Limits...
A role for S1P and S1P1 in immature-B cell egress from mouse bone marrow.

Pereira JP, Xu Y, Cyster JG - PLoS ONE (2010)

Bottom Line: B lymphocyte egress from secondary lymphoid organs requires sphingosine-1-phosphate (S1P) and S1P receptor-1 (S1P1).Transgenic expression of S1P1 in developing B cells was sufficient to mobilize pro- and pre-B cells from the BM.We conclude that the S1P1-S1P pathway contributes to egress of immature-B cells from BM, and that this mechanism is partially redundant with other undefined pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America. Joao.Pereira@ucsf.edu

ABSTRACT
B lymphocyte egress from secondary lymphoid organs requires sphingosine-1-phosphate (S1P) and S1P receptor-1 (S1P1). However, whether S1P contributes to immature-B cell egress from the bone marrow (BM) has not been fully assessed. Here we report that in S1P- and S1P1-conditionally deficient mice, the number of immature-B cells in the BM parenchyma increased, while it decreased in the blood. Moreover, a slower rate of bromodeoxyuridine incorporation suggested immature-B cells spent longer in the BM of mice in which S1P1-S1P signaling was genetically or pharmacologically impaired. Transgenic expression of S1P1 in developing B cells was sufficient to mobilize pro- and pre-B cells from the BM. We conclude that the S1P1-S1P pathway contributes to egress of immature-B cells from BM, and that this mechanism is partially redundant with other undefined pathways.

Show MeSH
Premature egress of B cell precursors from the BM of S1P1-transgenic mice.(A) Quantitative RT-PCR analysis of the expression of S1P1 encoding mRNA in purified developing BM B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice, presented relative to Hprt1 mRNA (hypoxanthine guanine phosphoribosyl transferase). Data shown was pooled from 3 independent experiments. (B) Migration assays of developing B cells from S1P1-transgenic (gray bars) and littermate control (white bars) mice to S1P (100 nM) or SDF-1 (0.3 µg/mL). Data are representative of 4 experiments. (C) Enumeration of developing B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice in the BM parenchyma, sinusoids, peripheral blood and spleen. In all panels, bars indicate the mean, circles indicate individual mice. * P<0.05; ** P<0.005 (unpaired, two-tailed Student's t-test).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2823786&req=5

pone-0009277-g005: Premature egress of B cell precursors from the BM of S1P1-transgenic mice.(A) Quantitative RT-PCR analysis of the expression of S1P1 encoding mRNA in purified developing BM B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice, presented relative to Hprt1 mRNA (hypoxanthine guanine phosphoribosyl transferase). Data shown was pooled from 3 independent experiments. (B) Migration assays of developing B cells from S1P1-transgenic (gray bars) and littermate control (white bars) mice to S1P (100 nM) or SDF-1 (0.3 µg/mL). Data are representative of 4 experiments. (C) Enumeration of developing B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice in the BM parenchyma, sinusoids, peripheral blood and spleen. In all panels, bars indicate the mean, circles indicate individual mice. * P<0.05; ** P<0.005 (unpaired, two-tailed Student's t-test).

Mentions: Finally, we asked if enforced expression of S1P1 in B lymphocytes was sufficient to promote premature egress of developing B cells. We generated transgenic mice expressing S1P1 under the control of the immunoglobulin heavy chain Eμ enhancer and Lck proximal promoter, and analyzed S1P1 expression during B cell development. S1P1 transcripts were significantly increased already at the Pro-B cell stage and remained higher in transgenic B cell subsets than in cells from littermate controls (Figure 5A). Moreover, in vitro chemotaxis assays showed increased migration of S1P1-transgenic Pro-B, Pre-B, and immature-B cells to S1P, indicating that S1P1 is functional in these cells (Figure 5B). Migration of B cell subsets from S1P1-transgenic and littermate controls to SDF-1 was similar (Figure 5B). Analysis of developing B cell numbers showed a 10-fold increase in Pro- and Pre-B cells in sinusoids, peripheral blood and spleens of S1P1-transgenic mice (Figure 5C). Immature-B cell distribution was altered as well, with reduced numbers in the BM parenchyma and increased numbers in sinusoids, blood and spleen (Figure 5C). Even though Pro- and Pre-B cells were substantially increased in sinusoids, blood and spleen, the total number of cells detected in the periphery was in the order of 104–105 and thus insufficient to cause a measurable decrease from the parenchyma (where the numbers are in the order of 106).


A role for S1P and S1P1 in immature-B cell egress from mouse bone marrow.

