L-DBF Elicits Cross Protection Against Different Serotypes of Shigella spp

Shigellosis is a severe diarrheal disease caused by members of the genus Shigella , with at least 80 million cases and 700,000 deaths annually around world. The type III secretion system (T3SS) primary virulence factor used shigellae, we have previously demonstrated that vaccination T3SS proteins IpaB IpaD, along an IpaD/IpaB fusion protein (DBF), protects mice from infection in lethal pulmonary model. To simplify formulation development DBF vaccine, genetically fused LTA1, active subunit heat-labile toxin enterotoxigenic E. coli to produce self-adjuvanting antigen L-DBF. Here immunized L-DBF via intranasal, intramuscular, intradermal routes challenged them dose S. flexneri 2a. While none vaccinated intramuscularly or intradermally were protected, intranasally protected challenges 2a, 1b, 3a, 6, sonnei . Intranasal induced both B cell T responses correlated protection against infection. Our results suggest candidate for developing effective serotype-independent vaccine spp.