Requirement for memory B-cell activation in protection from heterologous influenza virus reinfection

• Published in: International immunology Vol. 31; no. 12; pp. 771 - 779
• Main Authors: Leach, Sarah, Shinnakasu, Ryo, Adachi, Yu, Momota, Masatoshi, Makino-Okamura, Chieko, Yamamoto, Takuya, Ishii, Ken J, Fukuyama, Hidehiro, Takahashi, Yoshimasa, Kurosaki, Tomohiro
• Format: Journal Article
• Language: English
• Published: UK Oxford University Press 08.11.2019
• Subjects: Animals; B-Lymphocytes - immunology; B-Lymphocytes - metabolism; Immunologic Memory - immunology; Lymphocyte Activation - immunology; Macrophages - immunology; Macrophages - metabolism; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Orthomyxoviridae - immunology; Orthomyxoviridae - physiology; infection; antibody; immunity; virus; cross-reactive
• DOI: 10.1093/intimm/dxz049
• ISSN: 1460-2377

Memory B cells protect against heterologous influenza infection Abstract While two memory compartments, memory B cells and long-lived plasma cells, are thought to contribute to the successful establishment of memory recall responses, the unique roles of each cellular compartment are still unclear. Herein, by tracing influenza anti-hemagglutinin (HA)-specific antibodies in mice, we demonstrate that pre-existing antibodies secreted by long-lived plasma cells are essential for protection from reinfection with the same influenza virus, whereas protection from secondary infection with an antigenically distinct influenza virus requires memory B-cell activation. These activated memory B cells were largely specific for the conserved HA stem region, and generated sufficient levels of antibodies for protection from heterologous reinfection. Given that the anti-stem plasmablasts derived from the memory B cells were higher affinity than those from naive B cells, our results suggest that maturation of anti-stem memory B cells during primary influenza infection and their subsequent activation are required for protection from reinfection by mutant viruses.