Interestingly, there was no correlation between the ability of GBS to adhere versusinvade astrocytic cells. The interaction of bacterial surface components with host cell receptors to initiate cell and tissue penetration is a prerequisite for development of severe invasive disease. GBS surface expressed factors shown to promote GBS attachment and/or invasion of different host cell types include the invasion associated gene, iagA, capsule, ��-hemolysin/cytolysin serine-rich repeat glycoproteins, including Srr-1, fibrinogen-binding proteins, and a recently identified fibronectin binding protein, SfbA. To investigate the importance of certain bacterial components in the adherence and invasion of human astrocytes, wild-type GBS and isogenic mutants were used. Confluent monolayers of SVG-A cells were infected with an MOI of1 of wild type COH1 and NCTC10/84strains and indicated isogenic mutants. The iagA gene encodes aglycosyl transferase that is required for the synthesis of glycolipid diglucosyl diacylglycerol, a cell membrane anchor for lipoteichoic acid. Previous studies have shown that iagA function is important to Ipratropium Bromide properly anchor LTA in the GBS cell wall, and that LTA expression on the GBS surface plays a role in bacterial interaction with BBB endothelium and the pathogenesis of neonatal meningitis. Thus our data suggest that similar interactions are important for GBS attachment and entry into astrocytic cells. Our results also demonstrate that fibronectin binding protein, SfbA, is important for invasion into astrocytes, although it did not contribute to GBS attachment. These results are similar to that observed for the role of SfbA in the interaction of GBS with host endothelial and Sulindac epithelial cells. In contrast, the unencapsulated HY106 strain displayed an increase in both adherence and invasion. This is not completely unexpected as the polysaccharide capsule likely masks bacterial surface determinants that may promote interaction with the host cell. Proteins targeted for cell surface expression in GBS are predicted to share a C-terminal sequence for sort ase recognition and anchoring to the Gram-positive cell wall.