弓形虫RH株膜表面抗原2全长基因的高效表达与抗原性分析

目的　构建原核重组表达质粒pET23aSAG2,并在大肠埃希菌中实现高效表达,以及检测表达产物的抗原性。　方法　PCR扩增SAG2编码基因目的片段,琼脂糖凝胶电泳回收纯化,克隆至pMD18T载体,转化大肠埃希菌DH5α。测序后亚克隆至表达质粒载体pET23a,构建重组表达质粒pET2 3aSAG2,转化大肠埃希菌DH5α。筛选阳性克隆,经限制性酶切分析鉴定后,转化大肠埃希菌BL21(DE3),以异丙基 βD硫代半乳糖苷诱导表达。十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS PAGE)与免疫印迹分析表达产物。　结果　PCR扩增出约500bp的SAG2编码基因目的片段,与预期片段大小相符,经测序鉴定无基因突变;所构建的pET23aSAG2重组表达质粒阳性克隆经PCR与双酶切鉴定,与预期结果一致;含有pET23aSAG2重组质粒的大肠埃希菌BL21(DE3)诱导后得到了高效表达,SDS PAGE显示表达产物约Mr19000;免疫印迹结果表明表达产物具有良好的抗原性。　结论　成功构建了pET23aSAG2表达质粒,实现了全长成熟SAG2蛋白在大肠埃希菌中的高效表达;表达产物具有良好的抗原性。     

刚地弓形虫ROP2-P30复合基因在E.coliBL21中的表达和鉴定(英文)

目的获得编码弓形虫RH株棒状体蛋白2和主要表面抗原1重组复合蛋白为弓形虫病快速诊断试剂盒及蛋白质疫苗的研制作准备。方法用PCR技术从弓形虫基因组DNA中扩增出ROP2和P30基因片段,分别克隆入pMD18T载体,并对重组入外源基因的质粒通过PCR.,双酶切和测序鉴定,将pMD ROP2中的ROP2基因片段经EcoRⅠ和HindⅢ酶切,连接等反应,亚克隆入pET30a(+)原核表达载体构建pET ROP2载体,然后再将pMD P30中的P30基因片段与经BglⅡandEcoRⅠ酶切的pET ROP2载体连接,构建pET ROP2P30载体,经含卡那霉素的LB平板筛选,酶切和PCR鉴定。阳性重组质粒转化到大肠埃氏菌BL21(DE3)中,经IPTG诱导,表达产物用SDS PAGE进行鉴定。大量的表达融合蛋白经纯化和复性后,用Westernblot分析。结果从弓形虫RH株基因组DNA中扩增出特异的ROP2和P30基因片段,成功构建成pET ROP2和pET ROP2P30载体,成功表达了弓形虫棒状体蛋白2和弓形虫棒状体蛋白与主要表面抗原1的融合复合蛋白,表达出的蛋白经纯化复性后具有免疫反应性。结论ROP2和P30基因重组后,在原核表达载体中表达出的蛋白经纯化复性后具有活性,获得纯化和复性的弓形虫ROP2和ROP2P30的高效表达产物,为弓形虫病的诊断和疫苗研究奠定了基础。     

