BACKGROUNDConstruction of replication-deficient recombinant adenovirus expressing gag-pol and env genes of human immunodeficiency virus (HIV) in mice.

METHODSgag-polDelta and gp140TM genes were cloned into shuttle vector pAdTrack-CMV respectively, and then the plasmids containing gag-polDelta or gp140TM gene were cotransformed with the backbone of adenovirus into E.coli BJ5183. Transfections of the recombinants were performed to obtain recombinant adenoviruses. Its immunogenicity was evaluated by testing antibody levels of mice primed with DNA vaccines and boosted with recombinant adenoviruses.

RESULTSThe replication-deficient recombinant adenovirus could express Gp140TM, Gag P55 and P24 proteins correctly. The mice primed with DNA vaccines and boosted with recombinant adenoviruses elicited high titer of HIV-1-specific antibody compared with that inoculated with DNA vaccines only.

CONCLUSIONReplication-deficient recombinant adenovirus expressing gag-polDelta and gp140TM can elicit high titer HIV-1-specific antibodies.

AIDS Vaccines ; immunology ; Adenoviridae ; genetics ; Animals ; Female ; Fusion Proteins, gag-pol ; biosynthesis ; genetics ; Gene Products, env ; biosynthesis ; genetics ; HIV-1 ; genetics ; immunology ; Mice ; Mice, Inbred BALB C ; Recombination, Genetic ; Transfection ; Vaccines, DNA ; immunology ; env Gene Products, Human Immunodeficiency Virus

Strict regulation of HIV-1 PR function is critical for efficient production of mature viral particles. During viral protein expression and viral assembly, HIV-1 PR located within Gag-Pol precursor must be inactive to prevent premature cytoplasmic processing of the viral Gag and Gag-Pol precursors. Premature activation of HIV-1 precursors leads to major defects in viral assembly and production of viral particles. A cell-level premature activation of HIV-1 precursors assay using bioluminescence resonance energy transfer (BRET) was established. Three thousand compounds were screened to evaluate this assay. The results showed that the assay is sensitive, specific and stable (Z' factor is 0.905).
Anti-HIV Agents ; pharmacology ; Benzoxazines ; pharmacology ; Bioluminescence Resonance Energy Transfer Techniques ; methods ; Fusion Proteins, gag-pol ; genetics ; metabolism ; HEK293 Cells ; HIV Protease ; metabolism ; physiology ; HIV-1 ; enzymology ; High-Throughput Screening Assays ; methods ; Humans ; Plasmids ; genetics ; Protein Precursors ; metabolism ; physiology ; Pyridazines ; pharmacology ; Transfection ; Virion ; growth & development ; Virus Assembly ; gag Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism

To study the CTL antigen epitopes and drug resistance mutations of HIV-1 gag and pol genes through analyzing gag and pol gene sequences. The HIV-1 gag and pol gene fragments were amplified using nested polymerase chain reaction. A total of 23 PCR sequences, 449 cloned gag sequences and 402 cloned pol sequences were obtained. Sequence analyses showed the 23 samples were subtype B or B'. A total of 4 in 8 CTL antigen epitopes appeared 8 mutations in consensus sequence of subtype B and B'. There were no mutations found in the PCR sequences, whereas a few mutations were found in clone sequences (9.80%) in 5 antigen epitopes in p24 region. Eighteen PIs-related mutations and 24 RTIs-related mutations were found in PCR sequences and clone sequences in pol gene region, in which 17 (94.44%) PIs-related mutations and 15 (62.50%) RTIs-related mutations were found only in the clone sequences, respectively. The results showed that the prevalence of HIV-1 drug resistance strains in this study was at a higher level (17.39%), suggesting that some samples were resistant.to existing antiviral drugs.
Antigens, Viral ; immunology ; DNA Mutational Analysis ; Drug Resistance, Viral ; genetics ; Epitopes ; immunology ; HIV-1 ; classification ; drug effects ; genetics ; immunology ; Human Immunodeficiency Virus Proteins ; genetics ; Mutation ; Phylogeny ; T-Lymphocytes, Cytotoxic ; immunology ; gag Gene Products, Human Immunodeficiency Virus ; genetics ; pol Gene Products, Human Immunodeficiency Virus ; genetics

OBJECTIVETo investigate the subtype distribution and the prevalence of sequence characteristics of HIV-1 strains in Beijing residents during 2006 and to analyze the relationship between distribution of HIV-1 subtypes and transmission routines.

