• Title/Summary/Keyword: nef sequences

Search Result 8, Processing Time 0.021 seconds

Phylogenetic Analysis of the HIV-1 nef Gene from Korean Isolates

  • Lee, Dong-Hun;Yeup Yoon;Lee, Chan-Hee
    • Journal of Microbiology
    • /
    • v.41 no.3
    • /
    • pp.232-238
    • /
    • 2003
  • Previous phylogenetic studies on human immunodeficiency virus type 1 (HIV-1) isolated from Korean patients suggest that the major subtype of Korean isolate is subtype B. In this subtype, some of the Korean isolates seem to be clustered exclusively of foreign isolates. Presence of this so-called “Korean clade” among Korean isolates is unique but needs verification since the number of Korean isolates used in previous studies was limited. This study aimed to identify the presence of the “Korean clade” by molecular phylogenetic analysis using all the Korean nef gene sequences registered in the NCBI GenBank (N=243) together with 32 reference strains and 77 foreign isolates. Extensive analysis of the nef gene nucleotide sequences by neighbor-joining method revealed the following. Most (83.1 %) of the Korean isolates belonged to subtype B, and 81.2% of subtype B were clustered together and excluded foreign isolates (bootstrap value=91.9% ). Within Korean subtype B cluster, no characteristic subcluster formation was evident since the bootstrap values for the subcluster were very low. Due to limited information, the phylogenetic analysis failed to identify the epidemiological linkage among specific groups such as homosexuals and hemophiliacs within the Korean subtype B cluster. Detailed analysis and epidemiological information are needed to clarify the origin and significance of the Korean subtype B cluster.

Korean Red Ginseng-intake has Definite Clinical Usefulness and causes Nef Gene Variation including High Frequency of Deletion

  • Cho Young Keol;Lee Hee Kyung;Ahn Sun Hee;Lee Hee Jung;Nam Ki Yeul
    • Proceedings of the Ginseng society Conference
    • /
    • 2002.10a
    • /
    • pp.185-211
    • /
    • 2002
  • We have found many beneficial effects of the long-tenn intake of Korean red ginseng (KRG) in human immunodeficiency virus (HIV) type-I infected patients, including the maintenance of CD4+ T cell count for 10 years with KRG only and the delayed development of resistance mutation to ZDV. In this study, to investigate whether KRG-intake could affect the clinical progression and nef gene variation, we determined 200nef sequences from 70 patients. Follow-up period was $8.8{\pm}2.9$ years and annual decrease in CD4+T cell was $41{\pm}57/ul.$ Nested polymerase chain reaction (PCR) and direct sequencing were perfonned with peripheral blood mononuclear cells (PBMC) obtained at times during the study period. First, there was a significant correlation between survival duration and duration of KRG-intake $(36.8{\pm}38$ months)(P=0.000). There were significant correlations between the last NefProg score and CD4+ T cell count (r= 0.208, P<0.05) and annual decrease in CD4+ T cell count (r =0.346, P<0.01) in 70 patients. In addition, there were significant correlations between KRG-intake and annual decrease (r= 0.323, P<0.01), and the CD4+ T cell count itself (r=0.229, p<0.05). Furthennore, there was also a mild significance between the NefProg score and the duration of KRG-intake in only SP and RP (n=30, r=-0.281, P=0.067). In addition, we detected various defects in 21 patients $(30.0\%),$ not including 5 premature stop codons. Ten $(12.5\%)$ patients showed repeated deletion of an amino acid. Four of 10 patients were gross deletions and they were treated with KRG for more than 20 months. The number of patients with repeated gross deletions was significantly higher in the order of slow progressors $(18\%)$, typical progressors($3\%$), and rapid progressors($0\%$) (P<0.05). We also observed that long-tenn intake of KRG might make the change from A or D to T at position 54 and decrease NefProg score. Taken together, our results show clear evidence that the long-term intake of KRG has effects on nef gene variation as well as definite clinical usefulness.

