Haematopoietic function

The liver grows quickly, accounting for 10% of foetal mass by the 10th week. This is largely due to the number of newly formed sinusoids, but another important factor is the haematopoietic function of the... 

Most cytokines act upon, or are produced by, leukocytes (white blood cells), which constitute the immune and inflammatory systems (Box 8.1). They thus play a central role in regulating both immune and inflammatory function and in related processes such as haematopoiesis (the production of blood cells from haematopoietic stem cells in the adult bone marrow), as well as in wound healing. Indeed, several immunosuppressive and anti-inflammatory drugs are now known to induce their biological effects by regulating production of several cytokines. 

In addition to its effects on haematopoietic cells, GM-CSF can also affect the function of mature cells. GM-CSF treatment increases the survival, cytotoxicity and eicosanoid formation by eosinophils, and can increase the tu-mouricidal activity, cytokine expression, surface antigen expression and oxidative metabolism of macrophages. It is chemotactic for endothelial cells, can induce the proliferation of some tumour cells, stimulates histamine release from basophils and affects the viability and function of Langerhans cells. Its effects on mature neutrophils are described in 7.2.1, 7.3.4. 

The biological relevance of negative control of cytokine signalling by dephosphorylation becomes apparent in the phenotype of the mouse mutant, motheaten , which lacks a functional phosphotyrosine phosphatase. This mouse suffers from numerous haematopoietic defects and uncontrolled cell proliferation. 

Healey KM, Pavletic SZ, Al-Omaishi J, Leuschen MP, Pirrucello SJ, Eilipi ML, Enke C, Ursick MM, Hahn E, Bowen JD, Nash RA (2004) Discordant functional and inflammatory parameters in multiple sclerosis patients after autologous haematopoietic stem cell transplantation. Mult Seer 10 284-289. 

Discordant functional and inflammatory parameters in multiple sclerosis patients after autologous haematopoietic stem cell transplantation. Mult Scler 10 284-289. 

GM-CSF is a pleotropic cytokine that can stimulate the proliferation, maturation and function of haematopoietic cells. It is produced by several airway cells, including macrophages, eosinophils, T lymphocytes and epithelial cells. There is evidence for increased expression of GM-CSF in the epithelial cells of asthmatic patients (Sousa et al.,... 

Jeras M. The role of in vitro alloreactive T-cell functional tests in the selection of HLA matched and mismatched haematopoietic stem cell donors. Transplant Immunol 2002 10 205-214. 

Stacker Lung and skin is where we predominantly see VEGF-D. VEGF-C is a little more broadly expressed on the haematopoietic lineages. There is a report showing a role in B cell function, I think, for VEGF-C. 

Hock H, Hamblen MJ, Rooke HM, Schindler JW, Saleque S, Fujiwara Y, Orkin SH. 2004. Gfi-1 restricts proliferation and preserves functional integrity of haematopoietic stem cells. Nature A3 1002-1007. 

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