Mechanisms of mucosal invasion by pathogenic Neisseria.

Neisseria gonorrhoeae are transported across the mucosa of human fallopian tubes in organ culture by mucosal cells. The steps in this process are (1) attachment of gonococci to microvilli of nonciliated cells, (2) phagocytosis of gonococci by these cells, (3) transport of phagocytic vacuoles containing gonococci to the base of the cell, and (4) exocytosis of gonococci with phagocytic vacuoles into the subepithelial tissues. In vivo gonococci in the subepithelial tissues may cause extensive local disease (e.g., salpingitis) or invade blood vessels to cause disseminated disease. Preliminary studies of human nasopharyngeal tissue in organ culture infected with Neisseria meningitidis indicate that meningococci attach to microvilli of nonciliated cells and are phagocytized by these cells. They subsequently appear in subepithelial tissues, but the route they take is not yet certain. These observations suggest that the mechanisms of attachment to and penetration of fallopian tube and nasopharyngeal mucosa by N. gonorrhoeae and N. meningitidis are similar or possibly identical.