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Dendritic cells enhance growth and differentiation of CD40-activated B lymphocytes.

Dubois B, Vanbervliet B, Fayette J, Massacrier C, Van Kooten C, Brière F, Banchereau J, Caux C - J. Exp. Med. (1997)

Bottom Line: Furthermore, after CD40 ligation, DC enhanced by 30-300-fold the secretion of IgG and IgA by sIgD- B cells (essentially memory B cells).In the presence of DC, naive sIgD+ B cells produced, in response to interleukin-2, large amounts of IgM.Thus, in addition to activating naive T cells in the extrafollicular areas of secondary lymphoid organs, DC may directly modulate B cell growth and differentiation.

View Article: PubMed Central - PubMed

Affiliation: Schering Plough, Laboratory for Immunological Research, Dardilly, France.

ABSTRACT
After antigen capture, dendritic cells (DC) migrate into T cell-rich areas of secondary lymphoid organs, where they induce T cell activation, that subsequently drives B cell activation. Here, we investigate whether DC, generated in vitro, can directly modulate B cell responses, using CD40L-transfected L cells as surrogate activated T cells. DC, through the production of soluble mediators, stimulated by 3- to 6-fold the proliferation and subsequent recovery of B cells. Furthermore, after CD40 ligation, DC enhanced by 30-300-fold the secretion of IgG and IgA by sIgD- B cells (essentially memory B cells). In the presence of DC, naive sIgD+ B cells produced, in response to interleukin-2, large amounts of IgM. Thus, in addition to activating naive T cells in the extrafollicular areas of secondary lymphoid organs, DC may directly modulate B cell growth and differentiation.

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In the presence of IL-2, D–Lc strongly enhance IgM production by naive sIgD+ B cells. B cells were purified into IgD+ B cells and  IgD− B cells using the MACS system (purification detailed in Materials  and Methods). Increasing numbers of either total B cells, MACS-purified  IgD+ B cells or IgD− B cells were cultured under CD40 activation in  medium alone or in the presence of irradiated D–Lc. (A) Cytokine-independent proliferation of B cells was measured after 6 d of coculture. (B)  IL-2–dependent IgM production was measured after 15 d. Results are expressed as mean of triplicate cultures (SD ⩽ 10%). (results from 1 experiment representative of 6). (C) 104 highly purified B cells were cultured  over 2.5 × 103 irradiated CD40L L cells in the presence or absence of 103  D–Lc, either in medium alone or with IL-2 (20 U/ml), IL-4 (50 U/ml),  or IL-10 (20 ng/ml). Superposable results were obtained with IgD+ B cells.  Ig levels were determined after 15 d of culture. Results are expressed as  mean ± SD of triplicate cultures (1 experiment representative of 10). No  significant B cell proliferation and differentiation was observed in absence  of CD40L L cells.
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Figure 3: In the presence of IL-2, D–Lc strongly enhance IgM production by naive sIgD+ B cells. B cells were purified into IgD+ B cells and IgD− B cells using the MACS system (purification detailed in Materials and Methods). Increasing numbers of either total B cells, MACS-purified IgD+ B cells or IgD− B cells were cultured under CD40 activation in medium alone or in the presence of irradiated D–Lc. (A) Cytokine-independent proliferation of B cells was measured after 6 d of coculture. (B) IL-2–dependent IgM production was measured after 15 d. Results are expressed as mean of triplicate cultures (SD ⩽ 10%). (results from 1 experiment representative of 6). (C) 104 highly purified B cells were cultured over 2.5 × 103 irradiated CD40L L cells in the presence or absence of 103 D–Lc, either in medium alone or with IL-2 (20 U/ml), IL-4 (50 U/ml), or IL-10 (20 ng/ml). Superposable results were obtained with IgD+ B cells. Ig levels were determined after 15 d of culture. Results are expressed as mean ± SD of triplicate cultures (1 experiment representative of 10). No significant B cell proliferation and differentiation was observed in absence of CD40L L cells.

Mentions: In view of the weak stimulation of IgM production, we wondered whether sIgD+ B cells were sensitive to the stimulatory effect of D–Lc. As shown in Fig. 3 A and Table 1, D–Lc equally enhanced the CD40-induced proliferation of all B cell subsets (sIgD+, sIgD−, resting, and in vivo-activated B cells) in absence of any exogenous cytokines. As D–Lc enhanced growth of naive B cells, we wondered whether addition of exogenous cytokines could enhance the IgM production induced by D–Lc. Among the tested cytokines (IL-2, IL-3, IL-4, IL-6, IL-10, IL-12, IFN-γ and their combinations), only IL-2 yielded significant results. D–Lc did not significantly affect the low levels of IgM obtained in response to IL-4 and the high levels obtained in response to IL-10 (Fig. 3 C). However, in IL-2 supplemented cultures, addition of D–Lc induced CD40-activated B cells to secrete high levels of IgM, which reached 50 μg/ml (mean increase, 161-fold; n = 16). Separation of B cells into sIgD+ and sIgD− B cells showed that production of IgM was mainly a property of the naive sIgD+ B cell population (Fig. 3 B). Note, however, that sIgD− B cells can be induced to produce significant levels of IgM provided 10-fold more B cells (104) are added to cultures. In addition, results presented in Table 1 show that D–Lc can induce small resting naive B cells (high density sIgD+CD38− cells) to produce high amounts of IgM in the presence of CD40 triggering and IL-2.


