Humoral and Cell-Mediated Immunity in Mice to a 17-Kilodalton Lipoprotein of 'Francisella tularensis' Expressed by 'Salmonella typhimurium'.

摘要

A 17-kiloDalton (kDa) lipoprotein, TUL4, of the facultative intracellular bacterium Francisella tularensis is one of several membrane proteins that induce an in citro response in T-cells from F. tularensis-primed humans. A DNA fragment of the live vaccine strain F. tularensis LVS encoding TUL4 was cloned into Salmonella typhimurium. When mice were immunized with S. typhimurium, recombinant protein, some animals showed an antibody response and a T-cell response to TUL4. When the immunized mice were challenged with the live vaccine strain F. tularensis LVS, bacterial counts in the liver and spleen were lower than in animals immunized with S. typhimurium. Immunization with F. tularensis LVS caused a much stronger protection against the challenge than did immunization with S. typhimurium, recombinant protein. The present study demonstrated that the 17-kDa lipoprotein TUL4 of F. tularensis is involved in a protective immunity to tularemia.