The presence, abundance, population, and diversity of Tumor Infiltrating Lymphocytes (TILs) have been identified as prognostic indicators in several cancers. Emerging cancer therapeutics including immunomodulators and adoptive T-cell therapy highlight the need to better understand and track this population of T cells. We have developed a multiplex PCR amplification assay for the rearranged T-cell receptor Beta (TCRB), followed by deep sequencing to characterize the adaptive immune response spatially within ovarian tumor. Specifically, we used our assay to characterize the heterogeneity of ovarian tumor TIL populations. We sequenced 10 primary and metastatic ovarian tumors collected from 5 patients. Each tumor was divided into a grid pattern with 8-22 sections (tumor size dependent). For each tumor section we collected data on the number, diversity, and the unique CDR3 sequences carried by the TILs, to characterize the intra-tumor heterogeneity of TIL count, diversity, and T cell clone overlap. In addition, we sequenced the immune repertoire from a paired peripheral blood sample to identify if the immune response was tumor specific. We found that the immune response within peripheral blood was significant and quantifiably different than the tumor repertoire. TIL repertoire within sections of a tumor showed high similarity to each other. These data indicate that the TCR repertoire of the ovarian tumor environment is tumor specific and homogeneous.
- Copyright © 2013 by The American Association of Immunologists, Inc.