Wahlberg J, Albert J, Lundeberg J, Von Gegerfelt A, Broliden K, Utter G, Fenyö E M, Uhlén M
Department of Biochemistry and Biotechnology, Royal Institute of Technology, Stockholm, Sweden.
AIDS Res Hum Retroviruses. 1991 Dec;7(12):983-90. doi: 10.1089/aid.1991.7.983.
To study the molecular basis for the emergence of human immunodeficiency virus type 1 (HIV-1) variants with reduced sensitivity to neutralization by autologous sera, the DNA sequence of the envelope V3 loop was determined in HIV-1 isolates derived from four patients with primary HIV-1 infection and sequentially thereafter. The gene fragment encoding the V3 loop of gp120 was amplified by a nested polymerase chain reaction (PCR) and subsequently sequenced by a novel solid phase DNA sequencing approach allowing direct sequencing of the viral genome without the need for previous cloning. The results show that all patients have HIV-1 with unique primary sequence of the V3 loop and antibodies to this structure are produced at seroconversion. The structural analysis also demonstrates that the mechanism for virus escape from neutralization in vivo is complex. Thus, in one patient the emergence of neutralization-resistant viruses coincided with the introduction of several amino acid changes in the V3 loop, while in two other patients the V3 loop remained completely unchanged. These findings suggest that an understanding of the interaction between the humoral immune response and HIV-1 may require detailed structural studies of the entire envelope.
为研究对自体血清中和作用敏感性降低的1型人类免疫缺陷病毒（HIV-1）变体出现的分子基础，对来自4例原发性HIV-1感染患者及其后续随访分离出的HIV-1毒株包膜V3环的DNA序列进行了测定。通过巢式聚合酶链反应（PCR）扩增编码gp120 V3环的基因片段，随后采用一种新型固相DNA测序方法进行测序，该方法无需预先克隆即可直接对病毒基因组进行测序。结果显示，所有患者的HIV-1 V3环均具有独特的一级序列，且在血清转换时产生针对该结构的抗体。结构分析还表明，病毒在体内逃避中和的机制较为复杂。因此，在1例患者中，中和抗性病毒的出现与V3环中几个氨基酸的改变同时发生，而在另外2例患者中，V3环保持完全不变。这些发现表明，要理解体液免疫反应与HIV-1之间的相互作用，可能需要对整个包膜进行详细的结构研究。
