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Antitumor monoclonal antibodies enhance cross-presentation ofcCellular antigens and the generation of myeloma-specific killer T cells by dendritic cells.

Dhodapkar KM, Krasovsky J, Williamson B, Dhodapkar MV - J. Exp. Med. (2002)

Bottom Line: The mechanism of antitumor effect of monoclonal antibodies (mAbs) is not fully understood.Importantly, mAbs-coated tumor-loaded DCs were consistently superior to DCs loaded with peptides or dying cells for eliciting tumor-specific killer T cells.Cross-presentation was inhibited by pretreatment of DCs with Fc gamma receptor blocking antibodies.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Tumor Immunology and Immunotherapy, The Rockefeller University, New York, NY 10021, USA.

ABSTRACT
The mechanism of antitumor effect of monoclonal antibodies (mAbs) is not fully understood. Here we show that coating myeloma cells with anti-syndecan-1 antibody promotes cross-presentation of cellular antigens by dendritic cells (DCs) to autologous T cells from healthy donors. The tumor cells treated with anti-syndecan-1 or isotype-matched control antibody were fed to HLA-mismatched monocyte-derived immature DCs. Tumor cell-loaded mature DCs induced a strong CD8(+) T cell response that was specific for the cancer-testis (C-T) antigens expressed in the tumor. The CD8(+) T cells killed peptide-pulsed targets, as well as myeloma tumor cells. Importantly, mAbs-coated tumor-loaded DCs were consistently superior to DCs loaded with peptides or dying cells for eliciting tumor-specific killer T cells. This enhanced cross-presentation was not due to enhanced tumor cell uptake or to DC maturation. When mixtures of NY-Eso-1-positive and -negative myeloma cells were captured by DCs, the anti-syndecan-1 antibody had to be on the NY-Eso-1-positive cells to elicit NY-Eso-1-specific response. Cross-presentation was inhibited by pretreatment of DCs with Fc gamma receptor blocking antibodies. Targeting of mAb-coated tumors to DCs may contribute to the efficacy of tumor-reactive mAb and offers a new strategy for immunotherapy.

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Phagocytosis of mAb-coated tumor does not trigger extensive DC maturation. Monocyte-derived DCs at day 6 of culture were cultured in media alone, with inflammatory cytokine cocktail, or with tumor cells pretreated with anti–syndecan-1 or isotype control antibody. After 1 d of culture, the cells were stained with anti-HLA DR (FITC/PE) and one of the following antibodies (anti-CD80, CD86, CD83, CD40, and CD25). Percentage of HLA-DR +ve DCs expressing CD83, CD80, CD86, CD40, or CD25 (top right of each panel) were quantified by flow cytometry.
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fig2: Phagocytosis of mAb-coated tumor does not trigger extensive DC maturation. Monocyte-derived DCs at day 6 of culture were cultured in media alone, with inflammatory cytokine cocktail, or with tumor cells pretreated with anti–syndecan-1 or isotype control antibody. After 1 d of culture, the cells were stained with anti-HLA DR (FITC/PE) and one of the following antibodies (anti-CD80, CD86, CD83, CD40, and CD25). Percentage of HLA-DR +ve DCs expressing CD83, CD80, CD86, CD40, or CD25 (top right of each panel) were quantified by flow cytometry.

Mentions: Ligation of FcγR is known to induce the maturation of mouse DCs. In our system however, the uptake of antibody treated (both anti–syndecan-1 or isotype control), or untreated tumor cells was associated with partial, but equivalent phenotypic maturation of DCs, as measured by a slight increase in the surface expression of CD83, and considerable increases in CD80 and CD86. However, upregulation of HLA-DR, CD40, and CD25 was not noted, as with DCs matured using inflammatory cytokines (Fig. 2) . However these DCs could be fully matured by the addition of inflammatory cytokine cocktail after tumor cell uptake (data not shown). Therefore the anti–syndecan-1 antibody does not detectably influence DC uptake of myeloma cells or DC maturation.


