Vaccine potential of ESAT-6 protein fused with consensus CD4+ T-cell epitopes of PE/PPE proteins against highly pathogenic Mycobacterium tuberculosis strain HN878

Advance in strategies to build efficient vaccines against tuberculosis

Tuberculosis is a chronic consumptive infectious disease, which can cause great damage to human and animal health all over the world. The emergence of multi-drug resistant strains, the unstable protective effect of Bacillus Calmette-Guérin (BCG) vaccine on adults, and the mixed infection with HIV all warn people to exploit new approaches for conquering tuberculosis. At present, there has been significant progress in developing tuberculosis vaccines, such as improved BCG vaccine, subunit vaccine, DNA vaccine, live attenuated vaccine and inactivated vaccine. Among these candidate vaccines, there are some promising vaccines to improve or replace BCG vaccine effect. Meanwhile, the application of adjuvants, prime-boost strategy, immunoinformatic tools and targeting components have been studied concentratedly, and verified as valid means of raising the efficiency of tuberculosis vaccines as well. In this paper, the latest advance in tuberculosis vaccines in recent years is reviewed to provide reliable information for future tuberculosis prevention and treatment.

The chamber of secretome in Mycobacterium tuberculosis as a potential therapeutic target

Mycobacterium tuberculosis (MTB) causes one of the ancient diseases, Tuberculosis, affects people around the globe and its severity can be understood by its classification as a second infectious disease after COVID-19 and the 13th leading cause of death according to a WHO report. Despite having advanced diagnostic approaches and therapeutic strategies, unfortunately, TB is still spreading across the population due to the emergence of drug-resistance MTB and Latent TB infection (LTBI). We are seeking for effective approaches to overcome these hindrances and efficient treatment for this perilous disease. Therefore, there is an urgent need to develop drugs based on operative targeting of the bacterial system that could result in both efficient treatment and lesser emergence of MDR-TB. One such promising target could be the secretory systems and especially the Type 7 secretory system (T7SS-ESX) of Mycobacterium tuberculosis, which is crucial for the secretion of effector proteins as well as in establishing host-pathogen interactions of the tubercle bacilli. The five paralogous ESX systems (ESX-1 to EXS-5) have been observed by in silico genome analysis of MTB, among which ESX-1 and ESX-5 are substantial for virulence and mediating host cellular inflammasome. The bacterium growth and virulence can be modulated by targeting the T7SS. In the present review, we demonstrate the current status of therapeutics against MTB and focus on the function and cruciality of T7SS along with other secretory systems as a promising therapeutic target against Tuberculosis.

Peptide-Based Vaccines for Tuberculosis

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. As a result of the coronavirus disease 2019 (COVID-19) pandemic, the global TB mortality rate in 2020 is rising, making TB prevention and control more challenging. Vaccination has been considered the best approach to reduce the TB burden. Unfortunately, BCG, the only TB vaccine currently approved for use, offers some protection against childhood TB but is less effective in adults. Therefore, it is urgent to develop new TB vaccines that are more effective than BCG. Accumulating data indicated that peptides or epitopes play essential roles in bridging innate and adaptive immunity and triggering adaptive immunity. Furthermore, innovations in bioinformatics, immunoinformatics, synthetic technologies, new materials, and transgenic animal models have put wings on the research of peptide-based vaccines for TB. Hence, this review seeks to give an overview of current tools that can be used to design a peptide-based vaccine, the research status of peptide-based vaccines for TB, protein-based bacterial vaccine delivery systems, and animal models for the peptide-based vaccines. These explorations will provide approaches and strategies for developing safer and more effective peptide-based vaccines and contribute to achieving the WHO’s End TB Strategy.

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

Tuberculosis (TB) is the global leading cause of death from an infectious agent with approximately 10 million new cases of TB and 1.45 million deaths in 2018. Bacille Calmette-Guérin (BCG) remains the only approved vaccine for Mycobacterium tuberculosis (M. tb, causative agent of TB), however clinical studies have shown BCG has variable effectiveness ranging from 0–80% in adults. With 1.7 billion people latently infected, it is becoming clear that vaccine regimens aimed at both post-exposure and pre-exposure to M. tb will be crucial to end the TB epidemic. The two main strategies to improve or replace BCG are subunit and live attenuated vaccines. However, following the failure of the MVA85A phase IIb trial in 2013, more varied and innovative approaches are being developed. These include recombinant BCG strains, genetically attenuated M. tb and naturally attenuated mycobacteria strains, novel methods of immunogenic antigen discovery including for hypervirulent M. tb strains, improved antigen recognition and delivery strategies, and broader selection of viral vectors. This article reviews preclinical vaccine work in the last 5 years with focus on those tested against M. tb challenge in relevant animal models.

Personalized Approach as a Basis for the Future Diagnosis of Tuberculosis (Literature Review)

The global spread of tuberculosis remains one of actual problems of public health despite of introduction of public health safety programs. Early, rapid and accurate identification of M. tuberculosis and determination of drug susceptibility are essential for treatment and management of this disease. Delay in delivering results prolongs potentially inappropriate antituberculosis therapy, contributing to emergence of drug resistance, reducing treatment options and increasing treatment duration and associated costs, resulting in increased mortality and morbidity. Faster, more comprehensive diagnostics will enable earlier use of the most appropriate drug regimen, thus improving patient outcomes and reducing overall healthcare costs. The treatment of infection based on the using of massive antimicrobial therapy with analysis of bacterial strains resistance to first line drugs (FLD) isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), ethambutol (EMB) and streptomycin (SM). However, the public health practitioners pay no attention to functional activity of human immune system genes. The interaction of bacterial genomes and immune system genes plays the major role in infection progress. There is growing evidence that, together with human and environmental factors, Mycobacterium tuberculosis complex strain diversity contributes to the variable outcome of infection and disease in human TB. We suppose that the future of diagnosis and treatment of tuberculosis lies in the field of personal medicine with comprehensive analysis of host and pathogen genes.