  • PDF

The frequency of defective genes in vif and vpr genes in 20 hemophiliacs is associated with Korean Red Ginseng and highly active antiretroviral therapy: the impact of lethal mutations in vif and vpr genes on HIV-1 evolution

  • Cho, Young Keol;Kim, Jung-Eun
    • Journal of Ginseng Research
    • /
    • v.45 no.1
    • /
    • pp.149-155
    • /
    • 2021
  • Background: We have reported that internal deletions in the nef, gag, and pol genes in HIV-1-infected patients are induced in those treated with Korean Red Ginseng (KRG). KRG delays the development of resistance mutations to antiretroviral drugs. Methods: The vif-vpr genes over 26 years in 20 hemophiliacs infected with HIV-1 from a single source were sequenced to investigate whether vif-vpr genes were affected by KRG and KRG plus highly active antiretroviral therapy (ART) (hereafter called GCT) and compared the results with our previous data. Results: A significantly higher number of in-frame small deletions were found in the vif-vpr genes of KRG-treated patients than at the baseline, in control patients, and in ART-alone patients (p < 0.001). These were significantly reduced in GCT patients (p < 0.05). In contrast, sequences harboring a premature stop codon (SC) were more significant in GCT patients (10.1%) than in KRG-alone patients, control (p < 0.01), and ART-alone patients (p = 0.078 for peripheral blood mononuclear cells). The proportion of SC in Vpr was similar to that in Vif, whereas the proportion of sequences revealing SC in the env-nef genes was significantly lower than that in the pol-vif-vpr genes (p < 0.01). The genetic distance was 1.8 times higher in the sequences harboring SC than in the sequences without SC (p < 0.001). Q135P in the vif gene is significantly associated with rapid progression to AIDS (p < 0.01). Conclusion: Our data show that KRG might induce sD in the vif-vpr genes and that vif-vpr genes are similarly affected by lethal mutations.

Molecular Phylogenetic Analysis of HIV -1 vif Gene from Korean Isolates

  • Park, Chan-Seung;Kim, Mi-Sook;Lee, Sung-Duk;Kim, Sung-Soo;Lee, Keon-Myung;Lee, Chan-Hee
    • Journal of Microbiology
    • /
    • v.44 no.6
    • /
    • pp.655-659
    • /
    • 2006
  • Phylogenetic studies of nef, pol, and env gene sequences of HIV-1 isolated from Koreans suggested the presence of a Korean clade in which Korean sequences are clustered to the exclusion of foreign sequences. We attempted to identify and characterize the Korean clade using all vif gene sequences isolated from Koreans registered in the NCBI GenBank database (n = 233). Most (77 %) of the Korean isolates belonged to the Korean clade as a large subcluster in subtype B, designated the Korean clade subtype B ($K_{C}B$). $K_{C}B$ sequences were relatively homogenous compared to Korean subtype B sequences that did not belong to the $K_{C}B$ (non-Korean clade subtype B; $NK_{C}B$). Comparison of amino acid frequencies of $K_{C}B$ and $NK_{C}B$ sequences revealed several positions where the amino acid frequencies were significantly different. These amino acid residues were critical in separating $K_{C}B$ from $NK_{C}B$ or from foreign sequences, since substitution of these amino acids in $K_{C}B$ with the $NK_{C}B$ amino acids relocated the $K_{C}B$ sequences to $NK_{C}B$, and vice versa. Further analyses of $K_{C}B$ will help us to understand the origin and evolutionary history of $K_{C}B$.

Unity in HIV-1 Sequence Diversity: Identification and Characterization of Korean Clade in HIV-1 Isolated from Korean

  • Lee, Chan-Hee
    • Proceedings of the Microbiological Society of Korea Conference
    • /
    • 2006.05a
    • /
    • pp.129-131
    • /
    • 2006
  • Through molecular phylogenetic analysis using the nef gene sequences of HIV-l isolated from Korean registered in the NCBI GenBank together with 41 reference strains and 94 foreign isolates, we verified that most (${\sim}80%$) of Korean isolates belonged to subtype B and 78% of subtype B were clustered together exclusively of foreign isolates, and this cluster was named Korean clade subtype B ($K_cB$). Similarity study suggested that the $K_cB$ cluster was more homogeneous than and clearly distinctive from the non-Korean subtype B ($NK_cB$). Comparison of the consensus amino acid sequences of the $K_cB\;or\;NK_cB$ revealed characteristic $K_cB$ signature amino acid pattern comprised of 13 amino acid residues. The $K_cB$ signature amino acid residues were critical in separating the $K_cB$ ftom the $NK_cB$, since substitution of the $NK_cB$ sequences with $K_cB$ signature amino acids relocated them to the Koran clade, and vice versa. Synonymous and nonsynonymous substitution rate study suggested positive selection event for the $K_cB$.

