Lung Cancer SPORE

Projects

PROJECT 2: CYCLIN B1 IMMUNOTHERAPY
PROGRESS REPORT

Co-Project Leaders: Olivera J. Finn, PhD
Athanassios Argiris, MD

Specific aims

This project is a continuation of a project carried out in the first 5-year grant period that validated Cyclin B1 (CB1) as a lung tumor antigen. The first hypothesis that we proposed to test in the continuation of this project is that vaccines will elicit or boost CB1-specific immunity in lung cancer patients and this will result in an anti-tumor effect. The second hypothesis we proposed to test is that the immune response against CB1 could be a biomarker of risk for development of future lung cancer in subjects with a positive smoking history, or for recurrence among early-stage patients newly diagnosed with lung cancer. To test these hypotheses we proposed three specific aims.

SPECIFIC AIM 1. Test in phase I/II clinical trials toxicity and immunogenicity of cancer vaccines composed of CB1 peptides and proteins processed and presented by dendritic cells (DC), in combination with novel delivery of adjuvants, and evaluate immune effector mechanisms generated. Patients in these trials will be those with resectable stage I and II lung cancer. The first trial will be carried out in HLA-A2+ patients and will test a vaccine composed of DC loaded with two CB1 peptides known to elicit HLA-A2 restricted CTL, and transdermal adjuvant. The second trial will test DC loaded with recombinant CB1 protein plus transdermal adjuvant, and thus it will be open to patients of all HLA types. Vaccinated patients will be observed for signs of toxicity or adverse reactions to the vaccine, and examined pre and post vaccination for the following immune responses: CB1 specific antibodies (IgM, IgG, IgA) by ELISA; CB1 specific CD4 and CD8 T cells (IFN- or IL-4), by ELISPOT and intracellular cytokine staining; for general immune responsiveness that may reveal existence of T regulatory cells. Future trials will be designed based on the analysis of data from these two trials and availability of new adjuvants and methods to increase vaccine efficacy.

SPECIFIC AIM 2. Perform detailed quantitative and qualitative analysis of spontaneously occurring CB1 specific antibodies and T cells in lung cancer patients at different stages of disease and in the PLuSS High Risk Sub-Cohort (described in Clinical Core). We will analyze antibody isotype, titer, and affinity. T cells will be studied for their phenotype (nave, effector memory, regulatory T cells) and cytokine production (Type I versus Type II). Fine antigen specificity will also be analyzed using a CB1 peptide library composed of overlapping 15-mer peptides, to look for evidence of immunodominant versus sub-dominant epitopes, which may influence effectiveness of the immune response. This information will be analyzed in the context of clinical outcome, in an attempt to define immune correlates of protection. This information will also be important for defining certain immune responses as surrogate end-points for monitoring efficacy of CB1 vaccines.

SPECIFIC AIM 3. Assay for the presence or absence of CB1 specific antibodies in individuals at high risk for developing lung cancer (3,600 PluSS subjects) and in two retrospective sets of lung cancer cases, in order to evaluate the potential of the immune response to be a biomarker of risk for future lung cancer and/or a useful prognostic indicator. We will perform semi-automated high-throughput ELISA assays for detection of anti-CB1 antibodies that we have developed. ELISA will be designed to be isotype specific. Isotype switching is a T cell mediated event and different isotypes are promoted by the action of Th1 versus Th2 cells. The antibody data will be added to the information about other biomarkers defined elsewhere in the SPORE. Lung nodules that are resected as part of the diagnostic procedures for PLuSS participants with CT screening results of high suspicion will be stained for CB1 and immunohistology data correlated with ELISA data. A long-term follow up of antibody positive and antibody negative groups will test if the presence of antibody correlates with a higher or lower rate of lung cancer development in the entire PluSS cohort, and whether presence of antibody correlates with extent of CB1 expression in the resulting lung tumor. We will also determine whether CB1 immunity is associated with protection from recurrence by monitoring outcome of PLuSS participants as well as patients from Retrospective NSCLC Cohorts A and B. Data from this aim will be contributed to the data set on biomarkers being generated by Projects 3 and 4 using the PLuSS High-Risk Sub-Cohort, and the data on estrogen receptors and aromatase expression as it relates to clinical outcome in Project 1. The value of the immune response as a biomarker will be evaluated relative to the other markers.

Our aims have not changed and in this first year of our project we have focused on Aims 1 and 2.