[대학원 생명과학과 세미나 안내]
연사 : 이호석 교수(경희대학교 이과대학 생물학과)
연제 : When synthetic evolution rhymes with natural diversity
일시 : 2022년 12월 09일 (금) 오후 4시 30분
장소 : 하나과학관 A동 109호
초청교수 : 오은규 교수
Abstract
Immune systems restrict microbial pathogens by identifying ‘‘non-self’’ molecules called microbe-associated molecular patterns (MAMPs). It is unclear how immune responses are tuned to or by MAMP diversity present in commensal microbiota. We systematically studied the variability of commensal peptide derivatives of flagellin (flg22), a MAMP detected by plants. We define substantial functional diversity. Most flg22 peptides evade recognition, while others contribute to evasion by manipulating immunity through antagonism and signal modulation. We establish a paradigm of signal integration, wherein the sequential signaling outputs of the flagellin receptor are separable and allow for reprogramming by commensal-derived flg22 epitope variants. Plant-associated communities are enriched for immune evading flg22 epitopes, but upon physiological stress that represses the immune system, immune-activating flg22 epitopes become enriched. The existence of immune-manipulating epitopes suggests that they evolved to either communicate or utilize the immune system for host colonization and thus can influence commensal microbiota community composition.