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A novel cancer vaccine strategy based on HLA-A*0201 matched allogeneic plasmacytoid dendritic cells.

Aspord C, Charles J, Leccia MT, Laurin D, Richard MJ, Chaperot L, Plumas J - PLoS ONE (2010)

Bottom Line: The development of effective cancer vaccines still remains a challenge.This semi-allogeneic pDC vaccine was more effective than conventional myeloid DC-based vaccines.These findings highlight HLA-A*0201 matched allogeneic pDCs as potent inducers of tumor immunity and provide a promising immunotherapeutic strategy to fight cancer.

View Article: PubMed Central - PubMed

Affiliation: Etablissement Français du Sang Rhone-Alpes, R&D Laboratory, La Tronche, France. carolineaspord@yahoo.com

ABSTRACT

Background: The development of effective cancer vaccines still remains a challenge. Despite the crucial role of plasmacytoid dendritic cells (pDCs) in anti-tumor responses, their therapeutic potential has not yet been worked out. We explored the relevance of HLA-A*0201 matched allogeneic pDCs as vectors for immunotherapy.

Methods and findings: Stimulation of PBMC from HLA-A*0201(+) donors by HLA-A*0201 matched allogeneic pDCs pulsed with tumor-derived peptides triggered high levels of antigen-specific and functional cytotoxic T cell responses (up to 98% tetramer(+) CD8 T cells). The pDC vaccine demonstrated strong anti-tumor therapeutic in vivo efficacy as shown by the inhibition of tumor growth in a humanized mouse model. It also elicited highly functional tumor-specific T cells ex-vivo from PBMC and TIL of stage I-IV melanoma patients. Responses against MelA, GP100, tyrosinase and MAGE-3 antigens reached tetramer levels up to 62%, 24%, 85% and 4.3% respectively. pDC vaccine-primed T cells specifically killed patients' own autologous melanoma tumor cells. This semi-allogeneic pDC vaccine was more effective than conventional myeloid DC-based vaccines. Furthermore, the pDC vaccine design endows it with a strong potential for clinical application in cancer treatment.

Conclusions: These findings highlight HLA-A*0201 matched allogeneic pDCs as potent inducers of tumor immunity and provide a promising immunotherapeutic strategy to fight cancer.

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Related in: MedlinePlus

Vaccination with the peptide-loaded HLA-A*0201 matched allogeneic pDC line elicits strong antigen-specific T cell responses in humanized mice.(A-B) Immunodeficient NOD-SCIDβ2m-/- mice were reconstituted intraperitoneally with 50.106 human HLA-A*0201+ healthy donors' PBMC and vaccinated by the same route with 5.106 irradiated peptide-loaded GEN cells. Specific T cell induction was analyzed at the injection site (lavage), in the circulation (blood) and lymphoid organs (spleen, LN) by tetramer labelling of human T cells in cell suspensions. (A) Vaccination with peptide-loaded GEN cells induced specific T cell responses in vivo. Representative dot plots of tetramer labeled T cells induced after a single vaccination with peptide-loaded GEN cells in different organs at day 8 for anti-viral vaccine (Flu, CMV) and day 10 for anti-tumor vaccine (MelA) (gated on CD8+ T cells). One mice per group is shown. Initial levels of specific T cells within PBMC were 0.04%, 0.14% and 0.003% respectively. (B) Levels of specific T cells before (day 0) and after vaccination with GEN loaded with FluM1 (n = 22 mice, 4 donors, 1 vaccine), CMVpp65 (n = 18 mice, 2 donors, 1 vaccine) and MelA (n = 38 mice, 4 donors, 2–3 vaccines) peptides at the indicated times in different organs. Each dot represents one vaccinated HuPBL mice (bars at mean).
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pone-0010458-g003: Vaccination with the peptide-loaded HLA-A*0201 matched allogeneic pDC line elicits strong antigen-specific T cell responses in humanized mice.(A-B) Immunodeficient NOD-SCIDβ2m-/- mice were reconstituted intraperitoneally with 50.106 human HLA-A*0201+ healthy donors' PBMC and vaccinated by the same route with 5.106 irradiated peptide-loaded GEN cells. Specific T cell induction was analyzed at the injection site (lavage), in the circulation (blood) and lymphoid organs (spleen, LN) by tetramer labelling of human T cells in cell suspensions. (A) Vaccination with peptide-loaded GEN cells induced specific T cell responses in vivo. Representative dot plots of tetramer labeled T cells induced after a single vaccination with peptide-loaded GEN cells in different organs at day 8 for anti-viral vaccine (Flu, CMV) and day 10 for anti-tumor vaccine (MelA) (gated on CD8+ T cells). One mice per group is shown. Initial levels of specific T cells within PBMC were 0.04%, 0.14% and 0.003% respectively. (B) Levels of specific T cells before (day 0) and after vaccination with GEN loaded with FluM1 (n = 22 mice, 4 donors, 1 vaccine), CMVpp65 (n = 18 mice, 2 donors, 1 vaccine) and MelA (n = 38 mice, 4 donors, 2–3 vaccines) peptides at the indicated times in different organs. Each dot represents one vaccinated HuPBL mice (bars at mean).

