Structural alterations of marrow during inflammation

Abstract

In response to infections and inflammations, bone marrow reacts to mobilize its granulocyte reserve. Three sets of factors are involved in this mobilization. The structure of the sinus wall is altered and adventitial cells retract to permit interaction of migrating cells with the endothelium. During the maturation process, granulocytes lose their binding potential to the supporting stroma, but their motility, chemotactic ability, and deformability increase. Consequently, they move toward the sinus endothelium with which they interact to enter the circulation. Soluble factors are also involved in granulocyte mobilization. The best characterized of these factors is C3e, an acidic fragment of the alpha chain of C3 with MW of 10-12 KD and ability to bind to granulocyte membrane. Other soluble factors may also be involved, but due to lack of adequate methodology, this area has been relatively underexplored.