Description

The capacity of immune cells to migrate between the blood and tissues/organs; to interact with other cell types within the body and to adjust behavior and morphology upon environmental changes, are all crucial features for securing the survival of an organism as a whole. However, when leukocyte activities and/or functions become deregulated, such as in autoimmune diseases and in cancer, leukocyte function can also be deleterious. In such instances of homeostasis and disease, the capacity to image motile leukocytes in 3-dimensions in tissues and organs of a living organism over time (the 4th dimension) presents a unique and powerful tool that allows for real-time investigation into their functions and behavior. This approach to “seeing” cells in a live animal is called intravital imaging or in vivo microcopy.

Although intravital imaging is considered a new tool in biomedical research, in reality, its roots originated in the 19th century when Augustus Waller and Julius Cohnheim used very simple light microscopes to observe the vasculature within the tongue of a live frog. Although they did not fully understand what they saw, the technique led them to highly accurate and meaningful observations, including that of “diapedesis”, which is the emergence of colorless blood corpuscles from the interior of a vein to the outside, through an intact vessel wall. Since then, major technological advances have been made in the development of high-resolution fluorescence and confocal microscopy that have enabled us to gain a deeper understanding of various tissues and organ systems, including the immune system.

In this Research Topic, we aim to present the latest advances in research on leukocytes that have been made possible due to the application of intravital microscopy. This Research Topic will present state-of-the-art Original Research Articles, Reviews and Methods Articles on topics including, but not limited to, the following:

(i) New discoveries related to basic leukocyte biology achieved with intravital microscopy (IVM)
(ii) IVM-related progress in explaining mechanisms of various immune-related disorders including inflammatory (acute and chronic) diseases, autoimmune diseases, and cancer with emphasis on the roles of leukocytes in these diseases.
(iii) Comparative analysis of leukocyte functions in diverse tissues and organs using IVM
(iv) Interdisciplinary discoveries that have been made in the immunology field using IVM, e.g. in the field of immunometabolism or neuro-immuno-endocrine interactions
(v) Novel or significantly updated methodology – in terms of state-of-the-art microscopy and their applications to imaging of leukocytes