SALMONELLA-TYPHI TY2 OMPC PORIN INDUCES BACTERICIDAL ACTIVITY ON U937MONOCYTES

The immunogenic effect of Salmonella typhi OmpC porin during typhoid f ever in humans was evaluated in vitro, Peripheral blood mononuclear ce lls from 17 patients were challenged with outer membrane preparations from Escherichia coil UH302 and UH302/pSTP2K2 strains, both lacking E. coil OmpF and OmpC porins, although UH302/pSTP2K2 expressed a plasmid -encoded S. typhi Ty2 OmpC, The mononuclear cell supernatants, immuniz ed in vitro with OmpC antigen, derived from 10 out of 17 patients acti vated U937 bactericidal capacity, In contrast, the supernatants from t he immunization with outer membrane preparation lacking S. typhi Ty2 O mpC induced a significantly reduced bactericidal capacity of U937 cell s, This procedure should prove useful for in vitro characterization of cellular immunogens from exclusive human pathogens.