The neuropeptides α-MSH and NPY differentially modulate phagocytosis by macrophages (120.24)
| Autor: | Toan Phan, Hari Mylvaganam, Andrew Taylor |
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| Rok vydání: | 2012 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 188:120.24-120.24 |
| ISSN: | 1550-6606 0022-1767 |
| Popis: | The ocular microenvironment tightly regulates immunity to prevent inflammation. These anti-inflammatory mechanisms are partly mediated by immunomodulating neuropeptides. We previously found that alpha-melanocyte stimulating hormone (α-MSH) and Neuropeptide Y (NPY) together induce activation of myeloid suppressor-like macrophages. In this study, we examined the possibility that α-MSH and NPY also modulate phagocytosis by macrophages. The monocytic cell line RAW 246.7 was treated with α-MSH or NPY at 1 ng/ml each, a concentration produced by retinal cells in culture. The treated cells were feed florescent bioparticles of Gram(-) E. Coli or Gram(+) S. Aureus with or without opsonization. Also, tested was the formation of phagolysosomes using pH sensitive florescent E. Coli or S. Aureus bioparticles. Phagocytic activity was assayed by flow cytometry. The α-MSH and NPY treated macrophages were significantly suppressed in their capacity to phagocytize unopsonized E. coli; however, suppression of S. Aureus phagocytosis was limited to NPY treated macrophages. In addition, α-MSH/NPY co-treatment suppressed both phagocytosis and phagolysosome formation in the macrophages. There was no change in phagocytic activity if the bioparticles were opsonized with antibody or complement. Therefore, as α-MSH and NPY together induce suppressor macrophages within the ocular microenvironment, they also modulate in a stimulus-dependent manner phagocytic signals within the macrophages. |
| Databáze: | OpenAIRE |
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