粉尘螨Ⅱ类抗原cDNA原核表达质粒的构建与表达

目的　构建粉尘螨Ⅱ类抗原cDNA基因的重组表达质粒 ,并在大肠埃希菌中表达。　方法　采用亚克隆技术 ,用SacⅠ和NotⅠ从重组质粒pMD 18T Derf 2上切下Derf 2cDNA片段 ,插入表达载体 pET 3 2a( )质粒 ,转化大肠埃希菌BL2 1,在含氨苄青霉素的LB平板上筛选阳性重组子 ,并经双酶切及PCR扩增鉴定。重组质粒 pET 3 2a( ) Derf2转化大肠埃希菌 ,IPTG诱导表达后进行SDS PAGE电泳和薄层凝胶扫描定量分析。　结果　对重组质粒进行酶切和PCR鉴定 ,获得 45 5bp大小的目的基因片段 ,与预期结果相符 ,证明已成功构建携带Derf 2基因的重组原核表达质粒pET 3 2a( ) Derf 2。核酸序列测定及同源性分析证实 ,所构建的原核表达质粒pET 3 2a( ) Derf 2中所含的Derf 2cDNA片段与GenBank中的Derf 2序列同源性达到 10 0 %。Derf 2cDNA在大肠埃希菌诱导表达后获得分子质量单位为 3 4ku的蛋白 ,蛋白含量占菌体蛋白含量的 16%。　结论　成功构建了粉尘螨Ⅱ类抗原cDNA基因的重组表达质粒pET 3 2a( ) Derf 2 ,并在大肠埃希菌中获得高效表达 ,为获得重组纯化Derf 2变应原并用于尘螨变应性疾病的诊治奠定基础。     

十二指肠钩虫锰超氧化物岐化酶基因的克隆与表达

目的克隆十二指肠钩虫锰超氧化物岐化酶（AdMn-SOD）基因,并在大肠埃希菌中表达。方法用3′RACE及RT-PCR技术扩增获得AdMn-SOD全长cDNA编码序列;设计引物,克隆AdMn-SOD成熟肽编码序列,连接到原核表达载体pET32a,构建重组表达质粒,转化大肠埃希菌BL21（DE3）并用IPTG诱导表达,SDS-PAGE分析表达情况,诱导表达的重组蛋白用Ni亲和层析进行纯化。结果成功克隆获得AdMn-SOD全长cDNA序列,推导编码的氨基酸序列具有Mn-SOD的保守结构特征;构建了pET32a/AdMn-SOD原核表达重组质粒,AdMn-SOD在大肠埃希菌中得到高效表达,表达的融合蛋白的分子质量单位约为40ku。结论成功克隆并表达了十二指肠钩虫锰超氧化物岐化酶基因,为进一步了解十二指肠钩虫锰超氧化物岐化酶的特性与功能奠定了基础。     

多房棘球绦虫ELP抗原在大肠埃希菌中的表达及其在免疫诊断中的初步应用

目的 实现多房棘球绦虫ELP蛋白在大肠埃希菌中的表达，制备高纯度、高特异性的重组抗原，为多房棘球绦虫感染的流行病学调查和临床诊断提供新的工具。方法 在建立了多房棘球绦虫elp基因克隆的基础上，应用亚克隆方法将目的基因插入原核非融合表达载体pQE30（＋）。经酶切鉴定，转化于大肠埃希菌，以IPTG进行诱导表达。SDS-PAGE及Western blot进行鉴定。亲和层析纯化ELP蛋白，用于ELISA检测患者血清特异性抗体。结果 酶切鉴定、SDS-PAGE及Western blot分析证实，成功地构建了pQ-ELP原核非融合表达载体，该载体转化大肠埃希菌在IPTG诱导下能高效表达ELP蛋白。ELP重组抗原用于ELISA检测18份包虫病人血清均阳性，10份华支睾吸虫病、27份乙肝病毒感染者和10份健康人血清均为阴性。结论 多房棘球绦虫ELP抗原在大肠埃希菌中得到了高效非融合表达，初步实验结果显示该重组蛋白对包虫病具有较高的诊断价值。     