Mentions: The use of HLA matched allogeneic pDCs as a vaccine requires induction of antigen-specific T cell responses in vivo. Therefore we evaluated the vaccine potential of the pDC line in a humanized mouse model [42] constructed by xenotransplanting human PBMC into immunodeficient NOD-SCIDβ2m-/- mice (HuPBL SCID model). Twenty four hours after intraperitoneal transfer, human CD45+ haematopoietic cells were found at the injection site but also in the circulation and lymphoid organs (not shown). A single intra-peritoneal injection of the irradiated peptide-loaded HLA-A*0201 matched allogeneic pDC line induced strong antigen-specific T cell responses towards viral (FluM1, CMVpp65) and tumor (MelA) antigens in HuPBL mice (Figure 3A). Human tetramer+ CD8 T cells were found not only at the site of immunization (peritoneal lavage) but also in the circulation (blood) and lymphoid organs (spleen, lymph nodes) (Figure 3A). We then evaluated whether several weekly injections of the peptide-pulsed pDC line could enhance the level of the response. Interestingly, viral antigen (Flu) induced a high response that peaked 7 days after the first vaccine and decreased afterwards, whereas response to tumor antigen (MelA) kept increasing upon subsequent restimulations (Figure S4). Within all vaccinated HuPBL mice (n = 22, 18 and 38) reconstituted with human PBMC (baseline levels of tetramer+ CD8+ T cells were 0.11% (FluM1), 0.12% (CMVpp65) and 0.01% (MelA) tetramer+ T cells) levels of specific T cells recovered in the different organs ranged from 0.7 to 1.9% for FluM1, 1.1 to 5.9% for CMVpp65, and 0.2 to 1% for MelA (Figure 3B). Thus, the peptide-pulsed pDC line elicits strong and widespread antigen-specific T cell responses in vivo.


A novel cancer vaccine strategy based on HLA-A*0201 matched allogeneic plasmacytoid dendritic cells.

Aspord C, Charles J, Leccia MT, Laurin D, Richard MJ, Chaperot L, Plumas J - PLoS ONE (2010)

Vaccination with the peptide-loaded HLA-A*0201 matched allogeneic pDC line elicits strong antigen-specific T cell responses in humanized mice.(A-B) Immunodeficient NOD-SCIDβ2m-/- mice were reconstituted intraperitoneally with 50.106 human HLA-A*0201+ healthy donors' PBMC and vaccinated by the same route with 5.106 irradiated peptide-loaded GEN cells. Specific T cell induction was analyzed at the injection site (lavage), in the circulation (blood) and lymphoid organs (spleen, LN) by tetramer labelling of human T cells in cell suspensions. (A) Vaccination with peptide-loaded GEN cells induced specific T cell responses in vivo. Representative dot plots of tetramer labeled T cells induced after a single vaccination with peptide-loaded GEN cells in different organs at day 8 for anti-viral vaccine (Flu, CMV) and day 10 for anti-tumor vaccine (MelA) (gated on CD8+ T cells). One mice per group is shown. Initial levels of specific T cells within PBMC were 0.04%, 0.14% and 0.003% respectively. (B) Levels of specific T cells before (day 0) and after vaccination with GEN loaded with FluM1 (n = 22 mice, 4 donors, 1 vaccine), CMVpp65 (n = 18 mice, 2 donors, 1 vaccine) and MelA (n = 38 mice, 4 donors, 2–3 vaccines) peptides at the indicated times in different organs. Each dot represents one vaccinated HuPBL mice (bars at mean).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2864288&req=5