METHODSBlood samples from 32 new confirmed HIV-1 infected individuals from Beijing residents in 2006 and separated plasma specimens were collected. RNAs were extracted and the gag and env gene were amplified by RT-PCR and nest-PCR. PCR products were sequenced directly and phylogenetic analyses of gag and env gene were performed using the MEGA2 software.

RESULTSAmong 32 HIV-1 plasma samples, 22 gag and 4 env gene fragments were amplified and analyzed. Five HIV-1 subtypes or circulating recombinant forms(CRFs) of HIV-1 including Thai B (2 strains), B (9 strains), C (2 strains), CRF07_BC (5 strains), CRF01 AE (4 strains) were identified being circulated in Beijing. The gene divergences of gag gene inside the subtypes were 6.6%, 4.3%, 6.8%, 4.9% and 3.0% in subtype B, Thai B, C, CRF01_AE and CRF07_BC respectively. Subtypes B were predominant in Beijing, accounted for 40.9% among 22 samples.

CONCLUSIONFive HIV-1 subtypes were identified in Beijing and the surveillance of HIV-1 gene variation should be paid more attention to.

China ; HIV-1 ; classification ; genetics ; Humans ; Polymerase Chain Reaction ; Reverse Transcriptase Polymerase Chain Reaction ; env Gene Products, Human Immunodeficiency Virus ; genetics ; gag Gene Products, Human Immunodeficiency Virus ; genetics

This study aims to compare the influence of different genes to the results of HIV-1 subtype B' phylogenetic analyses. We first split 47 near full-length genome sequences of subtype B' into different regions (gag, pol, vif, vpr, vpu, env, nef), which derived from various risk populations and geographic regions from Thailand, Myanmar and China from published studies. Phylogenetic analyses were performed to each region obtained. The phylogenetic results of different regions were compared to that of the near full-length genome sequences. The pol gene was found to have the lowest diversity and evolutionary rate, and could repeat the phylogenetic results by using near full-length genome sequences. Although the env gene has the highest diversity and evolutionary rate, it could not achieve the similar results. This study compared the influence to the results of HIV-1 subtype B' phylogenetic analyses by using different genes and laid foundation for further molecular survey and analyses of the transmission of subtype B' in China.
Amino Acid Sequence ; China ; epidemiology ; Cluster Analysis ; Genes, Viral ; genetics ; HIV-1 ; classification ; genetics ; Molecular Epidemiology ; Molecular Sequence Data ; Phylogeny ; pol Gene Products, Human Immunodeficiency Virus ; chemistry ; genetics

OBJECTIVETo investigate the distribution and proportion of subtypes of pol gene in HIV-1 epidemic strains in Guangxi Autonomous Region.

METHODS152 HIV-1 patients were enrolled from 11 cities in Guangxi Autonomous Region from 2010 to 2012 by convenient sampling. Inclusion criterias were listed as the fdlowing: HIV-1 infection was confirmed by Western blot, HIV-1 viral load >1 000 copies/ml, > 18 year-old, and without any serious illnesses. 5 ml of peripheral blood samples were obtained from each patient. The viral RNA was isolated from plasma and used for amplification of full-length pol gene by nested RT-PCR. The amplified products were sequenced. After editing and modification, all sequences were characterized for preliminary subtyping by genotyping and confirmed with phylogenetic tree constructed by MEGA 5.03 software. The recombinant identification of 2 unknown recombinant strains was determined by RIP and jpHMM at GOBICS.

RESULTSAmong 152 patients, 137 full-length pol genes were successfully amplified and 127 HIV-1 subtypes were identified. The distribution and proportion of subtypes was summarized as the following 71 cases of CRF01_AE, accounting for 55.9% (71/127), 38 CRF08_BC, 29.9% (38/127), 13 CRF07_BC, 10.2% (13/127), and 3 B (B'), 2.4% (3/127), 2 unknown recombinant strains, 1.6% (2/127). In 11 cites of Guangxi Autonomous Region, subtype CRF01_AE was the dominant strain. Among heterosexual transmitted patients and drug abusers, the proportions of subtype CRF01_AE were 67.4% (58/86) and 34.1% (14/41), respectively. There was a significance different in the distribution of CRF01_AE in different routes of transmission (χ(2)=15.07, P<0.001). In age 21- 35, age 36- 60 and age>60 groups, the proportions of CRF01_AE was 43.6% (17/39), 57.6% (38/66), 77.3% (17/22), and CRF08_BC was 43.6% (17/39), 28.8% (19/66), 9.1% (2/22), respectively, the difference in proportions was significant(χ(2)=8.48, P= 0.014). The patterns of two unknown recombinant strains were found to be CRF01_AE/B (B') and CRF01_AE/C/B(B'), respectively.

