Inflammation of the choroid plexus in progressive multiple sclerosis: accumulation of granulocytes and T cells.
The choroid plexus (CP) is strategically located between the peripheral blood and the cerebrospinal fluid, and is involved in the regulation of central nervous system (CNS) homeostasis. In multiple sclerosis (MS), demyelination and inflammation occur in the CNS. While experimental animal models of MS pointed to the CP as a key route for immune cell invasion of the CNS, little is known about the distribution of immune cells in the human CP during progressive phases of MS. Here, we use immunohistochemistry and confocal microscopy to explore the main immune cell populations in the CP of progressive MS patients and non-neuroinflammatory controls, in terms of abundance and location within the distinct CP compartments. We show for the first time that the CP stromal density of granulocytes and CD8+ T cells is higher in progressive MS patients compared to controls. In line with previous studies, the CP of both controls and progressive MS patients contains relatively high numbers of macrophages and dendritic cells. Moreover, we found virtually no B cells or plasma cells in the CP. MHCII+ antigen-presenting cells were often found in close proximity to T cells, suggesting constitutive CNS immune monitoring functions of the CP. Together, our data highlights the role of the CP in immune homeostasis and indicates the occurrence of mild inflammatory processes in the CP of progressive MS patients. However, our findings suggest that the CP is only marginally involved in immune cell migration into the CNS in chronic MS.
['Rodríguez-Lorenzo|Sabela|S|', 'Konings|Julia|J|', 'van der Pol|Susanne|S|', 'Kamermans|Alwin|A|', 'Amor|Sandra|S|', 'van Horssen|Jack|J|', 'Witte|Maarten E|ME|', 'Kooij|Gijs|G|', 'de Vries|Helga E|HE|0000-0001-7904-7124']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D001402:B-Lymphocytes D002831:Choroid Plexus D003713:Dendritic Cells D005260:Female D006098:Granulocytes D006801:Humans D007249:Inflammation D008264:Macrophages D008297:Male D008875:Middle Aged D020528:Multiple Sclerosis, Chronic Progressive D013601:T-Lymphocytes
Choroid plexus Granulocytes T cells Immune cells Progressive MS Blood-CSF barrier