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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
21
pubmed:dateCreated
2001-11-5
pubmed:abstractText
Immunotherapy targeting for the induction of a T-cell-mediated antitumor response in patients with renal cell carcinoma (RCC) appears to hold significant promise. Here we describe a novel RCC vaccine strategy that allows for the concomitant delivery of dual immune activators: G250, a widely expressed RCC associated antigen; and granulocyte/macrophage-colony stimulating factor (GM-CSF), an immunomodulatory factor for antigen-presenting cells. The G250-GM-CSF fusion gene was constructed and expressed in Sf9 cells using a baculovirus expression vector system. The Mr 66,000 fusion protein (FP) was subsequently purified through a 6xHis-Ni2+-NTA affinity column and SP Sepharose/fast protein liquid chromatography. The purified FP retains GM-CSF bioactivity, which is comparable, on a molar basis, to that of recombinant GM-CSF when tested in a GM-CSF-dependent cell line. When combined with interleukin 4 (IL-4; 1000 units/ml), FP (0.34 microg/ml) induces differentiation of monocytes (CD14+) into dendritic cells (DCs) expressing surface markers characteristic for antigen-presenting cells. Up-regulation of mature DCs (CD83+CD19-; 17% versus 6%) with enhanced expression of HLA class I and class II antigens was detected in FP-cultured DCs as compared with DCs cultured with recombinant GM-CSF. Treatment of peripheral blood mononuclear cells (PBMCs) with FP alone (2.7 microg/10(7) cells) augments both T-cell helper 1 (Th1) and Th2 cytokine mRNA expression (IL-2, IL-4, GM-CSF, IFN-gamma, and tumor necrosis factor-alpha). Comparison of various immune manipulation strategies in parallel, bulk PBMCs treated with FP (0.34 microg/ml) plus IL-4 (1000 units/ml) for 1 week and restimulated weekly with FP plus IL-2 (20 IU/ml) induced maximal growth expansion of active T cells expressing the T-cell receptor and specific anti-RCC cytotoxicity, which could be blocked by the addition of anti-HLA class I, anti-CD3, or anti-CD8 antibodies. In one tested patient, an augmented cytotoxicity against lymph node-derived RCC target was determined as compared with that against primary tumor targets, which corresponded to an 8-fold higher G250 mRNA expression in lymph node tumor as compared with primary tumor. The replacement of FP with recombinant GM-CSF as an immunostimulant completely abrogated the selection of RCC-specific killer cells in peripheral blood mononuclear cell cultures. All FP-modulated peripheral blood mononuclear cell cultures with antitumor activity showed an up-regulated CD3+CD4+ cell population. These results suggest that GM-CSF-G250 FP is a potent immunostimulant with the capacity for activating immunomodulatory DCs and inducing a T-helper cell-supported, G250-targeted, and CD8+-mediated antitumor response. These findings may have important implications for the use of GM-CSF-G250 FP as a tumor vaccine for the treatment of patients with advanced kidney cancer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0008-5472
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
61
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7925-33
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed-meshheading:11691814-Animals, pubmed-meshheading:11691814-Antigen Presentation, pubmed-meshheading:11691814-Antigens, Neoplasm, pubmed-meshheading:11691814-Baculoviridae, pubmed-meshheading:11691814-Cancer Vaccines, pubmed-meshheading:11691814-Carcinoma, Renal Cell, pubmed-meshheading:11691814-Cytokines, pubmed-meshheading:11691814-Dendritic Cells, pubmed-meshheading:11691814-Gene Expression Regulation, Neoplastic, pubmed-meshheading:11691814-Granulocyte-Macrophage Colony-Stimulating Factor, pubmed-meshheading:11691814-Humans, pubmed-meshheading:11691814-Kidney Neoplasms, pubmed-meshheading:11691814-Leukocytes, Mononuclear, pubmed-meshheading:11691814-Recombinant Fusion Proteins, pubmed-meshheading:11691814-Spodoptera, pubmed-meshheading:11691814-T-Lymphocytes, Cytotoxic, pubmed-meshheading:11691814-Vaccines, Synthetic
pubmed:year
2001
pubmed:articleTitle
Induction of G250-targeted and T-cell-mediated antitumor activity against renal cell carcinoma using a chimeric fusion protein consisting of G250 and granulocyte/monocyte-colony stimulating factor.
pubmed:affiliation
Department of Urology, UCLA Kidney Cancer Program, University of California Los Angeles, Los Angeles, California 90095, USA.
pubmed:publicationType
Journal Article