HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by de Inés, C. Articles by Little, M. Search for Related Content PubMed PubMed Citation Articles by de Inés, C. Articles by Little, M.

Apoptosis of a Human Melanoma Cell Line Specifically Induced by Membrane-Bound Single-Chain Antibodies¹

Concepción de Inés^*, Björn Cochlovius, Stefanie Schmidt^*, Sergey Kipriyanov^*, Hans-Jürgen Rode^* and Melvyn Little^2,*

^* Recombinant Antibody Group and Department of Tumor Progression and Immune Defense, Experimental Therapy and Diagnosis Programme, German Cancer Research Center, Heidelberg, Germany

CD28 is a key regulatory molecule in T cell responses. Ag-TCR/CD3 interactions without costimulatory signals provided by the binding of B7 ligands to the CD28R appear to be inadequate for an effective T cell activation. Indeed, the absence of B7 on the tumor cell surface is probably one of the factors contributing to the escape of tumors from immunological control and destruction. Therefore, to increase the immunogenicity of tumor cell vaccines, we have expressed anti-CD3 and anti-CD28 single-chain Abs (scFv) separately on the surface of a human melanoma SkMel63 cell line (HLA-A*0201). A mixture of cells expressing anti-CD3 with cells expressing anti-CD28 resulted in a marked activation of allogeneic human PBL in vitro. The apparent induction of a Th1 differentiation pathway was accompanied by the proliferation of MHC-independent NK cells and MHC-dependent CD8⁺ T cells. PBL that had been cultured together with transfected SkMel63 tumor cells were able to specifically induce apoptosis in untransfected SkMel63 cells. In contrast, three other tumor cell lines expressing HLA-A*0201, including two melanoma cell lines, showed no significant apoptosis. These results provide valuable information for both adoptive immunotherapy and the generation of autologous tumor vaccines.