  • PDF

Complete Sequences of HIV-1 in a Korean Long-term Nonprogressor with HIV-1 Infection (장기간 진행하지 않는 인면역결핍바이러스(Human Immunodeficiency Virus, HIV)-1 감염자로부터 분리한 HIV-1의 전체 염기서열 결정)

  • Cho, Young-Keol;Lee, Hee-Jung;Desrosiers, Ronald C.
    • The Journal of Korean Society of Virology
    • /
    • v.29 no.2
    • /
    • pp.107-118
    • /
    • 1999
  • To characterize the molecular nature of human immunodeficiency virus (HIV)-1, we determined the full-length HIV-1 sequences from cultured peripheral blood mononuclear cells (PBMC) of a Korean long-term nonprogressor (LTNP). Without antiretroviral therapy, the individual has maintained CD4+ T counts over $500/{\mu}l$ from 1989 to 1999. Plasma viral RNA copy was 992 U/ml in 1998. Culture supernatant showed positive from culture days 9. A series of 9 overlapping PCR products were amplified from cultured PBMC and cloned About 9.2 kb from R of 5' LTR to R of 3' LTR was determined by automated sequencing. The G-to-A hypermutations were shown throughout the entire region. As a result of G to A hypermutations, premature stop codon was found in integrase coding region. Though there was no recombination between subtypes over all genomes, TATA box in both LTRs was TAAAA which is detected in subtype E instead of TATAA in subtype B. And, there were nucleotide GC insertion between $NF-{\kappa}B$ I and Sp1 III, and duplication of $TCF-1{\alpha}$ in LTR. We could not find any deletion of amino acid in Nef, Gag, Pol and Env gene. This study is the first report on molecular nature of full genomes of HIV-1 isolated in Korea.

  • PDF

Pseudo type HIV-1 Particles Carrying CD4

  • Park, Seung-Won;Kim, Tai-Gyu;You, Ji-Chang;Schubert, Manfred;Paik, Soon-Young
    • The Journal of Korean Society of Virology
    • /
    • v.30 no.1
    • /
    • pp.83-99
    • /
    • 2000
  • A defective HIV-1 helper virus DNA, pHyPC, was assembled by deleting the RNA packaging signal, env, nef and the 3'LTR sequences. HIV-1 like virus particles that carry the HIV-1 receptor, CD4 were generated by co expression of pHyPC and plasmid DNAs encoding different chimeric CD4 proteins. The CD4 particles, sharing the CD4 ectodomain, precisely fused to different membrane anchors. CD4(+) particles specifically bound to HIV-1 Env expressing cells, but any signs of infection into these cells were not detected. Binding was only partially blocked by either polyclonal anti-CD4 antibodies or by high concentrations of soluble CD4. Surprisingly, CD4(+) particles also adsorbed to HeLa, CHO, NIH3T3 and COS-7 cells in the absence of HIV-1 Env expression. Adsorption was comparable in strength and speed to the highly specific CD4-Env interaction. CD4(-) particles exhibited only background levels of binding. Cell binding was CD4. dependent, but it was independent of the cell type from which the CD4(+) particles originated. Interestingly, CD4-dependent/Env-independent binding was only found when CD4 was present on virus particles. This suggests that the micro-environment of CD4 on virus particles uniquely expose this new cell binding activity. Its high affinity could explain in part why infection of Env(+) cells by CD4(+) particles was not detected. Further experiments will be required to evaluate whether this strong membrane interaction could represent one step in the multiple-step viral entry process.

  • PDF