Nishana Mayilaadumveettil, Nilavar Namrata M, Kumari Rupa, Pandey Monica, Raghavan Sathees C
Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India.
Cell Death Dis. 2017 Jun 1;8(6):e2852. doi: 10.1038/cddis.2017.237.
Integrase inhibitors are a class of antiretroviral drugs used for the treatment of AIDS that target HIV integrase, an enzyme responsible for integration of viral cDNA into host genome. RAG1, a critical enzyme involved in V(D)J recombination exhibits structural similarity to HIV integrase. We find that two integrase inhibitors, Raltegravir and Elvitegravir, interfered with the physiological functions of RAGs such as binding, cleavage and hairpin formation at the recombination signal sequence (RSS), though the effect of Raltegravir was limited. Circular dichroism studies demonstrated a distinct change in the secondary structure of RAG1 central domain (RAG1 shares DDE motif amino acids with integrases), and when incubated with Elvitegravir, an equilibrium dissociation constant (K) of 32.53±2.9 μM was determined by Biolayer interferometry, leading to inhibition of its binding to DNA. Besides, using extrachromosomal assays, we show that Elvitegravir inhibited both coding and signal joint formation in pre-B cells. Importantly, treatment with Elvitegravir resulted in significant reduction of mature B lymphocytes in 70% of mice studied. Thus, our study suggests a potential risk associated with the use of Elvitegravir as an antiretroviral drug, considering the evolutionary and structural similarities between HIV integrase and RAGs.
整合酶抑制剂是一类用于治疗艾滋病的抗逆转录病毒药物，其作用靶点是HIV整合酶，该酶负责将病毒cDNA整合到宿主基因组中。RAG1是一种参与V(D)J重组的关键酶，与HIV整合酶存在结构相似性。我们发现，两种整合酶抑制剂拉替拉韦和埃替拉韦干扰了RAGs的生理功能，如在重组信号序列（RSS）处的结合、切割和发夹形成，不过拉替拉韦的作用有限。圆二色性研究表明，RAG1中央结构域的二级结构发生了明显变化（RAG1与整合酶共享DDE基序氨基酸），当与埃替拉韦孵育时，通过生物膜干涉测量法测定其平衡解离常数（K）为32.53±2.9 μM，导致其与DNA的结合受到抑制。此外，通过染色体外分析，我们表明埃替拉韦抑制了前B细胞中编码连接和信号连接的形成。重要的是，在70%的受试小鼠中，用埃替拉韦治疗导致成熟B淋巴细胞显著减少。因此，考虑到HIV整合酶与RAGs之间的进化和结构相似性，我们的研究表明使用埃替拉韦作为抗逆转录病毒药物存在潜在风险。
