NK cells are emerging as new effectors for immunotherapy of cancer. In particular, the genetic engraftment of chimeric Ag receptors (CARs) in NK cells is a promising strategy to redirect NK cells to otherwise NK cell–resistant tumor cells. On the basis of DNAX-activation protein 12 (DAP12), a signaling adaptor molecule involved in signal transduction of activating NK cell receptors, we generated a new type of CAR targeting the prostate stem cell Ag (PSCA). We demonstrate in this article that this CAR, designated anti–PSCA-DAP12, consisting of DAP12 fused to the anti-PSCA single-chain Ab fragment scFv(AM1) confers improved cytotoxicity to the NK cell line YTS against PSCA-positive tumor cells when compared with a CAR containing the CD3ζ signaling chain. Further analyses revealed phosphorylation of the DAP12-associated ZAP-70 kinase and IFN-γ release of CAR-engineered cells after contact with PSCA-positive target cells. YTS cells modified with DAP12 alone or with a CAR bearing a phosphorylation-defective ITAM were not activated. Notably, infused YTS cells armed with anti–PSCA-DAP12 caused delayed tumor xenograft growth and resulted in complete tumor eradication in a significant fraction of treated mice. The feasibility of the DAP12-based CAR was further tested in human primary NK cells and confers specific cytotoxicity against KIR/HLA-matched PSCA-positive tumor cells, which was further enhanced by KIR-HLA mismatches. We conclude that NK cells engineered with DAP12-based CARs are a promising tool for adoptive tumor immunotherapy.

Prognosis for patients suffering from malignant glioma has not substantially improved. Specific immunotherapy as a novel treatment concept critically depends on target antigens, which are highly overexpressed in the majority of gliomas, but the number of such antigens is still very limited. SOX2 was identified by screening an expression database for transcripts that are overexpressed in malignant glioma, but display minimal expression in normal tissues. Expression of SOX2 mRNA was further investigated in tumour and normal tissues by real-time PCR. Compared to cDNA from pooled normal brain, SOX2 was overexpressed in almost all (9 out of 10) malignant glioma samples, whereas expression in other, non-malignant tissues was almost negligible. SOX2 protein expression in glioma cell lines and tumour tissues was verified by Western blot and immunofluorescence. Immunohistochemistry demonstrated SOX2 protein expression in all malignant glioma tissues investigated ranging from 6 to 66% stained tumour cells. Human leucocyte antigen-A*0201-restricted SOX2-derived peptides were tested for the activation of glioma-reactive CD8 þ cytotoxic T lymphocytes (CTLs). Specific CTLs were raised against the peptide TLMKKDKYTL and were capable of lysing glioma cells. The abundant and glioma-restricted overexpression of SOX2 and the generation of SOX2-specific and tumour-reactive CTLs may recommend this antigen as target for T-cell-based immunotherapy of glioma.

Donor type is not a major prognostic factor for HCT in elderly patients with standard- or high-risk AML.

Identification of TAAs recognized by CD8؉ CTLs paved the way for new concepts in cancer therapy. In view of the heterogeneity of tumors and their diverse escape mechanisms, CTL-based cancer therapy largely depends on an appropriate number of TAAs. In prostate cancer, the number of antigens defined as suitable targets of CTLs remains rather limited. PSCA is widely distributed in prostate cancer. In this report, we define immunogenic peptides of PSCA which are recognized by circulating CD8 ؉ T cells from prostate cancer patients and able to activate CTLs in vitro. Screening the amino acid sequence of PSCA for peptides containing a binding motif for HLA-A*0201 resulted in 8 candidate peptides. Specificity and affinity of peptide binding were verified in a competition assay. Frequencies of CD8 ؉ T lymphocytes reactive against selected epitopes were determined in the blood of prostate cancer patients using the ELISPOT assay. Increased frequencies were revealed for CD8 ؉ T cells recognizing the peptides ALQPGTALL and AILALLPAL. CTLs from prostate cancer patients were raised against these 2 peptides in vitro when presented by autologous DCs. They specifically recognized peptide-pulsed T2 target cells and prostate cancer cells that were HLA-A*0201-and PSCA-positive, indicating that these peptides were naturally generated by tumor cells. These data suggest that PSCA is a promising target for the immunotherapy of prostate cancer.

