Lisa Budzinski

Deutsches Rheuma-Forschungszentrum Berlin, ein Leibniz-Institut, Berlin, Germany

Microbiology Session: Friday, October 1st, 2021: 11:00am-12:30pm

Multi-parameter flow cytometry to understand microbiota-host crosstalk in chronic inflammatory diseases

Chronic inflammatory diseases are often accompanied by dysbiosis, i.e. alterations in the intestinal microbiota. 16S rRNA gene sequencing allows the detailed analysis of the microbial composition but neglects cellular properties of the bacteria.

We analyze cell surface properties of human intestinal microbiota on the single cell level by multi-parameter flow cytometry to gain additional insights into the phenotype of the microbiota and the potential host-microbiota crosstalk. We want to understand the recognition of bacteria by the host and interpret the immunological context of this recognition by selectively analyzing the coating of bacteria by host immunoglobulin isotypes IgA1, IgA2, IgG and IgM. Further, we use lectins to characterize microbial surface sugars, which may relate to metabolic conditions, adhesion, and bacteria-host-crosstalk. We observe distinct populations of bacteria with increased lectin binding and enhanced host immunoglobulin coating in stool samples of patients with chronic inflammatory diseases, such as juvenile idiopathic arthritis, IgG4-related diseases and inflammatory bowel diseases. Thus, we hypothesize that lectin-bound bacteria induce an enhanced immune recognition and are critical in the induction and maintenance of chronic inflammation. We will address our hypothesis by analyzing the reactivity of memory T cells towards sorted Ig- or lectin-high bacteria.