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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 deficiency in high affinity AFC production in Aio−/− mice is B cell intrinsic. (A) BM from WT, Aio−/−, or a 50:50 mixture of the two was used to reconstitute irradiated RAG−/− chimeras. Mice were immunized from 6 to 9 wk after reconstitution and analyzed 14 d after boost. (B) Flow cytometric analysis of haplotype-specific expression of IgM and Thy1 molecules in the reconstituted chimeras. BM and spleens were stained with anti-IgMa (WT-derived) and anti-IgMb (Aio−/− derived) to determine B cell contributions. Spleens were stained with anti-Thy1a (WT-derived) and anti-Thy1b (Aio−/−-derived) Abs to determine T cell contributions. (C) IgG1-producing AFCs in the BM (left) and spleen (right) of WT (open bars) and Aio−/− (solid bars) were measured 14 d after secondary immunization with 50 μg NP-CGG. Data were obtained from ELISPOT assays using NP4 as the coating Ag. The revealing Abs used were specific for WT-derived (anti-IgG1a) or Aio−/−-derived (IgG1b) AFCs.
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fig4: The deficiency in high affinity AFC production in Aio−/− mice is B cell intrinsic. (A) BM from WT, Aio−/−, or a 50:50 mixture of the two was used to reconstitute irradiated RAG−/− chimeras. Mice were immunized from 6 to 9 wk after reconstitution and analyzed 14 d after boost. (B) Flow cytometric analysis of haplotype-specific expression of IgM and Thy1 molecules in the reconstituted chimeras. BM and spleens were stained with anti-IgMa (WT-derived) and anti-IgMb (Aio−/− derived) to determine B cell contributions. Spleens were stained with anti-Thy1a (WT-derived) and anti-Thy1b (Aio−/−-derived) Abs to determine T cell contributions. (C) IgG1-producing AFCs in the BM (left) and spleen (right) of WT (open bars) and Aio−/− (solid bars) were measured 14 d after secondary immunization with 50 μg NP-CGG. Data were obtained from ELISPOT assays using NP4 as the coating Ag. The revealing Abs used were specific for WT-derived (anti-IgG1a) or Aio−/−-derived (IgG1b) AFCs.

Mentions: Aiolos is not only expressed in B cells but also in T cells (11). Generation and maintenance of high affinity AFCs in the BM is dependent on adequate T cell help and BM stromal support (6). To determine whether the AFC deficit in Aio−/− mice was intrinsic to B cells or due to a defect in T cell help or stromal support, BM chimeras were generated. Irradiated RAG1−/− recipients were adoptively transferred with whole BM from WT C57BL/6-Igha Thy1a mice, Aio−/− Ighb Thy1b mice, or a 50:50 mixture of WT and Aio−/− cells. 6 wk after reconstitution, mice were immunized with 50 μg NP-CGG in alum, boosted at 3 wk, and killed 14 d later (Fig. 4 A). Analysis of BM and spleen populations in the RAG1−/− chimeras revealed a normal number of reconstituted B and T cells. All B cells from WT-reconstituted mice were of the Igha haplotype, whereas B cells from Aio−/−-reconstituted mice were of the Ighb haplotype (Fig. 4 B, IgMa vs. IgMb). Mice that had received a 50:50 BM mixture from WT and Aio−/− mice had B cells of both the Igha and Ighb haplotype. This was also the case for T cells, which were Thy1a in WT, Thy1b haplotype in Aio−/−, and an equal mixture of Thy1a/Thy1b in the 50:50 chimeras (Fig. 4 B). However, although T cells in the 50:50 chimeras were equally derived from WT and Aio−/− cells, there was a bias toward the generation of Aio−/−-derived B cells (∼3:1 ratio for Aio/WT instead of the expected 1:1; Fig. 4 B). This result did not, however, affect our ability to evaluate whether WT T cells, B cells, or BM could correct the Aio−/− AFC phenotype.


