Memory B Cells in Local and Systemic Sites

• Published in: Advances in experimental medicine and biology Vol. 1254; p. 55
• Main Authors: Moriyama, Saya, Adachi, Yu, Tonouchi, Keisuke, Takahashi, Yoshimasa
• Format: Journal Article
• Language: English
• Published: United States 01.01.2020
• Subjects: Memory B cell; Local tissue-resident memory; Germinal center; Vaccination; Recall response
• ISSN: 0065-2598
• DOI: 10.1007/978-981-15-3532-1_5

Memory B cells are a key cellular component of the protective humoral responses to infectious pathogens. Most of our knowledge of memory B-cell responses comes from studies using mono-epitopic model antigens that elicit systemic humoral responses dominated by canonical B-cell antigen receptors. This approach successfully dissected the systemic responses of memory B cells and greatly advanced our understanding of memory B-cell formation, maintenance, and reactivation to re-invading antigens in the secondary lymphoid organs. However, the canonical memory B-cell responses fail to fully recapitulate the heterogeneity of the protective memory responses. Indeed, accumulating studies using "natural" antigens and live pathogens have uncovered new aspects of memory B-cell responses, which are achieved by memory B cells with different phenotypes, tissue residence, and responsiveness to antigen stimulation. Such non-canonical memory B-cell responses are frequently observed in local sites where live pathogens initially infect and replicate. Importantly, the local memory B-cell responses often serve as the first line of defense against re-infecting pathogens, thereby playing an essential role in controlling the pathogens. Here, we provide a comprehensive overview of the systemic and local memory B-cell responses in the humoral protective immunity against pathogens.