biostudies-literatureMatsuzaki Cthe Institute for Fermentation, OsakaJapan Agency for Medical Research and Developmentthe Ministry of Health and Welfare of Japan and Public/Private R&amp;D Investment Strategic Expansion PrograMInstitute for Fermentation, Osaka1949097https://www.ebi.ac.uk/biostudies/studies/S-EPMC8550178biostudies-literatureUnknown13(1)<i>Leuconostoc mesenteroides</i> strain NTM048 produces an exopolysaccharide (EPS; glucose polymers 94% and fructose polymers 6%) with adjuvanticity for mucosal vaccination. Strain NTM048 includes three putative EPS-synthesizing genes, <i>gtf1</i> and <i>gtf2</i> for synthesizing glucose polymers, and <i>lvnS</i> for synthesizing fructose polymer. To elucidate the key polymer structure for adjuvanticity, two genes, <i>gtf1</i> and <i>gtf2</i>, which were annotated as glycoside hydrolase family 70 enzyme genes, were expressed in <i>Escherichia coli</i>. Glycosyl-linkage composition analysis and NMR analysis showed that the recombinant enzyme Gtf1 produced a soluble form of α-1,6-glucan, whereas the recombinant enzyme Gtf2 produced glucans with approximately equal percentages of α-1,6- and α-1,3-glucose residues both in the supernatant (S-glucan) and as a precipitate (P-glucan). Comparison of polysaccharides synthesized by Gtf1, Gtf2, and LvnS revealed that Gtf2-S-glucan, which was produced in the supernatant by Gtf2 and formed particles of 7.8 µm, possessed 1.8-fold higher ability to stimulate IgA production from murine Peyer's patch cells than native NTM048 EPS. Evaluation of adjuvanticity by intranasal administration of mice with an antigen (ovalbumin) and Gtf2-S-glucan or NTM048 EPS showed that Gtf2-S-glucan induced the production of higher antigen-specific antibodies in the airway mucosa and plasma, suggesting a pivotal role of Gtf2-S-glucan in the adjuvanticity of NTM048 EPS.Gut microbesEnzymatically synthesized exopolysaccharide of a probiotic strain <i>Leuconostoc mesenteroides</i> NTM048 shows adjuvant activity to promote IgA antibody responses.PMC8550178G-2020-3-06520gm1010007h000420ak0101068h0004Hisa KKunisawa JYamamoto KMatsuzaki CHigashimura YTomabechi YNakashima YEndo IItonori SHosomi KfalseEnzymatically synthesized exopolysaccharide of a probiotic strain <i>Leuconostoc mesenteroides</i> NTM048 shows adjuvant activity to promote IgA antibody responses.<i>Leuconostoc mesenteroides</i> strain NTM048 produces an exopolysaccharide (EPS; glucose polymers 94% and fructose polymers 6%) with adjuvanticity for mucosal vaccination. Strain NTM048 includes three putative EPS-synthesizing genes, <i>gtf1</i> and <i>gtf2</i> for synthesizing glucose polymers, and <i>lvnS</i> for synthesizing fructose polymer. To elucidate the key polymer structure for adjuvanticity, two genes, <i>gtf1</i> and <i>gtf2</i>, which were annotated as glycoside hydrolase family 70 enzyme genes, were expressed in <i>Escherichia coli</i>. Glycosyl-linkage composition analysis and NMR analysis showed that the recombinant enzyme Gtf1 produced a soluble form of α-1,6-glucan, whereas the recombinant enzyme Gtf2 produced glucans with approximately equal percentages of α-1,6- and α-1,3-glucose residues both in the supernatant (S-glucan) and as a precipitate (P-glucan). Comparison of polysaccharides synthesized by Gtf1, Gtf2, and LvnS revealed that Gtf2-S-glucan, which was produced in the supernatant by Gtf2 and formed particles of 7.8 µm, possessed 1.8-fold higher ability to stimulate IgA production from murine Peyer's patch cells than native NTM048 EPS. Evaluation of adjuvanticity by intranasal administration of mice with an antigen (ovalbumin) and Gtf2-S-glucan or NTM048 EPS showed that Gtf2-S-glucan induced the production of higher antigen-specific antibodies in the airway mucosa and plasma, suggesting a pivotal role of Gtf2-S-glucan in the adjuvanticity of NTM048 EPS.2021-01-01T00:00:00Z2021 Jan-Dec2026-04-08T08:44:43.231Z2025-02-19T01:25:51.954ZS-EPMC85501783428882010.1080/19490976.2021.1949097