Regulation of Teleost Macrophage and Neutrophil Cell Development by Growth Factors and Transcription Factors

Abstract

Additional information is available at the end of the chapter http://dx.doi.org/10.5772/53589 . IntroductionMacrophages and neutrophils are the sentinel cells of the innate immune response of vertebrates, such as bony fish teleosts . "s phagocytic myeloid cells, they are involved in homeostatic mechanisms, wound healing, and the detection, elimination and clearance of foreign entities including tumors, virus-infected cells and invading pathogens. Furthermore, macrophages and neutrophils are responsible for producing hundreds of bioactive molecules that are important in pathogen recognition and destruction, cellular communication and activation, initiation of an adaptive immune response and later, resolution of an inflammatory response and tissue repair. Neutrophils and macrophages, while essential to survival, have a finite lifespan. Therefore, a manufacturing centre, the hematopoietic niche, is needed for the production of myeloid cells. The hematopoietic niche must maintain basal myeloid cell production levels during homeostasis, yet retain the flexibility to ramp-up cell production in response to physiological demands, such as pathogenic insult. The development of macrophages monopoiesis and neutrophils granulopoiesis is collectively known as myelopoiesis, and is regulated by the complex interaction of colony-stimulating factors CSFs , their receptors, and intracellular transcription factor machinery that control lineage fate decisions and terminal differentiation events.Over the past years, research using the mouse model system has culminated in the identification of the site s of myelopoiesis, the progenitor cell types that give rise to mature myeloid cells, the extracellular and intracellular cues required, and a detailed understanding of the complex intracellular and extracellular milieu of factors that drive this tightly controlled © 2013 Katzenback et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.process. From these studies we understand hematopoiesis as an exquisitely fine-tuned, highly regulated, process whereby all blood cells develop from a small number of hematopoietic stem cells HSCs . HSCs are characterized as long-term repopulating, pluripotent, quiescent cells that undergo symmetrical self-renewal to sustain the population of HSCs within the hematopoietic niche, or asymmetrical division to give rise to hematopoietic progenitor cells HPCs [ ]. HPCs can develop along the lymphoid lineage, termed lymphopoiesis, to give rise to "-cells, T-cells, natural killer NK cells and dendritic cells DCs . "lternatively, HPCs can develop along an erythroid lineage, termed erythropoiesis, to give rise to erythrocytes and megakaryocytes, or develop along a myeloid lineage to give rise to granulocytes neutrophils, basophils, eosinophils, mast cells , mononuclear phagoc...

Priming European Sea Bass Female Broodstock Improves the Antimicrobial Immunity of Their Offspring

“…This hypothesis is also supported by the expression levels of hamp, lyz, Nk-lysin, and dic, which were not detected at egg stages, but were upregulated at certain sampling points during development, mainly at 5 or 5 and 7 dpf, and then later, at around 40 or 69 dpf. These two peaks in expression observed in most of the immune-related genes, as well as in the AMP levels analyzed in this work, might be related to the two waves of hematopoiesis, a primitive and a definitive wave, previously described in other vertebrates [52].…”