摘要目的研究糖尿病易感性NOD小鼠(I-Ag7)和非糖尿病性Balb/c(I-Ad)中谷氨酸去羰基酶 (GAD)-I-Ag7 and I-Ad 四聚体的交叉反应性.方法合成两种GAD多肽-I-Ag7 and I-Ad 四聚体,并比较这两种四聚体阳性细胞(tet +)的表现型及功能.结果交叉反应性不仅表现在四聚体阳性细胞率上,而且在四聚体染色强度上.NOD 和 Balb/c来源的tet+ T细胞均能被 GAD抗原肽-I-Ag7 和I-Ad 四聚体交叉染色,并在合成的和重组的GAD抗原肽刺激下均对辐射后的NOD和Balb/c脾细胞有交叉反应. 讨论虽然I-Ag7 and I-Ad 在生物化学和生物学特性上近似,关键的区别在于β57上的氨基酸种类,这与I型糖尿病的发病密切相关.

abstractsObjective To investigate the cross-reactivity between glutamic acid decarboxylase (GAD)- I-Ag7 and I-Ad tetramer in diabetes-prone non-obese diabetic (NOD) mice (I-Ag7) and diabetes-free Balb/c mice (I-Ad). Methods Two GAD peptide I-Ag7 and I-Ad tetramers were generated and compared for phenotype and function of sorted GAD peptide I-Ag7 and I-Ad tetrame r-positive (tet+) T cells.Results The cross-reactivity is shown in either tetramer positive percentage or tetramer staining intensity. The NOD and Balb/c derived-tet+ T cells were able to be cross-stained by GAD peptide I-Ag7 and I-Ad tetramers, and responded to both irradiated NOD and Balb/c splenotyes under stimulation by synthetic an drecombinant GAD peptides. Conclusion Although I-Ag7 and I-Ad are closely related in biochemical and biological aspects, their most notable difference is the presence or absence of a negat ively charged residue at position β57 that links to insulin-dependent diabetes mellitus.