PATHOGENIC DETERMINANTS OF THE SIV ENVELOPE TRANSMEMBRANE CYTOPLASMIC DOMAIN

SIV 包膜跨膜细胞质域的致病决定因素

• 批准号: 8173001
• 负责人: James A Hoxie
• 金额: $ 6.18万
• 依托单位: TULANE UNIVERSITY OF LOUISIANA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8173001
• 关键词: Acute; Animals; Attenuated; Autopsy; Biopsy; CD4 Positive T Lymphocytes; Cells; Chronic; Competence; Computer Retrieval of Information on Scientific Projects Database; Confocal Microscopy; Cytoplasmic Tail; Defect; Diffuse; Employee Strikes; Funding; Grant; Gut associated lymphoid tissue; Immune; Immune response; Infection; Infection Control; Institution; Intestines; Lamina Propria; Lymph; Lymphoid; Lymphoid Tissue; Macaca; Macaca mulatta; Nodule; Peripheral; Phenotype; Plasma; RNA; Research; Research Personnel; Resources; Signal Transduction; Site; Source; Structure of germinal center of lymph node; T-Lymphocyte; Tissues; United States National Institutes of Health; Viral; Virus; attenuation; lymph nodes; macrophage; trafficking; transmission process

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We previously showed that disrupting a highly conserved trafficking signal (GYxx¿) in the Env cytoplasmic tail of SIVmac239 (i.e. deleting Gly-721 and Tyr-721) produces a profoundly attenuated phenotype in rhesus and pigtailed macaques. Following iv inoculation, deltaGY replicates to a high acute viral peak comparable to SIVmac239, but is suppressed to 100 copies/ml with no loss of peripheral CD4 cells. To determine the pathological correlates of attenuation, 4 rhesus macaques were infected iv with deltaGY. Two animals were necropsied on day 28; 2 are being followed with serial biopsies of GALT and peripheral lymph nodes. Four animals were inoculated intravaginally to determine deltaGY's competence for mucosal transmission. For iv-infected animals, the acute viral peak was 1.8x10^6 (2.2x10^5-6.0x10^7) with levels for 2 chronically infected animals declining to 1.4x10^3 and 6.4x10^3 by week 16. For ivag-inoculated animals, 1 of 4 became infected (peak= 2.6x10^7) despite 8 weekly inoculations of 350 TCID50. For necropsied animals, abundant virus was detectable in germinal centers of organized lymphoid tissue in intestine and peripheral lymph nodes. However, in striking contrast to SIVmac239- or SIVmac251-infected controls, infection was limited to immune inductive sites (organized lymphoid nodules) and absent from immune effector sites (diffuse lamina propria). There was also little to no depletion of intestinal CD4+/CCR5+ cells in chronic, deltaGY-infected animals (average CD4+/CCR5+= 43.8% of T-cells pre-infection; 33.3% wk 22 post-infection). For necropsied animals there was also no detectable virus in CNS despite high acute levels of plasma RNA. Multilabel confocal microscopy of peripheral lymph tissue showed deltaGY in T-cells but not macrophages. Thus, deltaGY replication is driven by infected T-cells in immune inductive sites, but with sparing of macrophages and LPL in immune effector sites. How a defect in Env trafficking disrupts viral spread, and what host immune responses correlate with its control is being investigated.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们先前表明，破坏SIVmac 239的Env胞质尾区中高度保守的运输信号（GYxx？）（即缺失Gly-721和Tyr-721），在恒河猴和猪尾猕猴中产生显著减毒的表型。静脉内接种后，deltaGY复制到与SIVmac 239相当的高急性病毒峰，但被抑制到100拷贝/ml，没有外周CD 4细胞的损失。为了确定减毒的病理学相关性，用deltaGY静脉内感染4只恒河猴。在第28天对两只动物进行尸检;对其中2只动物进行GALT和外周淋巴结连续活检。四只动物阴道内接种，以确定deltaGY的粘膜传播能力。对于iv感染的动物，急性病毒峰值为1.8x10^6（2.2x10^5-6.0x10^7），到第16周，2只慢性感染动物的水平下降至1.4x10^3和6.4x10^3。对于ivag接种动物，尽管每周接种8次350 TCID 50，但4只动物中仍有1只发生感染（峰值= 2.6x10^7）。在剖检的动物中，在肠和外周淋巴结的有组织淋巴组织的生发中心可检测到大量的病毒。然而，与SIVmac 239或SIVmac 251感染的对照组形成鲜明对比，感染仅限于免疫诱导部位（有组织的淋巴结），而免疫效应部位（弥漫性固有层）则不存在。在慢性deltaGY感染的动物中，肠道CD 4 +/CCR 5+细胞也几乎没有消耗（平均CD 4 +/CCR 5 +=感染前T细胞的43.8%;感染后22周为33.3%）。对于尸检动物，尽管急性血浆RNA水平较高，但CNS中也未检出病毒。外周淋巴组织的多标记共聚焦显微镜检查显示T细胞中有deltaGY，但巨噬细胞中没有。因此，deltaGY复制由免疫诱导位点中的感染的T细胞驱动，但在免疫效应位点中保留巨噬细胞和LPL。Env运输缺陷如何破坏病毒传播，以及宿主免疫反应与其控制相关的情况正在调查中。