Editorial: New Insights Into B Cell Subsets in Health and Disease

Abstract

Editorial on the Research Topic New Insights Into B Cell Subsets in Health and Disease B cells play a pivotal role in both humoral and cell-mediated immune responses. The B cell population is made up of different B cell subsets depending on their developmental or proliferation status, location and function. B cells produce "natural" antibodies as part of innate immunity, but also generate antigen-specific immunity during adaptive immune responses. B cell development starts in the bone marrow from hematopoietic stem cells. Precursor B cells then enter the circulation as transitional B cells and further mature into naive B cells. After antigen recognition, naive B cells become activated and either develop into short-lived plasma cells secreting antigen-specific antibody, or enter a germinal center (GC) reaction where antigen binding is further optimized by hypermutation of the immunoglobulin genes and affinity maturation. The GC reaction occurs in secondary lymphoid tissue and leads to the generation of high affinity, long-lived, antibody-secreting and memory B cells. Antibody effector functions can be modified by isotype switching. An increasing number of different B cell subsets have been described in recent years in relation to different pathologies such as autoimmunity, immune deficiencies and cancer. Innovative technologies are now available that enable in-depth studies in B cells. This has resulted in a complex maze of human B cell subsets with different identifying markers and functions. Therefore, the goal of this Research Topic was to highlight these recent exciting studies of B cell subsets and their role in health and disease. The contributions received for this Research Topic consisted of high-quality research papers and detailed overview papers that covered four main areas: (1) newly-identified B cell subsets, (2) mechanisms of B cell biology and pathology, (3) vaccination response and (4) B cell metabolism. NEWLY-IDENTIFIED B CELL SUBSETS Studies analyzing novel B cell subsets using deep phenotyping and single-cell transcriptomics are an important section of this Research Topic. Unraveling the phenotype and function of different B cell subsets is crucial to understand complex B cell biology and its involvement in multifactorial pathologies in order to develop disease treatment strategies. In three original publications, deep Frontiers in Immunology | www.frontiersin.org February 2022 | Volume 13 | Article 854889 1 Edited and reviewed by: