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Recruitment of CTL activity by tumor-specific antibody-mediated targeting of single-chain class I MHC-peptide complexes.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2002 Sep 15; Vol. 169 (6), pp. 2988-96. - Publication Year :
- 2002
-
Abstract
- The MHC class I-restricted CD8 CTL effector arm of the adaptive immune response is uniquely equipped to recognize tumor cells as foreign and consequently initiates the cascade of events resulting in their destruction. However, tumors have developed sophisticated strategies to escape immune effector mechanisms; their most well-known strategy is down-regulation of MHC class I molecules. To overcome this and develop new approaches for immunotherapy, we have constructed a recombinant molecule in which a single-chain MHC is specifically targeted to tumor cells through its fusion to cancer-specific recombinant Ab fragments. As a model we used a single-chain HLA-A2 molecule genetically fused to the variable domains of an anti-IL-2Ralpha subunit-specific humanized Ab, anti-Tac. The construct, termed B2M-aTac(dsFv), was expressed in Escherichia coli, and functional molecules were produced by in vitro refolding in the presence of HLA-A2-restricted antigenic peptides. Flow cytometry studies revealed the ability to decorate Ag-positive, HLA-A2-negative human tumor cells with HLA-A2-peptide complexes in a manner that was entirely dependent upon the specificity of the targeting Ab fragment. Most importantly, the B2M-aTac(dsFv)-mediated coating of the target tumor cells made them susceptible for efficient and specific HLA-A2-restricted, melanoma gp100 peptide-specific CTL-mediated lysis. These results demonstrate the concept that Ab-guided, Ag-specific targeting of MHC-peptide complexes on tumor cells can render them susceptible and more receptive and thus potentiate CTL killing. This type of approach may open the way for the development of new immunotherapeutic strategies based on Ab targeting of natural cognate MHC ligands and CTL-based cytotoxic mechanisms.
- Subjects :
- Animals
Antibodies, Monoclonal genetics
Antibodies, Monoclonal metabolism
Antigens, Neoplasm genetics
Antineoplastic Agents administration & dosage
Antineoplastic Agents chemical synthesis
Antineoplastic Agents isolation & purification
Antineoplastic Agents metabolism
Binding Sites, Antibody genetics
Binding Sites, Antibody immunology
Carcinoma, Squamous Cell immunology
Carcinoma, Squamous Cell metabolism
Cytotoxicity Tests, Immunologic methods
Genetic Vectors chemical synthesis
Genetic Vectors isolation & purification
Genetic Vectors metabolism
HLA-A2 Antigen genetics
HLA-A2 Antigen metabolism
Humans
Immunoglobulin Fragments genetics
Injections, Subcutaneous
Membrane Glycoproteins genetics
Mice
Mice, Nude
Peptide Fragments genetics
Receptors, Interleukin-2 genetics
Receptors, Interleukin-2 immunology
Recombinant Fusion Proteins chemical synthesis
Recombinant Fusion Proteins isolation & purification
Recombinant Fusion Proteins metabolism
T-Lymphocytes, Cytotoxic metabolism
Tumor Cells, Cultured
beta 2-Microglobulin genetics
beta 2-Microglobulin metabolism
gp100 Melanoma Antigen
Antibody-Dependent Cell Cytotoxicity genetics
Genetic Vectors pharmacology
HLA-A2 Antigen immunology
Recombinant Fusion Proteins pharmacology
T-Lymphocytes, Cytotoxic immunology
beta 2-Microglobulin immunology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 169
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 12218113
- Full Text :
- https://doi.org/10.4049/jimmunol.169.6.2988