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Aiolos is required for the generation of high affinity bone marrow plasma cells responsible for long-term immunity.

Cortés M, Georgopoulos K - J. Exp. Med. (2004)

Bottom Line: Lack of Aiolos does not alter expression of any of the previously described factors required for general plasma cell differentiation.No defect in somatic hypermutation, the generation of memory B cells, or short-lived high affinity plasma cells in the spleen was observed upon rechallenge.These studies support a model by which the high affinity plasma cell population in the BM undergoes a unique differentiation program that is dependent on Aiolos.

View Article: PubMed Central - PubMed

Affiliation: Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.

ABSTRACT
Antigenic encounter generates long-term immunity sustained by long-lived high affinity plasma cells resident in the bone marrow (BM). Here we show that the Ikaros family member, Aiolos, is specifically required for the generation of these plasma cells. Failure to generate high affinity plasma cells in the BM and to sustain serum antibody titers is apparent after both primary and secondary immunization of Aiolos(-)(/)(-) mice with a range of hapten concentrations. Chimera reconstitutions demonstrate that the BM plasma cell defect is B cell intrinsic. Lack of Aiolos does not alter expression of any of the previously described factors required for general plasma cell differentiation. No defect in somatic hypermutation, the generation of memory B cells, or short-lived high affinity plasma cells in the spleen was observed upon rechallenge. These studies support a model by which the high affinity plasma cell population in the BM undergoes a unique differentiation program that is dependent on Aiolos.

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The ability of Aio−/− B cells to express plasma cell–specific and survival genes is unaffected. (A) Culture supernatants of purified B cells stimulated with LPS were assayed for production of different isotypes. Each point represents the average titer of a purified B cell culture from a pool of five mice. (B) RT-PCR analysis was performed on naive purified B cells as well as on LPS-stimulated cultures for XBP-1, Blimp-1, J-chain, and IRF-4. Actin was used as a control in all samples. (C–E) RT-PCR analysis was performed on sorted naive B cells (B220+ PNA−) and GC B cells (B220+ PNA+) from WT and Aio−/− mice for Fas, Bcl-2, Bcl-xL, Bcl-6, c-myc (C), J-chain, Blimp-1, XBP-1 (D), CXCR4, CXCR5, CCR7 (E), and actin.
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fig5: The ability of Aio−/− B cells to express plasma cell–specific and survival genes is unaffected. (A) Culture supernatants of purified B cells stimulated with LPS were assayed for production of different isotypes. Each point represents the average titer of a purified B cell culture from a pool of five mice. (B) RT-PCR analysis was performed on naive purified B cells as well as on LPS-stimulated cultures for XBP-1, Blimp-1, J-chain, and IRF-4. Actin was used as a control in all samples. (C–E) RT-PCR analysis was performed on sorted naive B cells (B220+ PNA−) and GC B cells (B220+ PNA+) from WT and Aio−/− mice for Fas, Bcl-2, Bcl-xL, Bcl-6, c-myc (C), J-chain, Blimp-1, XBP-1 (D), CXCR4, CXCR5, CCR7 (E), and actin.

Mentions: Given that AFC populations are primarily operationally defined, we examined the ability of Aio−/− B cells to differentiate into plasma cells in vitro. After 4 d of LPS stimulation of purified splenic B cells, we examined Ig levels in the culture supernatants. Although a decrease in IgM and IgG3 production was observed in Aio−/− cultures, there was no overall difference in the ability to produce different Ig isotypes under these conditions (Fig. 5 A). Similar results were obtained in B cell cultures treated with anti-CD40 or anti-CD40 and IL-4, stimuli that recapitulate the in vivo physiological response (not depicted). We also examined the expression of gene products whose activity has been shown to be critical for the differentiation of all plasma cells. XBP-1, Blimp-1, and IRF-4 are transcriptional regulators required in this process. The J chain is up-regulated upon plasma cell differentiation and is required for IgM and IgA secretion (19). Similar increases in the transcripts of three of the four genes were detected in cultures of Aio−/− and WT B cells stimulated for 4 d with LPS (Fig. 5 B). A greater induction of IRF-4 was detected in the Aio−/− cultures.


