The dynamic movement of immune cells from the bone marrow, through the circulation and into peripheral tissues is crucial for the daily battle against pathogens and injury every organism withstands to survive. The first account and drawings of leukocyte migration through the wall of microvessels was published by Dutrochet in 1824. Neutrophils tracking and phagocytosing bacteria were first visualized by David Rogers in the 1950’s, and then scanning electronic microscope revealed that movement of lymphocytes into lymph nodes in 1976. But it was not until the early 1990’s that Eugene Butcher and Timothy Springer defined the “leukocyte adhesion cascade” as a series of sequential steps utilizing specific adhesion molecules, which ultimately enables leukocytes to gain entry into peripheral tissues/organs. Tissue-specific address codes established by the hemodynamic forces of blood flow and the underlying tissue stroma further tailor the leukocyte trafficking profile seen in tissues. Additionally, systemic environmental cues from metabolism; circadian rhythm, and even the age of the host all influence the movement of leukocytes.
This highly coordinated and tightly regulated process is lost in patients with immune-mediated inflammatory diseases (IMIDs), where leukocytes freely enter and remained within the inflamed tissues unchecked. Whilst deleting specific leukocyte subpopulations or their cytokine products has been the focus of pharmaceutical companies, there is also a growing interest in utilizing our understanding of the leukocyte trafficking process to develop new interventions. For example, a drug that limits the movement of pathogenic effector leukocytes, whilst simultaneously allowing the movement of regulatory leukocytes has the potential to allow resolution of chronic inflammation and tissue repair. Alternatively selecting the time of day where leukocyte trafficking levels are naturally at their highest may be desirable to maximize a vaccine response.
In this Research Topic, we aim to present the latest insights into leukocyte trafficking in health, with age, and in disease; specifically highlighting those that have been translated into the clinical arena. This Research Topic will present state-of-the-art Original Research Articles, Systematic Reviews, Reviews, and Clinical Trials Articles on topics including, but not limited to, the following:
(i) New discoveries related to the glycome or lipidome that impact on leukocyte trafficking in health, with age, and in disease
(ii) Temporal analysis of leukocyte trafficking profiles in diverse tissues and organs throughout the day or the lifespan of an organism, i.e. circadian rhythm, aging
(iii) Stromal biology as a mechanism explaining leukocyte trafficking in various IMIDs, with emphasis on the clinical utility of targeting the stroma
(iv) Interdisciplinary discoveries that have been made in the leukocyte trafficking field, e.g. in the field of immunometabolism
(v) Advancements that utilize leukocyte trafficking profiles, including their cellular and molecular mechanisms, for clinical gain, e.g. new pharmacological tools or time-of-day interventions
Please note that articles on cancer are outside the scope of this Research Topic.
Dr. McGettrick receives financial support from VIATEM Ltd. The other Topic Editors declare no conflict of interest with regards to the Research Topic theme.
The dynamic movement of immune cells from the bone marrow, through the circulation and into peripheral tissues is crucial for the daily battle against pathogens and injury every organism withstands to survive. The first account and drawings of leukocyte migration through the wall of microvessels was published by Dutrochet in 1824. Neutrophils tracking and phagocytosing bacteria were first visualized by David Rogers in the 1950’s, and then scanning electronic microscope revealed that movement of lymphocytes into lymph nodes in 1976. But it was not until the early 1990’s that Eugene Butcher and Timothy Springer defined the “leukocyte adhesion cascade” as a series of sequential steps utilizing specific adhesion molecules, which ultimately enables leukocytes to gain entry into peripheral tissues/organs. Tissue-specific address codes established by the hemodynamic forces of blood flow and the underlying tissue stroma further tailor the leukocyte trafficking profile seen in tissues. Additionally, systemic environmental cues from metabolism; circadian rhythm, and even the age of the host all influence the movement of leukocytes.
This highly coordinated and tightly regulated process is lost in patients with immune-mediated inflammatory diseases (IMIDs), where leukocytes freely enter and remained within the inflamed tissues unchecked. Whilst deleting specific leukocyte subpopulations or their cytokine products has been the focus of pharmaceutical companies, there is also a growing interest in utilizing our understanding of the leukocyte trafficking process to develop new interventions. For example, a drug that limits the movement of pathogenic effector leukocytes, whilst simultaneously allowing the movement of regulatory leukocytes has the potential to allow resolution of chronic inflammation and tissue repair. Alternatively selecting the time of day where leukocyte trafficking levels are naturally at their highest may be desirable to maximize a vaccine response.
In this Research Topic, we aim to present the latest insights into leukocyte trafficking in health, with age, and in disease; specifically highlighting those that have been translated into the clinical arena. This Research Topic will present state-of-the-art Original Research Articles, Systematic Reviews, Reviews, and Clinical Trials Articles on topics including, but not limited to, the following:
(i) New discoveries related to the glycome or lipidome that impact on leukocyte trafficking in health, with age, and in disease
(ii) Temporal analysis of leukocyte trafficking profiles in diverse tissues and organs throughout the day or the lifespan of an organism, i.e. circadian rhythm, aging
(iii) Stromal biology as a mechanism explaining leukocyte trafficking in various IMIDs, with emphasis on the clinical utility of targeting the stroma
(iv) Interdisciplinary discoveries that have been made in the leukocyte trafficking field, e.g. in the field of immunometabolism
(v) Advancements that utilize leukocyte trafficking profiles, including their cellular and molecular mechanisms, for clinical gain, e.g. new pharmacological tools or time-of-day interventions
Please note that articles on cancer are outside the scope of this Research Topic.
Dr. McGettrick receives financial support from VIATEM Ltd. The other Topic Editors declare no conflict of interest with regards to the Research Topic theme.