Husain S, Goila R, Shahi S, Banerja A C
Department of Microbiology, Guru Nanak Dev University, Amritsar, India.
J Hum Virol. 1998 Mar-Apr;1(3):187-92.
The most common form of mutation found in the CCR5 gene has been the precise 32-base pair (bp) deletion in the region corresponding to second extracellular loop of the chemokine receptor CCR5. Individuals homozygous for the delta 32 allele of CCR5 usually remain uninfected despite multiple exposures to HIV, whereas heterozygous individuals support less virus replication and show slower progression of the disease. This mutant allele in either homozygous or heterozygous form is quite common in white people of European heritage. Earlier work involving large populations of Asians and Africans failed to detect the presence of this mutant allele. We screened 145 normal unrelated healthy Indians and found one person who was heterozygous for the delta 32 allele of CCR5. We studied the inheritance of this deleted allele in this person's family. One parent, one of two sons, and the only daughter possessed this mutant allele. We cloned the entire coding region of wild-type and mutant alleles of CCR5 gene from the heterozygous individual mentioned and studied its coreceptor functions. The mutant allele had only a moderate interfering effect on coreceptor activity of the wild-type CCR5 allele in a cell fusion assay. We also report an improved method of genotyping CCR5 gene in this communication.
在CCR5基因中发现的最常见突变形式是趋化因子受体CCR5第二个细胞外环对应区域精确缺失32个碱基对（bp）。CCR5基因δ32等位基因的纯合个体尽管多次接触HIV通常仍未感染，而异合子个体的病毒复制较少且疾病进展较慢。这种纯合或杂合形式的突变等位基因在欧洲裔白人中相当常见。早期涉及大量亚洲人和非洲人的研究未能检测到这种突变等位基因的存在。我们筛查了145名正常无亲缘关系的健康印度人，发现1人是CCR5基因δ32等位基因的杂合子。我们研究了该缺失等位基因在这个人家庭中的遗传情况。其父母之一、两个儿子中的一个以及唯一的女儿拥有这种突变等位基因。我们从上述杂合个体中克隆了CCR5基因野生型和突变等位基因的整个编码区，并研究了其共受体功能。在细胞融合试验中，突变等位基因对野生型CCR5等位基因的共受体活性只有中等程度的干扰作用。在本通讯中我们还报告了一种改进的CCR5基因分型方法。