CONCLUSIONCRF01_AE was the dominant HIV-1 subtype in Guangxi Autonomous Region from 2010 to 2012, with heterosexual transmission as its main spreading route. The two unknown recombinant strains in Guangxi Autonomous Region were reconstructed by subtype CRF01_AE and CRF_BC.

Blotting, Western ; China ; epidemiology ; Cities ; Drug Users ; Genes, pol ; Genotype ; HIV Infections ; epidemiology ; transmission ; virology ; HIV-1 ; genetics ; Humans ; Phylogeny ; Polymerase Chain Reaction ; RNA, Viral ; blood ; pol Gene Products, Human Immunodeficiency Virus ; genetics

Objective: To understand the epidemiological characteristics of one large HIV molecular transmission cluster in Jiaxing city, Zhejiang province, 2017 in order to select those people under high-risk and providing basis for programs on prevention. Methods: During 2017, newly diagnosed HIV/AIDS cases in this city were recruited. Plasma samples were collected from subjects, followed by RNA extraction, RT-PCR and nest-PCR for pol gene amplification, before being sequenced and aligned. Mega 6.0 software was used to construct phylogenetic tree, and Cytoscape 3.6.0 software was used to identify HIV molecular transmission clusters. Cases within the large transmission clusters were investigated, using a field-epidemiology-questionnaire. Data related to socio-demographics and previous sexual behaviors were collected and EpiData 3.0 and SPSS 20.0 software were used. Results: In the large transmission cluster with subtype identified as CRF07_BC, in Jiaxing, 2017, 26 cases of the total 30 cases were investigated. A total of 80.8% (21/26) could be identified as newly infected within the last two years and 30.8%(8/26) could be identified as newly infected within the last one year, including 22 cases infected locally. Among several infected cases who were at age 45 years or older, they admitted that they had experienced unprotected sexual contacts in local city for long time and having had more than 10 disclosed sexual contacts within the last two years at the local venues. Conclusions: This molecular cluster had been formed and scaled up quickly in recent two years, it has played an important role in promoting and scaling up the HIV transmission. Three cases identificed as high risk played an importantrde role in scaling up this cluster.
Amplified Fragment Length Polymorphism Analysis ; China/epidemiology* ; Genes, pol ; Genotype ; HIV Infections/transmission* ; HIV-1/isolation & purification* ; Humans ; Molecular Epidemiology ; Phylogeny ; Polymerase Chain Reaction ; RNA, Viral/blood* ; Sexual Behavior ; pol Gene Products, Human Immunodeficiency Virus

OBJECTIVETo understand the relationship between the HIV-1 viral sequence variation and host factors associated with HIV-1 disease progression.

METHODSEnv and gag fragments of HIV-1 were amplified with PCR, cloned and sequenced. Bioinformatics was employed to find the genetic variation, N-linked glycosylation, hypermutation etc. Host gene polymorphism was analysed by using restricted fragment length polymorphism (RFLP).

RESULTSSignificant difference was found in genetic divergence between Env PCR dominant and clonal sequences (0.1 and 0.06, respectively) in non-treated group, but no significant difference was found in the HAART treated group. V3 GPGQ accounted for the most part in both treated and nontreated groups, rare V3 loop such as GPGH, GQGR and GLGR was found in treated group, V3 substitutions of I/V (position 12) and Y/H (position 21) was associated with the relatively rapid progression (RRP). Glycosylation was significantly higher in RRP than in TP for Env region, GA substitution in RRP was also significantly higher than that in TP group. SDF1-3primeA and CCR2 V64I gene frequency was higher in TP than in RRP, but the difference was not significant.

CONCLUSIONDisease progression was associated with V3 AA change, glycosylation and GA substitution in env gene. SDF1-3primeA, CCR2 V64I and CX3CR1 V249I/M280T was not associated with disease progression significantly.

