Lactobacillus species as potential candidates for vectors of vaccine against tuberculosis

The goal of the project is to develop Lactobacillus as a vector for vaccine against tuberculosis (TB). Bacteria belonging to Lactobacillus species are known to interact with immune cells leading to induction of immune responses. Many Lactobacillus spp. modulate immune system towards pro-inflammatory responses which are desired in vaccine development and may potentially enhance the response of immune system to the carried antigen. In this project we aim to investigate four Lactobacillus species as vectors for vaccine against TB and compare their immunogenicity. Lactobacillus spp. were engineered to express and surface attach Mycobacterium tuberculosis antigens. The complexity of immune system and the interplay of immune system components with different systems and organs need to be considered in studies on a potential and efficacy of vaccine candidates. Therefore, animal models need to be included. For the present study, we selected mice, strain C57BL/6. This strain is commonly used in studies on development of vaccine against TB. Moreover, this strain has been previously used in similar studies done by applicant. This may allow to compare the observations from present experiment to previous studies. The present study includes 5 experimental groups. Each group consists of 8 animals. This number has been chosen based on previous studies and is sufficient to achieve valid scientific results and perform important statistical analysis. Mice will be immunized intranasally with Lactobacillus-based vaccines and boosted three times with two weeks intervals between each immunization. Immunization regimen is established based on previous similar experiments done by applicant as well as the literature. Animals will be anesthetized prior to intranasal immunization in order to minimize animals pain and discomfort. 3 weeks after the last immunization the experiment will be terminated and animals sacrificed.