Genetic engineering employing MPB70 and its promoter enables efficient secretion and expression of foreign antigen in bacillus Calmette Guérin (BCG) Tokyo.

Vaccination is an important factor in public health. The recombinant bacillus Calmette Guérin (rBCG) vaccine, which expresses foreign antigens, is expected to be a superior vaccine against infectious diseases. Here, we report a new recombination platform in which the BCG Tokyo strain is transformed with nucleotide sequences encoding foreign protein fused with the MPB70 immunogenic protein precursor. By RNA-sequencing, mpb70 was found to be the most transcribed among all known genes of BCG Tokyo. Small oligopeptide, namely, polyhistidine tag, was able to be expressed in and secreted from rBCG through a process in which polyhistidine tag fused with intact MPB70 were transcribed by an mpb70 promoter. This methodology was applied to develop an rBCG expressing the receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2. Immunoblotting images and mass spectrometry data showed that RBD was also secreted from rBCG. Sera from mice vaccinated with the rBCG showed a tendency of weak neutralizing capacity. The secretion was retained even after a freeze-drying process. The freeze-dried rBCG was administered to and recovered from mice. Recovered rBCG kept secreting RBD. Collectively, our recombination platform offers stable secretion of foreign antigens and can be applied to the development of practical rBCGs.

Limited proteolysis of mycobacterial DNA-binding protein 1 with an extended, lysine-rich, intrinsically disordered region to unveil posttranslational modifications.

The basic, intrinsically disordered regions of eukaryotic histones and their bacterial counterparts are presumed to act as signaling hubs to regulate the compaction of chromosomes or nucleoids and various DNA processes such as gene expression, recombination, and DNA replication. Posttranslational modifications (PTMs) on these regions are pivotal in regulating chromosomal or nucleoid compaction and DNA processes. However, the low sequence complexity and the presence of short lysine-rich repeats in the regions have hindered the accurate determination of types and locations of PTMs using conventional proteomic procedures. We described a limited proteolysis protocol using trypsin to analyze PTMs on mycobacterial DNA-binding protein 1 (MDP1), a nucleoid-associated protein in mycobacterial species that possesses an extended, lysine-rich, intrinsically disordered region in its C-terminal domain. This limited proteolysis approach successfully revealed significant methylation on many lysine residues in the C-terminal domain of MDP1 purified from Mycobacterium tuberculosis, which was lacking in the corresponding region of recombinant MDP1 expressed in Escherichia coli.

Association of disease severity with toll-like receptor polymorphisms in multidrug-resistant tuberculosis patients.

Background: The disease severity in pulmonary Multidrug-resistant tuberculosis (MDR-TB) varies from mild to severe, which is determined by host and pathogen virulence factors. The difference of symptoms felt by TB patients were interesting to investigate in discovering whether its the human immune response or bacteria's virulence gene that plays the role. The aim of this research was to analyze association between disease severity degree of pulmonary MDR-TB patients with Single nucleotide polymorphisms (SNPs) found in toll-like receptors (TLRs) gene. Method: Blood samples were obtained from pulmonary MDR-TB patients in Dr. Soetomo Hospital, Surabaya, Indonesia. Polymerase chain reaction (PCR) multiplex and target SNPs were analyze using DigiTag2 assay. The variant of esxA gene was determined using PCR and sequencing. Severity degree was determined by chest X-ray, the lesions were scored according to their severity, score of =2.5 ranking as mild, 2.5-6 as moderate and =6 as severe. Association level between SNP in TLRs gene degree of pulmonary MDR-TB was analyzed using Chi-square test. Bonferroni correction for multiple comparison was used to anticipate genotyping error. Results: A total of 22 MDR-TB patients were classified into severe degree group, while 16 patients were moderate/mild degree. SNPs in encoding gene of TLRs were mostly found in intron, specifically in TLR-1, TLR-2, and TLR-6. HWE P value in rs5743572 was 0.841; in rs3804100 was 0.0176; and in rs5743808 was 0.562. Association analysis between SNP in TLRs genes and degree of disease revealed significant association in rs5743572, SNP of TLR-1, with P < 0.05; odds ratio [OR] = 11.67 (95% confidence interval [CI]: 3.94-34.52); rs3804100, SNP of TLR-2 had P < 0.05; OR = 37.59 (95% CI: 9.30-151.88); and rs5743808, the SNP of TLR-6 had P < 0.05; OR = 31.5 (95% CI: 8.60-115.34). Conclusions: We concluded that SNPs in TLR-1, TLR-2, and TLR-6 of pulmonary MDR-TB patients was found to have an association with disease severity. TLRs polymorphism had significant association was present in TLR-1 rs5743572 in intron, TLR-2 rs3804100 in exon, and TLR-6 rs5743808 in exon and among MDR-TB isolates from patients with pulmonary MDR-TB of severe and moderate/mild degree.