Tumor stromal cells from pediatric tumors impair NK cell function and alter NKp receptor expression

Tumor stromal cells (TStrC) are key players in tumor growth and metastasis. Most clinical studies aim at overexpressed molecules on TStrC, however it is not fully understood how TStrC promote and orchestrate tumor growth. We established TStrC from ten pediatric tumors and compared these cultures with multipotent mesenchymal stromal cells (MSC) from bone marrow as physiological stroma. TStrC showed comparable growth behaviour as MSC. The morphological and immunological phenotype of TStrC and MSC were indistinguishable. As MSC are known to inhibit proliferation of peripheral blood mononuclear cells in vitro, we sp…