RAG2:GFP Knockin Mice Reveal Novel Aspects of RAG2 Expression in Primary and Peripheral Lymphoid Tissues

Monroe, R. J.; Seidl, Katherine J.; Gaertner, Frank; Han, Shuhua; Chen, Feng; Sekiguchi, JoAnn; Wang, Ji‐Yang; Ferrini, Roger; Davidson, Laurie A.; Kelsoe, Garnett; Alt, Frederick W.

doi:10.1016/s1074-7613(00)80095-3

Cited by 157 publications

(199 citation statements)

References 47 publications

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“…Using transgenic mice with a RAG2-GFP fusion gene inserted into the RAG2 locus (RAG2-GFP mice), Gartner et al (73) found that most RAG2 ϩ cells appearing in the SPL after immunization corresponded to migrant pre-B/immature B cells (B220 low CD43 low sIgM low ) from the BM. No GFP expression was detectable in sIgM high transitional splenic B cells or mature B cells (73,74). In transgenic mice with GFP under the control of RAG2 regulatory genes, Yu et al (75) reported that GFP expression does not occur in mature B cells during an immune response although it does occur in immature/transitional splenic B cells (B220 low CD24 ϩ CD93 ϩ ).…”

Section: Rag Expression and L Chain Editing In B Cells Deficient For mentioning

confidence: 99%

Antigen Receptor Editing in Anti-DNA Transitional B Cells Deficient for Surface IgM

Kiefer

Nakajima

Oshinsky

et al. 2008

The Journal of Immunology

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In response to encounter with self-Ag, autoreactive B cells may undergo secondary L chain gene rearrangement (receptor editing) and change the specificity of their Ag receptor. Knowing at what differentiative stage(s) developing B cells undergo receptor editing is important for understanding how self-reactive B cells are regulated. In this study, in mice with Ig transgenes coding for anti-self (DNA) Ab, we report dsDNA breaks indicative of ongoing secondary L chain rearrangement not only in bone marrow cells with a pre-B/B cell phenotype but also in immature/transitional splenic B cells with little or no surface IgM (sIgM−/low). L chain-edited transgenic B cells were detectable in spleen but not bone marrow and were still found to produce Ab specific for DNA (and apoptotic cells), albeit with lower affinity for DNA than the unedited transgenic Ab. We conclude that L chain editing in anti-DNA-transgenic B cells is not only ongoing in bone marrow but also in spleen. Indeed, transfer of sIgM−/low anti-DNA splenic B cells into SCID mice resulted in the appearance of a L chain editor (Vλx) in the serum of engrafted recipients. Finally, we also report evidence for ongoing L chain editing in sIgMlow transitional splenic B cells of wild-type mice.

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Section: Rag Expression and L Chain Editing In B Cells Deficient For mentioning

confidence: 99%

Antigen Receptor Editing in Anti-DNA Transitional B Cells Deficient for Surface IgM

Kiefer

Nakajima

Oshinsky

et al. 2008

The Journal of Immunology

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“…S1A). The use of the RAG2p‐GFP model allows to easily assess de novo thymopoiesis as expression of the GFP transgene, marking newly developed T cells, is controlled by the Rag2 promoter activity (Monroe et al ., 1999; Yu et al ., 1999; Rafei et al ., 2011). Thymic analysis 1 week following the last injection revealed a progressive increase in total thymocyte count in 15M but not 2M‐old rIL‐21‐treated mice with an optimal response rate achieved at a dose of 50 μg kg −1 (Fig.…”

Section: Resultsmentioning

confidence: 99%

Interleukin‐21 administration to aged mice rejuvenates their peripheral T‐cell pool by triggering de novo thymopoiesis

et al. 2016

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SummaryThe vaccination efficacy in the elderly is significantly reduced compared to younger populations due to thymic involution and age‐related intrinsic changes affecting their naïve T‐cell compartment. Interleukin (IL)‐21 was recently shown to display thymostimulatory properties. Therefore, we hypothesized that its administration to ageing hosts may improve T‐cell output and thus restore a competent peripheral T‐cell compartment. Indeed, an increase in the production of recent thymic emigrants (RTEs) attributable to intrathymic expansion of early thymic progenitors (ETPs), double‐negative (DN), and double‐positive (DP) thymocytes as well as thymic epithelial cell (TEC) was observed in recombinant (r)IL‐21‐treated aged mice. In sharp contrast, no alterations in the frequency of bone marrow (BM)‐derived progenitors were detected following rIL‐21 administration. Enhanced production of naïve T cells improved the T‐cell receptor (TCR) repertoire diversity and re‐established a pool of T cells exhibiting higher levels of miR‐181a and diminished amounts of the TCR‐inhibiting phosphatases SHP‐2 and DUSP5/6. As a result, stimulation of T cells derived from rIL‐21‐treated aged mice displayed enhanced activation of Lck, ZAP‐70, and ERK, which ultimately boosted their IL‐2 production, CD25 expression, and proliferation capabilities in comparison with T cells derived from control aged mice. Consequently, aged rIL‐21‐treated mice vaccinated using a tyrosinase‐related protein 2 (Trp2)‐derived peptide exhibited a substantial delay in B16 tumor growth and improved survival. The results of this study highlight the immunorestorative function of rIL‐21 paving its use as a strategy for the re‐establishment of effective immunity in the elderly.

