Limits...
B cell development in the spleen takes place in discrete steps and is determined by the quality of B cell receptor-derived signals.

Loder F, Mutschler B, Ray RJ, Paige CJ, Sideras P, Torres R, Lamers MC, Carsetti R - J. Exp. Med. (1999)

Bottom Line: They develop into the transitional B cells of type 2 (T2), which are cycling and found exclusively in the primary follicles of the spleen.Mice with genetic deletions of elements participating in the B cell receptor signaling cascade display developmental arrest at the T1 or T2 stage.The analysis of these defects showed that the development of T2 and mature B cells from T1 precursors requires defined qualitative and quantitative signals derived from the B cell receptor and that the induction of longevity and maturation requires different signals.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Immunology, University of Freiburg, Germany.

ABSTRACT
Only mature B lymphocytes can enter the lymphoid follicles of spleen and lymph nodes and thus efficiently participate in the immune response. Mature, long-lived B lymphocytes derive from short-lived precursors generated in the bone marrow. We show that selection into the mature pool is an active process and takes place in the spleen. Two populations of splenic B cells were identified as precursors for mature B cells. Transitional B cells of type 1 (T1) are recent immigrants from the bone marrow. They develop into the transitional B cells of type 2 (T2), which are cycling and found exclusively in the primary follicles of the spleen. Mature B cells can be generated from T1 or T2 B cells. Mice with genetic deletions of elements participating in the B cell receptor signaling cascade display developmental arrest at the T1 or T2 stage. The analysis of these defects showed that the development of T2 and mature B cells from T1 precursors requires defined qualitative and quantitative signals derived from the B cell receptor and that the induction of longevity and maturation requires different signals.

Show MeSH
T1 B cells are the precursors of T2 and mature B cells. (A) Splenocytes of 1- (left) and 3- (center) wk-old and adult (right) C57BL/6 mice were stained with Abs to CD21 and IgM and analyzed by flow cytometry. (B) Splenic cells from recipient RAG-2−/− mice were analyzed at the indicated times after transfer of 2 × 106 splenic B cells from a pool of 1-wk-old mice. Cells were stained with Abs to IgM, IgD, and CD21. Top panels, IgM vs. IgD staining. Bottom panels, the CD21 vs. IgM profile of IgD+IgM+ donor B cells. 200,000 events were collected. Data is shown as dot plots to highlight the few transferred cells that home to the spleen. In the dot plots corresponding to the control (adult) spleen, only 5% of the collected events are shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2195560&req=5

Figure 2: T1 B cells are the precursors of T2 and mature B cells. (A) Splenocytes of 1- (left) and 3- (center) wk-old and adult (right) C57BL/6 mice were stained with Abs to CD21 and IgM and analyzed by flow cytometry. (B) Splenic cells from recipient RAG-2−/− mice were analyzed at the indicated times after transfer of 2 × 106 splenic B cells from a pool of 1-wk-old mice. Cells were stained with Abs to IgM, IgD, and CD21. Top panels, IgM vs. IgD staining. Bottom panels, the CD21 vs. IgM profile of IgD+IgM+ donor B cells. 200,000 events were collected. Data is shown as dot plots to highlight the few transferred cells that home to the spleen. In the dot plots corresponding to the control (adult) spleen, only 5% of the collected events are shown.

Mentions: To investigate the developmental relationship between T1, T2, and mature B cells, we studied their distribution among splenocytes of mice at various ages. In the adult mouse, T1, T2, and mature B cells were present in the expected proportions (Fig. 2 A, right). In the spleens of 1-wk-old mice, all B cells were T1 B cells (Fig. 2 A, left). T2 and mature B cells started to appear at 2 wk of age (not shown) and were clearly detectable in the spleen of 3-wk-old mice (Fig. 2 A, center). At this time, the T1 population was still larger than in the adult mice (40%), and the fractions of T2 and mature B cells were reduced. MZ B cells are not present in the spleens of newborn mice; they are first detectable in the spleen at 4 wk of age 28.