pone-0010458-g003: Vaccination with the peptide-loaded HLA-A*0201 matched allogeneic pDC line elicits strong antigen-specific T cell responses in humanized mice.(A-B) Immunodeficient NOD-SCIDβ2m-/- mice were reconstituted intraperitoneally with 50.106 human HLA-A*0201+ healthy donors' PBMC and vaccinated by the same route with 5.106 irradiated peptide-loaded GEN cells. Specific T cell induction was analyzed at the injection site (lavage), in the circulation (blood) and lymphoid organs (spleen, LN) by tetramer labelling of human T cells in cell suspensions. (A) Vaccination with peptide-loaded GEN cells induced specific T cell responses in vivo. Representative dot plots of tetramer labeled T cells induced after a single vaccination with peptide-loaded GEN cells in different organs at day 8 for anti-viral vaccine (Flu, CMV) and day 10 for anti-tumor vaccine (MelA) (gated on CD8+ T cells). One mice per group is shown. Initial levels of specific T cells within PBMC were 0.04%, 0.14% and 0.003% respectively. (B) Levels of specific T cells before (day 0) and after vaccination with GEN loaded with FluM1 (n = 22 mice, 4 donors, 1 vaccine), CMVpp65 (n = 18 mice, 2 donors, 1 vaccine) and MelA (n = 38 mice, 4 donors, 2–3 vaccines) peptides at the indicated times in different organs. Each dot represents one vaccinated HuPBL mice (bars at mean).
Mentions: The use of HLA matched allogeneic pDCs as a vaccine requires induction of antigen-specific T cell responses in vivo. Therefore we evaluated the vaccine potential of the pDC line in a humanized mouse model [42] constructed by xenotransplanting human PBMC into immunodeficient NOD-SCIDβ2m-/- mice (HuPBL SCID model). Twenty four hours after intraperitoneal transfer, human CD45+ haematopoietic cells were found at the injection site but also in the circulation and lymphoid organs (not shown). A single intra-peritoneal injection of the irradiated peptide-loaded HLA-A*0201 matched allogeneic pDC line induced strong antigen-specific T cell responses towards viral (FluM1, CMVpp65) and tumor (MelA) antigens in HuPBL mice (Figure 3A). Human tetramer+ CD8 T cells were found not only at the site of immunization (peritoneal lavage) but also in the circulation (blood) and lymphoid organs (spleen, lymph nodes) (Figure 3A). We then evaluated whether several weekly injections of the peptide-pulsed pDC line could enhance the level of the response. Interestingly, viral antigen (Flu) induced a high response that peaked 7 days after the first vaccine and decreased afterwards, whereas response to tumor antigen (MelA) kept increasing upon subsequent restimulations (Figure S4). Within all vaccinated HuPBL mice (n = 22, 18 and 38) reconstituted with human PBMC (baseline levels of tetramer+ CD8+ T cells were 0.11% (FluM1), 0.12% (CMVpp65) and 0.01% (MelA) tetramer+ T cells) levels of specific T cells recovered in the different organs ranged from 0.7 to 1.9% for FluM1, 1.1 to 5.9% for CMVpp65, and 0.2 to 1% for MelA (Figure 3B). Thus, the peptide-pulsed pDC line elicits strong and widespread antigen-specific T cell responses in vivo.

Bottom Line: The development of effective cancer vaccines still remains a challenge.This semi-allogeneic pDC vaccine was more effective than conventional myeloid DC-based vaccines.These findings highlight HLA-A*0201 matched allogeneic pDCs as potent inducers of tumor immunity and provide a promising immunotherapeutic strategy to fight cancer.

View Article: PubMed Central - PubMed

Affiliation: Etablissement Français du Sang Rhone-Alpes, R&D Laboratory, La Tronche, France. carolineaspord@yahoo.com

ABSTRACT

Background: The development of effective cancer vaccines still remains a challenge. Despite the crucial role of plasmacytoid dendritic cells (pDCs) in anti-tumor responses, their therapeutic potential has not yet been worked out. We explored the relevance of HLA-A*0201 matched allogeneic pDCs as vectors for immunotherapy.

Methods and findings: Stimulation of PBMC from HLA-A*0201(+) donors by HLA-A*0201 matched allogeneic pDCs pulsed with tumor-derived peptides triggered high levels of antigen-specific and functional cytotoxic T cell responses (up to 98% tetramer(+) CD8 T cells). The pDC vaccine demonstrated strong anti-tumor therapeutic in vivo efficacy as shown by the inhibition of tumor growth in a humanized mouse model. It also elicited highly functional tumor-specific T cells ex-vivo from PBMC and TIL of stage I-IV melanoma patients. Responses against MelA, GP100, tyrosinase and MAGE-3 antigens reached tetramer levels up to 62%, 24%, 85% and 4.3% respectively. pDC vaccine-primed T cells specifically killed patients' own autologous melanoma tumor cells. This semi-allogeneic pDC vaccine was more effective than conventional myeloid DC-based vaccines. Furthermore, the pDC vaccine design endows it with a strong potential for clinical application in cancer treatment.

Conclusions: These findings highlight HLA-A*0201 matched allogeneic pDCs as potent inducers of tumor immunity and provide a promising immunotherapeutic strategy to fight cancer.

Show MeSH
Related in: MedlinePlus