Immunomodulatory properties of human commensal bacteria derived extracellular membrane vesicles

Seminar Date and Time: 02/06/2020 (Thu) 14:00 ~ 15:00
Venue: 1st Central Building 2F, 2-1 Seminar Room
Speaker (Name): Mayda Gursel
Affiliation, Title: Middle East Technical University, Ankara, Turkey/ Professor
Subject: Immunomodulatory properties of human commensal bacteria derived extracellular membrane vesicles
Abstract: Immunomodulatory commensal bacteria modify host immunity through delivery of regulatory microbial-derived products to host cells. Extracellular membrane vesicles (MVs) secreted from symbiont commensals represent one such transport mechanism. How MVs exert their anti-inflammatory effects or whether their tolerance-inducing potential can be utilized for therapeutic purposes remain poorly defined. Our study demonstrated that MVs isolated from the human lactic acid commensal bacteria Pediococcus pentosaceus, suppressed antigen-specific humoral and cellular responses. MV-treatment of bone marrow derived macrophages and bone marrow progenitors promoted M2-like macrophage polarization and myeloid-derived suppressor cell differentiation, respectively, in a TLR2-dependent manner. Consistent with their immunomodulatory activity, MV-differentiated cells up-regulated expression of IL-10, Arginase-1, PD-L1 and suppressed the proliferation of activated T cells. MVs' anti-inflammatory effects were further tested in acute inflammation models in mice. In carbon-tetrachloride-induced fibrosis and zymosan-induced peritonitis models, MVs ameliorated inflammation. In the dextran sodium sulphate-induced acute colitis model, systemic treatment with MVs prevented colon shortening and loss of crypt architecture. In an excisional wound healing model, intraperitoneal MV administration accelerated wound closure through recruitment of PD-L1 expressing myeloid cells to the wound site. Collectively, these results indicate that Pediococcus pentosaceus derived membrane vesicles hold promise as therapeutic agents in management/treatment of inflammatory conditions.
Language: English
Organizer (Host Researcher): Professor Cevayir Coban
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