Construction and characterization of a chimeric virus (BIV/HIV-1) carrying the bovine immunodeficiency virus gag-pol gene.

HIV-1(HXB2) 5'LTR region, most of BIV(R29) gag-pol segment and HIV-1(HXB2) pol IN-3'LTR region were respectively amplified. A chimeric clone, designated as pHBIV(3753), was constructed by cloning three fragments sequentially into pUC18. MT4 cells were transfected with pHBIV3753. The replication and expressions of the chimeric virus (HBIV3753) were monitored by RT activity and IFA. The results firstly demonstrated that it is possible to generate a new type of the BIV/HIV-1 chimeric virus containing BIV gag-pol gene.     

Emergence of new forms of human immunodeficiency virus type 1 intersubtype recombinants in central Myanmar

We have previously shown that HIV-1 env subtypes B' (a Thai-B cluster within subtype B) and E (CRF01_AE) are distributed in Yangon, the capital city of Myanmar. However, HIV strains from the rest of country have not yet been genetically characterized. In the present study, we determined env (C2/V3) and gag (p17) subtypes of 25 specimens from central Myanmar (Mandalay). Phylogenetic analyses identified 5 subtype C (20%), in addition to 10 CRF01_AE (40%) and 4 subtype B' (16%). Interestingly, the remaining six specimens (24%) showed discordance between gag and env subtypes; three gag subtype B'/env subtype C, one gag subtype B'/env subtype E, one gag subtype C/env subtype B', and one gag subtype C/env subtype E. These discordant specimens were found frequently among injecting drug users (4 of 12, 33%) and female commercial sex workers (2 of 8, 25%) engaging in high-risk behaviors. The recombinant nature of these HIV-1 strains was verified in three specimens, indicating the presence of new forms of HIV-1 intersubtype C/B' and C/B'/E recombinants with different recombination breakpoints. The data suggest that multiple subtypes of B', C, and CRF01_AE are cocirculating in central Myanmar, leading to the evolution of new forms of intersubtype recombinants among the risk populations exhibiting one of the highest HIV infection rates in the region.     

中国人类免疫缺陷病毒-1 vpr基因多态性及其临床意义

目的 分析来自中国不同地区HIV-1感染者的vpr基因序列变异位点及与国外以往研究的异同,为进一步研究HIV-1 vpr基因变异的意义及其与感染者临床病情的关系奠定基础.方法 RT-PCR及套式PCR法对398例HIV-1感染者行HIV-1 vpr基凶扩增,并进行氨基酸序列分析,了解HIV vpr基冈的多念性、离散率和常见变异位点.同时将发现常见变异位点感染者的相应病毒水平、淋巴细胞亚群及临床病程的进展进行对比分析.结果 对398份血标本行HIV-1 vpr基因扩增,分析后可用氨基酸序列为153份.HIV-1 Vpr氨基酸序列分型主要足CRF01_AE 51,63%,C亚型24.84%,B亚型17.65%,CRF03_AB 3.92%,CRF08_BC 1.31%.HIV Vpr序列中第77位氨基酸84.3%为谷氨酸,与以往国外报道的R77Q变异与AIDS长期病情无进展(LTNP)璃彳切卡廿关的观点有明显差异.HIV Vpr第、63、70、85、86、89、94位氨基酸的变异,有可能使感染者的临床进展趋缓.结论 我围HIV Vpr分型仍以M组为主,其中 CRF01_AE占优势.HIV-1 Vpr中氨基酸序列某些位点的变异可能与感染者临床表现相关.     

Full-length genome analysis of human immunodeficiency virus type 1 subtype C in Brazil

The most prevalent HIV-1 clade in the global epidemics is C, and this clade is also becoming important in the Brazilian epidemics. In this study, we characterized HIV-1 subtype C variants by sequencing their near full-length genomes. DNA was extracted from six samples previously classified in our laboratory as subtype C on the basis of partial genome sequencing. Amplification was carried out by overlapping PCR followed by direct sequencing. Phylogenetic analysis of full length genomes confirmed that all isolates belonged to subtype C, which formed a highly supported monophyletic cluster and showed a nucleotide distance of 5.4%. The core promoter of all isolates contained three NF-kappaB binding motifs. Our results suggest that subtype C viruses circulating in Brazil were likely introduced recently from a unique point source. The independent clustering of Brazilian subtype C on the phylogenetic tree suggests the profile of an ideal local candidate for the development of a single subtype vaccine.     

Structural prerequisites for intersubtype B and D antigenicity of the third variable envelope region (V3) of human immunodeficiency virus type 1

To elucidate the structural requirements for intersubtype antigenicity of human immunodeficiency virus type 1 (HIV-1) third variable envelope region (V3), synthetic peptides were used in enzyme immunoassays (EIAs) with serum samples from persons with proven or probable subtype B and D infections. Mathematical analyses of results from EIAs with singly substituted V3 peptides revealed important residues determining overall N-terminal V3 peptide antigenicity. This information was used to design V3 immunogens, rabbit antiserum to which were tested in EIA and for in vitro neutralization of molecular clones of HIV-1(MN) and HIV-1(MAL). Intersubtype-reactive epitopes were distributed toward the N-terminal half of the V3 loop. Lysine at position 310, arginine at position 311, and isoleucine at position 314, all derived from the MN primary sequence, were major determinants of intersubtype V3 antigenicity. Combinations of residues that enhanced antigenicity often contained lysine at position 310. Threonine at position 308 was common in the least advantageous combinations. V3 immunogens modified to achieve optimal antigenicity induced antiserum with augmented cross-neutralization of virus from MAL and MN molecular clones, suggesting one approach to subunit vaccine development.     

