Mishra Mamata, Varghese Rebu K, Verma Anjali, Das Sutanuka, Aguiar Renato Santana, Tanuri Amilcar, Mahadevan Anita, Shankar Susarla K, Satishchandra Parthasarathy, Ranga Udaykumar
HIV-AIDS Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India.
J Neurovirol. 2015 Aug;21(4):399-414. doi: 10.1007/s13365-015-0328-0. Epub 2015 Mar 7.
In India, the low prevalence of HIV-associated dementia (HAD) in the Human immunodeficiency virus type 1 (HIV-1) subtype C infection is quite paradoxical given the high-rate of macrophage infiltration into the brain. Whether the direct viral burden in individual brain compartments could be associated with the variability of the neurologic manifestations is controversial. To understand this paradox, we examined the proviral DNA load in nine different brain regions and three different peripheral tissues derived from ten human subjects at autopsy. Using a highly sensitive TaqMan probe-based real-time PCR, we determined the proviral load in multiple samples processed in parallel from each site. Unlike previously published reports, the present analysis identified uniform proviral distribution among the brain compartments examined without preferential accumulation of the DNA in any one of them. The overall viral DNA burden in the brain tissues was very low, approximately 1 viral integration per 1000 cells or less. In a subset of the tissue samples tested, the HIV DNA mostly existed in a free unintegrated form. The V3-V5 envelope sequences, demonstrated a brain-specific compartmentalization in four of the ten subjects and a phylogenetic overlap between the neural and non-neural compartments in three other subjects. The envelope sequences phylogenetically belonged to subtype C and the majority of them were R5 tropic. To the best of our knowledge, the present study represents the first analysis of the proviral burden in subtype C postmortem human brain tissues. Future studies should determine the presence of the viral antigens, the viral transcripts, and the proviral DNA, in parallel, in different brain compartments to shed more light on the significance of the viral burden on neurologic consequences of HIV infection.
在印度，鉴于巨噬细胞大量浸润入脑，1型人类免疫缺陷病毒（HIV-1）C亚型感染中与HIV相关的痴呆（HAD）患病率较低，这一现象颇为矛盾。个体脑区中直接的病毒载量是否与神经学表现的变异性相关，仍存在争议。为了解这一矛盾，我们在尸检时检测了来自10名人类受试者的9个不同脑区和3种不同外周组织中的前病毒DNA载量。使用基于TaqMan探针的高灵敏度实时PCR技术，我们测定了从每个部位并行处理的多个样本中的前病毒载量。与先前发表的报告不同，本分析发现所检测的脑区之间前病毒分布均匀，DNA未在任何一个脑区中优先积累。脑组织中的总体病毒DNA载量非常低，每1000个细胞中约有1个或更少的病毒整合。在一部分测试的组织样本中，HIV DNA大多以游离未整合的形式存在。V3-V5包膜序列在10名受试者中的4名中表现出脑特异性分区，在另外3名受试者的神经和非神经分区之间存在系统发育重叠。包膜序列在系统发育上属于C亚型，其中大多数为R5嗜性。据我们所知，本研究是对C亚型人类尸检脑组织中前病毒载量的首次分析。未来的研究应同时确定不同脑区中病毒抗原、病毒转录本和前病毒DNA的存在情况，以更深入了解病毒载量对HIV感染神经学后果的意义。
