Identification of Amino Acid Residues Critical for LD78β, a Variant of Human Macrophage Inflammatory Protein-1α, Binding to CCR5 and Inhibition of R5 Human Immunodeficiency Virus Type 1 Replication*
Identification of Amino Acid Residues Critical for LD78β, a Variant of Human Macrophage Inflammatory Protein-1α, Binding to CCR5 and Inhibition of R5 Human Immunodeficiency Virus Type 1 Replication*
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DOI：
10.1074/jbc.m109198200
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发表时间：
2002-02
期刊：
影响因子：
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通讯作者：
Toshikazu Miyakawa;K. Obaru;K. Maeda;S. Harada;H. Mitsuya
中科院分区：
文献类型：
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作者：
Toshikazu Miyakawa;K. Obaru;K. Maeda;S. Harada;H. Mitsuya
为了确定LD 78 β（人巨噬细胞炎性蛋白-1 α的变体）的哪些氨基酸在与CCR 5的相互作用中起关键作用，我们产生了6种LD 78 β变体，其中LD 78 β的NH 2末端的氨基酸被替换为Ala。除了LD 78 β T9 A显示出显著降低的活性外，在引起Ca 2+通量和趋化性方面在变体之间没有显著差异。对人类免疫缺陷病毒1型（HIV-1）复制抑制作用的比较顺序为：LD 78 β P8 A> LD 78 β D 6A> LD 78 βWT，LD 78 β L3 A> LD 78 β T7 A，LD 78 β P2 A> LD 78 β T9 A。在2D 7单克隆抗体与125 I标记的巨噬细胞炎性蛋白1α结合抑制试验中，比较顺序为：LD 78 β P8 A，LD 78 β D 6A> LD 78 βWT> LD 78 β L3 A> LD 78 β T7 A> LD 78 β T9 A，LD 78 β P2 A。CCR 5下调诱导的顺序与结合抑制的顺序相当。目前的数据表明Pro-2、Asp-6、Pro-8和Thr-9对于LD 78 β与CCR 5的结合和HIV-1复制抑制至关重要，并且LD 78 β与CCR 5的结合（无论亲和力如何）足以进行LD 78 β的初始信号转导，而更大的抗HIV-1活性需要更大的结合幅度。数据还表明，具有适当氨基酸取代的LD 78 β变体（如LD 78 β D 6A和LD 78 β P8 A）可能代表有效的基于趋化因子的抗HIV-1治疗剂，同时保留LD 78 β-CCR 5相互作用。
In an attempt to determine which amino acid(s) of LD78β, a variant of human macrophage inflammatory protein-1α, plays a critical role in the interaction with CCR5, we generated six LD78β variants with an amino acid substituted to Ala at the NH2 terminus of LD78β. There was no significant difference in eliciting Ca2+ flux and chemotaxis among the variants with the exception of LD78βT9A showing a substantially reduced activity. The comparative order for human immunodeficiency virus type 1 (HIV-1) replication inhibition was: LD78βP8A > LD78βD6A > LD78βWT, LD78βL3A > LD78βT7A, LD78βP2A > LD78βT9A. In binding inhibition assays of LD78β variants using 2D7 monoclonal antibody and 125I-labeled macrophage inflammatory protein-1α, the comparative order was: LD78βP8A, LD78βD6A > LD78βWT> LD78βL3A > LD78βT7A > LD78βT9A, LD78βP2A. The order for CCR5 down-regulation induction was comparable to that for binding inhibition. The present data suggest that Pro-2, Asp-6, Pro-8, and Thr-9 are critical for LD78β binding to CCR5 and HIV-1 replication inhibition, and that LD78β binding to CCR5, regardless of affinity, is sufficient for the initial signal transduction of LD78β, whereas the greater anti-HIV-1 activity requires the greater magnitude of binding. The data also suggest that LD78β variants with appropriate amino acid substitution(s) such as LD78βD6Aand LD78βP8A may represent effective chemokine-based anti-HIV-1 therapeutics while preserving LD78β-CCR5 interactions.