Lung cancer is the number one cause of cancer death in the United States. Lung cancers express tumor antigens but are ineffective as antigen presenting cells. We will utilize secondary lymphoid chemokine (SLC) to localize DC at the tumor site where they can function to present an array of antigenic epitopes. This approach to stimulate specific T cell immune responses would not exclude patients on the basis of HLA phenotype or because of lack of expression of a particular tumor antigen. Thus, this therapy would be available to all lung cancer patients in the appropriate clinical setting. We hypothesize that SLC therapy will lead to co-localization of dendritic cells (DC) and Th1 cytokine-expressing lymphocytes. We anticipate that DC will traffick to the tumor site where they will be positioned to process and present autologous tumor antigen (Ag) thus providing access to the entire repertoire of available antigens in situ, both increasing the likelihood of a response and reducing the potential for phenotypic modulation. The overall goal of this proposal is to use murine models to determine the mechanisms of SLC-mediated restoration of anti-tumor immune responses. Utilizing transplantable murine lung cancer models, different modes of SLC delivery will be evaluated that ultimately may have clinical relevance. The following modes of intratumoral SLC delivery will be assessed: 1) injection of recombinant SLC, 2) injection of irradiated SLC transduced tumor cells, and 3) injection of adenovirus vector expressing SLC. A spontaneous murine lung cancer model will be utilized to evaluate the antitumor efficacy of these modes of SLC delivery by intradermal, axillary lymph node region and systemic i.p. injections. Each of these systems will be evaluated because each has potential advantages in the development of immune based therapy for lung cancer.
Specific Aims : 1. To identify the mechanisms of anti-tumor responses in secondary lymphoid chemokine (SLC) therapy. (A) The capacity of SLC to enhance the generation of tumor-specific CTL will be investigated. Tumor infiltrating lymphocytes (TIL), splenic T cells and lymph node derived lymphocytes (LNDL) will be evaluated for cytolytic activity and cytokine release against specific and non-specific tumor targets. (B) The importance of cytokines IFN gamma, IL-10, GM-CSF, IL-12, MIG and IP10 in SLC- mediated anti-tumor responses will be assessed. 2. To identify the T cell subsets and cytokines important for the memory phenotype following SLC mediated tumor eradication. (A) Mice having rejected their tumors following SLC therapy will be treated with anti-CD3, anti-CD4, anti-CD8 antibodies before rechallenge with 3LL parental tumors, T cell subsets from mice having rejected their tumors following SLC therapy will be transferred to naive mice before challenge with 3LL parental tumors. (B) The importance of cytokines IFN gamma, IL-10, GM-CSF and IL-12 will be assessed in the memory phenotype after SLC mediated tumor eradication. 3. To evaluate the efficacy of different modes and routes of SLC therapy in a spontaneous murine lung cancer model. Dr. Sharma, has the requisite attributes that predict successful academic independence. He is in an excellent scientific environment and will spend 100 percent effort to this endeavor. Work resulting in this environment will prepare Dr. Sharma for a successful independent career in basic cancer research.
