Tu120 - Effect of monocolonization with Akkermansia muciniphila on the diabetes incidence and immune cell subsets in ex-germ-free NOD mice and in adoptive transfers of splenocytes to NOD-SCID recipients

Barbora Drabonova – Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, Prague,; Jarmila Jarkovska – Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Nový Hrádek, Czech Republic,; Radka Cisarova – Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic,; Dusan Nemec – Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic,; Tereza Tejklova – Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic,; Jaroslav Golias – Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Prague, Czech Republic,; Tomas Hudcovic – Institute of Microbiology of the Czech Academy of Sciences, v.v.i., Nový Hrádek, Czech Republic,; Vit Neuman – Charles University and University Hospital Motol, Department of Pediatrics, 2nd Faculty of Medicine, Prague, Czech Republic,; Ondrej Cinek – Charles University and University Hospital Motol, Department of Pediatrics, 2nd Faculty of Medicine, Prague, Czech Republic,; Zdenek Sumnik – Charles University and University Hospital Motol, Department of Pediatrics, 2nd Faculty of Medicine, Prague, Czech Republic,

Abstract Text: Akkermansia muciniphila is considered as a potentially beneficial, probiotic bacterium in type 1 diabetes (T1D). In order to discriminate a direct, causative effect of Akkermansia muciniphila, from effects caused by complex changes in gut microbiota, we assessed spontaneous diabetes incidence, insulitis and carried out flow-cytometry detection of immune cell-subsets in ex-germ-free NOD mice monocolonized with Akkermansia muciniphila. Monocolonization of germ-free NOD female mice with Akkermansia muciniphila either after weaning or if followed in litters born to already monocolonized NOD females, led to slightly delayed (statistically significant at p< 0.05) onset of hyperglycemia in Akkermansia-colonized but not in Akkermansia-born mice compared to germ-free controls. On the other hand, although not statistically significant, the Akkermansia-born NOD females tend to keep a lower diabetes incidence compared to germ-free NOD females. No changes in insulitis scoring were documented. Adoptive transfer of splenocytes to NOD-SCID recipients led to only slightly lowered and delayed onset of diabetes in NOD-SCID mice that was not statistically significant. Among the T- and NK-cell subsets in lymphoid organs only minor differences were found; the most prominent being increased proportions of Foxp3 Tregs and Tr1 cells in SPF controls, but a reciprocal increase of IL-10 positive Foxp3 Tregs was found in the germ-free and Akkermansia-colonized NOD mice. In conclusion, in gnotobiotic, well-defined conditions, colonization of NOD mice with Akkermansia muciniphila surprisingly displayed only limited influence on the development of T1D (supported by grant no. NU21-01-00085 fom the Ministry of Health of the Czech Republic and no. 22-21356S from the Czech Science Foundation).