Human IgM+CD27+ B cells: memory B cells or "memory" B cells?
نویسندگان
چکیده
Memory B cells are generated in germinal centers (GC) and contribute to serological immunity by rapidly differentiating into plasma cells. Human memory B cells can be identified by the expression of CD27. These cells exhibit more rapid responses than naive (CD27-) B cells following stimulation in vitro, consistent with the heightened kinetics of secondary responses in vivo. CD27+ B cells express mutated Ig V region genes; however a significant proportion continue to express IgM, suggesting the existence of IgM+ memory B cells. The observation that mutated IgM+CD27+ B cells are generated in humans who cannot form GC led to the conclusions that these cells are generated independently of GC and thus are not memory cells and that they mediate responses to T cell-independent Ag. Although some studies support the idea that IgM+CD27+ B cells participate in T cell-independent responses, many others do not. In this review we will provide alternate interpretations of the biology of IgM+CD27+ B cells and propose that they are indeed memory cells.
منابع مشابه
Molecular footprints of a germinal center derivation of human IgM+(IgD+)CD27+ B cells and the dynamics of memory B cell generation
The origin of IgM(+)CD27(+) B lymphocytes with mutated IgV genes, which account for approximately 20% of human peripheral blood (PB) B cells, is controversially discussed. A generation in a primary diversification pathway, in T cell-independent immune responses, or in T cell-dependent germinal center (GC) reactions has been proposed. We show here that IgM(+)IgD(+)CD27(+) and IgM(+)IgD(-/low)CD2...
متن کاملHuman Immunoglobulin (Ig)M+IgD+ Peripheral Blood B Cells Expressing the CD27 Cell Surface Antigen Carry Somatically Mutated Variable Region Genes: CD27 as a General Marker for Somatically Mutated (Memory) B Cells
Immunoglobulin (Ig)M+IgD+ B cells are generally assumed to represent antigen-inexperienced, naive B cells expressing variable (V) region genes without somatic mutations. We report here that human IgM+IgD+ peripheral blood (PB) B cells expressing the CD27 cell surface antigen carry mutated V genes, in contrast to CD27-negative IgM+IgD+ B cells. IgM+IgD+CD27(+) B cells resemble class-switched and...
متن کاملFunctional capacities of human IgM memory B cells in early inflammatory responses and secondary germinal center reactions.
The generation and functions of human peripheral blood (PB) IgM(+)IgD(+)CD27(+) B lymphocytes with somatically mutated IgV genes are controversially discussed. We determined their differential gene expression to naive B cells and to IgM-only and IgG(+) memory B cells. This analysis revealed a high similarity of IgM(+)(IgD(+))CD27(+) and IgG(+) memory B cells but also pointed at distinct functio...
متن کاملPeripheral Blood B Cells Expressing the CD27 Cell Surface Antigen Carry Somatically Mutated Variable Region Genes: CD27 as a General Marker for Somatically Mutated (Memory) B Cells
Immunoglobulin (Ig)M 1 IgD 1 B cells are generally assumed to represent antigen-inexperienced, naive B cells expressing variable (V) region genes without somatic mutations. We report here that human IgM 1 IgD 1 peripheral blood (PB) B cells expressing the CD27 cell surface antigen carry mutated V genes, in contrast to CD27-negative IgM 1 IgD 1 B cells. IgM 1 IgD 1 CD27 1 B cells resemble class-...
متن کاملComment on "phenotypic analysis of pneumococcal polysaccharide-specific B cells".
The phenotype of B cells responsible for the production of anti-pneumococcal polysaccharide Ab has been unclear. Although individuals that respond poorly to the 23-valent pneumococcal polysaccharide (PPS) vaccine, Pneumovax, such as children <2 y, the asplenic, and a subset of common variable immunodeficiency patients, are profoundly deficient or lack IgM memory cells (CD27(+)IgM(+)), they are ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of immunology
دوره 179 1 شماره
صفحات -
تاریخ انتشار 2007