PECAM1 and pneumococcal meningitis: In pneumococcal meningitis, for instance, polymeric immunoglobulin receptor (pIgR) and platelet endothelial cell adhesion molecule (PECAM-1) has been identified as the receptors on the BBB endothelial cells that mediate invasion of S. pneumoniaeinto the brain (Iovino et al., 2016); a combination of anti-pIgR and PECAM-1 antibodies with β-lactam antibiotics have proven to minimize pneumococci invasion of the brain, a proof of concept of a successful blockade of host-pathogen interaction in vivo (Iovino et al., 2017, 2018).