Characterization of the Canine MHC Class I DLA-88*50101 Peptide Binding Motif as a Prerequisite for Canine T Cell Immunotherapy

Abstract

There are limitations in pre-clinical settings using mice as a basis for clinical development in humans. In cancer, similarities exist between humans and dogs; thus, the dog patient can be a link in the transition from laboratory research on mouse models to clinical trials in humans. Knowledge of the peptides presented on MHC molecules is fundamental for the development of highly specific T cell-based immunotherapies. This information is available for human MHC molecules but is absent for the canine MHC. In the present study, we characterized the binding motif of dog leukocyte antigen (DLA) class I allele DLA-88*50101, using human C1R and K562 transfected cells expressing the DLA-88*50101 heavy chain. MHC class I immunoaffinity-purification revealed 3720 DLA-88*50101 derived peptides, which enabled the determination of major anchor positions. The characterized binding motif of DLA-88*50101 was similar to HLA-A*02:01. Peptide binding analyses on HLA-A*02:01 and DLA-88*50101 via flow cytometry showed weak binding of DLA-88*50101 derived peptides to HLA-A*02:01, and vice versa. Our results present for the first time a detailed peptide binding motif of the canine MHC class I allelic product DLA-88*50101. These data support the goal of establishing dogs as a suitable animal model for the evaluation and development of T cell-based cancer immunotherapies, benefiting both dog and human patients.

Unveiling the Peptide Motifs of HLA-C and HLA-G from Naturally Presented Peptides and Generation of Binding Prediction Matrices

“…HLA-E*01:01-transfected C1R cells present two MHC class I leader peptides, namely VMAPRTLIL derived from HLA-C*04:01 and VMAPRTLVL derived from HLA-A*02:01. The latter is to some extent surprising because there is no evidence for surface expression of HLA-A*02:01 in C1R (27,60). VMAPRTLVL was detected in every C1R transfectant (note: C1R is HLA-E*01:03 + ), ensuring that it is not a false positive (FP) but most probably derived from a defective ribosomal product.…”

The prevalent Boxer MHC class Ia allotype dog leukocyte antigen (DLA)‐88*034:01 preferentially binds nonamer peptides with a defined motif

“…A summary of the binding preferences of DLA‐88*034:01 , based on the three combined datasets, is shown in Table . This works brings the total number of DLA‐88 allotypes for which a binding motif has been deduced from eluted peptide sequences to three ( DLA‐88*501:01 ; * 508:01 and *034:01 ) . Of course, binding assays with synthetic peptides that have various combinations of favored and disfavored residues, as well as alanine substitutions at these positions, will be needed to verify the conclusions of this study.…”

Synthetic Peptides Elicit Strong Cellular Immunity in Visceral Leishmaniasis Natural Reservoir and Contribute to Long-Lasting Polyfunctional T-Cells in BALB/c Mice

“…After employing the immunoinformatics methodologies, we identified MHC class I and class II ligand epitopes comprising mouse and human alleles, due to the absence of predictors comprising dog alleles. However, based on some studies, we can verify that there are high levels of identity between MHC alleles of dogs and those of humans and mice [23,24]. For example, some loci of the MHC region II of dogs have an identity with those of humans and mice around 85% and 79%, respectively [23].…”