteins, Peptides, Phagocytosis, Phospholipases A, Protein Kinase C, Rosette Formation, Wasp Venoms, Receptors, IgG, Intercellular Signaling Peptides and Proteins, Group VI Phospholipases A2
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