日本血吸虫重组质粒pET28α-Sj32的构建及其在大肠埃希菌BL21(DE3)中的表达

目的构建日本血吸虫重组质粒pET28α-Sj32,研究该质粒在大肠埃希菌BL21(DE3)中的表达。方法超声粉碎日本血吸虫成虫,提取总RNA,通过RT-PCR扩增Sj32抗原编码基因;将该基因克隆至原核表达载体pET28α,构建重组质粒pET28α-Sj32并转化大肠埃希菌BL21(DE3),经异丙基硫代-β-D-半乳糖苷(IPTG)诱导表达后用SDS-PAGE和Western blot对表达产物进行分析和鉴定。结果RT-PCR扩增出1270bp的Sj32基因;双酶切和PCR鉴定证实Sj32基因成功插入pET28α中,SDS-PAGE分析显示表达产物为分子质量单位约为42ku的重组蛋白,与预期结果一致,表达的蛋白约占菌体总蛋白的24%;Western blot鉴定重组蛋白能被日本血吸虫感染的兔血清识别。结论成功构建了日本血吸虫重组质粒pET28α-Sj32,该质粒在大肠埃希菌BL21中获得了高效融合表达,表达的融合蛋白具有抗原特异性。     

融合基因IFN-α1b/CSPⅡ原核表达载体的构建及在大肠埃希菌中的表达

目的　构建融合基因IFN α1b/CSPⅡ的原核表达载体并予以表达。　方法　采用聚合酶链反应(PCR)从人基因组DNA中扩增出IFN α1b基因 ,克隆入原核表达载体 pGEX 4T 1,构建原核表达载体 pGEX 4T 1/IFN α1b。利用PCR法从恶性疟原虫基因组DNA中扩增出环子孢子蛋白Ⅱ区 (CSPⅡ )基因 ,克隆入原核表达载体 pGEX 4T 1,构建原核表达载体pGEX 4T 1/CSPⅡ 。用限制性内切酶BamHⅠ和EcoRⅠ将IFN α1b从原核重组质粒 pGEX 4T 1/IFN α1b中切下 ,克隆入经相同酶切的原核重组质粒pGEX 4T 1/CSPⅡ 中 ,构建融合基因的原核表达载体 pGEX 4T 1/IFN α1b/CSPⅡ。融合基因IFN α1b/CSPⅡ经异丙基 β D硫代半乳糖苷 (IPTG )诱导 ,在大肠埃希菌中进行初步表达。结果　构建的原核表达载体 pGEX 4T 1/IFN α1b、pGEX 4T 1/CSPⅡ和 pGEX 4T 1/IFN α1b/CSPⅡ经PCR和酶切鉴定与预期结果一致。证实融合基因IFN α1b/CSPⅡ拼接成功并正确地克隆入原核表达载体。在大肠埃希菌中表达出融合蛋白IFN α1b/CSPⅡ ,该融合蛋白经十二烷基磺酸钠 聚丙烯酰胺凝胶电泳 (SDS PAGE)分析与理论预测值相符。经蛋白质印迹法 (Westernblotting)鉴定具有免疫原性。　结论　构建了融合基因IFN α1b/CSPⅡ的原核表达载体 ,并在大肠埃希菌中表达了。     

弓形虫棒状体蛋白2和膜表面蛋白1融合基因的克隆与表达

目的 进行弓形虫棒状体蛋白2（ROP2）和膜表面蛋白1（P30）融合基因的克隆与表达，为弓形虫ROP2?鄄P30基因工程复合抗原的制备做准备。 方法 半套式PCR扩增编码弓形虫P30的基因片段，克隆至已构建成功的重组质粒pUC119/ROP2中，经PCR和酶切鉴定正确的重组质粒pUC119/ROP2-P30再以SacⅠ/HindⅢ双酶切克隆至表达载体pET28b上，鉴定正确的重组质粒pET28b/ROP2-P30转化大肠埃希菌表达菌株BL21-Codon Plus（DE3）-RIL，经异丙基-β-D-硫代半乳糖苷（IPTG）诱导表达。 结果 从弓形虫RH株基因组DNA中扩增出700 bp P30基因片段，成功构建重组质粒pET28b/ROP2-P30，该质粒经PCR和酶切鉴定，与预期结果一致，并在大肠埃希菌中高效表达，产生相对分子质量（Mr）约为 69 000的重组目的蛋白。 结论 弓形虫ROP2和P301融合基因克隆成功，并表达出预期的复合重组蛋白ROP2-P30。     

