Basic Information
Description
Transgenic mice that express human HLA molecules represent a unique in vivo experimental model for evaluating human immune system function.These models have been used to study the role of the human class I or class Il restricted T cell repertoire in autoimmune disease, infectious disease, and vaccine development. They are also valued tools for evaluating human HLA restrictec T cell-mediated vaccine efficacy in oncology applications. Biocytogen developed the B-HLA 2.1 mice. The model B2m gene (Exon1 to Exon3) of mouse were replaced by the sequence encompassing the human B2M CDS and HLA-A*0201 gene that included leader sequence, α1 and α2 domains ligated to a fragment of the murine H2-D1 gene containing the α3, transmembrane and cytoplasmic domains. Mice expressing human HLA molecules have helped advance the understanding of human immune system function, as well as potential novel therapeutics.
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Targeted allele
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Gene targeting strategy for B-HLA-2.1 mice. The B2M gene (Exon1 to Exon3) of mouse were replaced by the sequence encompassing the human B2M CDS and HLA-A*0201 gene that included leader sequence, α1 and α2 domains ligated to a fragment of the murine H2-D1gene containing the α3, transmembrane and cytoplasmic domains.
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Protein expression analysis
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Strain specific B2M and HLA expression analysis in homozygous B-HLA-A2.1 mice by flow cytometry. Splenocytes from both wild-type C57BL/6 (+/+) and homozygous B-HLA-A2.1 mice (H/H) were analyzed by flow cytometry. Mouse B2M and H-2Db were detectable in the wild-type C57BL/6 mice. Human B2M and HLA-A2.1 were only detectable in the homozygous B-HLA-A2.1 mice.
Protein expression analysis
Strain specific B2M and HLA expression analysis in homozygous B-HLA-A2.1 mice by flow cytometry. Splenocytes from both wild-type C57BL/6 (+/+) and homozygous B-HLA-A2.1 mice (H/H) stimulated with anti-CD3ε in vivo, and analyzed by flow cytometry. Mouse B2M and H-2Db were detectable in the wild-type C57BL/6 mice. Human B2M and HLA-A2 were only detectable in the homozygous B-HLA-A2.1 mice.
Analysis of spleen leukocytes cell subpopulations in B-HLA-A2.1 mice
Analysis of spleen leukocyte subpopulations by FACS
Splenocytes were isolated from C57BL/6 and B-HLA-A2.1 mice. The proportion of lymphocyte subpopulation was tested by flow cytometry. Single live cells were gated for CD45+ population and used for further analysis as indicated here. As a result, the expression profile of lymphocyte subpopulation in homozygous B-HLA-A2.1 mice is similar to that in the C57BL/6 mice, indicating that differentiation of T cells and B cells are not affected by the humanization of B2M and HLA-A2.1. The population of peripheral CD8+ T cells in B-HLA-A2.1 mice was lower than in C57BL/6 mice (except for the second mice).Peptide vaccines induced immune responses in B-HLA-A2.1 mice
Detection of vaccine-induced immune responses in B-HLA-A2.1 mice by IFN-γ ELISpot assay. Female B-HLA-A2.1 mice at the age of 9–10 weeks were divided into PBS group, Group 2 and Group 3 (n = 2), and then inoculated PBS or vaccines at the inside muscle of both legs. Three weeks after the last immunization, mice were sacrificed. The splenocytes were extracted, stimulated with individual peptide or target-unrelated polypeptide as negative control (NC) or anti-CD3 as positive control, and then measured for IFN-γ secretion. No significant difference in body weight among groups (Data was not shown). (A) Representative results showing stimulation of splenocytes harvested from immunized mice with negative control, or peptide vaccines, or positive control in duplicates. (B) Summary of results. The results demonstrate that B-HLA-2.1 mice provide a powerful preclinical model for in vivo evaluation of vaccines. NC: negative control. V1: the first peptide vaccine to be evaluated.
