CD209 and viral infectious disease: Although L. acidophilus and G. glabra were given to the infected Vero cells, the exact mechanism through which L. acidophilus fights viral infections L. acidophilus fights viral infections by blocking the pathogen's interaction with DC-specific intercellular adhesion molecule 3-grabbing non-integrin (DC-SIGN), a trans-membrane protein, through the surface layer protein (S-layer) present on the bacterial cell-envelope of L. acidophilus.