Cell Envelopes of Francisella tularensis: Immunogenic Activity and Toxicity

At present, development of effective vaccines of new generation is an actual problem, in particular concerning the tularemia causative agent.It determines the need to search antigen determinants with high immunogenic activity.Some authors demonstrate that outer membrane proteins of Francisella tularensis possess immunological activity.This fact gave occasion to isolation and comprehensive study of Francisella tularensis cellular envelopes as a perspective component in vaccine engineering.Toxicity and immunogenic activity of Cell Envelopes (CE) of Francisella tularensis different subspecies is complex studied.It is shown that these preparations in doses 6.3; 19.0; 57.0 and 100 µg fail to possess toxicity.The immunizing dose (95 µg) of CE Francisella tularensis subsp.holarctica 306, Francisella tularensis subsp.mediasiatica А-61 and Francisella tularensis subsp.tularensis B-399 A-Cole protecting white mice against experimental tularemia infection was determined.It is experimentally demonstrated that 83 % animals survive only after using CE Francisella tularensis subsp.mediasiatica А-61.It is shown that F. tularensis CE preparations influence on activation of T and B lympho-cytes of white mice blood cells.New data concerning the possibility of F. tularensis antigen preparation application for increase of experimental animal resistance to F. tularensis are obtained.On the basis of the findings there is need for the further detailed investigation of immunogenic properties of CE F. tularensis subsp.holarctica 306, F. tularensis subsp.mediasiatica А-61 and F. tularensis subsp.tularensis B-399 A-Cole as perspective components in development of tularemia vaccines.