幽门螺杆菌金属蛋白酶原核表达载体的构建与重组表达及纯化北大核心CSCD

目的构建幽门螺杆菌(Helicobacter pylori, Hp)金属蛋白酶(metalloprotease, Mtp)基因mtp与麦芽糖结合蛋白基因mbp融合表达载体,诱导Mtp重组表达并纯化表达产物,为Hp致病机制和疫苗研究奠定基础。方法应用PCR从Hp郑州分离株MEL-Hp27的DNA扩增mtp基因,经纯化回收后与克隆载体pMD19-T连接,并进行测序验证。对重组质粒pMD19-T-mtp双酶切,酶切目的片段克隆至表达载体pMAL-c2X,然后用重组质粒pMAL-mtp转化大肠埃希菌(E.coli TB1)。从大肠埃希菌重组子中提取重组质粒,进行酶切和测序鉴定。用分光光度计测定重组菌的生长曲线。用IPTG诱导mtp表达,用SDS-PAGE法分析表达产物,并用Amylose树脂预装柱纯化Mtp蛋白。结果 PCR扩增的mtp基因片段长度为621 bp,重组菌株的酶切和测序鉴定正确;重组菌生长曲线显示重组质粒的转入对受体菌的生长无显著影响;Mtp诱导表达和纯化产物的SDS-PAGE显示,Mtp表达产物为相对分子质量为66.4×10^3的水溶性融合蛋白(rMtp),纯化产物的纯度约为85.6%。结论成功构建mtp基因与麦芽糖结合蛋白mbp基合表达载体,并纯化制备了重组蛋白,为探索Mtp在Hp感染发病机制和抗Hp感染疫苗研究奠定了基础。     

粉尘螨6类变应原（Der f6）的克隆表达、纯化及免疫学特性鉴定

目的 构建粉尘螨6类变应原（Dermatophagoides farinae，Der f6）基因的高效原核表达载体，并进行表达、纯化及生物学功能分析。 方法 根据Der f6基因已知序列，设计1对引物，通过对纯培养的粉尘螨提取总RNA，采用RT-PCR方法扩增出Der f6基因片段，PCR产物克隆入pMD18-T载体，转化大肠埃希菌（E.coli Top10），经PCR和酶切鉴定并测序。将上述所得阳性克隆菌株扩大培养，碱裂解法提取质粒，所得重组质粒pMD18-T-Der f6和空质粒pET-24a同时用限制性内切酶EcoRⅠ和XhoⅠ双酶切，经纯化后连接并转化至E.coli Top10。构建的重组质粒pET24a-Der f6经PCR、酶切和测序鉴定后，再转化至E.coli BL21（DE3）， 异丙基-β-D-硫代半乳糖苷（IPTG）诱导表达。用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）和蛋白质印迹法（Western blotting）鉴定其表达效果，用Ni+离子亲和层析柱纯化重组质粒pET24a-Der f6表达产生的组氨酸重组蛋白。 结果 构建了重组质粒pMD18-T-Der f6和pET24a-Der f6。SDS-PAGE 结果表明Der f6基因在E.coli Bl21(DE3）中获得良好的表达，所得重组蛋白相对分子质量(Mr) 为31 000, 与理论值一致, 经亲和层析纯化后，SDS-PAGE 结果显示单一条带。该蛋白以尘螨过敏患者血清进行Western blotting, 结果表明具有良好的IgE结合活性。 结论 克隆、表达并纯化了具有良好尘螨致敏患者IgE结合活性的Der f6。     

