CD22 is required for formation of memory B cell precursors within germinal centers

• Published in: PloS one Vol. 12; no. 3; p. e0174661
• Main Authors: Chappell, Craig P, Draves, Kevin E, Clark, Edward A
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.03.2017; Public Library of Science (PLoS)
• Subjects: Animals; Antigens; B cells; B-Lymphocytes - immunology; B-Lymphocytes - metabolism; Biology and Life Sciences; Bone marrow; Cell Differentiation - immunology; Cell division; Differentiation; Experiments; Germinal Center - immunology; Germinal Center - metabolism; Homeostasis; Immune response; Immune system; Immunization; Immunology; Influenza; Ligands; Lymph nodes; Lymphocyte receptors; Lymphocytes; Lymphocytes T; Medicine; Medicine and Health Sciences; Mice; Mice, Inbred C57BL; Phosphatase; Precursor Cells, B-Lymphoid - immunology; Precursor Cells, B-Lymphoid - metabolism; Precursors; Research and Analysis Methods; Rodents; Sialic Acid Binding Ig-like Lectin 2 - metabolism; Signal transduction; T cells
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0174661

CD22 is a BCR co-receptor that regulates B cell signaling, proliferation and survival and is required for T cell-independent Ab responses. To investigate the role of CD22 during T cell-dependent (TD) Ab responses and memory B cell formation, we analyzed Ag-specific B cell responses generated by wild-type (WT) or CD22-/- B cells following immunization with a TD Ag. CD22-/- B cells mounted normal early Ab responses yet failed to generate either memory B cells or long-lived plasma cells, whereas WT B cells formed both populations. Surprisingly, B cell expansion and germinal center (GC) differentiation were comparable between WT and CD22-/- B cells. CD22-/- B cells, however, were significantly less capable of generating a population of CXCR4hiCD38hi GC B cells, which we propose represent memory B cell precursors within GCs. These results demonstrate a novel role for CD22 during TD humoral responses evident during primary GC formation and underscore that CD22 functions not only during B cell maturation but also during responses to both TD and T cell-independent antigens.