scholarly journals Immunogenic Properties of Lactobacillus plantarum Producing Surface-Displayed Mycobacterium tuberculosis Antigens

2016 ◽  
Vol 83 (2) ◽  
Author(s):  
Katarzyna Kuczkowska ◽  
Charlotte R. Kleiveland ◽  
Rajna Minic ◽  
Lars F. Moen ◽  
Lise Øverland ◽  
...  

ABSTRACT Tuberculosis (TB) remains among the most deadly diseases in the world. The only available vaccine against tuberculosis is the bacille Calmette-Guérin (BCG) vaccine, which does not ensure full protection in adults. There is a global urgency for the development of an effective vaccine for preventing disease transmission, and it requires novel approaches. We are exploring the use of lactic acid bacteria (LAB) as a vector for antigen delivery to mucosal sites. Here, we demonstrate the successful expression and surface display of a Mycobacterium tuberculosis fusion antigen (comprising Ag85B and ESAT-6, referred to as AgE6) on Lactobacillus plantarum. The AgE6 fusion antigen was targeted to the bacterial surface using two different anchors, a lipoprotein anchor directing the protein to the cell membrane and a covalent cell wall anchor. AgE6-producing L. plantarum strains using each of the two anchors induced antigen-specific proliferative responses in lymphocytes purified from TB-positive donors. Similarly, both strains induced immune responses in mice after nasal or oral immunization. The impact of the anchoring strategies was reflected in dissimilarities in the immune responses generated by the two L. plantarum strains in vivo. The present study comprises an initial step toward the development of L. plantarum as a vector for M. tuberculosis antigen delivery. IMPORTANCE This work presents the development of Lactobacillus plantarum as a candidate mucosal vaccine against tuberculosis. Tuberculosis remains one of the top infectious diseases worldwide, and the only available vaccine, bacille Calmette-Guérin (BCG), fails to protect adults and adolescents. Direct antigen delivery to mucosal sites is a promising strategy in tuberculosis vaccine development, and lactic acid bacteria potentially provide easy, safe, and low-cost delivery vehicles for mucosal immunization. We have engineered L. plantarum strains to produce a Mycobacterium tuberculosis fusion antigen and to anchor this antigen to the bacterial cell wall or to the cell membrane. The recombinant strains elicited proliferative antigen-specific T-cell responses in white blood cells from tuberculosis-positive humans and induced specific immune responses after nasal and oral administrations in mice.

2013 ◽  
Vol 79 (19) ◽  
pp. 6059-6066 ◽  
Author(s):  
Arancha Hevia ◽  
Noelia Martínez ◽  
Víctor Ladero ◽  
Miguel A. Álvarez ◽  
Abelardo Margolles ◽  
...  

ABSTRACTAutoaggregation in lactic acid bacteria is directly related to the production of certain extracellular proteins, notably, aggregation-promoting factors (APFs). Production of aggregation-promoting factors confers beneficial traits to probiotic-producing strains, contributing to their fitness for the intestinal environment. Furthermore, coaggregation with pathogens has been proposed to be a beneficial mechanism in probiotic lactic acid bacteria. This mechanism would limit attachment of the pathogen to the gut mucosa, favoring its removal by the human immune system. In the present paper, we have characterized a novel aggregation-promoting factor inLactobacillus plantarum. A mutant with a knockout of the D1 gene showed loss of its autoaggregative phenotype and a decreased ability to bind to mucin, indicating an adhesion role of this protein. In addition, heterologous production of the D1 protein or an internal fragment of the protein, characterized by its abundance in serine/threonine, strongly induced autoaggregation inLactococcus lactis. This result strongly suggested that this internal fragment is responsible for the bioactivity of D1 as an APF. To our knowledge, this is the first report on a gene coding for an aggregation-promoting factor inLb. plantarum.


2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Ding Zhou ◽  
Zhennan Jiang ◽  
Qingxiao Pang ◽  
Yuan Zhu ◽  
Qian Wang ◽  
...  