Broadly neutralizing antibodies suppress HIV in the persistent viral reservoir

Several highly potent and broadly neutralizing monoclonal antibodies against HIV have recently been isolated from B cells of infected individuals. However, the effects of these antibodies on the persistent viral reservoirs in HIV-infected individuals receiving antiretroviral therapy (ART) are unknown. We show that several HIV-specific monoclonal antibodies—in particular, PGT121, VRC01, and VRC03—potently inhibited entry into CD4⁺ T cells of HIV isolated from the latent viral reservoir of infected individuals whose plasma viremia was well controlled by ART. In addition, we demonstrate that HIV replication in autologous CD4⁺ T cells derived from infected individuals receiving ART was profoundly suppressed by three aforementioned and other HIV-specific monoclonal antibodies. These findings have implications for passive immunotherapy as an approach toward controlling plasma viral rebound in patients whose ART is withdrawn.The sustained suppression of HIV replication by antiretroviral therapy (ART) has dramatically improved the clinical outcome of infected individuals (1). In addition, research directed at potential pathways toward the development of an effective preventive HIV vaccine has provided insights into the nature of the immune response to HIV infection (2, 3). In this regard, recent advances in antibody-cloning technologies have led to the discovery of several highly potent and broadly neutralizing monoclonal antibodies against HIV from B cells of HIV-infected individuals (4–7). Of interest, several studies have demonstrated that certain broadly neutralizing HIV-specific monoclonal antibodies can prevent acquisition of the virus, suppress viral replication, delay and/or prevent plasma viral rebound following treatment interruption in infected animals (8–14), and block cell-to-cell transmission of laboratory-adapted HIV in vitro (15). However, it is unclear what in vivo effects these antibodies might have on HIV in humans and, in particular, what effects they may have on the virus contained in the persistently infected CD4⁺ T cells of individuals whose plasma viremia is controlled by ART. These infected CD4⁺ T cells are considered to be the major obstacle to viral eradication (16–18) as well as a potential source of plasma viral rebound following discontinuation of ART in patients whose viremia had been well controlled in therapy (1). In this regard, considerable efforts in current HIV therapeutic research have been focused on developing strategies aimed at achieving sustained virologic remission in the absence of ART (1). This focus is especially important given that viral rebound and sustained HIV replication has been observed in almost all infected individuals whose plasma viremia had been well controlled while receiving ART and whose ART was subsequently withdrawn (19). Therefore, it is important to determine which, if any, of the many recently characterized HIV-specific monoclonal antibodies can inhibit viral entry into CD4⁺ T cells of HIV isolated from the latent viral reservoir as well as replication of reservoir virus in autologous CD4⁺ T cells derived from infected individuals whose plasma viremia was well-controlled on ART. Such knowledge is critical to establishing novel opportunities for passive immunotherapy to prevent plasma viral rebound following discontinuation of antiretroviral drugs. We conducted the present study to address this issue.     

Protein conformational dynamics in the mechanism of HIV-1 protease catalysis

We have used chemical protein synthesis and advanced physical methods to probe dynamics-function correlations for the HIV-1 protease, an enzyme that has received considerable attention as a target for the treatment of AIDS. Chemical synthesis was used to prepare a series of unique analogues of the HIV-1 protease in which the flexibility of the "flap" structures (residues 37-61 in each monomer of the homodimeric protein molecule) was systematically varied. These analogue enzymes were further studied by X-ray crystallography, NMR relaxation, and pulse-EPR methods, in conjunction with molecular dynamics simulations. We show that conformational isomerization in the flaps is correlated with structural reorganization of residues in the active site, and that it is preorganization of the active site that is a rate-limiting factor in catalysis.     

