Harnessing Mycobacterium bovis BCG Trained Immunity to Control Human and Bovine Babesiosis

Mycobacterium bovis BCG reverses deleterious effects of H. pylori components towards gastric barrier cells in vitro

Mycobacterium bovis (M. bovis) Bacillus Calmette-Guerin (BCG) strain used in immunotherapy of bladder cancer (onco-BCG) due to its acid tolerance can be a candidate for prevention or reversion of deleterious effects towards gastric cell barrier initiated by gastric pathogen Helicobacter pylori (Hp) with high resistance to commonly used antibiotics. Colonization of gastric mucosa by Hp promotes oxidative stress, apoptosis resulting in the gastric barrier damage. The aim of this study was to examine the ability of onco-BCG bacilli to control the Hp driven gastric damage using the model of Cavia porcellus primary gastric epithelial cells or fibroblasts in vitro. These cells were treated with Hp surface antigens (glycine acid extract-GE or lipopolysaccharide-LPS) alone or with onco-BCG bacilli and evaluated for cell apoptosis and proliferation in conjunction with the level of soluble lipid peroxidation marker (s4HNE). The cell migration was determined by "wound healing assay", while cytokine response of cells, including interleukin (IL)-33, IL-1β, IL-8 and tumor necrosis factor alpha (TNF-α), by the ELISA. The apoptosis of cells pulsed in vitro with Hp surface components present in GE or with LPS was reduced after exposure of cells to mycobacteria. Similarly, the cell regeneration which was diminished by Hp LPS has been improved in response to mycobacteria. This study reveals that vaccine mycobacteria may reduce gastric barrier damage induced by Hp infection.

Trained immunity: a cutting edge approach for designing novel vaccines against parasitic diseases?

The preventive situation of parasitosis, a global public health burden especially for developing countries, is not looking that good. Similar to other infections, vaccines would be the best choice for preventing and controlling parasitic infection. However, ideal antigenic molecules for vaccine development have not been identified so far, resulting from the complicated life history and enormous genomes of the parasites. Furthermore, the suppression or down-regulation of anti-infectious immunity mediated by the parasites or their derived molecules can compromise the effect of parasitic vaccines. Comparing the early immune profiles of several parasites in the permissive and non-permissive hosts, a robust innate immune response is proposed to be a critical event to eliminate the parasites. Therefore, enhancing innate immunity may be essential for designing novel and effective parasitic vaccines. The newly emerging trained immunity (also termed innate immune memory) has been increasingly recognized to provide a novel perspective for vaccine development targeting innate immunity. This article reviews the current status of parasitic vaccines and anti-infectious immunity, as well as the conception, characteristics, and mechanisms of trained immunity and its research progress in Parasitology, highlighting the possible consideration of trained immunity in designing novel vaccines against parasitic diseases.

Advances in Babesia Vaccine Development: An Overview

Babesiosis is a tick-borne zoonotic disease, which is caused by various species of intracellular Babesia parasite. It is a problem not only for the livestock industry but also for global health. Significant global economic losses, in particular in cattle production, have been observed. Since the current preventive measures against babesiosis are insufficient, there is increasing pressure to develop a vaccine. In this review, we survey the achievements and recent advances in the creation of antibabesiosis vaccine. The scope of this review includes the development of a vaccine against B. microti, B. bovis, B. bigemina, B. orientalis and B. divergens. Here, we present different strategies in their progress and evaluation. Scientists worldwide are still trying to find new targets for a vaccine that would not only reduce symptoms among animals but also prevent the further spread of the disease. Molecular candidates for the production of a vaccine against various Babesia spp. are presented. Our study also describes the current prospects of vaccine evolution for successful Babesia parasites elimination.

Genetic Engineering in Mycobacteria

Abstract

Genetic tools for targeted modification of the mycobacterial genome contribute to the understanding of the physiology and virulence mechanisms of mycobacteria. Human and animal pathogens, such as the Mycobacterium tuberculosis complex, which causes tuberculosis, and M. leprae, which causes leprosy, are of particular importance. Genetic research opens up novel opportunities to identify and validate new targets for antibacterial drugs and to develop improved vaccines. Although mycobacteria are difficult to work with due to their slow growth rate and a limited possibility to transfer genetic information, significant progress has been made in developing genetic engineering methods for mycobacteria. The review considers the main approaches to changing the mycobacterial genome in a targeted manner, including homologous and site-specific recombination and use of the CRISPR/Cas system.

A vaccine for human babesiosis: prospects and feasibility

Babesiosis is a tick-borne disease caused by intraerythrocytic Babesia parasites. It is a well-known illness in companion animals and livestock, resulting in substantial economic losses in the cattle industry. Babesiosis is also recognized as an emerging zoonosis of humans in many countries worldwide. There is no vaccine against human babesiosis. Currently, preventive measures are focused on vector avoidance. Although not always effective, treatment includes antimicrobial therapy and exchange transfusion. In this review, we discuss the host's immune response to the parasite, vaccines being used to prevent babesiosis in animals, and lessons from malaria vaccine development efforts to inform the development of a human babesiosis vaccine. An effective human vaccine would be a significant advance towards curtailing this rapidly emerging disease.