<분자과학기술세미나> 안내 드립니다. 

♠ 주제 : Understanding B cell Biology for Rational Vaccine Design (from Empiricism to Rationalism) 
♠ 연사 : 곽기혁 교수님 (연세대학교 의과대학 미생물교실)         
♠ 일시 : 2021년 9월 14일 17:00~18:00  
♠ 초청 : 김욱교수님(내선 2513) 

Abstract 

Some pathogens such as HIV use molecular mimicry to avoid immune attack, and our immune system maintains moderately autoreactive clones that fight against these pathogens to fill the gap in the immune repertoire. Invading pathogens are displayed to B cell mostly as membrane-associated antigen, however we don’t understand how these mildly autoreactive B cells respond differentially to pathogens while maintaining tolerance to self. A variety of studies have established that B cell responses to antigens presented on membranes versus antigens in solution are quantitatively and qualitatively different. Here we show that the affinity threshold for B cell responses to membrane-associated antigens was higher than that required for soluble antigens and that the signaling outcomes were qualitatively different. B cells fluxed calcium when placed on glass surfaces that promoted cell spreading and increased membrane tension, a response that was significantly enhanced by B cell receptor (BCR) cross-linking suggesting that membrane stretching and BCR crosslinking may independently induce calcium fluxes. We show that B cells express the mechanosensitive membrane calcium channel PIEZO1 and that inhibition of the regulator of PIEZO1 inhibits calcium fluxes and downstream activation of B cells responding to membrane-associated anti-Ig but not to soluble anti-Ig. Anergic IgMlo IgD+ peripheral blood human B cells responded to BCR crosslinking by anti-Ig on membranes but not in solution and HEL-specific anergic mouse B cells were induced to undergo germinal center responses in vivo in mice immunized with membrane-associated but not soluble HEL. Taken together these studies provide evidence for a role for mechanosensitive membrane channels in B cell responses to membrane antigens that may contribute to the control of B cell anergy. 

♠ ZOOM LINK 

Topic: MST6016_ 분자과학기술세미나Ⅱ(O1413-1) [곽기혁교수님] 
Time: Sep 14, 2021 05:00 PM Seoul 
https://ajou-ac-kr.zoom.us/j/86720393146?pwd=UFA5UHpuZklWbHlYUHlub09aVXlXZz09 
Meeting ID: 867 2039 3146 
Passcode: 488159