A tyrosine-based motif in the HIV-1 envelope glycoprotein tail mediates cell-type– and Rab11-FIP1C–dependent incorporation into virions

Lentiviruses such as HIV-1 encode envelope glycoproteins (Env) with long cytoplasmic tails (CTs) that include motifs mediating interactions with host-cell–trafficking factors. We demonstrated recently that Rab11-family interacting protein 1C (FIP1C) is required for CT-dependent incorporation of Env into HIV-1 particles. Here, we used viruses bearing targeted substitutions within CT to map the FIP1C-dependent incorporation of Env. We identified YW₇₉₅ as a critical motif mediating cell-type–dependent Env incorporation. Disruption of YW₇₉₅ reproduced the cell-type–dependent particle incorporation of Env that had previously been observed with large truncations of CT. A revertant virus bearing a single amino acid change near the C terminus of CT restored wild-type levels of Env incorporation, Gag–Env colocalization on the plasma membrane, and viral replication. These findings highlight the importance of YW₇₉₅ in the cell-type–dependent incorporation of Env and support a model of HIV assembly in which FIP1C/RCP mediates Env trafficking to the particle assembly site.Lentiviruses such as HIV encode envelope glycoproteins (Envs) with long cytoplasmic tails (CTs) of 150 amino acids or more, whereas avian and murine retroviruses generally encode CTs of 20–30 residues. The reasons for this difference are not entirely clear, but may be attributable to interactions with host-trafficking pathways that define the specificity of Env incorporation into viral particles. A large number of tyrosine- and dileucine-based motifs are present in the HIV-1 Env CT, some of which have been shown to interact with factors involved in vesicular trafficking. The membrane-proximal Yxxϕ motif (Y₇₁₂) has been well studied and serves as a docking site for the μ-subunit of the clathrin adaptor AP-2 (1, 2). Disruption of this motif enhances cell-surface Env concentration, yet somewhat paradoxically reduces Env incorporation into particles and particle infectivity (3–6). Disruption of YW₈₀₂ has also been shown to reduce Env incorporation and infectivity (5, 7). The C-terminal dileucine LL₈₅₅ motif interacts with the AP-1 (8) or AP-2 (9) clathrin adaptor proteins and plays a role in endocytosis and in determining the cell-surface levels of Env. We recently performed a systematic mutagenesis of tyrosine- and dileucine-based motifs in the Env CT that confirmed the importance of Y₇₁₂ on cell-surface levels of Env (3). This study also illuminated an important region of the CT-spanning residues 795–803, in which disruption of YW or LL motifs had dramatic effects on viral replication.In an important advance to our understanding of the role of the Env CT, Murakami and Freed demonstrated that the incorporation of Env into viral particles was cell-type–dependent and that this incorporation in most T-cell lines and macrophages requires an intact long cytoplasmic tail (10). They demonstrated that Env incorporation in 293T cells did not require the long CT, nor was the CT absolutely required for incorporation in particles produced from HeLa or MT-4 cells. However, Env incorporation into particles produced from other T-cell lines and macrophages was severely impaired by CT truncation, and productive replication of virus bearing an Env with a truncated tail was possible only in MT-4 cells. This study strongly implicated host factors in the CT-dependent incorporation of Env.We recently reported that Rab11-FIP1C (FIP1C) (also known as Rab coupling protein or RCP) and Rab14 are required for Env incorporation and that the effect of FIP1C was dependent upon the Env CT (11). This suggested to us that the cell-type–dependent findings reported by Murakami and Freed (10) may be related to FIP1C-mediated transport of Env mediated through motifs on the Env CT. To test this hypothesis, we examined a panel of viruses bearing mutations of tyrosine- and dileucine-based motifs for their ability to redistribute FIP1C to the plasma membrane. We identified YW₇₉₅ as a critical motif that is required for CT-dependent FIP1C redistribution out of the endosomal recycling compartment. Remarkably, the disruption of YW₇₉₅ completely recreated the pattern of cell-type dependence on Env incorporation previously observed with CT truncation, and FIP1C depletion had no effect on the level of incorporation of this mutant Env. A downstream second-site revertant was derived that restored Env incorporation and dependence on FIP1C for particle incorporation, suggesting that YW₇₉₅ and FIP1C mediate Env incorporation in a cell-type–specific manner.     

