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Epigenetic Regulation of Antibody Responses by the Histone H2A Deubiquitinase MYSM1.

Jiang XX, Chou Y, Jones L, Wang T, Sanchez S, Huang XF, Zhang L, Wang C, Chen SY - Sci Rep (2015)

Bottom Line: In this study, we found that mice deficient in the histone H2A deubiquitinase MYSM1, despite their severe defect in B cell development, exhibit an enhanced antibody response against both T cell-dependent and independent antigens.Mechanistic studies demonstrated that MYSM1 is a transcriptional activator of Pax5, the repressors of plasma cell differentiation, by facilitating key transcriptional factor recruitment and coordinating histone modifications at the Pax5 loci.Importantly, this study further provides a new target and strategy to modulate antibody production and responses with profound therapeutic implications.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA.

ABSTRACT
B cell-mediated antibody response plays critical roles in protective immunity, as well as in the pathogenesis of allergic and autoimmune diseases. Epigenetic histone and DNA modifications regulate gene transcription and immunity; however, so far, little is known about the role of epigenetic regulation in antibody responses. In this study, we found that mice deficient in the histone H2A deubiquitinase MYSM1, despite their severe defect in B cell development, exhibit an enhanced antibody response against both T cell-dependent and independent antigens. We revealed that MYSM1 intrinsically represses plasma cell differentiation and antibody production. Mechanistic studies demonstrated that MYSM1 is a transcriptional activator of Pax5, the repressors of plasma cell differentiation, by facilitating key transcriptional factor recruitment and coordinating histone modifications at the Pax5 loci. Hence, this study uncovers a critical role for MYSM1 in epigenetically repressing plasma cell differentiation and antibody production, in addition to its opposing, active role in B cell development. Importantly, this study further provides a new target and strategy to modulate antibody production and responses with profound therapeutic implications.

No MeSH data available.


Related in: MedlinePlus

Enhanced primary TI and TD antibody responses in Mysm1βˆ’/βˆ’ mice despite the severe defect in FO B cell development.(a) Representative flow cytometry analysis of WT and Mysm1βˆ’/βˆ’ splenocytes stained with indicated antibodies from four independent experiments. Numbers are the percentage of events within the indicated gates. (b) Absolute numbers (top) of indicated B cell subsets in spleen of Mysm1βˆ’/βˆ’ mice and WT littermates and fold reduction (bottom) of Mysm1βˆ’/βˆ’ cell numbers compared to WT cell numbers (n = 5–8 per group) from one of three independent experiments. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (c) Graphs show the absolute numbers of B220+ B cells in the spleen (left) and bone marrow (right) from WT and Mysm1βˆ’/βˆ’ mice. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (d) Serum from naΓ―ve WT and Mysm1βˆ’/βˆ’ mice was analyzed for resting levels of IgM, IgG3, and IgG1 by ELISA. (e) Mice were immunized with NP-Ficoll (50 μg) and serum was collected at day 14 for examining NP-specific IgM and IgG3 levels by ELISA with plates coated with NP26-BSA. (f) WT and Mysm1βˆ’/βˆ’ mice were immunized with NP-KLH (100 μg) precipitated in Alum. Serum was harvested at day 14 after immunization to quantitate NP-specific IgM, IgG3, IgG1, IgG2a, and IgG2b antibodies by ELISA. (g,h) ELISPOT analysis of anti-NP IgM (top) and IgG (bottom) production by cells pooled from spleens or lymph nodes of WT and Mysm1βˆ’/βˆ’ mice 14 d after immunization with NP-Ficoll (g) or NP-KLH (h). **p < 0.01, *p < 0.05, Mysm1βˆ’/βˆ’vs. WT.
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f1: Enhanced primary TI and TD antibody responses in Mysm1βˆ’/βˆ’ mice despite the severe defect in FO B cell development.(a) Representative flow cytometry analysis of WT and Mysm1βˆ’/βˆ’ splenocytes stained with indicated antibodies from four independent experiments. Numbers are the percentage of events within the indicated gates. (b) Absolute numbers (top) of indicated B cell subsets in spleen of Mysm1βˆ’/βˆ’ mice and WT littermates and fold reduction (bottom) of Mysm1βˆ’/βˆ’ cell numbers compared to WT cell numbers (n = 5–8 per group) from one of three independent experiments. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (c) Graphs show the absolute numbers of B220+ B cells in the spleen (left) and bone marrow (right) from WT and Mysm1βˆ’/βˆ’ mice. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (d) Serum from naΓ―ve WT and Mysm1βˆ’/βˆ’ mice was analyzed for resting levels of IgM, IgG3, and IgG1 by ELISA. (e) Mice were immunized with NP-Ficoll (50 μg) and serum was collected at day 14 for examining NP-specific IgM and IgG3 levels by ELISA with plates coated with NP26-BSA. (f) WT and Mysm1βˆ’/βˆ’ mice were immunized with NP-KLH (100 μg) precipitated in Alum. Serum was harvested at day 14 after immunization to quantitate NP-specific IgM, IgG3, IgG1, IgG2a, and IgG2b antibodies by ELISA. (g,h) ELISPOT analysis of anti-NP IgM (top) and IgG (bottom) production by cells pooled from spleens or lymph nodes of WT and Mysm1βˆ’/βˆ’ mice 14 d after immunization with NP-Ficoll (g) or NP-KLH (h). **p < 0.01, *p < 0.05, Mysm1βˆ’/βˆ’vs. WT.

