Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.742791
Title: Control of macrophage homeostasis
Author: Davies, Luke C.
ISNI:       0000 0004 7231 8421
Awarding Body: Cardiff University
Current Institution: Cardiff University
Date of Award: 2014
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Abstract:
Tissue resident macrophages are extremely heterogeneous, which reflects their unique microenvironments and tissue specific functions. They are a constituent of all tissues, and are involved in homeostatic processes and inflammatory disease. Recent studies have shown that select tissue resident macrophage populations, such as Langerhans cells of the skin and microglia of the brain, are able to self-renew independently from the bone marrow. This is contrary to the prevailing model macrophage origins, the ‘mononuclear phagocyte system’, which dictates that all macrophages are derived from bone marrow monocytes. The work carried out in this thesis investigated the self-renewing potential of peritoneal tissue resident macrophages, and its control. Several novel discoveries were made: i) peritoneal resident macrophages proliferate at low levels to maintain their numbers during homeostasis, at higher levels during neonatal growth, and undergo a burst in proliferation during acute inflammation to restore their depleted population; ii) renewal of peritoneal resident macrophages during an acute inflammatory episode was found to be independent from the bone marrow, and dependent upon macrophage colony stimulating factor, but importantly, not interleukin-4; iii) Monocyte-derived macrophages could also proliferate within an inflammatory lesion. Collectively, these observations challenge the dogma of the mononuclear phagocyte system: they demonstrate that in vascular tissues, tissue resident macrophages could self-renewal independently of monocytes, and that monocyte-derived cells are not terminally-differentiated. Additional work leading up to these studies implicated Gata6 as a peritoneal macrophage-specific transcription factor. In this thesis, Gata6 was found to be necessary for peritoneal macrophage phenotype, normal proliferation, euploidy, and normal responses to inflammation. In summary, these studies demonstrate not only are macrophages capable of self-renewal, but this is dependent upon discrete transcriptional control. Understanding the molecular controls of tissue macrophage heterogeneity and renewal could provide novel avenues for the therapeutic manipulation of their activities.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.742791  DOI: Not available
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