Host Molecule Incorporation into HIV Virions,Potential Influences in HIV Pathogenesis

During the last phase of HIV viral production, nascent HIV virions acquire a fraction of the cellular lipid membrane to create the external lipid envelope, a process by which cellular proteins present on the surface of the infected cell can be incorporated along with Env trimers. Interestingly, several studies indicated that these incorporated host molecules could conserve their biological activity and consequently contribute to HIV pathogenesis either by enhancing the infectivity of HIV virions, their tissue tropism or by affecting immune cell functions. The following review will describe the main approaches used to characterize membrane bound host molecule incorporation into HIV virions, the proposed mechanisms involved, and the role of a non-exhaustive list of incorporated molecules.     

Distinct Plasma Concentrations of Acyl-CoA-Binding Protein (ACBP) in HIV Progressors and Elite Controllers

HIV elite controllers (ECs) are characterized by the spontaneous control of viral replication, and by metabolic and autophagic profiles which favor anti-HIV CD4 and CD8 T-cell responses. Extracellular acyl coenzyme A binding protein (ACBP) acts as a feedback inhibitor of autophagy. Herein, we assessed the circulating ACBP levels in ECs, compared to people living with HIV (PLWH) receiving antiretroviral therapy (ART) or not. We found lower ACBP levels in ECs compared to ART-naïve or ART-treated PLWH (p < 0.01 for both comparisons), independently of age and sex. ACBP levels were similar in ECs and HIV-uninfected controls. The expression of the protective HLA alleles HLA-B*27, *57, or *58 did not influence ACBP levels in ECs. ACBP levels were not associated with CD4 or CD8 T-cell counts, CD4 loss over time, inflammatory cytokines, or anti-CMV IgG titers in ECs. In ART-treated PLWH, ACBP levels were correlated with interleukin (IL)-1β levels, but not with other inflammatory cytokines such as IL-6, IL-8, IL-32, or TNF-α. In conclusion, ECs are characterized by low ACBP plasma levels compared to ART-naïve or ART-treated PLWH. As autophagy is key to anti-HIV CD4 and CD8 T-cell responses, the ACBP pathway constitutes an interesting target in HIV cure strategies.     

The trans-Golgi network-associated human ubiquitin-protein ligase POSH is essential for HIV type 1 production

HIV type 1 (HIV-1) was shown to assemble either at the plasma membrane or in the membrane of late endosomes. Now, we report an essential role for human ubiquitin ligase POSH (Plenty of SH3s; hPOSH), a trans-Golgi network-associated protein, in the targeting of HIV-1 to the plasma membrane. Small inhibitory RNA-mediated silencing of hPOSH ablates virus secretion and Gag plasma membrane localization. Reintroduction of native, but not a RING finger mutant, hPOSH restores virus release and Gag plasma membrane localization in hPOSH-depleted cells. Furthermore, expression of the RING finger mutant hPOSH inhibits virus release and induces accumulation of intracellular Gag in normal cells. Together, our results identify a previously undescribed step in HIV biogenesis and suggest a direct function for hPOSH-mediated ubiquitination in protein sorting at the trans-Golgi network. Consequently, hPOSH may be a useful host target for therapeutic intervention.     

HPLC-Based Purification and Isolation of Potent Anti-HIV and Latency Reversing Daphnane Diterpenes from the Medicinal Plant Gnidia sericocephala (Thymelaeaceae)

