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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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Cross-presentation requirements beyond tumor cell uptake. (A) Antibody enhances cross-presentation only when coating the tumor antigen-expressing myeloma cell. arp (NY-Eso-1−ve) and cag (NY-Eso-1 +ve) cells were treated with anti–syndecan-1 or isotype control antibody and fed to HLA A2.1 +ve DCs, either alone, or together, at DC/tumor ratio of 1:1. Tumor cell–loaded DCs (after maturation with cytokine cocktail), were used to stimulate autologous T cells. After two stimulations, the number of peptide-specific T cells was quantified using peptide-pulsed DCs as APCs in an ELISPOT assay. (B) FcγR blocking antibodies decrease cross-presentation. DCs were pretreated with anti-FcγR blocking antibodies (CD16+CD32) or with isotype controls, before feeding tumor cells treated with anti-syndecan (mAb-Tum) or isotype (Iso-Tum) control antibody, as described in the legend to Fig. 3 A. Antigen-specific T cells were quantified after two stimulations, in an ELISPOT assay using peptide-pulsed DCs as APCs.
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fig6: Cross-presentation requirements beyond tumor cell uptake. (A) Antibody enhances cross-presentation only when coating the tumor antigen-expressing myeloma cell. arp (NY-Eso-1−ve) and cag (NY-Eso-1 +ve) cells were treated with anti–syndecan-1 or isotype control antibody and fed to HLA A2.1 +ve DCs, either alone, or together, at DC/tumor ratio of 1:1. Tumor cell–loaded DCs (after maturation with cytokine cocktail), were used to stimulate autologous T cells. After two stimulations, the number of peptide-specific T cells was quantified using peptide-pulsed DCs as APCs in an ELISPOT assay. (B) FcγR blocking antibodies decrease cross-presentation. DCs were pretreated with anti-FcγR blocking antibodies (CD16+CD32) or with isotype controls, before feeding tumor cells treated with anti-syndecan (mAb-Tum) or isotype (Iso-Tum) control antibody, as described in the legend to Fig. 3 A. Antigen-specific T cells were quantified after two stimulations, in an ELISPOT assay using peptide-pulsed DCs as APCs.

Mentions: To examine the role of antibody and FcγR in the cross-presentation of antigens by DCs, DCs were first fed with a mixture of antigen (NY-Eso-1)-positive (cag cells) and negative (arp cells) tumors. The tumor cells were internalized similarly with or without antibody coating, implying substantial direct recognition of tumor cells by DCs. However, NY-Eso-1–specific T cells were efficiently expanded in these cultures only if the NY-Eso-1-positive tumor cells (cag cells) were coated with anti–syndecan-1 antibody (Fig. 6 A). Therefore, antibody coating directly promotes the cross-presentation of tumor cells.


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)

Cross-presentation requirements beyond tumor cell uptake. (A) Antibody enhances cross-presentation only when coating the tumor antigen-expressing myeloma cell. arp (NY-Eso-1−ve) and cag (NY-Eso-1 +ve) cells were treated with anti–syndecan-1 or isotype control antibody and fed to HLA A2.1 +ve DCs, either alone, or together, at DC/tumor ratio of 1:1. Tumor cell–loaded DCs (after maturation with cytokine cocktail), were used to stimulate autologous T cells. After two stimulations, the number of peptide-specific T cells was quantified using peptide-pulsed DCs as APCs in an ELISPOT assay. (B) FcγR blocking antibodies decrease cross-presentation. DCs were pretreated with anti-FcγR blocking antibodies (CD16+CD32) or with isotype controls, before feeding tumor cells treated with anti-syndecan (mAb-Tum) or isotype (Iso-Tum) control antibody, as described in the legend to Fig. 3 A. Antigen-specific T cells were quantified after two stimulations, in an ELISPOT assay using peptide-pulsed DCs as APCs.
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Related In: Results  -  Collection

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fig6: Cross-presentation requirements beyond tumor cell uptake. (A) Antibody enhances cross-presentation only when coating the tumor antigen-expressing myeloma cell. arp (NY-Eso-1−ve) and cag (NY-Eso-1 +ve) cells were treated with anti–syndecan-1 or isotype control antibody and fed to HLA A2.1 +ve DCs, either alone, or together, at DC/tumor ratio of 1:1. Tumor cell–loaded DCs (after maturation with cytokine cocktail), were used to stimulate autologous T cells. After two stimulations, the number of peptide-specific T cells was quantified using peptide-pulsed DCs as APCs in an ELISPOT assay. (B) FcγR blocking antibodies decrease cross-presentation. DCs were pretreated with anti-FcγR blocking antibodies (CD16+CD32) or with isotype controls, before feeding tumor cells treated with anti-syndecan (mAb-Tum) or isotype (Iso-Tum) control antibody, as described in the legend to Fig. 3 A. Antigen-specific T cells were quantified after two stimulations, in an ELISPOT assay using peptide-pulsed DCs as APCs.
Mentions: To examine the role of antibody and FcγR in the cross-presentation of antigens by DCs, DCs were first fed with a mixture of antigen (NY-Eso-1)-positive (cag cells) and negative (arp cells) tumors. The tumor cells were internalized similarly with or without antibody coating, implying substantial direct recognition of tumor cells by DCs. However, NY-Eso-1–specific T cells were efficiently expanded in these cultures only if the NY-Eso-1-positive tumor cells (cag cells) were coated with anti–syndecan-1 antibody (Fig. 6 A). Therefore, antibody coating directly promotes the cross-presentation of tumor cells.

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