Part of the book: Adult Stem Cell Niches
It is now known that neutrophils make up a population of complex cells with great plasticity, challenging the old view of neutrophil association with tissue damage and early phases of infection. Here, we discuss different contexts in which these cells can induce anti-inflammatory responses. Although distinct surface markers and cytokines profiles were shown, the most reliable characterization of suppressor neutrophil subtypes relies on their functional characteristics. One important example of inhibitory neutrophils generation comes from in vivo treatment with G-CSF, for 5 days, as for hematopoietic-stem-cell-transplantation (HSCT). In this case,donor blood is enriched in degranulated granulocytes harboring a functional regulatory phenotype, characterized by IL-10 production. These cells, when transferred together with HSCT, are able to reduce graft-versus-host-disease, being influenced by Treg cells and influencing them back. Importantly, this protection is long lasting and specific, keeping immunocompetence to other antigens. This regulation is paramount in HSCT, and represents a simple approach to be applied in humans. In summary, we discuss the interaction of neutrophils with other cell types and its consequence in immunomodulation. We believe these features confer an important bridge between innate and adaptive immune system, building a new knowledge for an underestimated cell type.
Part of the book: Role of Neutrophils in Disease Pathogenesis
The bone marrow is a dynamic organ where osteogenesis and bone remodeling take place side by side with hematopoiesis and the maintenance of immunological memory. It provides a unique microenvironment favoring the colonization and outgrowth of breast cancer cells. The outcome of breast-cancer-derived bone metastases depends on the formation of a pre-metastatic niche, which is initiated through “education” of non-tumoral cells present in the primary cancerous niche. Among other participants, immune cells and their secreted factors can boost the successful seeding of the distant disease. In this chapter, we discuss the reciprocal interplay between bone and T and B cells, particularly in pathological contexts. In the first part, we are exploring the knowledge brought by the osteoimmunology field, especially from the best studied disease in this area, rheumatoid arthritis. In the second part, we summarize the latest findings on underlying cellular and molecular mechanisms for breast-cancer-derived bone pre-metastatic niche formation. In addition, we explore the concept that breast-tumor-primed T and B cells function as messengers from the periphery to the bone marrow, alter bone turnover homeostasis in favor of osteoclasts, before tumor colonization, leading to a pre-metastatic niche formation to further the development of bone metastases.
Part of the book: Bone Tumours