Despite the success of combination antiretroviral therapy (cART), HIV persists in low- and middle-income countries (LMIC) due to emerging drug resistance and insufficient drug accessibility. Furthermore, cART does not target latently-infected CD4+ T cells, which represent a major barrier to HIV eradication. The “shock and kill” therapeutic approach aims to reactivate provirus expression in latently-infected cells in the presence of cART and target virus-expressing cells for elimination. An attractive therapeutic prototype in LMICs would therefore be capable of simultaneously inhibiting viral replication and inducing latency reversal. Here we report that Gnidia sericocephala, which is used by traditional health practitioners in South Africa for HIV/AIDS management to supplement cART, contains at least four daphnane-type compounds (yuanhuacine A (1), yuanhuacine as part of a mixture (2), yuanhuajine (3), and gniditrin (4)) that inhibit viral replication and/or reverse HIV latency. For example, 1 and 2 inhibit HIV replication in peripheral blood mononuclear cells (PBMC) by >80% at 0.08 µg/mL, while 1 further inhibits a subtype C virus in PBMC with a half-maximal effective concentration (EC₅₀) of 0.03 µM without cytotoxicity. Both 1 and 2 also reverse HIV latency in vitro consistent with protein kinase C activation but at 16.7-fold lower concentrations than the control prostratin. Both 1 and 2 also reverse latency in primary CD4+ T cells from cART-suppressed donors with HIV similar to prostratin but at 6.7-fold lower concentrations. These results highlight G. sericocephala and components 1 and 2 as anti-HIV agents for improving cART efficacy and supporting HIV cure efforts in resource-limited regions.     

The individual and combined influence of HIV and hepatitis C virus on dyslipidaemia in a high-risk Hispanic population

Objectives

To assess the effects of chronic hepatitis C (HCV) and HIV infection on dyslipidaemia in a Hispanic population at high risk of insulin resistance.

Methods

We compared serum lipids and C‐reactive protein (CRP) in 257 Hispanic adults including 47 HIV‐ mono‐infected, 43 HCV‐mono‐infected and 59 HIV/HCV‐co‐infected individuals as well as 108 healthy controls. We also assessed the effect of HCV on lipid alterations associated with antiretroviral therapy (ART), and the impact of HCV and HIV on the associations among insulin resistance, triglycerides and cholesterol.

Results

HCV infection was associated with lower total and low‐density lipoprotein (LDL) cholesterol, but not high‐density lipoprotein (HDL) cholesterol or triglycerides compared with healthy controls. HIV infection was associated with higher triglycerides and lower HDL, but not total or LDL cholesterol. HCV mitigated the elevation of triglycerides associated with ART. In healthy Hispanic adults, insulin resistance was significantly correlated with higher triglycerides, CRP and lower HDL. HIV infection nullified the association of insulin resistance with triglycerides and HDL, and the association of triglycerides with LDL. HCV infection nullified the association of insulin resistance with triglycerides, HDL and CRP.

Conclusions

HCV co‐infection alters the profile of HIV‐associated dyslipidaemia. The clinical significance of these findings for cardiovascular complications in HIV merits further study.     

Influence of a monocyte chemoattractant protein 1 mutated allele on the response to protease inhibitor-based antiretroviral therapy

Background

Antiretroviral drug efficacy has been widely studied in relation to viral factors. Mutations in the HIV co‐receptors and their natural chemokines, however, may be critical in HIV infection and treatment response. We compared the efficacy of protease inhibitor (PI) treatment among PI‐naïve patients grouped according to whether they carried the chemokine CC motif receptor 2 (CCR‐2) 64I and monocyte chemoattractant protein 1 (MCP‐1)–2518G alleles.

Methods and results

HIV‐infected patients who were PI‐naive were selected for the study (n=164) but there was no restriction on lymphocyte CD4 count or plasma HIV viral load. Follow‐up was for the first 24 months of treatment. Clinical and laboratory data were obtained every 3 months. All the participants were genotyped for the MCP‐1–2518G, CCR‐2 64I, CCR‐5Δ32 and stromal derived factor 1 (SDF1) 3′A mutated alleles. The results indicated that patients carrying the mutated allele of MCP‐1 had a higher mean CD4 cell count throughout the follow‐up period than those with the common allele (P=0.01). Also, patients with the MCP‐1 and CCR‐2 mutated alleles were more likely to continue to have an undetectable viral load following treatment (P=0.05).

Conclusion

A better response to PI treatment appears to be conferred by mutations in the host MCP‐1 and CCR‐2 genes, and may be related to the cellular axis‐of‐entry used by the retrovirus.