There is substantial need to improve the outcome of patients with high-risk acute myeloid leukemia (AML). The clinical trial reported here investigated a new approach of up-front allogeneic hematopoietic stem cell transplantation (HSCT), provided a median of 40 days (range 22-74) after diagnosis, in twenty-six consecutive patients with newly-diagnosed high-risk AML characterized by poor-risk cytogenetics (n ¼ 19) or inadequate blast clearance by induction chemotherapy (IC, n ¼ 7). The median age was 49 years (range 17-68). During IC-induced aplasia after the 1st (n ¼ 11) or 2nd (n ¼ 15) cycle, patients received allogeneic peripheral blood stem cells (PBSC) from related (n ¼ 11) or unrelated (n ¼ 15) donors following a fludarabine-based reduced-intensity regimen. Seventeen patients were not in remission before HSCT with a median marrow blast count of 34% (range 6-70). All patients achieved rapid engraftment and went into remission with complete myeloid and lymphatic chimerism. Grades II to IV acute GvHD occurred in 14 (56%) and extensive chronic GvHD was documented in 8 (35%) patients. The probability of disease-free survival was 61% with only three patients relapsing 5, 6 and 7 months after transplantation, respectively. Up-front allogeneic HSCT as part of primary induction therapy seems to be an effective strategy in highrisk AML patients and warrants further investigation.

These results suggest that the loss of HLA class I haplotype also occurs in AML relapse after HLA-matched related HSCT. Partial loss of several HLA class I genes and subsequent reduced presentation of minor histocompatibility antigens and reduced ligation of activating natural killer-cell receptors may explain the loss of graft-versus-leukemia response and extramedullary AML relapse in tissue with reduced immunologic surveillance.

Currently, stem cell donor registries include more than 35 million potential donors worldwide to provide HLA‐matched stem cell products for patients in need of an unrelated donor transplant. DKMS is a leading stem cell donor registry with more than 9 million donors from Germany, Poland, the United States, the United Kingdom, India and Chile. DKMS donors have donated hematopoietic stem cells more than 80,000 times. Many aspects of donor registry work are closely related to topics from immunogenetics or population genetics. In this two‐part review article, we describe, analyse and discuss these areas of donor registry work by using the example of DKMS. Part 1 of the review gives a general overview on DKMS and includes typical donor registry activities with special focus on the HLA system: high‐throughput HLA typing of potential stem cell donors, HLA haplotype frequencies and resulting matching probabilities, and donor file optimization with regard to HLA diversity.

result of the deletions resulting from these rearrangements, clonal B cells or plasma cells will have unique patterns of deletion in the V H yD H yJ H region of the IgH loci. At later stages of B-cell development, IgH switch recombination can reposition the V H D H J H sequence near downstream constant regions (C H ). As a result, clonal B cells or plasma cells that have undergone IgH switch recombination also will have clonal patterns of deletion in the C H region of the IgH locus. Often the B-cell specific deletions described above are large enough to be detected as a homozygous copy number loss using comparative genomic hybridization or single-nucleotide polymorphism arrays. Therefore, copy number changes in the IgH locus have the potential to provide a measure of contamination of clonal B or plasma cells with other cells.Recently, Lopez-Corral et al.2 reported increasing DNA copy number changes detectable in samples from patients with premalignant monoclonal gammopathy of undetermined significance (MGUS) to smoldering multiple myeloma (SMM) to multiple myeloma (MM). As shown in Figure 1a, the inability to detect homozygous, or near-homozygous, deletions within the D H -J H -C H region indicates that substantially more germline D H -J H -C H was detected in the MGUS than in SMM or MM samples they analyzed, indicative of the presence of contaminating DNA from non-tumor cells. This indicates that the purity estimate of their CD138-selected cells (SMM and MM 495%, and MGUS 490%) is inaccurate, particularly for MGUS samples. The extent of this contaminating DNA correlates with the inability to detect whole-genome changes in many MGUS samples (Figure 1b). Therefore, their detection of increasing genomic changes between MGUS, SMM and MM likely relates more to the increasing purity of the samples than to underlying genetic differences between these diseases.Isolation of tumor cells from bone marrow aspirates of patients with MM can achieve a purity of 90-95% by bead selection of cells expressing CD138. However, as the fraction of tumor cells from bone marrow aspirates of patients with MGUS can be 1-2 logs lower than for MM, substantial contamination of purified MGUS tumor cells with non-tumor cells is a significant problem that needs to be rigorously addressed when analyzing purified tumor cells.