Leukocyte migration

About: Leukocyte migration is a research topic. Over the lifetime, 3224 publications have been published within this topic receiving 119682 citations.

Rapid leukocyte migration by integrin-independent flowing and squeezing

Abstract: All metazoan cells carry transmembrane receptors of the integrin family, which couple the contractile force of the actomyosin cytoskeleton to the extracellular environment In agreement with this principle, rapidly migrating leukocytes use integrin-mediated adhesion when moving over two-dimensional surfaces As migration on two-dimensional substrates naturally overemphasizes the role of adhesion, the contribution of integrins during three-dimensional movement of leukocytes within tissues has remained controversial We studied the interplay between adhesive, contractile and protrusive forces during interstitial leukocyte chemotaxis in vivo and in vitro We ablated all integrin heterodimers from murine leukocytes, and show here that functional integrins do not contribute to migration in three-dimensional environments Instead, these cells migrate by the sole force of actin-network expansion, which promotes protrusive flowing of the leading edge Myosin II-dependent contraction is only required on passage through narrow gaps, where a squeezing contraction of the trailing edge propels the rigid nucleus

Chemotaxis under agarose: a new and simple method for measuring chemotaxis and spontaneous migration of human polymorphonuclear leukocytes and monocytes.

Abstract: A variety of methods have been devised for the study of spontaneous and directed cell migration. Among these, the membrane filter method introduced by Boyden in 1962, with its more recent modifications, has become the technique of choice for studies of leukocyte migration in vitro. This method, however, cannot be applied without alteration to studies of chemotaxis and spontaneous migration of cells of different types. We describe in this report a new and simple method for studying human leukocyte chemotaxis, in vitro, which is based upon migration of cells under agarose gel. This method has application to both polymorphonuclear leukocytes and monocytes, permits measurement of both chemotaxis and spontaneous migration, requires fewer cells per test, and is rapid, simple, reproducible, and inexpensive to set up.

Role of cytokines in intervertebral disc degeneration: pain and disc content.

Abstract: Degeneration of the intervertebral discs (IVDs) is a major contributor to back, neck and radicular pain. IVD degeneration is characterized by increases in levels of the proinflammatory cytokines TNF, IL-1α, IL-1β, IL-6 and IL-17 secreted by the IVD cells; these cytokines promote extracellular matrix degradation, chemokine production and changes in IVD cell phenotype. The resulting imbalance in catabolic and anabolic responses leads to the degeneration of IVD tissues, as well as disc herniation and radicular pain. The release of chemokines from degenerating discs promotes the infiltration and activation of immune cells, further amplifying the inflammatory cascade. Leukocyte migration into the IVD is accompanied by the appearance of microvasculature tissue and nerve fibres. Furthermore, neurogenic factors, generated by both disc and immune cells, induce expression of pain-associated cation channels in the dorsal root ganglion. Depolarization of these ion channels is likely to promote discogenic and radicular pain, and reinforce the cytokine-mediated degenerative cascade. Taken together, an enhanced understanding of the contribution of cytokines and immune cells to these catabolic, angiogenic and nociceptive processes could provide new targets for the treatment of symptomatic disc disease. In this Review, the role of key inflammatory cytokines during each of the individual phases of degenerative disc disease, as well as the outcomes of major clinical studies aimed at blocking cytokine function, are discussed.

Three or more routes for leukocyte migration into the central nervous system

Abstract: Leukocyte migration into and through tissues is fundamental to normal physiology, immunopathology and host defence. Leukocyte entry into the central nervous system (CNS) is restricted, in part, because of the blood–brain barrier (BBB). During the past decade, crucial components that are involved in the process of leukocyte migration have been identified and progress has been made in understanding the mechanisms of neuroinflammatory reactions. In this review, present knowledge of the trafficking determinants that guide the migration of leukocytes is superimposed onto the vascular and compartmental anatomy of the CNS. We discuss three distinct routes for leukocytes to enter the CNS and consider how different populations of leukocytes use trafficking signals to gain entry.