Parkos C A, Dinauer M C, Jesaitis A J, Orkin S H, Curnutte J T
Department of Immunology, Research Institute of Scripps Clinic, La Jolla, CA 92037.
Blood. 1989 May 1;73(6):1416-20.
Chronic granulomatous disease (CGD) is a group of inherited disorders in which phagocytic cells fail to generate antimicrobial oxidants. The various forms of CGD can be classified in terms of the mode of inheritance (either X-linked or autosomal recessive), and whether the neutrophils display the absorbance spectrum of a unique b-type cytochrome important for the function of the respiratory burst oxidase. The finding that purified neutrophil cytochrome b is a heterodimer consisting of a 91kD glycosylated and a 22kD nonglycosylated polypeptide has raised the question of which subunits are absent (or defective) in the various types of CGD. To address this question we have studied the expression of the cytochrome b subunits in three genetically distinct forms of CGD: X-linked/cytochrome b-negative (X-), autosomal recessive/cytochrome b-negative (A-), and autosomal recessive/cytochrome b-positive (A+). Using polyclonal antibodies to each of the two subunits, we prepared Western blots of lysates of intact neutrophils from ten CGD patients. In the controls and three patients with A+ CGD, both cytochrome subunits were easily detected. Consistent with the previously reported finding in five X- patients, neither subunit could be identified in neutrophils from three additional X- patients. Both subunits were also undetectable in four patients with A- CGD (three females, one male). This latter group of patients most likely bears a normal 91kD gene, since the patients are genetically distinct from the 91kD-defective X- group. The mutation in A- CGD, therefore, probably involves the 22kD gene and the eventual expression of the 22kD subunit. Furthermore, the expression of the 91kD subunit in this group of patients appears to be prevented due to the 22kD mutation in a manner converse to that seen in the X- CGD patients. Based on these studies, we hypothesize that the stable of expression of either of the two cytochrome subunits is dependent upon the other.
慢性肉芽肿病（CGD）是一组遗传性疾病，其中吞噬细胞无法产生抗菌氧化剂。CGD的各种形式可根据遗传方式（X连锁或常染色体隐性遗传）以及中性粒细胞是否显示对呼吸爆发氧化酶功能重要的独特b型细胞色素的吸收光谱进行分类。纯化的中性粒细胞细胞色素b是由一个91kD糖基化多肽和一个22kD非糖基化多肽组成的异二聚体，这一发现引发了一个问题，即在各种类型的CGD中哪些亚基缺失（或有缺陷）。为了解决这个问题，我们研究了三种遗传上不同形式的CGD中细胞色素b亚基的表达：X连锁/细胞色素b阴性（X-）、常染色体隐性/细胞色素b阴性（A-）和常染色体隐性/细胞色素b阳性（A+）。我们使用针对两个亚基中每一个的多克隆抗体，制备了来自10名CGD患者的完整中性粒细胞裂解物的蛋白质印迹。在对照组和三名A+型CGD患者中，两种细胞色素亚基都很容易检测到。与之前在五名X-患者中报道的发现一致，在另外三名X-患者的中性粒细胞中均未鉴定出任何一个亚基。在四名A-型CGD患者（三名女性，一名男性）中也未检测到这两个亚基。后一组患者很可能携带正常的91kD基因，因为这些患者在基因上与91kD缺陷的X-组不同。因此，A-型CGD中的突变可能涉及22kD基因以及22kD亚基的最终表达。此外，由于22kD突变，该组患者中91kD亚基的表达似乎以与X-型CGD患者中所见相反的方式受到抑制。基于这些研究，我们假设两个细胞色素亚基中任何一个的稳定表达都依赖于另一个。
