Limits...
Expansion of melanoma-specific cytolytic CD8+ T cell precursors in patients with metastatic melanoma vaccinated with CD34+ progenitor-derived dendritic cells.

Paczesny S, Banchereau J, Wittkowski KM, Saracino G, Fay J, Palucka AK - J. Exp. Med. (2004)

Bottom Line: Cancer vaccines aim at inducing (a) tumor-specific effector T cells able to reduce/eliminate the tumor mass, and (b) long-lasting tumor-specific memory T cells able to control tumor relapse.Thus, CD34-DC vaccines can expand melanoma-specific CTL precursors that can kill melanoma antigen-expressing targets.These results justify the design of larger follow-up studies to assess the immunological and clinical response to peptide-pulsed CD34-DC vaccines.

View Article: PubMed Central - PubMed

Affiliation: Baylor Institute for Immunology Research, Dallas, TX 75204, USA.

ABSTRACT
Cancer vaccines aim at inducing (a) tumor-specific effector T cells able to reduce/eliminate the tumor mass, and (b) long-lasting tumor-specific memory T cells able to control tumor relapse. We have shown earlier, in 18 human histocompatibility leukocyte antigen (HLA)-A*0201 patients with metastatic melanoma, that vaccination with peptide-loaded CD34-dendritic cells (DCs) leads to expansion of melanoma-specific interferon gamma-producing CD8+ T cells in the blood. Here, we show in 9 out of 12 analyzed patients the expansion of cytolytic CD8+ T cell precursors specific for melanoma differentiation antigens. These precursors yield, upon single restimulation with melanoma peptide-pulsed DCs, cytotoxic T lymphocytes (CTLs) able to kill melanoma cells. Melanoma-specific CTLs can be grown in vitro and can be detected in three assays: (a) melanoma tetramer binding, (b) killing of melanoma peptide-pulsed T2 cells, and (c) killing of HLA-A*0201 melanoma cells. The cytolytic activity of expanded CTLs correlates with the frequency of melanoma tetramer binding CD8+ T cells. Thus, CD34-DC vaccines can expand melanoma-specific CTL precursors that can kill melanoma antigen-expressing targets. These results justify the design of larger follow-up studies to assess the immunological and clinical response to peptide-pulsed CD34-DC vaccines.

Show MeSH

Related in: MedlinePlus

Flow cytometry analysis of tetramer binding by expanded CD8+ T cells. Restimulated CD8+T cells are labeled with anti–CD8-FITC (abscissa) and PE tetramers of a given specificity (ordinate). The analysis is performed on T cells gated on CD8 expression and the high affinity T cells are distinguished based on the intensity of tetramer fluorescence (square). (a) Patient number 17 and (b) patient number 21. For details, see Table S2. (c) Comparison of the percentage of high intensity tetramer binding CD8+ T cells (ordinate, log scale) at baseline and after fourth DC vaccination. Wilcoxon paired test.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2211788&req=5

fig4: Flow cytometry analysis of tetramer binding by expanded CD8+ T cells. Restimulated CD8+T cells are labeled with anti–CD8-FITC (abscissa) and PE tetramers of a given specificity (ordinate). The analysis is performed on T cells gated on CD8 expression and the high affinity T cells are distinguished based on the intensity of tetramer fluorescence (square). (a) Patient number 17 and (b) patient number 21. For details, see Table S2. (c) Comparison of the percentage of high intensity tetramer binding CD8+ T cells (ordinate, log scale) at baseline and after fourth DC vaccination. Wilcoxon paired test.

Mentions: Fig. 4 shows examples of tetramer staining in cultured CD8+ T cells, which efficiently killed Me275 melanoma cells (Fig. 3, #17 and #21). CD8+ T cells from patient number 17 (Fig. 4 a) displayed predominant specificity for one antigen, i.e., gp100, with 16% of total tetramer-binding T cells, even higher than for Flu-MP–specific T cells (Fig. 4 a, 13.5%). MART-1–specific CD8+ T cells, and tyrosinase- and MAGE-3–specific T cells, were barely detectable. CD8+ T cells from patient number 21 contained cells specific for three of the four melanoma peptides used for immunization, i.e., gp100 (13.5%), MART-1 (1.6%), and MAGE-3 (2.2%; Fig. 4 b). CD8+ T cells specific for gp100 could be detected in this patient (patient no. 21) in the cultured prevaccination T cells, albeit at a lower frequency (5 vs. 13.5%), a finding consistent with the CTL data shown above (Fig. 3) and the earlier ELISPOT data from this patient (28).