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 deficiency in high affinity AFC production in Aio−/− mice is B cell intrinsic. (A) BM from WT, Aio−/−, or a 50:50 mixture of the two was used to reconstitute irradiated RAG−/− chimeras. Mice were immunized from 6 to 9 wk after reconstitution and analyzed 14 d after boost. (B) Flow cytometric analysis of haplotype-specific expression of IgM and Thy1 molecules in the reconstituted chimeras. BM and spleens were stained with anti-IgMa (WT-derived) and anti-IgMb (Aio−/− derived) to determine B cell contributions. Spleens were stained with anti-Thy1a (WT-derived) and anti-Thy1b (Aio−/−-derived) Abs to determine T cell contributions. (C) IgG1-producing AFCs in the BM (left) and spleen (right) of WT (open bars) and Aio−/− (solid bars) were measured 14 d after secondary immunization with 50 μg NP-CGG. Data were obtained from ELISPOT assays using NP4 as the coating Ag. The revealing Abs used were specific for WT-derived (anti-IgG1a) or Aio−/−-derived (IgG1b) AFCs.
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Related In: Results  -  Collection

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fig4: The deficiency in high affinity AFC production in Aio−/− mice is B cell intrinsic. (A) BM from WT, Aio−/−, or a 50:50 mixture of the two was used to reconstitute irradiated RAG−/− chimeras. Mice were immunized from 6 to 9 wk after reconstitution and analyzed 14 d after boost. (B) Flow cytometric analysis of haplotype-specific expression of IgM and Thy1 molecules in the reconstituted chimeras. BM and spleens were stained with anti-IgMa (WT-derived) and anti-IgMb (Aio−/− derived) to determine B cell contributions. Spleens were stained with anti-Thy1a (WT-derived) and anti-Thy1b (Aio−/−-derived) Abs to determine T cell contributions. (C) IgG1-producing AFCs in the BM (left) and spleen (right) of WT (open bars) and Aio−/− (solid bars) were measured 14 d after secondary immunization with 50 μg NP-CGG. Data were obtained from ELISPOT assays using NP4 as the coating Ag. The revealing Abs used were specific for WT-derived (anti-IgG1a) or Aio−/−-derived (IgG1b) AFCs.
Mentions: Aiolos is not only expressed in B cells but also in T cells (11). Generation and maintenance of high affinity AFCs in the BM is dependent on adequate T cell help and BM stromal support (6). To determine whether the AFC deficit in Aio−/− mice was intrinsic to B cells or due to a defect in T cell help or stromal support, BM chimeras were generated. Irradiated RAG1−/− recipients were adoptively transferred with whole BM from WT C57BL/6-Igha Thy1a mice, Aio−/− Ighb Thy1b mice, or a 50:50 mixture of WT and Aio−/− cells. 6 wk after reconstitution, mice were immunized with 50 μg NP-CGG in alum, boosted at 3 wk, and killed 14 d later (Fig. 4 A). Analysis of BM and spleen populations in the RAG1−/− chimeras revealed a normal number of reconstituted B and T cells. All B cells from WT-reconstituted mice were of the Igha haplotype, whereas B cells from Aio−/−-reconstituted mice were of the Ighb haplotype (Fig. 4 B, IgMa vs. IgMb). Mice that had received a 50:50 BM mixture from WT and Aio−/− mice had B cells of both the Igha and Ighb haplotype. This was also the case for T cells, which were Thy1a in WT, Thy1b haplotype in Aio−/−, and an equal mixture of Thy1a/Thy1b in the 50:50 chimeras (Fig. 4 B). However, although T cells in the 50:50 chimeras were equally derived from WT and Aio−/− cells, there was a bias toward the generation of Aio−/−-derived B cells (∼3:1 ratio for Aio/WT instead of the expected 1:1; Fig. 4 B). This result did not, however, affect our ability to evaluate whether WT T cells, B cells, or BM could correct the Aio−/− AFC phenotype.

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