Apparently, T cell-reactivity depends on HLA-restriction of the UTY-peptides which might be due to differential tissue-distribution of tissue-specific splice-variants. In dogs,
splice-variants DAPT supplier might also exist and be differentially expressed in organs/cell-types. Another possibility to identify UTY-tissue-distribution is to test UTY-specific CTLs in a skin-explant-model [52]. In any case only transplantation and adoptive immunotherapy will give answers regarding GvHD and conversion of chimerism after transfusion of UTY-specific CTLs obtained from immunized female donors or generated in vitro using autologous-DCs + peptides [53]. During our dog-UTY-studies, canine-Y-chromosome-/UTY sequence was not available in database (canine-genome data rose from female-dog material), but finally the dog-UTY Caspase activation sequence
was published [54]. Blast-analysis of canine-UTY- and human-UTY-protein-/peptide sequences including their corresponding X-chromosomal counterparts (UTX) was used to confirm the postulated UTY-analogies. Amino acid (AA) differences were present for W248 (AA6 + 9) and T368 (AA4 + 8) in the canine-sequence but substituted AAs bear comparable chemical properties (exception: T368-AA9: human: F-polar; dog: Y-unpolar), therefore showing high similarity. K1234-peptide sequence and UTY-homologue UTX sequences for all three peptides were identical in dogs. These alterations can also explain the different recognition-patterns of the three peptides in the context of the different dogs’ DLA-genotypes producing UTY-specific T cell reactivity or not (#1, #4, #6 versus #2, #3, #5, #7–#15). Therefore, the supposed similarities of canine- and human-UTY sequences were evidently proved by dog-UTY sequence explaining binding of human-peptides to canine-DLA [32]. Despite the use of the cUTY-sequence in Phospholipase D1 our experiments,
we could clearly demonstrate the generation of specific male- and MHC-I-restricted cCTL-reactivity evidently verifying UTY-expression, presentation and immunogenicity in dogs, although we cannot show data with the native canine-UTY peptides. As canine-sequences are expected to be highly homologous to their human orthologues, further scientific strategies have to focus on the amplification and sequence of the relevant canine cDNA-sequences using human-, mouse- and rat-UTY-sequences, resulting in the use of completely authentic canine-minor-epitopes. Indeed, BLAST-sequence alignments of dog-UTY with human-, mouse- and rat-UTY DNA, mRNA and protein revealed accordance in 89% for humans, 86% and 84% for mouse and rat, respectively.