Understanding human immunodeficiency virus type 1 and hepatitis C virus coinfection

In recent years, there has been an alarming increase in the number of cases of coinfection with the human immunodeficiency virus type 1 (HIV-1) and the hepatitis C virus (HCV). It is now known that coinfection of HIV-1 patients by HCV can complicate the treatment of these patients with highly active antiretroviral therapy and the interactions between anti-HIV-1 and anti-HCV medications can also affect treatment efficacy and efficiency. Equally concerning, the bidirectional interferences between the two viruses are complex and can modify the natural history of both infections. This review aims to summarize the findings of numerous scientific investigations in the area of HIV/HCV coinfection. These investigations can be broadly classified into 3 groups; (a) immune evasion mechanisms (b) viral evolution and quasispecies diversity and (c) functions of viral proteins and their interactions with host factors. Our cumulative knowledge in this area and future research on the interplay between these two viruses will be important to the development of better antiviral therapeutics.     

A new human immunodeficiency virus type 1 circulating recombinant form from Tanzania

It is becoming increasingly important to identify and to study human immunodeficiency virus type 1 (HIV-1) circulating recombinant forms (CRFs) with evidence of epidemic spread, since mosaic strains arise frequently, especially in populations where multiple subtypes cocirculate. We describe the almost complete nucleotide sequence of 3 subtype C and D recombinant viruses, selected from a pool of 13 D(gag)-D/C/D(env) perinatally infected infants from Dar es Salaam, Tanzania. All three genomes had cross-over points with approximately the same genomic localization. The subtype C-like sequences were located within pol, vif, vpr, vpu, the first exons of rev and tat, V3, and the U3-R regions of the LTR. Phylogenetic analyses of the full-length genomic sequences from these viruses showed the formation of a distinct subcluster on the HIV-1 subtype D branch. The pattern of recombination of genomes belonging to this new CRF, named CRF10_CD, might have resulted from independent recombination events occurring at high frequency or from a single source that originated earlier in this population. Future surveys will be needed to determine the potential of this CRF for epidemic spread.     

RNA secondary structure and squence conservation in C1 region of human immunodeficiency virus type 1 env gene

We have analyzed amino acid, nucleotide sequence, and RNA secondary structure variability in the env gene of human immunodeficiency virus type (HIV-1). In applying algorithms for computing optimal RNA-folding patterns to a nonredundant data set of 178 env nucleotide sequences, we found a conserved RNA stem-loop structure in the first conserved (C1) region of the env gene. This detailed examination also revealed the known secondary structure conservation of the Rev-responsive element (RRE). This finding is also supported by a higher third position conservation of the translatable reading frame along these subregions. The typical folding of the C1 region consists of two isolated stem-loop structures. These highly conserved structures are likely to have a biological function. This assumption is supported by the conservation of the third position along the coding region of these structures. The third position retains a conservation level above what would be statistically expected.     

CRF07-BC亚型HIV的gag-pol区基因序列分析

目的对2株人类免疫缺陷病毒1型(HIV-1)CRF07-BC亚型病毒的完整gag基因和部分pol基因进行基因重组和耐药位点突变分析。方法从确诊的HIV感染者的全血样本中提取基因组DNA,经套式聚合酶链反应(Nested-PCR)扩增后,将扩增产物进行纯化和测序,然后将所得序列进行系统进化树和氨基酸变异分析。用Simplot软件进行序列重组分析以确定重组断点区域,并分析其pol基因的耐药位点突变。结果在所研究的基因区段内,2份样本均未发现重组断点的变化,在蛋白酶区(PR)出现2个次要耐药相关突变,而未发现主要耐药相关突变。结论所研究的2株HIV-1CRF07-BC亚型病毒与在我国新疆地区广泛流行的CRF07-BC模式毒株非常接近,且不存在天然耐药的情况,适于抗逆转录类药物的应用。     

Genetic subtypes of human immunodeficiency virus type 1 (HIV-1) in Istanbul, Turkey.

BACKGROUND: Epidemiological surveillance of HIV-1 subtypes is an important and ongoing element of preparation for global antiviral interventions. OBJECTIVE: To assess the molecular epidemiology of HIV-1 in Istanbul, Turkey. STUDY DESIGN: 27 HIV/AIDS patients were investigated. Data on age, sex, country of birth, and HIV acquisition route were collected. Following amplification with PCR the sequences of the gp41 region of the env gene were determined using a 310 DNA sequencer (ABI prism, Foster City, USA) and phylogenetically analyzed. RESULTS: Among the 27 patients (26 adults and 1 infant), 22 were male, born in Turkey, and 20 infected through heterosexual contact. Two patients acquired the virus through blood and/or blood transfusion and one infant by vertical transmission. The distribution of the subtypes was as follows: four were subtype A, 19 subtype B, one subtype C, one subtype D, and two subtype F1. According to our results, although the B subtype is still predominant, non-B subtypes are also present, even though the number of registered HIV/AIDS patients is low. CONCLUSION: These are the first subtyped HIV-1 strains in Turkey where a low level of HIV prevalence has been observed since the first reported case in 1985. These findings and Turkey's specific geographic localization indicate the need for a nationwide surveillance to detect all subtypes including the new recombinant ones.     

