Search

ABSTRACTCD40 triggering may result in antitumor effects of potentially high clinical relevance. To gain insights important for patient selection and to identify adequate targeting techniques, we investigated CD40 expression in human cancer tissues and generated a replication-incompetent recombinant vaccinia virus expressing CD40 ligand (rVV40L). Its effects were explored in vitroand in vivoupon direct CD40 targeting on malignant cells or macrophage activation. CD40 expression was analyzed by immunohistochemistry in tumor and stromal cells in a multi-tumor array including 836 specimens from 27 different tumor types. Established tumor cell lines were used to explore the capacity of rVV40L to induce malignant cell apoptosis and modulate functional profiles of polarized macrophages. CD40 expression was detectable in significantly higher numbers of stromal as compared to malignant cells in lung and breast cancers. CD40 ligation following rVV40L infection induced apoptosis in CD40(+) cancer cells, but only in the presence of intact specific signal transduction chain. Importantly, rVV40L infection promoted the induction of TNF-α-dependent antitumor activity of M1-like macrophages directed against CD40(-) targets. CD40-activated M1-like macrophages also displayed enhanced ability to CXCL10-dependently recruit CD8+ T cells and to efficiently present cancer cell intracellular antigens through cross-priming. Moreover, rVV-driven CD40L expression partially “re-educated” M2-like macrophages, as suggested by detectable CXCL10 and IL-12 production. Most importantly, we observed that intra-tumoral injection of rVV40L-infected human macrophages inhibits progression of human CD40(-) tumors in vivo. First evidences of anticancer activity of rVV40L strongly encourage further evaluations.

ABSTRACTInteraction between cancerous, non-transformed cells, and non-cellular components within the tumor microenvironment plays a key role in response to treatment. However, short-term culture or xenotransplantation of cancer specimens in immunodeficient animals results in dramatic modifications of the tumor microenvironment, thus preventing reliable assessment of compounds or biologicals of potential therapeutic relevance.We used a perfusion-based bioreactor developed for tissue engineering purposes to successfully maintain the tumor microenvironment of freshly excised breast cancer tissue obtained from 27 breast cancer patients and used this platform to test the therapeutic effect of antiestrogens as well as checkpoint-inhibitors on the cancer cells.Viability and functions of tumor and immune cells could be maintained for over 2 weeks in perfused bioreactors. Next generation sequencing authenticated cultured tissue specimens as closely matching the original clinical samples. Anti-estrogen treatment of cultured estrogen receptor positive breast cancer tissue as well as administration of pertuzumab to a Her2 positive breast cancer both had an anti-proliferative effect. Treatment with anti-programmed-death-Ligand (PD-L)-1 and anti-cytotoxic T lymphocyte-associated protein (CTLA)-4 antibodies lead to immune activation, evidenced by increased lymphocyte proliferation, increased expression of IFNγ, and decreased expression of IL10, accompanied by a massive cancer cell death in ex vivotriple negative breast cancer specimens.In the era of personalized medicine, the ex vivoculture of breast cancer tissue represents a promising approach for the pre-clinical evaluation of conventional and immune-mediated treatments and provides a platform for testing of innovative treatments.