Various glial cell culture systems: (A) astrocyte mono-culture; (B) microglial cell mono-culture; (C) astrocyte mono-culture pre-stimulated with SN of uninfected microglial cell cultures; (D) microglial cell mono-culture pre-stimulated with SN of uninfected astrocyte cultures; (E) astrocyte-microglial cell co-culture (low amount of microglial cells); and (F) astrocyte-microglial cell co-culture (high amount of microglial cells), were infected with CFSE-labeled strain 10, 10at a MOI 10:1 for 2 h. meningitis, arthritis, endocarditis, in some cases encephalitis and other pathologies [1,2]. Moreover, it is a zoonotic pathogen. Most human infections occur in Southeast Asia with meningitis as the main pathology . possesses a variety of virulence and virulence-associated factors including the capsule (CPS) and suilysin . The capsule was shown to protect against killing by phagocytes and deposition of complement [5,6,7,8]. Moreover, in pig contamination experiments capsular mutants of were completely avirulent . Suilysin, the hemolysin of to cross epi- and endothelial barriers [9,10]. To cause meningitis has to enter the central nervous system (CNS) via the blood brain barrier (BBB) or the blood cerebrospinal fluid barrier (BCSFB) . Adhesion to and invasion of brain microvascular endothelial cells (part of the BBB) and cells of the plexus chorioideus (a part BMS-193885 of BCSFB) by were shown BMS-193885 [11,12,13,14,15]. Astrocytes form together with endothelial cells the BBB and individual the neuronal parenchyma from non-neuronal cells along the blood vessels and the meninges . Besides providing structural support and nutrients for neuronal cells,  astrocytes have barrier functions, liming the spread of infections to the CNS parenchyma, and have pro- as well as anti-inflammatory properties . Although it is usually hypothesized that astrocytes play a crucial role in host-pathogen conversation during streptococcal meningitis, interactions of streptococci and astrocytes are only poorly investigated . A further glial cell subtype, the microglial cells, represents macrophages of the CNS, which play an important role as phagocytic and antigen-presenting cells . It has been described that activation of microglial cells is usually modulated by astrocytes  and astrocytes are necessary for activation of microglial cells in co-culture e.g., during borna computer virus infection . Moreover, both cell types respond to bacterial infections of the CNS [22,23,24], have direct contact in brain tissue, and were shown to interact through signaling in cell culture [25,26]. Conversation of with human astrocyte and microglial cell lines as well as with primary murine astrocytes has been previously reported, and an involvement of these cell types in infections of the CNS was shown [27,28,29,30], but so far primary astrocyte and microglial cell co-cultures were not studied. Co-cultures enable analysis of interactions with and between those most abundant and important cell types of the CNS. A further advantage of a murine primary co-culture system is the use of cells from genetically altered animals. For that reason the aim of this study was to establish murine primary astrocyte microglial cell co-cultures for infections and to compare conversation of with mono- and co-cultured astrocytes and microglial cells. 2. Results and Discussion 2.1. Association of S. suis with Primary Astrocytes and Microglial Cells For analysis of serotype 2 wildtype (wt) strain 10, its non-encapsulated mutant strain 10and a suilysin-deficient strain 10to 28.7% (Figure 2D). A comparable number of CFSE-positive cells (Physique 2E; 28.6%) was found in the 10was observed in the co-culture with a high amount of microglial cells (Physique 2F; BMS-193885 41.6%). In contrast, both encapsulated strains (strain 10 and 10with primary mouse glial cells. Various glial cell culture systems: (A) astrocyte mono-culture, (B) microglial cell mono-culture, (C) astrocyte mono-culture pre-incubated with supernatants (SN) of uninfected microglial cell cultures, (D) microglial cell mono-culture pre-incubated with SN of uninfected astrocyte cultures, (E) astrocyte-microglial cell co-culture (low amount of microglial cells), and Mouse monoclonal to IL-10 (F) astrocyte-microglial cell co-culture (high.