5and data not shown). T1D susceptibility to NOD-cMHCI?/? mice. These next-generation HLA-humanized NOD models may provide improved platforms for T1D therapy development. Introduction The study of NOD mice has greatly advanced knowledge of the genetics and pathogenic mechanisms underlying autoimmune-mediated type 1 diabetes (T1D) (1). However, as a model for translating this knowledge into clinically applicable therapies, NOD mice have been less successful (2). A potential way to improve NOD as a preclinical platform is to humanize the strain with a variety of genes relevant to T1D patients (3,4). A desired humanization process would turn an inbred mouse potentially representing one T1D patient profile, into a multiplex platform capable of representing an array of such individuals. Such pipeline models could be used to test therapies with potential efficacy in heterogeneous at-risk T1D subjects. While polygenic in nature, specific MHC (designated HLA in humans) haplotypes provide the strongest T1D risk factor (5,6). Hence, a flexible panel of HLA-humanized NOD mice may provide improved models for testing potentially clinically applicable T1D interventions. In humans, particular HLA class II variants, such as DQ8 and DR3/4, mediating autoreactive CD4+ T-cell responses strongly contribute to T1D susceptibility ST3932 (7C9). Similarly, the murine H2-Ag7 class II variant, highly homologous with the human DQ8 molecule, is a primary T1D contributor in NOD mice (10). ST3932 However, findings that NOD mice made deficient in MHC class I expression and CD8+ T cells by introduction of an inactivated allele (NOD.2m?/?) are completely T1D resistant (11) indicated that this immunological arm is also critical to disease development. It was subsequently found that particular HLA class I variants also contribute to T1D susceptibility in patients (12C16). Thus, a desirable pipeline model system would enable generation Rabbit Polyclonal to SLC25A12 of NOD mice expressing chosen combinations of human T1DCassociated HLA class I and II variants in the absence of their murine counterparts that could then serve to test potential clinically relevant disease interventions. T1D-associated class I susceptibility variants in humans include HLA-A*02:01 (hereafter HLA-A2.1) and HLA-B*39:06 (hereafter HLA-B39) (12C19). HLA-A2 is in strong linkage disequilibrium with the DR4/DQ8 class II haplotype, the primary contributor ST3932 to T1D development in Caucasians (14). Hence, the A2 class I variant ST3932 will be present in the preponderance of T1D patients. While representing a relatively low frequency allele, the B39 variant supports aggressive early-age-of-onset T1D development (15,16). The original HHD transgene construct contains the genomic promoter and first three exons of HLA-A*02:01, encoding the antigen-presenting 1 and 2 domains, as well as a covalently linked human 2m with the 3, transmembrane, and cytoplasmic domains of murine H2-Db origin, allowing for proper signaling within mice (20). When introduced into normally disease-resistant NOD.2m?/? mice, HHD transgene expression of HLA-A2.1 in the absence of any murine class I molecules restored the generation of pathogenic CD8+ T cells mediating insulitis and T1D development (21). These mice allowed identification of HLA-A2.1Crestricted autoantigenic epitopes derived from the pancreatic -cell proteins insulin and IGRP (21C23) also targeted by CD8+ T cells from human patients expressing this class I variant (24C29). This subsequently led to development of some proof-of-principle antigen-specific therapeutics (30). The B39 variant appears to be a highly potent.