Limits...
Lin28b promotes fetal B lymphopoiesis through the transcription factor Arid3a.

Zhou Y, Li YS, Bandi SR, Tang L, Shinton SA, Hayakawa K, Hardy RR - J. Exp. Med. (2015)

Bottom Line: Here, we report key advances in our understanding of the regulation of B-1/B-2 development.Second, intact BCR signaling is required for the generation of B1a B cells from Lin28b-transduced BM progenitors, supporting a requirement for ligand-dependent selection, as is the case for normal B1a B cells.Third, the VH repertoire of Lin28b-induced BM B1a B cells differs from that of normal B1a, suggesting persisting differences from fetal progenitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fox Chase Cancer Center, Philadelphia, PA 19111.

Show MeSH

Related in: MedlinePlus

Lin28b BM–generated CD5+ B cells require intact BCR signaling but do not express the usual B1a repertoire, regardless of TdT expression. (A) Btk-deficient BM pro-B cells, transduced with Lin28b or empty (pMIG) retrovirus, were transferred to SCID mice, and spleen cells were analyzed 3 wk after transfer by flow cytometry using the indicated markers. Plots are gated for CD19+GFP+ cells. Data are representative of two independent transfer experiments with two mice per group. (B) The level of N-addition and distribution of VH gene usage was analyzed in individual sorted follicular/B2 (Fo) and CD5+ B1 (B1a) B cells from intact mice and in B cells from SCID mice repopulated with BM pro-B cells (transduced with empty vector [pMIG] or Lin28b-containing retrovirus). Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample. (C) The VH gene distribution in B cells from SCID mice repopulated with BM pro-B cells from TdT− mice (transduced as in B) is illustrated in pie charts. Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4387290&req=5

fig5: Lin28b BM–generated CD5+ B cells require intact BCR signaling but do not express the usual B1a repertoire, regardless of TdT expression. (A) Btk-deficient BM pro-B cells, transduced with Lin28b or empty (pMIG) retrovirus, were transferred to SCID mice, and spleen cells were analyzed 3 wk after transfer by flow cytometry using the indicated markers. Plots are gated for CD19+GFP+ cells. Data are representative of two independent transfer experiments with two mice per group. (B) The level of N-addition and distribution of VH gene usage was analyzed in individual sorted follicular/B2 (Fo) and CD5+ B1 (B1a) B cells from intact mice and in B cells from SCID mice repopulated with BM pro-B cells (transduced with empty vector [pMIG] or Lin28b-containing retrovirus). Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample. (C) The VH gene distribution in B cells from SCID mice repopulated with BM pro-B cells from TdT− mice (transduced as in B) is illustrated in pie charts. Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample.

Mentions: The generation of normal CD5+ B cells depends on the presence of antigen (Hayakawa et al., 1999). Furthermore, mouse mutants that weaken BCR signaling have a deficit in CD5+ B cells (Tarakhovsky et al., 1995; Inaoki et al., 1997; Suzuki et al., 1999). For example, the Btk-deficient Xid mouse has fewer B cells in spleen, accumulates B cells with a distinctive phenotype, has very low levels of serum IgM, and completely lacks CD5+ B cells (Hayakawa et al., 1983; Khan et al., 1995). However, the ability of ectopic expression of Lin28B to divert cells to the B-1 fate in progenitors with defective BCR signaling has never been directly tested. Therefore, we asked whether BCR signaling is required for production of Lin28b-induced BM-derived B1a B cells. For this purpose, transduced pro-B cell isolated from BM of Xid mice were transferred into SCID mice, and then engrafted cells were examined for generation of CD5+ B cells. As shown in Fig. 5 A, even provision of Lin28b did not induce production of CD5+ B cells from Btk-deficient pro-B cells, demonstrating a continuing dependence on intact (Btk dependent) BCR signaling.


Lin28b promotes fetal B lymphopoiesis through the transcription factor Arid3a.

Zhou Y, Li YS, Bandi SR, Tang L, Shinton SA, Hayakawa K, Hardy RR - J. Exp. Med. (2015)

Lin28b BM–generated CD5+ B cells require intact BCR signaling but do not express the usual B1a repertoire, regardless of TdT expression. (A) Btk-deficient BM pro-B cells, transduced with Lin28b or empty (pMIG) retrovirus, were transferred to SCID mice, and spleen cells were analyzed 3 wk after transfer by flow cytometry using the indicated markers. Plots are gated for CD19+GFP+ cells. Data are representative of two independent transfer experiments with two mice per group. (B) The level of N-addition and distribution of VH gene usage was analyzed in individual sorted follicular/B2 (Fo) and CD5+ B1 (B1a) B cells from intact mice and in B cells from SCID mice repopulated with BM pro-B cells (transduced with empty vector [pMIG] or Lin28b-containing retrovirus). Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample. (C) The VH gene distribution in B cells from SCID mice repopulated with BM pro-B cells from TdT− mice (transduced as in B) is illustrated in pie charts. Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4387290&req=5

fig5: Lin28b BM–generated CD5+ B cells require intact BCR signaling but do not express the usual B1a repertoire, regardless of TdT expression. (A) Btk-deficient BM pro-B cells, transduced with Lin28b or empty (pMIG) retrovirus, were transferred to SCID mice, and spleen cells were analyzed 3 wk after transfer by flow cytometry using the indicated markers. Plots are gated for CD19+GFP+ cells. Data are representative of two independent transfer experiments with two mice per group. (B) The level of N-addition and distribution of VH gene usage was analyzed in individual sorted follicular/B2 (Fo) and CD5+ B1 (B1a) B cells from intact mice and in B cells from SCID mice repopulated with BM pro-B cells (transduced with empty vector [pMIG] or Lin28b-containing retrovirus). Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample. (C) The VH gene distribution in B cells from SCID mice repopulated with BM pro-B cells from TdT− mice (transduced as in B) is illustrated in pie charts. Data were combined from three separate experiments for each cell type, each experiment using two mice for each sample.
Mentions: The generation of normal CD5+ B cells depends on the presence of antigen (Hayakawa et al., 1999). Furthermore, mouse mutants that weaken BCR signaling have a deficit in CD5+ B cells (Tarakhovsky et al., 1995; Inaoki et al., 1997; Suzuki et al., 1999). For example, the Btk-deficient Xid mouse has fewer B cells in spleen, accumulates B cells with a distinctive phenotype, has very low levels of serum IgM, and completely lacks CD5+ B cells (Hayakawa et al., 1983; Khan et al., 1995). However, the ability of ectopic expression of Lin28B to divert cells to the B-1 fate in progenitors with defective BCR signaling has never been directly tested. Therefore, we asked whether BCR signaling is required for production of Lin28b-induced BM-derived B1a B cells. For this purpose, transduced pro-B cell isolated from BM of Xid mice were transferred into SCID mice, and then engrafted cells were examined for generation of CD5+ B cells. As shown in Fig. 5 A, even provision of Lin28b did not induce production of CD5+ B cells from Btk-deficient pro-B cells, demonstrating a continuing dependence on intact (Btk dependent) BCR signaling.

Bottom Line: Here, we report key advances in our understanding of the regulation of B-1/B-2 development.Second, intact BCR signaling is required for the generation of B1a B cells from Lin28b-transduced BM progenitors, supporting a requirement for ligand-dependent selection, as is the case for normal B1a B cells.Third, the VH repertoire of Lin28b-induced BM B1a B cells differs from that of normal B1a, suggesting persisting differences from fetal progenitors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fox Chase Cancer Center, Philadelphia, PA 19111.

Show MeSH
Related in: MedlinePlus