Studies on the application of CRISPR in BCG with a focus on the generation of improved vaccines

• Grant number: 22/10136-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: December 01, 2022
• End date: July 31, 2027
• Field of knowledge: Biological Sciences - Biochemistry - Molecular Biology
• Principal Investigator: Luciana Cezar de Cerqueira Leite
• Grantee: Paulo Henrique Santana Silveira
• Host Institution: Instituto Butantan. Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Bacillus of Calmette and Guérin (BCG) is a live attenuated vaccine of the pathogenic strain Mycobacterium bovis. Its emergence occurred from subsequent cultures of the strain in a medium containing bovine bile, which resulted, empirically, in the attenuation of virulence and pathogenicity in animal models. In the following years, BCG became widely used, being the only vaccine against tuberculosis used in the world. Some studies indicate that BCG still inherits immune-evasive mechanisms from this pathogenic ancestor, which may decrease its effectiveness over time. While vaccinated children are shown to be protected against the more aggressive forms of the disease, adults are less protected and therefore susceptible to the pulmonary form of the disease. In adults, the variation in its effectiveness ranges from 0 to 80%. What if we could continue the work started by Calmette and Guérin on vaccine attenuation to produce an improved BCG vaccine? With the advent of the biotechnological application of CRISPR/Cas, it is possible to more easily perform multiple knock-outs and knock-ins of genes aiming at increasing the immunogenicity of the vaccine. However, there are not many studies on the application of CRISPR/Cas in mycobacteria, much less focusing on vaccine generation. In this sense, the objective of this work is to study the application of CRISPR/Cas in BCG with a focus on the generation of improved vaccines. (AU)