Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-3-30
pubmed:abstractText
The 65KD isoform of GAD is considered to be a major target autoantigen in many humans with autoimmune prediabetes or diabetes. The major histocompatibility complex class II allele DQA1*0301, DQB1*0302, which encodes HLA-DQ8, confers susceptibility to type 1 diabetes and occurs in up to 80% of affected individuals. To map T-cell epitopes for GAD65 restricted to the diabetes-associated DQ8 heterodimer, we generated transgenic NOD mice expressing HLA-DQ8 and human CD4 while having the mouse class II gene (IA(beta)) deleted. These mice were immunized with full-length purified recombinant GAD65, and the fine specificity of T-cell responses was mapped by examining recall responses of bulk splenocytes to an overlapping set of 20-mer peptides encompassing the entire GAD65 protein. Four different peptides (P121-140, P201-220, P231-250, and P471-490) gave significant T-cell recall responses. P201-220 and P231-250 have been shown previously to bind DQ8, whereas the other two peptides had been classified as nonbinders. Interestingly, the peptide giving the greatest response (P201-220) encompasses residues 206-220 of GAD65, a region that has been shown to be a dominant T-cell epitope in wild-type IA(g7) NOD mice. Overlap in this T-cell epitope likely reflects structural similarities between DQ8 and IA(g7). The fine specificity of antibody responses in the GAD65-immunized mice was also examined by testing the antisera by enzyme-linked immunosorbent assay (ELISA) against the same overlapping set of peptides. The two dominant B-cell epitopes were P361-380 and P381-400; P121-140 and P471-490 appeared to correspond to both B- and T-cell epitopes. Although the NOD human CD4, DQ8, IA(null) transgenic mice generated in these studies do not develop autoimmune diabetes either spontaneously or after cyclophosphamide treatment, they can be used to map DQ8-restricted T-cell epitopes for a variety of human islet autoantigens. They can also be used to test T-cell-specific reagents, such as fluorescently labeled DQ8 tetramers containing GAD65 peptides or other beta-cell peptides, which we believe will be useful in analyzing human immune responses in diabetic and prediabetic patients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD4, http://linkedlifedata.com/resource/pubmed/chemical/Autoantibodies, http://linkedlifedata.com/resource/pubmed/chemical/Epitopes, http://linkedlifedata.com/resource/pubmed/chemical/Glutamate Decarboxylase, http://linkedlifedata.com/resource/pubmed/chemical/HLA-DQ Antigens, http://linkedlifedata.com/resource/pubmed/chemical/HLA-DQ alpha-Chains, http://linkedlifedata.com/resource/pubmed/chemical/HLA-DQ beta-Chains, http://linkedlifedata.com/resource/pubmed/chemical/HLA-DQ8 antigen, http://linkedlifedata.com/resource/pubmed/chemical/HLA-DQA1 antigen, http://linkedlifedata.com/resource/pubmed/chemical/HLA-DQB1 antigen, http://linkedlifedata.com/resource/pubmed/chemical/Histocompatibility Antigens Class II, http://linkedlifedata.com/resource/pubmed/chemical/Isoenzymes
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0012-1797
pubmed:author
pubmed:issnType
Print
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
469-77
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:10078545-Amino Acid Sequence, pubmed-meshheading:10078545-Animals, pubmed-meshheading:10078545-Antigens, CD4, pubmed-meshheading:10078545-Autoantibodies, pubmed-meshheading:10078545-B-Lymphocytes, pubmed-meshheading:10078545-Diabetes Mellitus, Type 1, pubmed-meshheading:10078545-Epitopes, pubmed-meshheading:10078545-Flow Cytometry, pubmed-meshheading:10078545-Genetic Predisposition to Disease, pubmed-meshheading:10078545-Glutamate Decarboxylase, pubmed-meshheading:10078545-HLA-DQ Antigens, pubmed-meshheading:10078545-HLA-DQ alpha-Chains, pubmed-meshheading:10078545-HLA-DQ beta-Chains, pubmed-meshheading:10078545-Histocompatibility Antigens Class II, pubmed-meshheading:10078545-Humans, pubmed-meshheading:10078545-Isoenzymes, pubmed-meshheading:10078545-Lymphocyte Activation, pubmed-meshheading:10078545-Mice, pubmed-meshheading:10078545-Mice, Inbred NOD, pubmed-meshheading:10078545-Mice, Knockout, pubmed-meshheading:10078545-Mice, Transgenic, pubmed-meshheading:10078545-Molecular Sequence Data, pubmed-meshheading:10078545-Spleen, pubmed-meshheading:10078545-T-Lymphocytes
pubmed:year
1999
pubmed:articleTitle
Major DQ8-restricted T-cell epitopes for human GAD65 mapped using human CD4, DQA1*0301, DQB1*0302 transgenic IA(null) NOD mice.
pubmed:affiliation
Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't