ABSTRACT Lactobacillus plantarum is a potential starter and health-promoting probiotic bacterium. Effective, precise, and diverse genome editing of Lactobacillus plantarum without introducing exogenous genes or plasmids is of great importance. In this study, CRISPR/Cas9-assisted double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) recombineering was established in L. plantarum WCFS1 to seamlessly edit the genome, including gene knockouts, insertions, and point mutations. To optimize our editing method, phosphorothioate modification was used to improve the dsDNA insertion, and adenine-specific methyltransferase was used to improve the ssDNA recombination efficiency. These strategies were applied to engineer L. plantarum WCFS1 toward producing N-acetylglucosamine (GlcNAc). nagB was truncated to eliminate the reverse reaction of fructose-6-phosphate (F6P) to glucosamine 6-phosphate (GlcN-6P). Riboswitch replacement and point mutation in glmS1 were introduced to relieve feedback repression. The resulting strain produced 797.3 mg/liter GlcNAc without introducing exogenous genes or plasmids. This strategy may contribute to the available methods for precise and diverse genetic engineering in lactic acid bacteria and boost strain engineering for more applications. IMPORTANCE CRISPR/Cas9-assisted recombineering is restricted in lactic acid bacteria because of the lack of available antibiotics and vectors. In this study, a seamless genome editing method was carried out in Lactobacillus plantarum using CRISPR/Cas9-assisted double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA) recombineering, and recombination efficiency was effectively improved by endogenous adenine-specific methyltransferase overexpression. L. plantarum WCFS1 produced 797.3 mg/liter N-acetylglucosamine (GlcNAc) through reinforcement of the GlcNAc pathway, without introducing exogenous genes or plasmids. This seamless editing strategy, combined with the potential exogenous GlcNAc-producing pathway, makes this strain an attractive candidate for industrial use in the future.


2012 ◽  
Vol 79 (4) ◽  
pp. 1086-1094 ◽  
Author(s):  
Catherine Daniel ◽  
Sabine Poiret ◽  
Véronique Dennin ◽  
Denise Boutillier ◽  
Bruno Pot

ABSTRACTLactic acid bacteria, especially lactobacilli, are common inhabitants of the gastrointestinal tract of mammals, for which they have received considerable attention due to their putative health-promoting properties. In this study, we describe the development and application of luciferase-expressingLactobacillus plantarumandLactococcus lactisstrains for noninvasivein vivomonitoring in the digestive tract of mice. We report for the first time the functionalin vitroexpression inLactobacillus plantarumNCIMB8826 and inLactococcus lactisMG1363 of the click beetle luciferase (CBluc), as well asGaussiaand bacterial luciferases, using a combination of vectors, promoters, and codon-optimized genes. We demonstrate that a CBluc construction is the best-performing luciferase system for the noninvasivein vivodetection of lactic acid bacteria after oral administration. The persistence and viability of both strains was studied by bioluminescence imaging in anesthetized mice and in mouse feces.In vivobioluminescence imaging confirmed that after a single or multiple oral administrations,L. lactishas shorter survival times in the mouse gastrointestinal tract thanL. plantarum, and it also revealed the precise gut compartments where both strains persisted. The application of luciferase-labeled bacteria has significant potential to allow thein vivoandex vivostudy of the interactions of lactic acid bacteria with their mammalian host.


Author(s):  
M Gonzalez Yanez ◽  
R Mcginn ◽  
D H Anderson ◽  
A R Henderson ◽  
P Phillips

It Is claimed that the use of the correct enzyme system as an additive on grass silage will satisfactorily control the fermentation and reduce the cell-wall fibre content, thus preserving the nutrients In the silage and aiding their utilisation by the animal (Henderson and McDonald, 1977; Huhtanen et al, 1985; Raurama et al, 1987; Chamberlain and Robertson, 1989; Gordon, 1989;).The aim of the present experiment was to assess the effect of biological additives, enzymes or a combination of enzymes with an Inoculum of lactic acid bacteria, on the composition of silage and on its nutritive value when offered to store lambs as the sole constituent of their diet.On 1st June 1988, first cut perennial ryegrass (Lolium perenne L) at pre-ear emergence was ensiled direct cut untreated (U), treated with a commercial enzyme (E) or with a commercial inoculum of lactic acid bacteria with enzymes (I) in 6t capacity bunker silos. The grass was cut with a mower and lifted with a New Holland precision chop forage harvester. The additives were pumped onto the grass using a dribble bar sited over the pick-up drum.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 963
Author(s):  
Jon Kepa Izaguirre ◽  
Leire Barañano ◽  
Sonia Castañón ◽  
Itziar Alkorta ◽  
Luis M. Quirós ◽  
...  