Dendritic cells enhance growth and differentiation of CD40-activated B lymphocytes.

Dubois B, Vanbervliet B, Fayette J, Massacrier C, Van Kooten C, Brière F, Banchereau J, Caux C - J. Exp. Med. (1997)

In the presence of IL-2, D–Lc strongly enhance IgM production by naive sIgD+ B cells. B cells were purified into IgD+ B cells and  IgD− B cells using the MACS system (purification detailed in Materials  and Methods). Increasing numbers of either total B cells, MACS-purified  IgD+ B cells or IgD− B cells were cultured under CD40 activation in  medium alone or in the presence of irradiated D–Lc. (A) Cytokine-independent proliferation of B cells was measured after 6 d of coculture. (B)  IL-2–dependent IgM production was measured after 15 d. Results are expressed as mean of triplicate cultures (SD ⩽ 10%). (results from 1 experiment representative of 6). (C) 104 highly purified B cells were cultured  over 2.5 × 103 irradiated CD40L L cells in the presence or absence of 103  D–Lc, either in medium alone or with IL-2 (20 U/ml), IL-4 (50 U/ml),  or IL-10 (20 ng/ml). Superposable results were obtained with IgD+ B cells.  Ig levels were determined after 15 d of culture. Results are expressed as  mean ± SD of triplicate cultures (1 experiment representative of 10). No  significant B cell proliferation and differentiation was observed in absence  of CD40L L cells.
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Related In: Results  -  Collection

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Figure 3: In the presence of IL-2, D–Lc strongly enhance IgM production by naive sIgD+ B cells. B cells were purified into IgD+ B cells and IgD− B cells using the MACS system (purification detailed in Materials and Methods). Increasing numbers of either total B cells, MACS-purified IgD+ B cells or IgD− B cells were cultured under CD40 activation in medium alone or in the presence of irradiated D–Lc. (A) Cytokine-independent proliferation of B cells was measured after 6 d of coculture. (B) IL-2–dependent IgM production was measured after 15 d. Results are expressed as mean of triplicate cultures (SD ⩽ 10%). (results from 1 experiment representative of 6). (C) 104 highly purified B cells were cultured over 2.5 × 103 irradiated CD40L L cells in the presence or absence of 103 D–Lc, either in medium alone or with IL-2 (20 U/ml), IL-4 (50 U/ml), or IL-10 (20 ng/ml). Superposable results were obtained with IgD+ B cells. Ig levels were determined after 15 d of culture. Results are expressed as mean ± SD of triplicate cultures (1 experiment representative of 10). No significant B cell proliferation and differentiation was observed in absence of CD40L L cells.
Mentions: In view of the weak stimulation of IgM production, we wondered whether sIgD+ B cells were sensitive to the stimulatory effect of D–Lc. As shown in Fig. 3 A and Table 1, D–Lc equally enhanced the CD40-induced proliferation of all B cell subsets (sIgD+, sIgD−, resting, and in vivo-activated B cells) in absence of any exogenous cytokines. As D–Lc enhanced growth of naive B cells, we wondered whether addition of exogenous cytokines could enhance the IgM production induced by D–Lc. Among the tested cytokines (IL-2, IL-3, IL-4, IL-6, IL-10, IL-12, IFN-γ and their combinations), only IL-2 yielded significant results. D–Lc did not significantly affect the low levels of IgM obtained in response to IL-4 and the high levels obtained in response to IL-10 (Fig. 3 C). However, in IL-2 supplemented cultures, addition of D–Lc induced CD40-activated B cells to secrete high levels of IgM, which reached 50 μg/ml (mean increase, 161-fold; n = 16). Separation of B cells into sIgD+ and sIgD− B cells showed that production of IgM was mainly a property of the naive sIgD+ B cell population (Fig. 3 B). Note, however, that sIgD− B cells can be induced to produce significant levels of IgM provided 10-fold more B cells (104) are added to cultures. In addition, results presented in Table 1 show that D–Lc can induce small resting naive B cells (high density sIgD+CD38− cells) to produce high amounts of IgM in the presence of CD40 triggering and IL-2.

Bottom Line: Furthermore, after CD40 ligation, DC enhanced by 30-300-fold the secretion of IgG and IgA by sIgD- B cells (essentially memory B cells).In the presence of DC, naive sIgD+ B cells produced, in response to interleukin-2, large amounts of IgM.Thus, in addition to activating naive T cells in the extrafollicular areas of secondary lymphoid organs, DC may directly modulate B cell growth and differentiation.

View Article: PubMed Central - PubMed

Affiliation: Schering Plough, Laboratory for Immunological Research, Dardilly, France.

ABSTRACT
After antigen capture, dendritic cells (DC) migrate into T cell-rich areas of secondary lymphoid organs, where they induce T cell activation, that subsequently drives B cell activation. Here, we investigate whether DC, generated in vitro, can directly modulate B cell responses, using CD40L-transfected L cells as surrogate activated T cells. DC, through the production of soluble mediators, stimulated by 3- to 6-fold the proliferation and subsequent recovery of B cells. Furthermore, after CD40 ligation, DC enhanced by 30-300-fold the secretion of IgG and IgA by sIgD- B cells (essentially memory B cells). In the presence of DC, naive sIgD+ B cells produced, in response to interleukin-2, large amounts of IgM. Thus, in addition to activating naive T cells in the extrafollicular areas of secondary lymphoid organs, DC may directly modulate B cell growth and differentiation.

Show MeSH
Related in: MedlinePlus