A 320-Kilobase Artificial Chromosome Encoding the Human HLA DR3-DQ2 MHC Haplotype Confers HLA Restriction in Transgenic Mice

Abstract

MHC class II haplotypes control the specificity of Th immune responses and susceptibility to many autoimmune diseases. Understanding the role of HLA class II haplotypes in immunity is hampered by the lack of animal models expressing these genes as authentic cis-haplotypes. In this study we describe transgenic expression of the autoimmune prone HLA DR3-DQ2 haplotype from a yeast artificial chromosome (YAC) containing an intact ∼320-kb region from HLA DRA to DQB2. In YAC-transgenic mice HLA DR and DQ gene products were expressed on B cells, macrophages, and dendritic cells, but not on T cells indicating cell-specific regulation. Positive selection of the CD4 compartment by human class II molecules was 67% efficient in YAC-homozygous mice lacking endogenous class II molecules (Aβnull/null) and expressing only murine CD4. A broad range of TCR Vβ families was used in the peripheral T cell repertoire, which was also purged of Vβ5-, Vβ11-, and Vβ12-bearing T cells by endogenous mouse mammary tumor virus-encoded superantigens. Expression of the HLA DR3-DQ2 haplotype on the Aβnull/null background was associated with normal CD8-dependent clearance of virus from influenza-infected mice and development of CD4-dependent protection from otherwise lethal infection with Salmonella typhimurium. HLA DR- and DQ-restricted T cell responses were also elicited following immunization with known T cell determinants presented by these molecules. These findings demonstrate the potential for human MHC class II haplotypes to function efficiently in transgenic mice and should provide valuable tools for developing humanized models of MHC-associated autoimmune diseases.

Resistance to Celiac Disease in Humanized HLA-DR3-DQ2-Transgenic Mice Expressing Specific Anti-Gliadin CD4+ T Cells

“…These mice demonstrate cell-specific regulation of the HLA-DR3 and DQ2 gene products, with fully functional CD4 ϩ and CD8 ϩ T cells (15). In the present study, we have bred mice with the HLA-DR3-DQ2 transgene to a complete class II knockout background (MHCII ⌬/⌬ ) (16), introduced human CD4 (hCD4) (17), and also generated a HLA-DQ2-restricted, gliadin-specific CD4 ϩ TCR Tg mouse to examine the pathological effect of dietary gluten on these mice.…”

“…Our laboratory has previously generated Tg mice that express the HLA-DR3-DQ2 haplotype (spanning HLA-DRA to DQB2) on a partial murine class II knockout background (A␤ o/o ) (15). These mice demonstrate cell-specific regulation of the HLA-DR3 and DQ2 gene products, with fully functional CD4 ϩ and CD8 ϩ T cells (15).…”

“…MHCII ⌬/⌬ mice were subsequently crossed with hCD4 Tg mice or HLA-DR3-DQ2 haplotype Tg mice (15), creating hCD4.MHCII ϩ/Ϫ mice and DR3-DQ2.MHCII ϩ/Ϫ mice. These double transgenic lines were mated to generate F 1 mice expressing HLA-DR3, DQ2, and hCD4 in the complete absence of endogenous MHCII (hCD4.DR3-DQ2.MHCII ⌬/⌬ Tg mice).…”

T cell epitopes of the La/SSB autoantigen in humanized transgenic mice expressing the hLa class II haplotype DRB1*0301/DQB1*0201

“…Production and characterization of C57BL/6 mice homozygous or heterozygous for the HLA-DRB1*0301;-DRB3*0101;DRA1*0101;DQB1*0201;DQA1*0501 transgene haplotype and lacking endogenous class II I-A MHC molecules (DR3/DQ2 ϩ A␤ 0/0 ) have been described previously (23). Mice were maintained at the University of Melbourne Microbiology and Immunology Department animal facility.…”

“…Computer analysis was performed using the SYFPEITHI (34) and ProPred (35) programs to find similarities between the hLa epitope sequences and putative DR3 binding motifs. Probable DRB1*0301 binding registers for each of the DR3-restricted epitopes uncovered in this study were identified ( Figure 4A), indicating that the most conserved residue is the p4 position, consisting of an aspartic acid (hLa [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] , hLa 55-72 , hLa 151-168 , hLa 211-228 , hLa [241][242][243][244][245][246][247][248][249][250][251][252][253][254][255][256][257][258] , and hLa 313-330 ) or conservatively substituted glutamic acid (hLa [46][47][48][49][50][51][52][53][54] ), in 7 of 7 epitopes, followed by p1 (in 5 of 7 epitopes), p6 (in 4 of 7 epitopes), and p9 (in 3 of 7 epitopes).…”