Y levels within 10 d. Subsequent in vitro studies of antibodies derived from these recipient mice showed that B10 cell-derived serum contains antigen-specific IgM and IgG, as well as IgM that is significantly enriched for autoreactivity when compared to IgM derived from non-B10 cells. This is consistent with the observation that B10 cells represent a population of B cells with diverse, predominantly germline BCRs, including those with reactivity for self-antigens. Thus, B10 cells secrete both foreign antigen-specific and autoreactive antibodies. Despite the demonstrated importance of BCR signals in B10 cell activity, B10 cells are not measurably restricted in their usage of BCR genes. Single-cell repertoire analyses in spleen and peritoneal cavity B10 cell populations have revealed diverse heavy and light chain gene usage with a remarkable absence of H 4065 molecular weight somatic mutations in B10 cell immunoglobulin genes (24, 27). Even in the peritoneal cavity, where some restricted gene usage has been reported in B1a and B1b cells, IL-10+ B cells contain diverse BCR genes associated with both the B1 and the B2 subsets. These studies bolster the hypothesis that B10 cells are a functionallydefined population and are not a restricted lineage with a single cell type of origin.NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptB10 cell regulation of immune responsesThe observation that B-cell-derived IL-10 could suppress T-cell-mediated inflammation in a diverse array of mouse models led us to study the role of B10 cells in autoimmunity, hematologic malignancy, and infection. In the context of autoimmunity and transplantation, B-cell-derived IL-10 acts on a local, antigen-specific level to combat T-cell autoimmune responses and dampen inflammation (26). During infection, however, B10 cells have significant regulatory effects on the innate immune system that can negatively affect the clearance of certain pathogens (29). In a separate mouse model of hematologic malignancy, B10 cells were enriched during chronic lymphocytic leukemia (30). Thus, B10 cell interactions with the immune system are context-dependent, and additional studies have expanded upon those described above to conclusively demonstrate a potent and importantImmunol Rev. Author manuscript; available in PMC 2015 May 01.Candando et al.Pagefunction for B10 cells in immune system homeostasis as well as the suppression of both appropriate and deleterious immune responses (31?6).NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptB10 cell regulation of autoimmunity A role for B10 cells in the regulation of autoimmunity was first observed by characterizations of B10 cell numbers in several autoimmune-prone mouse R848 chemical information strains. Both CD1dhi CD5+ and IL-10+ spleen B cells are significantly increased in non-obese diabetic mice as well as in NZB/W F1 and MRL.lprfas mice, both of which are prone to lupuslike disease (20). Subsequent studies to understand how both endogenous and adoptively transferred B10 cells regulate autoimmunity have revealed that B-cell-derived IL-10 is a potent inhibitor of autoimmune inflammation with great promise for translation into human therapies. EAE The role of B10 cells during autoimmunity has been investigated most thoroughly in the antigen-specific model of MS, EAE. In this experimental system, mice are immunized with myelin oligodendrocyte (MOG) peptides, and autoimmune disease development is typically observed over a 28 days time course. H.Y levels within 10 d. Subsequent in vitro studies of antibodies derived from these recipient mice showed that B10 cell-derived serum contains antigen-specific IgM and IgG, as well as IgM that is significantly enriched for autoreactivity when compared to IgM derived from non-B10 cells. This is consistent with the observation that B10 cells represent a population of B cells with diverse, predominantly germline BCRs, including those with reactivity for self-antigens. Thus, B10 cells secrete both foreign antigen-specific and autoreactive antibodies. Despite the demonstrated importance of BCR signals in B10 cell activity, B10 cells are not measurably restricted in their usage of BCR genes. Single-cell repertoire analyses in spleen and peritoneal cavity B10 cell populations have revealed diverse heavy and light chain gene usage with a remarkable absence of somatic mutations in B10 cell immunoglobulin genes (24, 27). Even in the peritoneal cavity, where some restricted gene usage has been reported in B1a and B1b cells, IL-10+ B cells contain diverse BCR genes associated with both the B1 and the B2 subsets. These studies bolster the hypothesis that B10 cells are a functionallydefined population and are not a restricted lineage with a single cell type of origin.NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptB10 cell regulation of immune responsesThe observation that B-cell-derived IL-10 could suppress T-cell-mediated inflammation in a diverse array of mouse models led us to study the role of B10 cells in autoimmunity, hematologic malignancy, and infection. In the context of autoimmunity and transplantation, B-cell-derived IL-10 acts on a local, antigen-specific level to combat T-cell autoimmune responses and dampen inflammation (26). During infection, however, B10 cells have significant regulatory effects on the innate immune system that can negatively affect the clearance of certain pathogens (29). In a separate mouse model of hematologic malignancy, B10 cells were enriched during chronic lymphocytic leukemia (30). Thus, B10 cell interactions with the immune system are context-dependent, and additional studies have expanded upon those described above to conclusively demonstrate a potent and importantImmunol Rev. Author manuscript; available in PMC 2015 May 01.Candando et al.Pagefunction for B10 cells in immune system homeostasis as well as the suppression of both appropriate and deleterious immune responses (31?6).NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptB10 cell regulation of autoimmunity A role for B10 cells in the regulation of autoimmunity was first observed by characterizations of B10 cell numbers in several autoimmune-prone mouse strains. Both CD1dhi CD5+ and IL-10+ spleen B cells are significantly increased in non-obese diabetic mice as well as in NZB/W F1 and MRL.lprfas mice, both of which are prone to lupuslike disease (20). Subsequent studies to understand how both endogenous and adoptively transferred B10 cells regulate autoimmunity have revealed that B-cell-derived IL-10 is a potent inhibitor of autoimmune inflammation with great promise for translation into human therapies. EAE The role of B10 cells during autoimmunity has been investigated most thoroughly in the antigen-specific model of MS, EAE. In this experimental system, mice are immunized with myelin oligodendrocyte (MOG) peptides, and autoimmune disease development is typically observed over a 28 days time course. H.
