天花粉蛋白诱发人体免疫抑制的遗传控制——Ⅲ.HLA-DQA1和DQB1基因的顺式和反式互补作用

根据天花粉蛋白（Tk）作用了淋巴细胞体外增殖的抑制是否由CD8细胞所介导,健康人群被分成介导型（M~+）和非介导型（M~-）两类。我们已有的工作证明,性状M~+/M~-由HLA连锁的一对孟德尔基因控制。本文采用分子生物学手段,对M~+”和M~-个体作HLAⅡ类基因的精细分型,发现编码DQ异二聚体分子的DQA和DQB两个基因同时决定M~+的表达,而且等位基因DQA1*0501和DQB1*0201以顺式和反式两种形式发挥互补作用,从而把人体中调控Tk免疫应答的遗传成份直接定位在该特定DQ分子的编码基因上。这一互补现象同时解释了DR3、DR5和DR7与M~+呈现次级关联的复杂格局。

Genetic Control of Trichosanthin -induced Immunosuppression in Man III. Detection of Cis-and Trans-coinplementations between HLA-DQA1 and DQB1 Alleles

As regards whether their CD8-possible T cells were active in suppression of the Tri-chosanthin (Tk) -induced lymphoproliferation in vitro, two kinds of healthy subjects in population, the CDS cell-mediators (M+) and non-mediators (M-), have been identified in our previous study, and we were able to show that the traits M+/M- were inherited in a manner controlled by a pair of HLA-associated Mendelian genes. In this communication we report the results of fine HLA typing with molecular biological approaches for the M+/M- subjects. It was found that not only the DQA and DQB, two encoding genes for the DQ heterodimer, were equally contributed to the expression of the trait M+, but also two involved alleles, DQAl*0501 and DQB1*0201, worked in a form either as cis- or as frans-complementation in two seperated loci, strongly suggesting that the DQAl*0501-DQB1*201 are the primary genetic elements involved in determining and/or regulating the human immune response to Tk. Besides,the complementation could also be used to explanation of the complicated patterns of secondary association of M+ with DR2, DR5, and DR7.