Generation of a Novel HLA Class I Transgenic Mouse Model Carrying a Knock-in Mutation at the β2-Microglobulin Locus

Abstract

We generated a series of monochain HLA class I knock-in (KI) mouse strains, in which a chimeric HLA class I molecule (α1/α2 domain of HLA-A*0201, HLA-A*0301, HLA-A*2402, or HLA-A*3101 and α3 domain of H-2D) was covalently linked with 15 aa to human β-microglobulin (βm) and introduced into the endogenous mouse βm locus. In homozygous KI mice, mouse βm gene disruption resulted in loss of the endogenous H-2 class I molecules and reduction in the peripheral CD8 T cell population that was partially restored by monochain HLA class I expression. A gene dosage-dependent expression of HLA, similar to that in human PBMCs, was detected in heterozygous and homozygous HLA KI mice. Upon vaccination with various virus epitopes, HLA-restricted, epitope-specific CTLs were induced in HLA KI mice, similar to the response in the commonly used HLA transgenic mice. Importantly, the CTL responses induced in heterozygous KI mice were similar to those in homozygous KI mice. These results suggest that coexpression of H-2 class I does not affect HLA-restricted CTL responses in HLA KI mice, which differs from the situation reported for monochain HLA Tg × β2m mice. Furthermore, we generated double KI mice harboring two different HLA (HLA-A*2402 and HLA-A*0301) KI alleles, which showed a CTL response against both HLA-A24 and HLA-A3 epitopes when immunized with a mixture of both peptides. These results indicated that this HLA class I KI mouse model provides powerful research tools not only for the study of HLA class I-restricted CTL responses, but also for preclinical vaccine evaluation.

TAS0314, a novel multi-epitope long peptide vaccine, showed synergistic antitumor immunity with PD-1/PD-L1 blockade in HLA-A*2402 mice

“…First, we evaluated the CTL induction ability of TAS0314 by using HLA knock-in (KI) mice that were established previously 28 . The CTL induction ability of HLA-A*2402-restricted epitopes SART2 93-101 and SART3 109-118 was determined by using HLA-A*2402 KI mice (Fig.…”

“…Heterozygous HLA-A*2402, heterozygous HLA-A*0201, and heterozygous HLA-A*3101 KI mice were generated as previously described 28 . All animal procedures were performed in compliance with the National Institutes of Health Guidelines, and were approved by the Taiho Institutional Animal Care and Use Committee.…”

Development of a novel immunoproteasome digestion assay for synthetic long peptide vaccine design

“…HLA-A2 transgenic (Tg) mice were purchased from Taconic Biosciences, Inc. (Hudson, NY, USA). and HLA-A24 and HLA-A31 knock-in (KI) mice were generated in our group as previously described [ 23 ]. Mice were injected subcutaneously twice at intervals of 7 days with a mixture of peptides emulsified in incomplete Freund's adjuvant (IFA) or Montanide ISA-51VG (Seppic, Paris, France, 100 μg/100 μL/mouse).…”

“…However, there are screening strategies that can be used to confirm whether multivalent SLP vaccines can induce all individual epitope-specific CTLs. Though in vivo screening using mice expressing human leukocyte antigen (HLA) molecules has been reported, such studies are expensive and the procedure is complicated [ 23 ]. Therefore, a simpler screening method is greatly in demand.…”

Lynch syndrome cancer vaccines: A roadmap for the development of precision immunoprevention strategies

“…Importantly, these models have ablated endogenous murine MHC ( 157 ). More recently, a series of HLA class I knock-in (KI) mouse strains have been generated ( 160 ). In these novel HLA class I transgenic mice, a chimeric HLA class I molecule (α1/α2 domain of HLA-A and α3 domain of H-2D b ) was covalently linked with 15 aa to human Beta-2-Microglobulin (B2M) and introduced into the endogenous mouse B2m locus, resulting in the loss of endogenous mouse MHC class molecules in homozygous KI mice.…”