In vitro activation of cancer patient-derived dendritic cells by tumor cells genetically modified to express CD154.
OBJECTIVE
Triggering of CD40 on antigen-presenting cells via its ligand CD154 is an important event in the initial phase of an immune response against cancer cells. In this study, we investigated the effects of adenoviral CD154 immunomodulatory gene therapy on the activation of human dendritic cells (DCs) in a well-defined in vitro system.


METHODS
Human bladder cancer cell lines and tumor cells from patients with renal cell carcinoma (RCC) were transduced with Ad-CD154 vectors or control vectors. Activation of human in vitro generated DCs after coculture with transduced tumor cells was analyzed. Therapeutic efficacy and cytotoxic T-lymphocyte (CTL) activity were assessed in a subcutaneous (s.c.) murine bladder cancer model.


RESULTS
Human bladder cancer cell lines expressing CD154 showed a decreased growth rate, increased apoptosis, and modulated expression of molecules important for recognition by cytotoxic lymphocytes. Further, CD154-expressing allogeneic bladder tumor cell lines and autologous tumor cells from patients with renal cell cancer induced maturation of DCs and stimulated IFN-gamma production from lymphocytes cocultured with mature DCs. In vivo studies showed that CD154 gene therapy was highly effective in wild-type mice but only minimally effective in nude mice. Consequently, strong tumor-specific CTL activity was detected in mice vaccinated with tumor cells expressing CD154.


CONCLUSIONS
Using tumor cell lines as well as patient-derived material, we could show that tumor cells expressing CD154 efficiently induce maturation and activation of DCs as well as activation of lymphocytes. Our murine in vivo studies demonstrate that lymphocytes contribute to the observed antitumor effect in a s.c. bladder tumor model. These studies should stimulate CD154 gene therapy approaches for the treatment of urologic malignancies.
Loskog
Angelica
A
Clinical Immunology Division, Rudbeck Laboratory, University of Uppsala, Uppsala, Sweden.
Tötterman
Thomas H
TH
Böhle
Andreas
A
Brandau
Sven
S
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D017209:Apoptosis; D023201:CD40 Ligand / Q000235:genetics*; D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000276:immunology; D002295:Carcinoma, Transitional Cell / Q000235:genetics* / Q000276:immunology; D002455:Cell Division; D003713:Dendritic Cells / Q000276:immunology*; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D005818:Genetic Engineering; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000378:metabolism; D007680:Kidney Neoplasms / Q000235:genetics* / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D017710:Lymphocyte Transfusion; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000235:genetics* / Q000276:immunology
D023201:CD40 Ligand; D007371:Interferon-gamma