Adult ; Disease Progression ; Female ; Genetic Variation ; Glycosylation ; HIV Infections ; pathology ; virology ; HIV-1 ; classification ; genetics ; isolation & purification ; metabolism ; Humans ; Male ; Phylogeny ; Polymorphism, Genetic ; Receptors, Chemokine ; genetics ; env Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism ; gag Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism

Proteolytic processing of viral polyproteins is indispensible for the lifecycle of coronaviruses. The main protease (M(pro)) of SARS-CoV is an attractive target for anti-SARS drug development as it is essential for the polyprotein processing. M(pro) is initially produced as part of viral polyproteins and it is matured by autocleavage. Here, we report that, with the addition of an N-terminal extension peptide, M(pro) can form a domain-swapped dimer. After complete removal of the extension peptide from the dimer, the mature M(pro) self-assembles into a novel super-active octamer (AO-M(pro)). The crystal structure of AO-M(pro) adopts a novel fold with four domain-swapped dimers packing into four active units with nearly identical conformation to that of the previously reported M(pro) active dimer, and 3D domain swapping serves as a mechanism to lock the active conformation due to entanglement of polypeptide chains. Compared with the previously well characterized form of M(pro), in equilibrium between inactive monomer and active dimer, the stable AO-M(pro) exhibits much higher proteolytic activity at low concentration. As all eight active sites are bound with inhibitors, the polyvalent nature of the interaction between AO-M(pro) and its polyprotein substrates with multiple cleavage sites, would make AO-M(pro) functionally much more superior than the M(pro) active dimer for polyprotein processing. Thus, during the initial period of SARS-CoV infection, this novel active form AOM(pro) should play a major role in cleaving polyproteins as the protein level is extremely low. The discovery of AOM(pro) provides new insights about the functional mechanism of M(pro) and its maturation process.
Coronavirus ; metabolism ; Cysteine Endopeptidases ; Endopeptidases ; metabolism ; Humans ; Peptides ; chemistry ; metabolism ; Polyproteins ; chemistry ; metabolism ; Protein Binding ; SARS Virus ; chemistry ; metabolism ; Viral Proteins

Objective: To understand prevalence and transmission of transmitted drug resistance (TDR) among HIV infected men who have sex with men (MSM) in Tianjin from 2014 to 2017. Methods: A total of 225 blood samples were collected from HIV infected MSM in Tianjin from 2014 to 2017. Pol gene fragments were obtained by viral RNA extraction and nested PCR amplification. Phylogenetic and drug resistance analyses were conducted. Results: A total of 205 samples were successfully sequenced and analyzed. Based on pol sequences, 53.2% (109/205), 28.8% (59/205), 10.2% (21/205), 4.9% (10/205) and 2.9% (6/205) of the samples were positive for HIV subtypes CRF01_AE, CRF07_BC, B, CRF55_01B and unique recombinant forms (URFs). Twenty transmission clusters, including 75 sequences, were identified and 62.5% (10/16) of sequences with TDR were in 5 clusters. The prevalence of TDR was 7.8% between 2014 and 2017. The annual prevalence rate increased from 3.9% (2/51) in 2014, 5.7% (3/53) in 2015, 9.6% (5/52) in 2016 to 12.2%(6/49) in 2017, the difference was not significant (χ(2)=2.504, P=0.127). CRF01_AE and B strains had high TDR prevalence (3.4%, 7/205) and (2.9%, 6/205), respectively. The TDR mutation was mainly NNRTIs, the TDR prevalence was 6.3% (13/205). In contract, the TDR prevalence of NRTIs and PIs were 1.5% (3/205) and 1.0% (2/205) respectively. Conclusion: Results from this study suggested that the prevalence of HIV-1 TDR strains in MSM was serious in Tianjin. It is necessary to take effective prevention and control measures.
China ; Drug Resistance, Viral/genetics* ; Genes, pol ; Genotype ; HIV Infections/transmission* ; HIV Reverse Transcriptase/genetics* ; HIV Seropositivity/genetics* ; HIV-1/isolation & purification* ; Homosexuality, Male/statistics & numerical data* ; Humans ; Male ; Mutation ; Phylogeny ; Polymerase Chain Reaction ; Prevalence ; RNA, Viral/genetics* ; pol Gene Products, Human Immunodeficiency Virus/genetics*