Aiolos is required for the generation of high affinity bone marrow plasma cells responsible for long-term immunity.

Cortés M, Georgopoulos K - J. Exp. Med. (2004)

The ability of Aio−/− B cells to express plasma cell–specific and survival genes is unaffected. (A) Culture supernatants of purified B cells stimulated with LPS were assayed for production of different isotypes. Each point represents the average titer of a purified B cell culture from a pool of five mice. (B) RT-PCR analysis was performed on naive purified B cells as well as on LPS-stimulated cultures for XBP-1, Blimp-1, J-chain, and IRF-4. Actin was used as a control in all samples. (C–E) RT-PCR analysis was performed on sorted naive B cells (B220+ PNA−) and GC B cells (B220+ PNA+) from WT and Aio−/− mice for Fas, Bcl-2, Bcl-xL, Bcl-6, c-myc (C), J-chain, Blimp-1, XBP-1 (D), CXCR4, CXCR5, CCR7 (E), and actin.
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Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211773&req=5

fig5: The ability of Aio−/− B cells to express plasma cell–specific and survival genes is unaffected. (A) Culture supernatants of purified B cells stimulated with LPS were assayed for production of different isotypes. Each point represents the average titer of a purified B cell culture from a pool of five mice. (B) RT-PCR analysis was performed on naive purified B cells as well as on LPS-stimulated cultures for XBP-1, Blimp-1, J-chain, and IRF-4. Actin was used as a control in all samples. (C–E) RT-PCR analysis was performed on sorted naive B cells (B220+ PNA−) and GC B cells (B220+ PNA+) from WT and Aio−/− mice for Fas, Bcl-2, Bcl-xL, Bcl-6, c-myc (C), J-chain, Blimp-1, XBP-1 (D), CXCR4, CXCR5, CCR7 (E), and actin.
Mentions: Given that AFC populations are primarily operationally defined, we examined the ability of Aio−/− B cells to differentiate into plasma cells in vitro. After 4 d of LPS stimulation of purified splenic B cells, we examined Ig levels in the culture supernatants. Although a decrease in IgM and IgG3 production was observed in Aio−/− cultures, there was no overall difference in the ability to produce different Ig isotypes under these conditions (Fig. 5 A). Similar results were obtained in B cell cultures treated with anti-CD40 or anti-CD40 and IL-4, stimuli that recapitulate the in vivo physiological response (not depicted). We also examined the expression of gene products whose activity has been shown to be critical for the differentiation of all plasma cells. XBP-1, Blimp-1, and IRF-4 are transcriptional regulators required in this process. The J chain is up-regulated upon plasma cell differentiation and is required for IgM and IgA secretion (19). Similar increases in the transcripts of three of the four genes were detected in cultures of Aio−/− and WT B cells stimulated for 4 d with LPS (Fig. 5 B). A greater induction of IRF-4 was detected in the Aio−/− cultures.

Bottom Line: Lack of Aiolos does not alter expression of any of the previously described factors required for general plasma cell differentiation.No defect in somatic hypermutation, the generation of memory B cells, or short-lived high affinity plasma cells in the spleen was observed upon rechallenge.These studies support a model by which the high affinity plasma cell population in the BM undergoes a unique differentiation program that is dependent on Aiolos.

View Article: PubMed Central - PubMed

Affiliation: Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.

ABSTRACT
Antigenic encounter generates long-term immunity sustained by long-lived high affinity plasma cells resident in the bone marrow (BM). Here we show that the Ikaros family member, Aiolos, is specifically required for the generation of these plasma cells. Failure to generate high affinity plasma cells in the BM and to sustain serum antibody titers is apparent after both primary and secondary immunization of Aiolos(-)(/)(-) mice with a range of hapten concentrations. Chimera reconstitutions demonstrate that the BM plasma cell defect is B cell intrinsic. Lack of Aiolos does not alter expression of any of the previously described factors required for general plasma cell differentiation. No defect in somatic hypermutation, the generation of memory B cells, or short-lived high affinity plasma cells in the spleen was observed upon rechallenge. These studies support a model by which the high affinity plasma cell population in the BM undergoes a unique differentiation program that is dependent on Aiolos.

Show MeSH
Related in: MedlinePlus