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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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The secretion of IgM by B cells is dependent on the production of soluble factor(s) by D–Lc after CD40 engagement. 1.5 × 104  sIgD+ B cells were cultured in the presence of 3.75 × 103 CD40L L cells  or CD32 control L cells in the top of the transwell. 105 D–Lc were cultured in the lower compartment with 2.5 × 104 CD40L L cells or CD32  L cells used as controls. (A) DNA synthesis of B cells of the upper compartment, in absence of cytokine, was determined after 6 d of coculture.  (B) IgM production in the presence of IL-2 was determined by ELISA after 15 d. Cultures were carried out in triplicates (one experiment representative of three).
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Figure 8: The secretion of IgM by B cells is dependent on the production of soluble factor(s) by D–Lc after CD40 engagement. 1.5 × 104 sIgD+ B cells were cultured in the presence of 3.75 × 103 CD40L L cells or CD32 control L cells in the top of the transwell. 105 D–Lc were cultured in the lower compartment with 2.5 × 104 CD40L L cells or CD32 L cells used as controls. (A) DNA synthesis of B cells of the upper compartment, in absence of cytokine, was determined after 6 d of coculture. (B) IgM production in the presence of IL-2 was determined by ELISA after 15 d. Cultures were carried out in triplicates (one experiment representative of three).

Mentions: Experiments were designed to determine whether the functions of D–Lc on B cells were mediated through soluble factors and/or cell–cell interactions and whether D–Lc had to be activated through their CD40 antigen. Neither D–Lc supernatants nor fixed D–Lc significantly stimulated B cell growth and differentiation. As an alternative, D–Lc were separated from B cells by a permeable membrane using Transwells®. As shown in Fig. 8 A, D–Lc cultured in the lower compartment, with or without CD40 triggering, can enhance CD40-dependent B cell proliferation as much as if they were cocultured in direct contact. In the presence of IL-2, CD40-activated D–Lc, but not unactivated D-Lc, can support IgM production by B cells activated through CD40 (Fig. 8 B). However, IgM levels obtained were lower than those observed in direct contact coculture (6.1 ± 0.8 μg/ml versus 15.5 ± 2.5 μg/ml), suggesting that cell– cell contacts may also contribute. Note that D–Lc do not deliver any signal when B cells are not activated (Fig. 8; B plus CD32 L cells).


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)

The secretion of IgM by B cells is dependent on the production of soluble factor(s) by D–Lc after CD40 engagement. 1.5 × 104  sIgD+ B cells were cultured in the presence of 3.75 × 103 CD40L L cells  or CD32 control L cells in the top of the transwell. 105 D–Lc were cultured in the lower compartment with 2.5 × 104 CD40L L cells or CD32  L cells used as controls. (A) DNA synthesis of B cells of the upper compartment, in absence of cytokine, was determined after 6 d of coculture.  (B) IgM production in the presence of IL-2 was determined by ELISA after 15 d. Cultures were carried out in triplicates (one experiment representative of three).
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Related In: Results  -  Collection

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Figure 8: The secretion of IgM by B cells is dependent on the production of soluble factor(s) by D–Lc after CD40 engagement. 1.5 × 104 sIgD+ B cells were cultured in the presence of 3.75 × 103 CD40L L cells or CD32 control L cells in the top of the transwell. 105 D–Lc were cultured in the lower compartment with 2.5 × 104 CD40L L cells or CD32 L cells used as controls. (A) DNA synthesis of B cells of the upper compartment, in absence of cytokine, was determined after 6 d of coculture. (B) IgM production in the presence of IL-2 was determined by ELISA after 15 d. Cultures were carried out in triplicates (one experiment representative of three).
Mentions: Experiments were designed to determine whether the functions of D–Lc on B cells were mediated through soluble factors and/or cell–cell interactions and whether D–Lc had to be activated through their CD40 antigen. Neither D–Lc supernatants nor fixed D–Lc significantly stimulated B cell growth and differentiation. As an alternative, D–Lc were separated from B cells by a permeable membrane using Transwells®. As shown in Fig. 8 A, D–Lc cultured in the lower compartment, with or without CD40 triggering, can enhance CD40-dependent B cell proliferation as much as if they were cocultured in direct contact. In the presence of IL-2, CD40-activated D–Lc, but not unactivated D-Lc, can support IgM production by B cells activated through CD40 (Fig. 8 B). However, IgM levels obtained were lower than those observed in direct contact coculture (6.1 ± 0.8 μg/ml versus 15.5 ± 2.5 μg/ml), suggesting that cell– cell contacts may also contribute. Note that D–Lc do not deliver any signal when B cells are not activated (Fig. 8; B plus CD32 L cells).

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