Intranasal vaccination with Listeria ivanovii as vector of Mycobacterium tuberculosis antigens promotes specific lung-localized cellular and humoral immune responses

Abstract

We have previously demonstrated that a recombinant Listeria ivanovii (LI) strain expressing the ESAT-6 or Ag85C protein of Mycobacterium tuberculosis (Mtb) as a tuberculosis (TB) vaccine candidates induced antigen-specific cellular immune responses after intravenous immunization of mice. However, whether such recombinant strains could induce desired immune responses in the lung, where TB infection occurs, is not clear. In this paper, C57BL/6 J mice were intranasally vaccinated with attenuated LIΔactAplcB-Rv3875 (Δ refers to gene deletion in the bacterial genome) or LIΔactAplcB-Rv0129c, the two vaccine candidates that utilize LI as an antigen delivery vector. Bacterial load in the target organs, histological changes in the infected organs, the percentage of specific cytokine-secreting T cells in the lung and spleen, IgG levels in the serum and secretory IgA (SIgA) levles in bronchoalveolar lavage (BAL) fluid were determined at specific days post inoculation (dpi). The results showed that both strains were mainly confined to the lung and were eliminated at 10 dpi. The histological damage caused by the infection in the lung was slight and recovered by day 5. Intranasal vaccination of the mice twice at an interval of 4 weeks notably elicited TB antigen-specific CD4 + and CD8 + T cell responses in the lung and SIgA secretion in the pulmonary mucosa, and significantly enhanced the percentage of double-functional CD8 + t cells (IFN-γ + TNF-α + CD8 + ). To our knowledge, this is the first report regarding the used of LI vector vaccines to induce promising lung-localized cellular and humoral immune responses by intranasal vaccination. These data suggest that LI could be a novel and promising live vector to construct an intranasal vaccine against respiratory diseases.Mice. Six-to eight-week-old female C57BL/6 J mice were purchased from the Animal Centre of Sichuan Province Hospital (Chengdu, China). All mice were maintained under specific pathogen-free conditions throughout the experiments at the Animal Centre of the School of Public Health at Sichuan University. Mouse experiments were performed according to the guidelines of the Animal Care and Use Committee of Sichuan University, and the protocols for mouse experiments were approved by this committee as well.Strains. LIΔ-Rv3875 and LIΔ-Rv0129c, expressing Mtb ESAT-6 or Ag85C protein respectively were constructed as described in a previous study 17 . LIΔ was constructed and maintained in our laboratory as a vector control 17 . All strains were cultured at 37 °C with shaking at 180 r/m in brain heart infusion (BHI) broth. Scientific RepoRtS |(2020) 10:302 | https://doi.

Heterologous Boosting With Listeria-Based Recombinant Strains in BCG-Primed Mice Improved Protection Against Pulmonary Mycobacterial Infection

“…Several studies reported that repeated immunization with the same attenuated LM-based TB vaccine candidate could induce potent antigen-specific T cell responses by intraperitoneal ( 14 ), intracutaneous ( 12 ) vaccination as well as intravenous ( 13 ) inoculation. Similar to these results, Jiang et al ( 15 ) found that mice vaccinated intranasally with the same LI-vectored TB vaccine candidate induced promising lung-localized cellular and humoral immune responses. As shown in Figure 4 , our results also confirmed that repeated immunization with the same strain was more effective than single-dose immunization.…”

“…Attenuated LM has been developed as a vaccine vector for TB vaccine candidates ( 11 – 14 ). Recently, we constructed two attenuated LI recombinant strains expressing Ag85A or ESAT-6, which induced potent CD4 + and CD8 + T cell responses either in the spleen after intravenous immunization ( 10 ) or in the lung after intranasal vaccination ( 15 ). Therefore, the facultative intracellular Listeria strain is considered as a promising delivery system since it induces strong CD4 + and CD8 + cell-mediated immune response ( 9 – 11 ).…”

“…Results are expressed as average of three independent reactions. The left lung of each mice was excised and examined for histological lesions as described before ( 15 ). Briefly, Lung sections were stained with hematoxylin-eosin.…”

Preclinical Progress of Subunit and Live Attenuated Mycobacterium tuberculosis Vaccines: A Review following the First in Human Efficacy Trial

“…As an alternative to viral vector vaccines, attenuated bacterial vector vaccines are also being considered. An intriguing bacterial vector for TB vaccine development is attenuated Listeria [105,111]. Listeria-vectored vaccines are well established to be safe in immunocompetent humans, inexpensive to produce, present antigens to both MHC-I and MHC-II, and importantly, prior immunity to the vector also does not affect its efficacy unlike viral vectors [105].…”

High-Throughput Screen for Cell Wall Synthesis Network Module in Mycobacterium tuberculosis Based on Integrated Bioinformatics Strategy

“…The nine genes contained in this module are all involved in the biosynthetic process for arabinose. For example, the Rv0129c coding protein plays a role in the addition of mycosyl residues in the cell wall arabinose (Jiang et al, 2020) and Rv3806c plays a role in the synthesis of decenyl phosphate D-arabinose (Safi et al, 2013).…”