Soybeans and soy-based products contain isoflavones which can be used for nutraceutical and medical applications. In soybeans and in unfermented soy foods, isoflavones are normally present as glycosides. Isoflavone glycosides can be enzymatically converted to isoflavone aglycones, thus releasing the sugar molecule. The effective absorption of isoflavones in humans requires the bioconversion of isoflavone glycosides to isoflavone aglycones through the activity of the enzyme β-glucosidase. The objective was to assess the capacity of 42 bacterial strains (belonging to Lactobacillus, Streptococcus and Enterococcus) to produce β-glucosidase activity. The strain that showed the highest β-glucosidase activity (Lactobacillus plantarum 128/2) was then used for the optimization of the bioconversion of genistin and daidzin present in commercial soymilk to their aglycone forms genistein and daidzein. The contribution of process parameters (temperature, inoculum size, time) to the efficiency of such bioactivation was tested. Lactobacillus plantarum 128/2 was able to completely bioactivate soymilk isoflavones under the following conditions: 25 °C temperature, 2% inoculum size and 48 h process time. These results confirm the suitability of lactic acid bacteria for the bioactivation of isoflavones present in soymilk and provide an interesting candidate (L. plantarum 182/2) for food industries to perform this transformation.


2021 ◽  
Vol 11 (13) ◽  
pp. 5765
Author(s):  
Joo-Yun Kim ◽  
Eun-Jung Choi ◽  
Jae-Ho Lee ◽  
Myeong-Seok Yoo ◽  
Keon Heo ◽  
...  

Vitamin B2, also known as riboflavin, is essential for maintaining human health. The purpose of this study was to isolate novel lactic acid bacteria that overproduce vitamin B2 and to validate their potential as probiotics. In this study, Lactobacillus plantarum HY7715 (HY7715) was selected among lactic acid bacteria isolated from Kimchi. HY7715 showed a very high riboflavin-producing ability compared to the control strain due to the high expression of ribA, ribB, ribC, ribH, and ribG genes. HY7715 produced 34.5 ± 2.41 mg/L of riboflavin for 24 h without consuming riboflavin in the medium under optimal growth conditions. It was able to produce riboflavin in an in vitro model of the intestinal environment. In addition, when riboflavin deficiency was induced in mice through nutritional restriction, higher levels of riboflavin were detected in plasma and urine in the HY7715 administration group than in the control group. HY7715 showed high survival rate in simulated gastrointestinal conditions and had antibiotic resistance below the cutoff MIC value suggested by the European Food Safety Authority; moreover, it did not cause hemolysis. In conclusion, HY7715 could be considered a beneficial probiotic strain for human and animal applications, suggesting that it could be a new alternative to address riboflavin deficiency.


2013 ◽  
Vol 79 (18) ◽  
pp. 5670-5681 ◽  
Author(s):  
Philipp Adler ◽  
Christoph Josef Bolten ◽  
Katrin Dohnt ◽  
Carl Erik Hansen ◽  
Christoph Wittmann

ABSTRACTIn the present work, simulated cocoa fermentation was investigated at the level of metabolic pathway fluxes (fluxome) of lactic acid bacteria (LAB), which are typically found in the microbial consortium known to convert nutrients from the cocoa pulp into organic acids. A comprehensive13C labeling approach allowed to quantify carbon fluxes during simulated cocoa fermentation by (i) parallel13C studies with [13C6]glucose, [1,2-13C2]glucose, and [13C6]fructose, respectively, (ii) gas chromatography-mass spectrometry (GC/MS) analysis of secreted acetate and lactate, (iii) stoichiometric profiling, and (iv) isotopomer modeling for flux calculation. The study of several strains ofL. fermentumandL. plantarumrevealed major differences in their fluxes. TheL. fermentumstrains channeled only a small amount (4 to 6%) of fructose into central metabolism, i.e., the phosphoketolase pathway, whereas onlyL. fermentumNCC 575 used fructose to form mannitol. In contrast,L. plantarumstrains exhibited a high glycolytic flux. All strains differed in acetate flux, which originated from fractions of citrate (25 to 80%) and corresponding amounts of glucose and fructose. Subsequent, metafluxome studies with consortia of differentL. fermentumandL. plantarumstrains indicated a dominant (96%) contribution ofL. fermentumNCC 575 to the overall flux in the microbial community, a scenario that was not observed for the other strains. This highlights the idea that individual LAB strains vary in their metabolic contribution to the overall fermentation process and opens up new routes toward streamlined starter cultures.L. fermentumNCC 575 might be one candidate due to its superior performance in flux activity.


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