It is well known that lipopolysaccharides (LPSs) from outer membranes and capsular polysaccharides of Gram-negative bacteria activate in- nate immune system of humans and mammals and can produce septic shock clinical signs. A beneficial effect of LPSs consists in moderate stimulation of production of endogenous mediators by immune system cells, thus increasing the resistance of the organism to infections. In this respect the development of non-toxic derivatives of bacterial glycopolymers with improved immunostimulary properties becomes urgent.