003, Wilcoxon-test). Male-target cells pulsed with the control-peptide I540S did not influence T cell reactivity compared with naïve cells (I540S: 12–29/100,000; median: 23; P < 0.106 to P < 0.066). In vivo-primed female T cells recognized peptide-loaded T2-cells (W248: 85 ± 28/100,000 T cells; T368: 35 ± 12/100,000; K1234: 50 ± 17/100,000) being UTY-specific as indicated by Anti-MHC-I-antibody-blockage

(W248: 30 ± 10/100,000 T cells; T368: 26 ± 9/100,000; K1234: 10 ± 3/100,000; P < 0.026 to P < 0.018, Wilcoxon-test). In contrast, T2-cells alone or loaded with the I540S-control-peptide demonstrated only low unspecific-reactions (20–1/100,000 T cells, median: 9; P < 0.113 to P < 0.018, Wilcoxon-test). According to Cobimetinib the in vitro experiments (Table 2, Fig. 3) in vivo primed female T cells mostly reacted with male-BM (<45 specific-spots/100,000 CD3+T cells)

followed by monocytes (<29 spots) and PBMCs (<15 spots) and in vivo immunogenicity of the hUTY-peptides was comparable with those in vitro: W248 exhibited the most immunogenic potential on T2-cells (85 spots/100,000 T cells > K1234 (50 spots) >T368 (35 spots)). We provide evidence that hUTY-derived male-peptides specifically expand T lymphocytes derived from female-DLA-identical-dogs either using autologous-peptide-pulsed-female DCs as APC in vitro or male-DLA-identical PBMCs in vivo. The expanded female T cells recognized HLA-A2-binding hUTY-derived endogenously presented peptides W248, K1234 and T368 only on BGB324 in vivo DLA-identical

male-cells (mostly BM) representing a male-specific restriction. Thereby, W248 appeared to be the most immunogenic-peptide. Importantly, no response against autologous- and female-DLA-identical cells, not expressing the male-specific-UTY antigen, was detected. Therefore, we conclude that the mHA UTY is very homologous Cell press in male-humans and dogs, and the canine-system could serve as a large-animal model to study T cell applications in terms of immunotherapeutic approaches after alloSCT in male patients with female donors. Consequently hUTY-(especially W248)-pulsed female DCs might be used in male hematopoietic-SCT recipients with female stem-cell donors [3, 6, 7]. CD8+T cell-proliferation was induced up to 3-fold within 3–4 weeks (Fig. 1). After in vitro stimulation expanded CD8+T cells specifically reacted against the hUTY-derived peptides presented on autologous-female DCs in up to 3.1% of all T cells (IFN-γ-ELISPOT assay, Fig. 2), but not against autologous-naïve DCs and monocytes. This proves that HLA-A2-restricted peptides selected from human-UTY protein bind to canine-DLA-identical molecule(s), and these peptides are immunogenic in dogs and can induce UTY-specific T cell reactivity. Detected amounts of reactive-UTY-specific CD8+T cells after in vitro culture with IFN-γ-ELISPOT and [51Cr]-release-assays were comparable. This is in accordance with findings by others, although both the assays address different CTL-mechanisms [41].