Mentions: In the absence of MYSM1, there is a block in early B cell development with a severe reduction in the frequency and absolute number of both peripheral immature and mature B cells21. In order to further define the role of MYSM1 in peripheral B cell subpopulation development, we analyzed splenic subpopulations of B cells in WT and Mysm1βˆ’/βˆ’ mice by flow cytometry. We observed a drastic decrease in the percentages and numbers of immature, transitional B-lineage precursor marker CD93/AA4.1+ B cell populations (IgM+CD23βˆ’ (T1), IgM+CD23+ (T2), and IgMloCD23+ (T3)) in the spleens of Mysm1βˆ’/βˆ’ mice relative to WT controls (Fig. 1a,b). Frequencies of both B220+CD93/AA4.1lo mature B cell and B220+CD93/AA4.1high immature B cell populations, and absolute B220+ B cell numbers in the spleen and bone marrow of Mysm1βˆ’/βˆ’ mice were drastically reduced (Fig. 1a–c). We further observed a drastic reduction in both the percent and cell number of CD21lo FO B cells (FO I and FO II) in the spleens of Mysm1βˆ’/βˆ’ mice. However, the percentages of CD21hi MZ B cells were increased in the spleens of Mysm1βˆ’/βˆ’ mice. The absolute cell numbers of both MZP and MZ B cells were reduced at lesser degrees in the Mysm1βˆ’/βˆ’ mice. Thus, these data demonstrate a severe defect in the development of follicular B cells, but a much milder developmental defect in MZ B cells in Mysm1βˆ’/βˆ’ mice.


Epigenetic Regulation of Antibody Responses by the Histone H2A Deubiquitinase MYSM1.

Jiang XX, Chou Y, Jones L, Wang T, Sanchez S, Huang XF, Zhang L, Wang C, Chen SY - Sci Rep (2015)

Enhanced primary TI and TD antibody responses in Mysm1βˆ’/βˆ’ mice despite the severe defect in FO B cell development.(a) Representative flow cytometry analysis of WT and Mysm1βˆ’/βˆ’ splenocytes stained with indicated antibodies from four independent experiments. Numbers are the percentage of events within the indicated gates. (b) Absolute numbers (top) of indicated B cell subsets in spleen of Mysm1βˆ’/βˆ’ mice and WT littermates and fold reduction (bottom) of Mysm1βˆ’/βˆ’ cell numbers compared to WT cell numbers (n = 5–8 per group) from one of three independent experiments. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (c) Graphs show the absolute numbers of B220+ B cells in the spleen (left) and bone marrow (right) from WT and Mysm1βˆ’/βˆ’ mice. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (d) Serum from naΓ―ve WT and Mysm1βˆ’/βˆ’ mice was analyzed for resting levels of IgM, IgG3, and IgG1 by ELISA. (e) Mice were immunized with NP-Ficoll (50 μg) and serum was collected at day 14 for examining NP-specific IgM and IgG3 levels by ELISA with plates coated with NP26-BSA. (f) WT and Mysm1βˆ’/βˆ’ mice were immunized with NP-KLH (100 μg) precipitated in Alum. Serum was harvested at day 14 after immunization to quantitate NP-specific IgM, IgG3, IgG1, IgG2a, and IgG2b antibodies by ELISA. (g,h) ELISPOT analysis of anti-NP IgM (top) and IgG (bottom) production by cells pooled from spleens or lymph nodes of WT and Mysm1βˆ’/βˆ’ mice 14 d after immunization with NP-Ficoll (g) or NP-KLH (h). **p < 0.01, *p < 0.05, Mysm1βˆ’/βˆ’vs. WT.
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Related In: Results  -  Collection

