743 0007-4888/18/16460743--©-2018--Springer-Science+Business-Media,-LLC Bulletin  of  Experimental  Biology  and  Medicine,  Vol.  164,  No.  6,  April,  2018 VIROLOGY Modeling of 3D Structure of Chimeric Constructs Based on Hemagglutinin of Infuenza Virus and Immunogenic Epitopes of Streptococcus Agalactiae E. A. Fedorova 1 , T. A. Smolonogina 1 , I. N. Isakova-Sivak 1 , D. A. Koren’kov 1 , T. S. Kotomina 1 , G. F. Leont’eva 2 , A. N. Suvorov 2 , and L. G. Rudenko 1 Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 164, No. 12, pp. 712-717, December, 2017 Original article submitted June 28, 2017 A project of an experimental recombinant vector vaccine for prevention of diseases caused by pathogenic streptococci based on ScaAB lipoprotein of Streptococcus agalactiae and a cold- adapted strain of live infuenza vaccine as a vector was developed. The sequence of ScaAB lipoprotein was analyzed and fragments forming immunodominant epitopes were determined. Chimeric molecules of infuenza virus hemagglutinin H7 carrying insertions of bacterial origin were constructed. Based on the results of simulation, the most promising variants were selected; they represented fragments of lipoprotein ScaAB lacking N-terminal domain bound to hemagglutinin via a fexible linker. These insertions should minimally modulate the properties of the infuenza strain, while retaining potential immunogenicity to a wide group of pathogenic streptococci. Key Words: vector vaccine; infuenza viruses; group B Streptococci 1 A. A. Smorodintsev Department of Virology, 2 Department of Mo- lecular Microbiology, Institute of Experimental Medicine, St. Peters- burg, Russia. Address for correspondence: fedorova.iem@gmail. com. E. A. Fedorova Group B streptococci (Streptococcus agalactiae) the most common bacterial pathogens that causes a variety of severe diseases of newborns, pregnant women, and elderly people. The most dangerous manifestations of infection are sepsis and meningitis of newborns, as well as septicemia that develops in frail elderly patients. The development of antibiotic resistance in Streptococcus strains raises a question of effective prevention of the infection. The development of vac- cines against streptococcal infection requires special techniques: traditional approaches cannot be used due to unsatisfactory safety or immunogenicity of the preparations [6]. An alternative approach is the use of vector vac- cine. Competent design of the vaccine allows achiev- ing complex stimulation of the immune response while maintaining safety. Cold-adapted infuenza vi- rus, live attenuated infuenza vaccine (LAIV) strain, can be used as the vector system. The safety of the vaccine is confrmed by long experience of long-term use of the drug in humans, as well as the presence of many attenuating mutations in genes of the vaccine strain [11,12]. The possibility of genetic manipula- tions with this cold-adapted strain is provided by the previously developed reverse genetic system [7]. Alien genetic information can be inserted in various genetic segments of the infuenza A virus. Infuenza A viruses with recombinant genes of hemaggluti- nin, neuraminidase, and nonstructural protein were constructed [3,4]. Viruses with recombinant hemag- glutinin stimulate humoral immunity to the inserted DOI 10.1007/s10517-018-4071-4