Expansion of melanoma-specific cytolytic CD8+ T cell precursors in patients with metastatic melanoma vaccinated with CD34+ progenitor-derived dendritic cells.

Paczesny S, Banchereau J, Wittkowski KM, Saracino G, Fay J, Palucka AK - J. Exp. Med. (2004)

Flow cytometry analysis of tetramer binding by expanded CD8+ T cells. Restimulated CD8+T cells are labeled with anti–CD8-FITC (abscissa) and PE tetramers of a given specificity (ordinate). The analysis is performed on T cells gated on CD8 expression and the high affinity T cells are distinguished based on the intensity of tetramer fluorescence (square). (a) Patient number 17 and (b) patient number 21. For details, see Table S2. (c) Comparison of the percentage of high intensity tetramer binding CD8+ T cells (ordinate, log scale) at baseline and after fourth DC vaccination. Wilcoxon paired test.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211788&req=5

fig4: Flow cytometry analysis of tetramer binding by expanded CD8+ T cells. Restimulated CD8+T cells are labeled with anti–CD8-FITC (abscissa) and PE tetramers of a given specificity (ordinate). The analysis is performed on T cells gated on CD8 expression and the high affinity T cells are distinguished based on the intensity of tetramer fluorescence (square). (a) Patient number 17 and (b) patient number 21. For details, see Table S2. (c) Comparison of the percentage of high intensity tetramer binding CD8+ T cells (ordinate, log scale) at baseline and after fourth DC vaccination. Wilcoxon paired test.
Mentions: Fig. 4 shows examples of tetramer staining in cultured CD8+ T cells, which efficiently killed Me275 melanoma cells (Fig. 3, #17 and #21). CD8+ T cells from patient number 17 (Fig. 4 a) displayed predominant specificity for one antigen, i.e., gp100, with 16% of total tetramer-binding T cells, even higher than for Flu-MP–specific T cells (Fig. 4 a, 13.5%). MART-1–specific CD8+ T cells, and tyrosinase- and MAGE-3–specific T cells, were barely detectable. CD8+ T cells from patient number 21 contained cells specific for three of the four melanoma peptides used for immunization, i.e., gp100 (13.5%), MART-1 (1.6%), and MAGE-3 (2.2%; Fig. 4 b). CD8+ T cells specific for gp100 could be detected in this patient (patient no. 21) in the cultured prevaccination T cells, albeit at a lower frequency (5 vs. 13.5%), a finding consistent with the CTL data shown above (Fig. 3) and the earlier ELISPOT data from this patient (28).

Bottom Line: Cancer vaccines aim at inducing (a) tumor-specific effector T cells able to reduce/eliminate the tumor mass, and (b) long-lasting tumor-specific memory T cells able to control tumor relapse.Thus, CD34-DC vaccines can expand melanoma-specific CTL precursors that can kill melanoma antigen-expressing targets.These results justify the design of larger follow-up studies to assess the immunological and clinical response to peptide-pulsed CD34-DC vaccines.

View Article: PubMed Central - PubMed

Affiliation: Baylor Institute for Immunology Research, Dallas, TX 75204, USA.

ABSTRACT
Cancer vaccines aim at inducing (a) tumor-specific effector T cells able to reduce/eliminate the tumor mass, and (b) long-lasting tumor-specific memory T cells able to control tumor relapse. We have shown earlier, in 18 human histocompatibility leukocyte antigen (HLA)-A*0201 patients with metastatic melanoma, that vaccination with peptide-loaded CD34-dendritic cells (DCs) leads to expansion of melanoma-specific interferon gamma-producing CD8+ T cells in the blood. Here, we show in 9 out of 12 analyzed patients the expansion of cytolytic CD8+ T cell precursors specific for melanoma differentiation antigens. These precursors yield, upon single restimulation with melanoma peptide-pulsed DCs, cytotoxic T lymphocytes (CTLs) able to kill melanoma cells. Melanoma-specific CTLs can be grown in vitro and can be detected in three assays: (a) melanoma tetramer binding, (b) killing of melanoma peptide-pulsed T2 cells, and (c) killing of HLA-A*0201 melanoma cells. The cytolytic activity of expanded CTLs correlates with the frequency of melanoma tetramer binding CD8+ T cells. Thus, CD34-DC vaccines can expand melanoma-specific CTL precursors that can kill melanoma antigen-expressing targets. These results justify the design of larger follow-up studies to assess the immunological and clinical response to peptide-pulsed CD34-DC vaccines.

Show MeSH
Related in: MedlinePlus