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f1: Enhanced primary TI and TD antibody responses in Mysm1βˆ’/βˆ’ mice despite the severe defect in FO B cell development.(a) Representative flow cytometry analysis of WT and Mysm1βˆ’/βˆ’ splenocytes stained with indicated antibodies from four independent experiments. Numbers are the percentage of events within the indicated gates. (b) Absolute numbers (top) of indicated B cell subsets in spleen of Mysm1βˆ’/βˆ’ mice and WT littermates and fold reduction (bottom) of Mysm1βˆ’/βˆ’ cell numbers compared to WT cell numbers (n = 5–8 per group) from one of three independent experiments. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (c) Graphs show the absolute numbers of B220+ B cells in the spleen (left) and bone marrow (right) from WT and Mysm1βˆ’/βˆ’ mice. **P < 0.01, WT vs. Mysm1βˆ’/βˆ’. (d) Serum from naΓ―ve WT and Mysm1βˆ’/βˆ’ mice was analyzed for resting levels of IgM, IgG3, and IgG1 by ELISA. (e) Mice were immunized with NP-Ficoll (50 μg) and serum was collected at day 14 for examining NP-specific IgM and IgG3 levels by ELISA with plates coated with NP26-BSA. (f) WT and Mysm1βˆ’/βˆ’ mice were immunized with NP-KLH (100 μg) precipitated in Alum. Serum was harvested at day 14 after immunization to quantitate NP-specific IgM, IgG3, IgG1, IgG2a, and IgG2b antibodies by ELISA. (g,h) ELISPOT analysis of anti-NP IgM (top) and IgG (bottom) production by cells pooled from spleens or lymph nodes of WT and Mysm1βˆ’/βˆ’ mice 14 d after immunization with NP-Ficoll (g) or NP-KLH (h). **p < 0.01, *p < 0.05, Mysm1βˆ’/βˆ’vs. WT.
Mentions: In the absence of MYSM1, there is a block in early B cell development with a severe reduction in the frequency and absolute number of both peripheral immature and mature B cells21. In order to further define the role of MYSM1 in peripheral B cell subpopulation development, we analyzed splenic subpopulations of B cells in WT and Mysm1βˆ’/βˆ’ mice by flow cytometry. We observed a drastic decrease in the percentages and numbers of immature, transitional B-lineage precursor marker CD93/AA4.1+ B cell populations (IgM+CD23βˆ’ (T1), IgM+CD23+ (T2), and IgMloCD23+ (T3)) in the spleens of Mysm1βˆ’/βˆ’ mice relative to WT controls (Fig. 1a,b). Frequencies of both B220+CD93/AA4.1lo mature B cell and B220+CD93/AA4.1high immature B cell populations, and absolute B220+ B cell numbers in the spleen and bone marrow of Mysm1βˆ’/βˆ’ mice were drastically reduced (Fig. 1a–c). We further observed a drastic reduction in both the percent and cell number of CD21lo FO B cells (FO I and FO II) in the spleens of Mysm1βˆ’/βˆ’ mice. However, the percentages of CD21hi MZ B cells were increased in the spleens of Mysm1βˆ’/βˆ’ mice. The absolute cell numbers of both MZP and MZ B cells were reduced at lesser degrees in the Mysm1βˆ’/βˆ’ mice. Thus, these data demonstrate a severe defect in the development of follicular B cells, but a much milder developmental defect in MZ B cells in Mysm1βˆ’/βˆ’ mice.

Bottom Line: In this study, we found that mice deficient in the histone H2A deubiquitinase MYSM1, despite their severe defect in B cell development, exhibit an enhanced antibody response against both T cell-dependent and independent antigens.Mechanistic studies demonstrated that MYSM1 is a transcriptional activator of Pax5, the repressors of plasma cell differentiation, by facilitating key transcriptional factor recruitment and coordinating histone modifications at the Pax5 loci.Importantly, this study further provides a new target and strategy to modulate antibody production and responses with profound therapeutic implications.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Microbiology and Immunology, Norris Comprehensive Cancer Center Keck School of Medicine, University of Southern California, Los Angeles, California, 90033, USA.

ABSTRACT
B cell-mediated antibody response plays critical roles in protective immunity, as well as in the pathogenesis of allergic and autoimmune diseases. Epigenetic histone and DNA modifications regulate gene transcription and immunity; however, so far, little is known about the role of epigenetic regulation in antibody responses. In this study, we found that mice deficient in the histone H2A deubiquitinase MYSM1, despite their severe defect in B cell development, exhibit an enhanced antibody response against both T cell-dependent and independent antigens. We revealed that MYSM1 intrinsically represses plasma cell differentiation and antibody production. Mechanistic studies demonstrated that MYSM1 is a transcriptional activator of Pax5, the repressors of plasma cell differentiation, by facilitating key transcriptional factor recruitment and coordinating histone modifications at the Pax5 loci. Hence, this study uncovers a critical role for MYSM1 in epigenetically repressing plasma cell differentiation and antibody production, in addition to its opposing, active role in B cell development. Importantly, this study further provides a new target and strategy to modulate antibody production and responses with profound therapeutic implications.

No MeSH data available.


Related in: MedlinePlus