| Popis: |
To examine the effect of macrophage colony stimulating factor (M-CSF) or CSF-1 on the differentiation and maturation of nonlymphoid dendritic cells (DCs) in vivo, the osteopetrotic mouse (op/op mouse) is a useful tool. This is because the op mutation is shown to be a defect in the coding region of the macrophage colony stimulating factor (Csfm) gene and because CSF-1 produced is nonfunctional, although this mouse does produce Csfm messenger RNA at normal levels.1 This mutation is transmitted by an autosomal recessive trait and homozygous (op/op) mice are characterized by the absence of incisors, a distinctly domed skull, a short tail, and a small body size.2 These phenotypic abnormalities become evident by ten days after birth. In addition to a marked reduction of osteoclasts, deficiencies of monocytes and monocyte-derived macrophages occur in op/op mice.3,4 All these result from the lack of CSF-1 activity. In a recent study, we found immature macrophages in various organs and tissues of op/op mice, suggesting that these CSF-1-independent macrophages are derived from granulocyte/macrophage colony forming cells (GM-CFCs) or earlier hematopoietic progenitors.5 However, little is known about the DCs of op/op mice, including interdigitating cells (IDCs) in the thymus or peripheral lymphoid tissues, epidermal Langerhans cells (LCs), or indeterminate dendritic cells (IDDCs). |
