Volume 2 Supplement 2

Abstracts from the 1st Immunotherapy of Cancer Conference (ITOC1)

Open Access

P65. Minor-histocompatibility-antigen UTY as target for graft-versus-leukaemia and graft-versus-haematopoiesis in the canine-model

  • D Bund1,
  • FG Gökmen1,
  • J Zorn2,
  • R Buhmann1,
  • HJ Kolb1 and
  • H Schmetzer1
Journal for ImmunoTherapy of Cancer20142(Suppl 2):P39

DOI: 10.1186/2051-1426-2-S2-P39

Published: 12 March 2014

Background

In haploidentical-SCT male-patients with female-donors have better prognosis compared to female-to-male-combinations due to Y-encoded minor-histocompatibility-antigens recognised by female-allo-immune effector-lymphocytes in the context of a graft-versus-leukaemia-(GvL)-effect. We provide data in a dog-model that the minor-histocompatibility-antigen UTY might be a promising target to further improve GvL-immune-reactions after allogeneic-SCT.

Materials and methods

Canine (c) purebred-beagle-dogs’ PB and BM were studied. T2-cells (HLA-A2+, TAP-deficient) were used. These human-(h)-UTY-sequence-derived HLA-A2-binding-peptides were investigated: W248 (WMHHNMDLV), T368 (TLAARIKFL), K1234 (KLFEMIKYC). In vitro: Autologous-cDCs were generated with best of three DC-methods (Calcium-Ionophore, Picibanil, Cytokines). Generation cUTY-specific-CTLs: CD3+ T-cells were co-cultured with autologous-mature cDCs+hUTY-peptides (weekly restimulation for 21 days; +hIL-2, +hIL-7). Cytotoxicity and antigen-specificity were determined by [51Cr]-release- and cIFN-g-ELISPOT-assays. Cells were quantified day 0 and of harvest using anti-cmAbs/hmAbs (FACS), UTY-mRNA-expression via RT-PCR-analysis. In vivo: A female-dog was immunised with PBMCs from a DLA-identical-male-dog (day 0 and 14). PB-derived T-cells were harvested 35 days post 2nd-injection followed by analysing UTY-specific-reactivity.

Results

Female cUTY-specific-CTLs were stimulated in vitro using autologous-DCs loaded with three HLA-A2-restricted UTY-derived-peptides (≤2.9-fold-expansion) and specific T-cell-responses were determined in 3/6 female-dogs. CTLs specifically recognised/lysed autologous-female peptide-loaded-DCs (900 spots/100,000 T-cells (median)/≤47.9%), but not naive autologous-female-DCs and -monocytes (p≤0.026). They mainly recognized BM and to a lower extent DCs, monocytes, PBMCs and B-cells from DLA-identical-male-littermates and peptide-loaded T2-cells in an MHC-I-restricted manner (up to p≤ 0.046). UTY-mRNA was only expressed in male-cells. A UTY-/male-specific-reactivity was also obtained in vivo after stimulation of a female-dog with DLA-identical-male-PBMCs.

Conclusions

We demonstrated natural UTY-processing/presentation in dogs. Female-dog-CTLs were specifically stimulated by HLA-A2-restricted-UTY-peptides, thereby enabling recognition of DLA-identical-male-cells, mainly BM-cells. These observations suggest UTY as a promising candidate-antigen to improve GvL-reactions in the course of immunotherapy. Next-generation-sequencing and specialised-bioinformatics-algorithms are now focus for human-individualised-leukaemia-treatment (T-cell-receptor-Profiling, detection/selection of T-cell-receptor-clones or DC-based-immunotherapies).

Authors’ Affiliations

(1)
Haematopoietic Cell Transplantation MED III, University of Munich-Grosshadern
(2)
Helmholtz Center Munich, CCG Haematopoietic Cell Transplantation

Copyright

© Bund et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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