Immunobiology of hematopoietic colony-stimulating factors: potential application to disease prevention in the bovine.

Colony-stimulating factors are a family of glycoproteins instrumental in regulation of hematopoiesis and inflammation. Clinical effects of various colony-stimulating factors have been reported in murine and human hosts. This review summarizes findings from some clinical trial evaluations of macrophage colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, interleukin-1, interleukin-3, interleukin-4, interleukin-5, interleukin-6, and interleukin-7 administration to other species. These factors stimulate clonal expansion of progenitor cells in the bone marrow, induce differentiation of various cell lineages to a mature phenotype, and, in some cases, enhance the effector activities of immune cells. Each colony-stimulating factor has distinct lineages of bone marrow cells upon which they act, although there is some overlap in lineage activity and synergy between colony-stimulating factors. The close relationship in biological activity among different colony-stimulating factors is also reflected at the genomic level at which genes for some hematopoietic growth factors have been mapped to a region of human chromosome 5. Recently, colony-stimulating factor administration to cattle and its potential application to disease control in bovine preventive medicine programs has been investigated. Data from recent hematological, immunological, and intramammary bacterial (Staphylococcus aureus and Klebsiella pneumoniae) challenge studies in dairy cows are reviewed. These studies, with limited numbers of cows, found that rate of new infections, as well as duration and severity of infection, were reduced by pretreatment of cows with granulocyte-colony stimulating factor. The dose-dependent hematological and immunomodulatory effects of granulocyte colony-stimulating factor administration may explain reduced severity and incidence of mastitis in dairy cows given granulocyte colony-stimulating factor.