Hepatic encephalopathy in primary human immunodeficiency virus type 1 (HIV-1) infection

Primary infection of human immunodeficiency virus type 1 (HIV-1) is occasionally associated with common cold-like symptoms, and rarely with a self-limited illness resembling infectious mononucleosis. We report a 32-year-old man who presented with infectious mononucleosis-like blood picture on admission. Five days after admission he developed hepatic encephalopathy, which was ameliorated by administration of bolus corticosteroid. Based on the results of serologic studies, we diagnosed that he had primary HIV-1 infection. To our knowledge, this is the first published report of hepatic encephalopathy as a clinical manifestation of primary HIV-1 infection.     

Variation characteristics of gag gene of human immunodeficiency virus type 1 strain in the main epidemic areas of acquired immunodeficiency syndrome in Yunnan Province

<正>Objective To analyze the variation characteristics of gag gene sequence of human immunodeficiency virus type 1 (HIV-1) epidemic strains in four major acquired immunodeficiency syndrome (AIDS) endemic areas in Yunnan Province. Methods A total of 480 human immunodeficiency virus (HIV)/AIDS patients from designated antiviral treatment institutions in Kunming City,Dehong Dai and Jingpo Autonomous Prefecture,Hani-Yi Autonomous Prefecture of Honghe and Lincang City in Yunnan Province from Jan...     

Molecular epidemiology of human immunodeficiency virus type 1 and hepatitis C virus in former blood donors in central China

The prevalence of hepatitis C virus (HCV) among human immunodeficiency virus (HIV-1)-positive former blood donors (FBDs) in Hubei province, central China, and the subtypes of these two viruses are identified. HIV-1-positive specimens were collected from FBDs, transfusion recipients, and their sexual partners in Hubei province, central China. The prevalence of HCV in HIV-1-positive FBDs was 78.6%. The dominant circulating HIV-1 subtype of FBDs was subtype B' (Thai-B); one belonged to U.S.-European subtype B. HCV genotypes 2a (78.6%) and 1b (21.4%) were detected. No recombinant form of HIV-1 was identified. Non-B' subtypes occurring among FBDs indicate the complexity of the HIV-1 prevalence in central China, where HIV is beginning to spread into the general population.     

河南及上海患者的HIV-1 gag基因p24蛋白编码序列及亚型初步分析

目的了解河南及上海地区人类免疫缺陷病毒(HIV)感染者p24蛋白编码区的基因变异性以及亚型的分布状况.方法收集37份HIV-1感染患者的血浆标本,河南25份,感染途径主要是有偿供血;上海12份,主要是血制品感染及性接触感染.采用逆转录和套式聚合酶链反应(PCR)扩增并直接测序,然后进行序列比对及进化树分析.结果83.8%(31/37)为B亚型,河南患者中23例为B亚型,2例为A亚型;上海患者中8例为B亚型,1例为A亚型,2例为CRF01-AE亚型,1例为CRF02-AG亚型.与国际共享序列相比,B亚型p24编码区中发生核苷酸改变的位点比例河南为1.6%～4.2%,平均3 2%;上海为2.0%～3.8%,平均3.4%.在所有变异位点中均未发现连续G-＞A的高度突变.两组B亚型内平均基因离散率分别为3.7%和3.5%,B亚型与其他亚型之间的基因离散率则为11.1%～12.5%.河南及上海地区B亚型共享序列与国际共享序列进行比对,氨基酸变异的比例均为2.2%(5/231),其中有3个变异位点相同,分别为A14P、191V及E180D,而这两个共享序列之间的差异仅为0.9%(2/231).进化树分析亦表明所有样本中大多为B亚型,且与源自泰国的B'亚型相距较近.结论河南及上海地区的B亚型之间有较高的同源性,p24蛋白有共同的氨基酸变异位点.     

Friend strain of spleen focus-forming virus is a recombinant between ecotropic murine type C virus and the env gene region of xenotropic type C virus.

The spleen focus-forming virus (SFFV), a replication-defective murine leukemia virus that causes the rapid transformation of certain hematopoietic target cells, has acquired specific xenotropic viral genetic information not contained in Friend helper virus. In the current studies, it is shown that a cDNA that represents a xenotropic virus portion of SFFV detects genetic sequences derived from the env gene region of murine xenotropic virus. The significance of the acquisition of these xenotropic viral sequences by SFFV is discussed with regard to their possible role in the rapid leukemogenicity of SFFV, and an analogy is drawn between the formation of SFFV and the formation of the Kirsten and Harvey sarcoma viruses.