Pereira JP, Xu Y, Cyster JG - PLoS ONE (2010)

Premature egress of B cell precursors from the BM of S1P1-transgenic mice.(A) Quantitative RT-PCR analysis of the expression of S1P1 encoding mRNA in purified developing BM B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice, presented relative to Hprt1 mRNA (hypoxanthine guanine phosphoribosyl transferase). Data shown was pooled from 3 independent experiments. (B) Migration assays of developing B cells from S1P1-transgenic (gray bars) and littermate control (white bars) mice to S1P (100 nM) or SDF-1 (0.3 µg/mL). Data are representative of 4 experiments. (C) Enumeration of developing B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice in the BM parenchyma, sinusoids, peripheral blood and spleen. In all panels, bars indicate the mean, circles indicate individual mice. * P<0.05; ** P<0.005 (unpaired, two-tailed Student's t-test).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2823786&req=5

pone-0009277-g005: Premature egress of B cell precursors from the BM of S1P1-transgenic mice.(A) Quantitative RT-PCR analysis of the expression of S1P1 encoding mRNA in purified developing BM B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice, presented relative to Hprt1 mRNA (hypoxanthine guanine phosphoribosyl transferase). Data shown was pooled from 3 independent experiments. (B) Migration assays of developing B cells from S1P1-transgenic (gray bars) and littermate control (white bars) mice to S1P (100 nM) or SDF-1 (0.3 µg/mL). Data are representative of 4 experiments. (C) Enumeration of developing B cell subsets from S1P1-transgenic (gray bars) and littermate control (white bars) mice in the BM parenchyma, sinusoids, peripheral blood and spleen. In all panels, bars indicate the mean, circles indicate individual mice. * P<0.05; ** P<0.005 (unpaired, two-tailed Student's t-test).
Mentions: Finally, we asked if enforced expression of S1P1 in B lymphocytes was sufficient to promote premature egress of developing B cells. We generated transgenic mice expressing S1P1 under the control of the immunoglobulin heavy chain Eμ enhancer and Lck proximal promoter, and analyzed S1P1 expression during B cell development. S1P1 transcripts were significantly increased already at the Pro-B cell stage and remained higher in transgenic B cell subsets than in cells from littermate controls (Figure 5A). Moreover, in vitro chemotaxis assays showed increased migration of S1P1-transgenic Pro-B, Pre-B, and immature-B cells to S1P, indicating that S1P1 is functional in these cells (Figure 5B). Migration of B cell subsets from S1P1-transgenic and littermate controls to SDF-1 was similar (Figure 5B). Analysis of developing B cell numbers showed a 10-fold increase in Pro- and Pre-B cells in sinusoids, peripheral blood and spleens of S1P1-transgenic mice (Figure 5C). Immature-B cell distribution was altered as well, with reduced numbers in the BM parenchyma and increased numbers in sinusoids, blood and spleen (Figure 5C). Even though Pro- and Pre-B cells were substantially increased in sinusoids, blood and spleen, the total number of cells detected in the periphery was in the order of 104–105 and thus insufficient to cause a measurable decrease from the parenchyma (where the numbers are in the order of 106).

Bottom Line: B lymphocyte egress from secondary lymphoid organs requires sphingosine-1-phosphate (S1P) and S1P receptor-1 (S1P1).Transgenic expression of S1P1 in developing B cells was sufficient to mobilize pro- and pre-B cells from the BM.We conclude that the S1P1-S1P pathway contributes to egress of immature-B cells from BM, and that this mechanism is partially redundant with other undefined pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Microbiology and Immunology, University of California San Francisco, San Francisco, California, United States of America. Joao.Pereira@ucsf.edu

ABSTRACT
B lymphocyte egress from secondary lymphoid organs requires sphingosine-1-phosphate (S1P) and S1P receptor-1 (S1P1). However, whether S1P contributes to immature-B cell egress from the bone marrow (BM) has not been fully assessed. Here we report that in S1P- and S1P1-conditionally deficient mice, the number of immature-B cells in the BM parenchyma increased, while it decreased in the blood. Moreover, a slower rate of bromodeoxyuridine incorporation suggested immature-B cells spent longer in the BM of mice in which S1P1-S1P signaling was genetically or pharmacologically impaired. Transgenic expression of S1P1 in developing B cells was sufficient to mobilize pro- and pre-B cells from the BM. We conclude that the S1P1-S1P pathway contributes to egress of immature-B cells from BM, and that this mechanism is partially redundant with other undefined pathways.

Show MeSH