The triad of blood, deep lymphatics and CSF in MS

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease affecting brain and spinal cord. Although the underlying cause of MS is not yet known, it is well reported that immune cells of the so-called T and B propagate inflammation and pathogenesis in MS. The T and B cells of MS patients behave differently compared to healthy people, e.g. they produce other kinds proteins and react differently to stimuli. Usually, studies focus only on immune cells in the blood and the fluid around brain and spinal cord (CSF). However, in order to identify new disease-implicated immune cell subtypes a third, until now totally neglected, compartment is the lymphatic system. It composes of specialized vessels, which are used by immune cells to move throughout the body and to get activated. As part of the lymphatics, the thoracic duct is particularly interesting in MS research since it contains large amounts of immune cells that directly travel from the brain; including all kinds of disease-implicated cell subsets. Therefore, we believe that is of utmost importance to study this so far neglected compartment in MS patients as well and to assess the relationship between blood, CSF and lymphatics in order to refine MS-specific immune functions. The main goal of this project is to find new disease-implicated immune cell subtypes by studying, besides the blood and CSF, the lymphatic system. The thoracic duct drains half of the brains egressing immune cells as well as the gut-associated lymph tissue. As it is recognized that immune cells can traffic between the blood and the CNS using the lymphoid tissue as well as the gut:brain axis is increasingly being considered important we expected to exhibit a higher concentration of MS disease-relevant immune cell subsets. This approach has not been done in MS research before. We will also study the distribution of the different immune cell subtypes between the different compartments (blood, CSF, lymphatics) in order to investigate their movement patterns. We will involve 20 untreated MS patients and 10 healthy controls. Immune cells will be isolated from the blood, cerebrospinal fluid and thoracic duct lymph. After immune cell isolation, we will study disease-implicated immune cell subtypes via single-cell RNA sequencing, which allows us to assess the gene expression profile of each individual immune cell. Subsequently, we will validate our findings as well as test for previously described cell subtypes via multi-color flow cytometry which allows us to tag certain immune cells and quantify them. This project will expand the knowledge on immune cell subtypes implicated in MS pathophysiology and their distribution between anatomically distinct yet interconnected compartments (blood, CSF and lymphatics). The potentially identified cell subtypes could eventually contribute to the development of new therapeutic strategies and help to increase our understanding of MS pathophysiology.

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease affecting brain and spinal cord. Although the underlying cause of MS is not yet known, it is well reported that immune cells of the so-called T and B propagate inflammation and pathogenesis in MS. The T and B cells of MS patients behave differently compared to healthy people, e.g. they produce other kinds proteins and react differently to stimuli. Usually, studies focus only on immune cells in the blood and the fluid around brain and spinal cord (CSF). However, in order to identify new disease-implicated immune cell subtypes a third, until now totally neglected, compartment is the lymphatic system. It composes of specialized vessels, which are used by immune cells to move throughout the body and to get activated. As part of the lymphatics, the thoracic duct is particularly interesting in MS research since it contains large amounts of immune cells that directly travel from the brain; including all kinds of disease-implicated cell subsets. Therefore, we believe that is of utmost importance to study this so far neglected compartment in MS patients as well and to assess the relationship between blood, CSF and lymphatics in order to refine MS-specific immune functions. The main goal of this project is to find new disease-implicated immune cell subtypes by studying, besides the blood and CSF, the lymphatic system. The thoracic duct drains half of the brain's egressing immune cells as well as the gut-associated lymph tissue. As it is recognized that immune cells can traffic between the blood and the CNS using the lymphoid tissue as well as the gut:brain axis is increasingly being considered important we expected to exhibit a higher concentration of MS disease-relevant immune cell subsets. This approach has not been done in MS research before. We will also study the distribution of the different cell subtypes between the different compartments (blood, CSF, lymphatics) to investigate their movement patterns. We will involve 20 untreated MS patients and 10 healthy controls. Immune cells will be isolated from the blood, cerebrospinal fluid and thoracic duct lymph. We will study disease-implicated immune cell subtypes via single-cell RNA sequencing, which allows us to assess the gene expression profile of each individual immune cell. Subsequently, we will validate our findings as well as test for previously described cell subtypes via multi-color flow cytometry which allows us to tag certain immune cells and quantify them. This project will expand the knowledge on immune cell subtypes implicated in MS pathophysiology and their distribution between anatomically distinct yet interconnected compartments (blood, CSF and lymphatics). The potentially identified cell subtypes could eventually contribute to the development of new therapeutic strategies and help to increase our understanding of MS pathophysiology.