B cell development in the spleen takes place in discrete steps and is determined by the quality of B cell receptor-derived signals.

Loder F, Mutschler B, Ray RJ, Paige CJ, Sideras P, Torres R, Lamers MC, Carsetti R - J. Exp. Med. (1999)

T1 B cells are the precursors of T2 and mature B cells. (A) Splenocytes of 1- (left) and 3- (center) wk-old and adult (right) C57BL/6 mice were stained with Abs to CD21 and IgM and analyzed by flow cytometry. (B) Splenic cells from recipient RAG-2−/− mice were analyzed at the indicated times after transfer of 2 × 106 splenic B cells from a pool of 1-wk-old mice. Cells were stained with Abs to IgM, IgD, and CD21. Top panels, IgM vs. IgD staining. Bottom panels, the CD21 vs. IgM profile of IgD+IgM+ donor B cells. 200,000 events were collected. Data is shown as dot plots to highlight the few transferred cells that home to the spleen. In the dot plots corresponding to the control (adult) spleen, only 5% of the collected events are shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2195560&req=5

Figure 2: T1 B cells are the precursors of T2 and mature B cells. (A) Splenocytes of 1- (left) and 3- (center) wk-old and adult (right) C57BL/6 mice were stained with Abs to CD21 and IgM and analyzed by flow cytometry. (B) Splenic cells from recipient RAG-2−/− mice were analyzed at the indicated times after transfer of 2 × 106 splenic B cells from a pool of 1-wk-old mice. Cells were stained with Abs to IgM, IgD, and CD21. Top panels, IgM vs. IgD staining. Bottom panels, the CD21 vs. IgM profile of IgD+IgM+ donor B cells. 200,000 events were collected. Data is shown as dot plots to highlight the few transferred cells that home to the spleen. In the dot plots corresponding to the control (adult) spleen, only 5% of the collected events are shown.
Mentions: To investigate the developmental relationship between T1, T2, and mature B cells, we studied their distribution among splenocytes of mice at various ages. In the adult mouse, T1, T2, and mature B cells were present in the expected proportions (Fig. 2 A, right). In the spleens of 1-wk-old mice, all B cells were T1 B cells (Fig. 2 A, left). T2 and mature B cells started to appear at 2 wk of age (not shown) and were clearly detectable in the spleen of 3-wk-old mice (Fig. 2 A, center). At this time, the T1 population was still larger than in the adult mice (40%), and the fractions of T2 and mature B cells were reduced. MZ B cells are not present in the spleens of newborn mice; they are first detectable in the spleen at 4 wk of age 28.

Bottom Line: They develop into the transitional B cells of type 2 (T2), which are cycling and found exclusively in the primary follicles of the spleen.Mice with genetic deletions of elements participating in the B cell receptor signaling cascade display developmental arrest at the T1 or T2 stage.The analysis of these defects showed that the development of T2 and mature B cells from T1 precursors requires defined qualitative and quantitative signals derived from the B cell receptor and that the induction of longevity and maturation requires different signals.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Immunology, University of Freiburg, Germany.

ABSTRACT
Only mature B lymphocytes can enter the lymphoid follicles of spleen and lymph nodes and thus efficiently participate in the immune response. Mature, long-lived B lymphocytes derive from short-lived precursors generated in the bone marrow. We show that selection into the mature pool is an active process and takes place in the spleen. Two populations of splenic B cells were identified as precursors for mature B cells. Transitional B cells of type 1 (T1) are recent immigrants from the bone marrow. They develop into the transitional B cells of type 2 (T2), which are cycling and found exclusively in the primary follicles of the spleen. Mature B cells can be generated from T1 or T2 B cells. Mice with genetic deletions of elements participating in the B cell receptor signaling cascade display developmental arrest at the T1 or T2 stage. The analysis of these defects showed that the development of T2 and mature B cells from T1 precursors requires defined qualitative and quantitative signals derived from the B cell receptor and that the induction of longevity and maturation requires different signals.

Show MeSH