Tumor-specific dendritic cells generated by genetic redirection of Toll-like receptor signaling against the tumor-associated antigen, erbB2

Abstract

Dendritic cells (DC) perform an important role in the initiation of the immune response through the local secretion of inflammatory mediators within diseased tissue in response to Toll-like receptor (TLR) ligation. However, DC vaccine strategies fail to make use of this capability against cancer. To harness the TLR response capability of DC against cancer, we tested a series of recombinant genes for their ability to redirect DC function specifically against a tumor-associated antigen. Each gene encoded a cell surface chimeric protein made up of extracellular single-chain immunoglobulin anti-erbB2 linked to an intracellular TLR-signaling component composed of either myeloid differentiation factor 88, interleukin-1 receptor-associated kinase-1 (IRAK-1) or the cytoplasmic domain of TLR4. Each gene was expressed in the DC line, JAWS II, to a similar degree following retroviral transduction. However, only the chimera containing IRAK-1 was able to mediate interleukin-12 and tumor necrosis factor-a secretion. Since TLR engagement can also activate DC and enhance their ability to stimulate T cells, we ligated the chimeric anti-erbB2-IRAK-1 receptor and determined the effect on the stimulation of T cells. We found that JAWS II cells triggered through chimeric anti-erbB2-IRAK-1 displayed an enhanced ability to stimulate ovalbumin-specific OT-II CD4 þ T cells. This first description of the generation of tumorreactive DC may lead to the development of new cell-based vaccines that can act at both the tumor site to induce danger and at the lymph node to stimulate a specific T-cell response.

Cancer Immunotherapy UsingIn vitroGenetically Modified Targeted Dendritic Cells

“…In addition, we will investigate the generality of this strategy through construction of other TAA-specific CR. Recently, Xu and colleagues (48) reported that a chimeric gene linking ErbB2-specific scFv to IRAK-1 signaling is able to mediate cytokine secretion and enhance T-cell stimulation capacity of DC cell line, which is consistent with our results. Perhaps integrating the components of TLR signaling into the CRs will reinforce the efficacy of targeted DC as reported recently by Lapteva and colleagues (49).…”

Characterization of Murine Dendritic Cell Line JAWS II and Primary Bone Marrow-Derived Dendritic Cells inChlamydia muridarumAntigen Presentation and Induction of Protective Immunity

“…This cell line has been used for studies of antitumor (15,24,39) and pathogen-specific (23) immunity. In this study, we compared the characteristics of JAWS II cells to those of primary BMDCs and investigated their capacities to present Chlamydia antigens in vitro and in vivo in order to determine their potential for Chlamydia vaccine and antigen discovery studies.…”

Dendritic Cells and Lentiviral Vectors: Mapping the Way to Successful Immuno Gene Therapy

“…electroporation with mRNA encoding caTLR4, was recently shown to activate human DCs, resulting in priming of Melan-A CTL responses (Bonehill et al 2008). Using a similar cloning strategy Xu et al (Xu et al 2007) generated RVs encoding MyD88 or IRAK-1, two major adaptor molecules in TLR triggered activation pathways. Again they used the JAWSII DC line to evaluate the chimeric proteins, demonstrating that only the IRAK-1 chimera mediated IL-12 and TNF-α secretion, and enhanced OVA-specific CD4 + T cell responses.…”

“…However, its clinical use is limited by its cytotoxicity. Therefore, the feasibility of using RVs encoding a constitutive active TLR4 (caTLR4) for DC maturation has been evaluated (Xu et al 2007). This was achieved by linking the cytoplasmic domain of TLR4 to the extracellular single-chain immunoglobulin anti-erbB2.…”