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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 vitro generated D–Lc enhance DNA synthesis and viable cell number of  B lymphocytes activated through their CD40. (A) 104  highly purified B cells were cultured over 2.5 × 103 irradiated CD40L L  cells (right) or in medium alone (left) in the presence or absence of 104 irradiated D–Lc, as detailed in Materials and Methods. Thymidine uptake,  determined after 6 d, is expressed as mean ± SD of triplicate cultures. (B)  Kinetic of DNA synthesis of 104 CD40-activated B cells cultured in the  presence or absence of 104 D–Lc was monitored between day 0 and day 8.  (C) For numeration experiments, 5 × 104 highly purified B cells were  cultured over 2.5 × 104 irradiated CD40L L cells in the presence or absence of 5 × 104 D–Lc in 24-well plates. Viable cell recovery was determined at many timepoints using Trypan blue dye exclusion between day  0 and day 15. (D) Increasing D–Lc numbers were added to 104 CD40activated B cells, and thymidine uptake was determined after 6 d of coculture (results from experiments representative of 15).
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Figure 1: In vitro generated D–Lc enhance DNA synthesis and viable cell number of  B lymphocytes activated through their CD40. (A) 104 highly purified B cells were cultured over 2.5 × 103 irradiated CD40L L cells (right) or in medium alone (left) in the presence or absence of 104 irradiated D–Lc, as detailed in Materials and Methods. Thymidine uptake, determined after 6 d, is expressed as mean ± SD of triplicate cultures. (B) Kinetic of DNA synthesis of 104 CD40-activated B cells cultured in the presence or absence of 104 D–Lc was monitored between day 0 and day 8. (C) For numeration experiments, 5 × 104 highly purified B cells were cultured over 2.5 × 104 irradiated CD40L L cells in the presence or absence of 5 × 104 D–Lc in 24-well plates. Viable cell recovery was determined at many timepoints using Trypan blue dye exclusion between day 0 and day 15. (D) Increasing D–Lc numbers were added to 104 CD40activated B cells, and thymidine uptake was determined after 6 d of coculture (results from experiments representative of 15).

Mentions: The D–Lc preparation used in this study contains 70– 90% CD1a+ as well as CD1a− cells including granulocytes and monocytes (see Materials and Methods). The role of the latter cells will be discussed later on (Fig. 4). As shown in Fig. 1 A, D–Lc strongly enhanced CD40-induced B cell proliferation as measured by [3H]TdR uptake after 6 d of coculture (three to eight-fold enhancement of [3H]TdR uptake). Note that in the absence of CD40L L cells, D–Lc can not induce B cell proliferation (Fig. 1 A, left). Kinetics analysis shows that addition of 104 D–Lc to CD40 triggering resulted in a twofold increase of [3H]TdR incorporation at day 2, which reached fourfold at day 4, when a plateau is reached (Fig. 1 B). This enhancement of B cell DNA synthesis by D–Lc is associated to an important increase in number of viable B cells (Fig. 1 C) that reaches a plateau at day 10, a time when D–Lc increased B cell number by fivefold. As few as 500 D–Lc are sufficient to induce a two- to threefold increase of CD40-induced B cell proliferation (Fig. 1 D), a maximal effect being obtained with 104 D–Lc (ratio 1:1). Thus, D–Lc enhance the proliferation of CD40-activated B cells in absence of any exogenous cytokine.


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 vitro generated D–Lc enhance DNA synthesis and viable cell number of  B lymphocytes activated through their CD40. (A) 104  highly purified B cells were cultured over 2.5 × 103 irradiated CD40L L  cells (right) or in medium alone (left) in the presence or absence of 104 irradiated D–Lc, as detailed in Materials and Methods. Thymidine uptake,  determined after 6 d, is expressed as mean ± SD of triplicate cultures. (B)  Kinetic of DNA synthesis of 104 CD40-activated B cells cultured in the  presence or absence of 104 D–Lc was monitored between day 0 and day 8.  (C) For numeration experiments, 5 × 104 highly purified B cells were  cultured over 2.5 × 104 irradiated CD40L L cells in the presence or absence of 5 × 104 D–Lc in 24-well plates. Viable cell recovery was determined at many timepoints using Trypan blue dye exclusion between day  0 and day 15. (D) Increasing D–Lc numbers were added to 104 CD40activated B cells, and thymidine uptake was determined after 6 d of coculture (results from experiments representative of 15).
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2196162&req=5

Figure 1: In vitro generated D–Lc enhance DNA synthesis and viable cell number of  B lymphocytes activated through their CD40. (A) 104 highly purified B cells were cultured over 2.5 × 103 irradiated CD40L L cells (right) or in medium alone (left) in the presence or absence of 104 irradiated D–Lc, as detailed in Materials and Methods. Thymidine uptake, determined after 6 d, is expressed as mean ± SD of triplicate cultures. (B) Kinetic of DNA synthesis of 104 CD40-activated B cells cultured in the presence or absence of 104 D–Lc was monitored between day 0 and day 8. (C) For numeration experiments, 5 × 104 highly purified B cells were cultured over 2.5 × 104 irradiated CD40L L cells in the presence or absence of 5 × 104 D–Lc in 24-well plates. Viable cell recovery was determined at many timepoints using Trypan blue dye exclusion between day 0 and day 15. (D) Increasing D–Lc numbers were added to 104 CD40activated B cells, and thymidine uptake was determined after 6 d of coculture (results from experiments representative of 15).
Mentions: The D–Lc preparation used in this study contains 70– 90% CD1a+ as well as CD1a− cells including granulocytes and monocytes (see Materials and Methods). The role of the latter cells will be discussed later on (Fig. 4). As shown in Fig. 1 A, D–Lc strongly enhanced CD40-induced B cell proliferation as measured by [3H]TdR uptake after 6 d of coculture (three to eight-fold enhancement of [3H]TdR uptake). Note that in the absence of CD40L L cells, D–Lc can not induce B cell proliferation (Fig. 1 A, left). Kinetics analysis shows that addition of 104 D–Lc to CD40 triggering resulted in a twofold increase of [3H]TdR incorporation at day 2, which reached fourfold at day 4, when a plateau is reached (Fig. 1 B). This enhancement of B cell DNA synthesis by D–Lc is associated to an important increase in number of viable B cells (Fig. 1 C) that reaches a plateau at day 10, a time when D–Lc increased B cell number by fivefold. As few as 500 D–Lc are sufficient to induce a two- to threefold increase of CD40-induced B cell proliferation (Fig. 1 D), a maximal effect being obtained with 104 D–Lc (ratio 1:1). Thus, D–Lc enhance the proliferation of CD40-activated B cells in absence of any exogenous cytokine.

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