The observed lower percentage

of CD4+CD25high FoxP3+ regulatory T cells in CAPRI cultures compared to CD3-activated PBMC (Fig. 6) could augment the cytolytic activity of CAPRI cells. Whereas CD3 stimulation of T lymphocytes favours pathways leading to IL-10-producing cells expressing CD25highFoxP3+CD4+ [43], the activation pathway via the αβ TCR [44] may favour the amplification of CD4+ T cells not expressing FoxP3. Furthermore, activation of dendritic cells during the CAPRI procedure may enhance their ability to abrogate the regulatory activities of CD25highFoxP3+CD4+ cells [45]. Our results demonstrate the importance of monocytes and CD4+ T cells for immune responses against cancer. In the CAPRI procedure, tumour-immunogenic

peptides need not Smoothened Agonist manufacturer be identified and can be presented by (at least) six HLA class I and six HLA class II molecules. Tumour-immunogenic peptide design should ideally fit HLA class I and HLA class II molecules. Alternatively, tumour-immunogenic peptides could be isolated from activated monocytes of find more patients with cancer showing a benign course [59]. The first controlled study with CD3-activated PBMC showed a small but significant increase in the survival rate of patients with hepatocellular carcinoma [60]. The results were interpreted as evidence for the amplification of cancer-specific T memory cells and not effector maturation [61]. This interpretation is compatible with our in vitro results showing marginal lysis of cancer cells by CD3-activated PBMC. Preclinical evidence of the CAPRI cell concept was obtained by establishing breast cancer tumours in twelve female nude mice. In this breast cancer model, the size of the tumour increased in the control group but was significantly decreased by CAPRI cells (P = 7.56 × 10−6, Table 2). A significant increase in survival time was also observed for CAPRI

cell-treated mice (P = 5.06 × 10−4, Fig. 6A). In human patients, circumstantial clinical evidence of the CAPRI cell concept was provided in an adjuvant treatment attempt for breast cancer patients with metastasis (T1-4N0-2M1, G2-3, N = 42) PI-1840 by comparing their survival times with those of breast cancer patients (T1-4N0-2M1, G2-3, N = 428) from the Munich Tumor Center (Fig. 6B). The survival curves of female patients with breast cancer and metastases collected in the Munich Tumor Center are nearly identical with those published in text books like Harrison’s ‘Principles of Internal Medicine’ (7th edition) [62] or Conn’s ‘Current Therapy’ (2010) [63]. Both patient groups received standard combinations of chemotherapy and radiation. The average survival time of patients with adjuvant CAPRI cell treatment was 55.19 ± 1.68 months; patients receiving only standard therapy survived an average of 28.60 ± 0.95 months (Fig. 6B, P = 1.36 × 10−14).