The relationship between surface immunoglobulin isotype and immune function of murine B lymphocytes V. IgD‐bearing cells in immunological tolerance

Abstract

The role of IgD (delta) in the induction of tolerance in murine B lymphocytes was explored in the in vivo adoptive antibody response to bovine serum albumin (BSA). Delta+ or delta- B cells purified on the fluorescence-activated cell sorter were injected, with or without purified T cells, into lethally irradiated intermediate hosts, which were rendered tolerant by an injection of deaggregated BSA one day after the cell transfer. Spleen cells from the intermediate hosts were treated with anti-Thy-1.2 antiserum and complement mixed with normal T cells and were transferred to final hosts. The ability of the B cells of the final hosts to respond to the tolerogen BSA and to dinitrophenylated human gamma globulin antigen was examined. This approach enabled examination of the function of the B cell subpopulations in an environment free of tolerogen and of induced T suppressor cells. The results revealed that in the presence of T cells the delta+ subpopulation was highly resistant to tolerance induction, whereas the delta- subpopulation was highly susceptible to tolerance induction. However, there was no difference in susceptibility to tolerance induction between the two subpopulations when tolerance was induced in the absence of T cells.

Human IgM+CD27+ B Cells: Memory B Cells or “Memory” B Cells?

“…Thus, the most likely source of the Ag-specific IgM-secreting B cells would be IgM ϩ CD27 ϩ B cells, suggesting that they can efficiently respond to TD Ag. These findings are entirely consistent with data obtained in rodents, indicating that IgM-expressing memory B cells can be generated following immunization with TD Ag (6,9,(31)(32)(33)(34).…”

“…They provide the first evidence of somatically mutated B cells expressing IgM, thereby suggesting 1) the existence of IgM memory B cells; and 2) that memory to TD Ag may not be restricted to isotype-switched B cells (11, 26 -29). These conclusions were also supported by in vivo studies of murine memory B cells, which found that IgM-memory B cells comprise a substantial proportion of secondary responses to TD Ag (6,9,(31)(32)(33)(34).…”

CD11c+ T-bet+ memory B cells: Immune maintenance during chronic infection and inflammation?

“…ELISA performed on day 12 post-antigen challenge revealed a major reduction of the amnestic antigen-specific IgG2c response, formally demonstrating that CD11c+ B cells were required for recall responses, demonstrating that the population contained antigen-specific IgM memory B cells [48]. Similarly-defined memory B cells had been described in the literature [51, 52], but the cells received limited attention in mouse model studies prior to two reports in 2009 and 2011 [49, 53]. Those studies revealed that IgM memory cells were a major reservoir of long-term immunity.…”

Immunoglobulin D-deficient mice can mount normal immune responses to thymus-independent and -dependent antigens.

“…Experiments in vitro have shown that the signals mediated by engagement of surface IgD (sIgD) differ from those mediated by surface IgM: only the latter caused apoptotic death of the cells (7,8). In vivo the functions attributed to the engagement of sIgD vary from the acquisition of resistance to tolerance induction (10)(11)(12) and the initiation ofthe B-cell response (13) to a role in B-cell memory (6,14,15). Some ofthese functions were studied by using chronic anti-IgD treatment from birth (16,17), by in vitro sorting of sIgD+ and sIgD-B cells (10,18,19), by enzymatic removal of sIgD in vitro (11), or by transgenic mouse models (20).…”

“…In vivo the functions attributed to the engagement of sIgD vary from the acquisition of resistance to tolerance induction (10)(11)(12) and the initiation ofthe B-cell response (13) to a role in B-cell memory (6,14,15). Some ofthese functions were studied by using chronic anti-IgD treatment from birth (16,17), by in vitro sorting of sIgD+ and sIgD-B cells (10,18,19), by enzymatic removal of sIgD in vitro (11), or by transgenic mouse models (20). Discrepancies of results were found in these studies that could be generated by the nature of the indirect experimental systems used.…”