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“…38 Most GFP ϩ cells in the spleen were phenotypically identical to pre-B and immature B cells. 38 Our experiments studied the expression of RAG1/GFP in GCs of the Ag-immunized spleen. GFP expression was not detected in the central region of GCs, nor was it down-regulated.…”

Section: Discussionmentioning

confidence: 97%

Localization of recombination activating gene 1/green fluorescent protein (RAG1/GFP) expression in secondary lymphoid organs after immunization with T-dependent antigens in rag1/gfpknockin mice

Igarashi

Kuwata

Kiyota

et al. 2001

Blood

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IntroductionB cells are generated in the fetal liver or the adult bone marrow (BM) after immunoglobulin gene rearrangements that create a primary repertoire of random antibody (Ab) specificity. 1-3 B cells that react to various self-antigens (Ags) at immature stages are thought to experience anergy after encountering Ags or to be eliminated by apoptotic mechanisms in the BM microenvironment. [4][5][6] It has been suggested that a substantial proportion of B cells reactive to self-Ags undergoes a process known as receptor editing in which secondary immunoglobulin gene rearrangements replace variable (V) gene segments, generating a new Ab specificity as a part of the primary Ab repertoire. 7-11 B cells recruited to the circulation are stimulated by Ags and helper-T (Th) cells in the T cell area of secondary lymphoid organs. 12-14 Such Ag-driven B cells subsequently undergo rapid proliferation to become centroblasts located in the dark zone of germinal centers (GCs) and then arrest cell cycling and become small centrocytes in the light zone. [15][16][17][18][19][20] Recent studies proposed an interesting model in which mature B cells also undergo a similar process, termed receptor editing, in GCs of secondary lymphoid follicles after stimulation by Tdependent (TD) Ags. [21][22][23][24][25] This notion has been supported by the detection of rag1/rag2 transcripts and by the evidence of immunoglobulin gene rearrangements in situ, suggesting that receptor editing occurs in the GC light zone. 21 In addition, stimulation with anti-CD40 monoclonal antibody (mAb) plus interleukin-4 (IL-4), or lipopolysaccharide (LPS) plus IL-4, induced the up-regulation of rag1/rag2 transcripts and immunoglobulin gene rearrangements in mature surface immunoglobulin M (sIgM) ϩ B cells in vitro. 22,[24][25][26] These results suggested that mature B cells frequently undergo receptor editing in GCs after stimulation with Ags. The receptor editing mechanism might provide a more flexible and diverse Ab specificity response than the one produced solely by the somatic mutation mechanism. The receptor editing in GCs could be a requisite molecular event for an immediate and effective response producing high-affinity Abs against various antigenic stimuli. Alternatively, receptor editing could salvage B cells carrying anti-self specificities.The reactivation of rag gene expression has been suggested as one mechanism for the immunoglobulin gene rearrangements that occur in receptor revision. 27,28 To demonstrate direct in vivo evidence of the induction of RAG molecules in GCs and to measure the frequency of cells undergoing receptor editing (or receptor revision), we examined lymphoid organs for RAG1/green fluorescent protein (GFP) signal using immunized or unimmunized rag1/gfp knockin mice. Unimmunized heterozygous rag1/gfp knockin mice express GFP that can be detected at high sensitivity by microscopic observation of splenic sections. Surprisingly, when we examined GCs of immunized mice, we observed that the RAG1/GFP signal was not significantly indu...

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RAG2:GFP Knockin Mice Reveal Novel Aspects of RAG2 Expression in Primary and Peripheral Lymphoid Tissues

Cited by 157 publications

References 47 publications

Antigen Receptor Editing in Anti-DNA Transitional B Cells Deficient for Surface IgM

Antigen Receptor Editing in Anti-DNA Transitional B Cells Deficient for Surface IgM

Interleukin‐21 administration to aged mice rejuvenates their peripheral T‐cell pool by triggering de novo thymopoiesis

Localization of recombination activating gene 1/green fluorescent protein (RAG1/GFP) expression in secondary lymphoid organs after immunization with T-dependent antigens in rag1/gfpknockin mice

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