Antitumor monoclonal antibodies enhance cross-presentation ofcCellular antigens and the generation of myeloma-specific killer T cells by dendritic cells.

Dhodapkar KM, Krasovsky J, Williamson B, Dhodapkar MV - J. Exp. Med. (2002)

Phagocytosis of mAb-coated tumor does not trigger extensive DC maturation. Monocyte-derived DCs at day 6 of culture were cultured in media alone, with inflammatory cytokine cocktail, or with tumor cells pretreated with anti–syndecan-1 or isotype control antibody. After 1 d of culture, the cells were stained with anti-HLA DR (FITC/PE) and one of the following antibodies (anti-CD80, CD86, CD83, CD40, and CD25). Percentage of HLA-DR +ve DCs expressing CD83, CD80, CD86, CD40, or CD25 (top right of each panel) were quantified by flow cytometry.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2196013&req=5

fig2: Phagocytosis of mAb-coated tumor does not trigger extensive DC maturation. Monocyte-derived DCs at day 6 of culture were cultured in media alone, with inflammatory cytokine cocktail, or with tumor cells pretreated with anti–syndecan-1 or isotype control antibody. After 1 d of culture, the cells were stained with anti-HLA DR (FITC/PE) and one of the following antibodies (anti-CD80, CD86, CD83, CD40, and CD25). Percentage of HLA-DR +ve DCs expressing CD83, CD80, CD86, CD40, or CD25 (top right of each panel) were quantified by flow cytometry.
Mentions: Ligation of FcγR is known to induce the maturation of mouse DCs. In our system however, the uptake of antibody treated (both anti–syndecan-1 or isotype control), or untreated tumor cells was associated with partial, but equivalent phenotypic maturation of DCs, as measured by a slight increase in the surface expression of CD83, and considerable increases in CD80 and CD86. However, upregulation of HLA-DR, CD40, and CD25 was not noted, as with DCs matured using inflammatory cytokines (Fig. 2) . However these DCs could be fully matured by the addition of inflammatory cytokine cocktail after tumor cell uptake (data not shown). Therefore the anti–syndecan-1 antibody does not detectably influence DC uptake of myeloma cells or DC maturation.

Bottom Line: The mechanism of antitumor effect of monoclonal antibodies (mAbs) is not fully understood.Importantly, mAbs-coated tumor-loaded DCs were consistently superior to DCs loaded with peptides or dying cells for eliciting tumor-specific killer T cells.Cross-presentation was inhibited by pretreatment of DCs with Fc gamma receptor blocking antibodies.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Tumor Immunology and Immunotherapy, The Rockefeller University, New York, NY 10021, USA.

ABSTRACT
The mechanism of antitumor effect of monoclonal antibodies (mAbs) is not fully understood. Here we show that coating myeloma cells with anti-syndecan-1 antibody promotes cross-presentation of cellular antigens by dendritic cells (DCs) to autologous T cells from healthy donors. The tumor cells treated with anti-syndecan-1 or isotype-matched control antibody were fed to HLA-mismatched monocyte-derived immature DCs. Tumor cell-loaded mature DCs induced a strong CD8(+) T cell response that was specific for the cancer-testis (C-T) antigens expressed in the tumor. The CD8(+) T cells killed peptide-pulsed targets, as well as myeloma tumor cells. Importantly, mAbs-coated tumor-loaded DCs were consistently superior to DCs loaded with peptides or dying cells for eliciting tumor-specific killer T cells. This enhanced cross-presentation was not due to enhanced tumor cell uptake or to DC maturation. When mixtures of NY-Eso-1-positive and -negative myeloma cells were captured by DCs, the anti-syndecan-1 antibody had to be on the NY-Eso-1-positive cells to elicit NY-Eso-1-specific response. Cross-presentation was inhibited by pretreatment of DCs with Fc gamma receptor blocking antibodies. Targeting of mAb-coated tumors to DCs may contribute to the efficacy of tumor-reactive mAb and offers a new strategy for immunotherapy.

Show MeSH
Related in: MedlinePlus