Immunological Analysis of Brain Cancer

Division Of Basic Sciences - Nci

Investigators

Linked publications, trials & patents

Abstract

In the first project, previously we observed that the tumor growth was significantly slower in NKT cell-deficient CD1d KO mice compared with NKT cell-intact wild-type mice and type I NKT cell-deficient Ja18 KO mice with an orthotopic syngeneic mouse glioma SB28 model. We observed that SB28 cells express CD1d on their surface. Thus, we decided to take multiple approaches to confirm that significantly slower tumor growth in CD1d KO mice is not due to immune responses against CD1d lacking in CD1d KO mice. The first is to create CD1d KO SB28 cells to compare growth in wild-type and CD1d KO mice. We completed creating the cells by using a CRISPR-Cas9 technology that are ready for the in vivo experiments. The second is to create conditional CD1d KO mice that do not express CD1d in only T cells that are essential for NKT cell development. This mouse cannot develop NKT cells, but still express CD1d in non-T cells. Thus, the mouse will not mount immune responses against CD1d expressed in SB28. We successfully obtained CD1d floxed mice and CD4 cre mice and currently crossing them to create the CD1d conditional KO mice. We also observed MR1 gene expression in SB28 and created MR1 KO SB28 for in vivo experiments in which we will examine tumor growth in wild-type and MAIT cell-deficient MR1 KO mice. We also examine the expression of MR1 by using the TCGA data and found that MR1 gene is highly expressed in glioblastoma tissues. In the second project, we are preparing lipid samples from multiple human glioblastoma cell lines and a normal human astrocyte cell line for the lipid antigen analysis. We also obtained T cell hybridomas transfected with a human NKT cell TCR. We are currently purifying cells expressing transfected human NKT cell TCR by multiple rounds of flow sorting and setting up an in vitro stimulation assay to measure the antigenic activity of lipid antigens that we will identify in glioblastomas. This assay is also used for the third project in which we will examine the antigenic activity of sulfatide analogs.