Evaluation of the genetic stability of recombinant flu vectors encoding Mycobacterium bovis proteins using RT-PCR and optimization of their cultivation conditions

Prevention by immunizing cattle against tuberculosis with traditional vaccines and regular testing has long been the main method of controlling this infection. However, the non-specificity of the traditional method shows the need for alternative approaches in the creation of anti-infective vaccines. The development of recombinant vector vaccines based on influenza vectors shows great potential and advantages in providing a specific immune response.The purpose of the study is to evaluate the growth properties of the recombinant influenza virus strains expressing protective proteins of mycobacteria for further use in creating a vector vaccine against bovine tuberculosis.This article presents the results of work on the cultivation and reproduction of recombinant influenza virus strains. Using reverse genetics methods, recombinant strains of the influenza virus carrying the mycobacterial Mycobacterium bovis ESAT-6 and TB10.4 proteins in the NS gene sequence were constructed. Based on the results of the work carried out, the optimal conditions for cultivating recombinant influenza virus strains were determined. Both variants of the recombinant strain showed reproductive activity in the developing chick embryo system, under optimal cultivation conditions.The evaluation of the genetic stability of the insertion of mycobacterial proteins into the NS gene of the influenza virus was confirmed using the RT-PCR method. As a result, it was found that the NS gene segment contains an insertion of mycobacterial proteins TB10.4 and ESAT-6, which is retained throughout the studied 5 passages.