• BMB Reports
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• v.33 no.1
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• pp.92-95
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• 2000

The HIV-1 p24(202-221) sequence ETINNEEEWDRVHPV HAGP contains a B-cell epitope with the earliest immune response and the highest antibody titer against anti-mouse sera obtained by immunization with p24 antigens. A novel mouse monoclonal antibody (mAb) was generated against the immunodominant B-cell epitope of the HIV-1 p24 capsid protein, p24(202-221). BALB/c mice were immunized with the four branched multiple antigenic peptide (MAP) containing the HIV-1p24(202-221) sequence, and antibody-secreting hybridoma were produced by fusion of mouse splenocytes with P3X63Ag8.653, mouse myeloma cells. One clone which produced the antigen-specific mAb named KI-24 (Isotype IgG1, light chain: ${\kappa}$) was identified. mAb KI-24 was highly specific for both the p24(202-221) and p24 proteins when analyzed by ELISA and Western blotting. Since p24(202-221) also contains a cytotoxic T-lymphocyte epitope, this specfic peptide epitope and the monoclonal antibody with specific reactivity against the p24 protein and p24(202-221) can be used in peptide vaccine development and p24 antigen detection from HIV patients.

• The Journal of the Korean Society for Microbiology
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• v.35 no.1
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• pp.9-18
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• 2000

Immunological mechanisms involving the release of inflammatory factors by HIV-1 infected microglia in the brain have been implicated in the pathogenesis of HIV dementia (HIVD). Since the regulation of matrix metalloproteinases (MMPs) activity can be influenced by variety of inflammatory mediators, this study was undertaken to look for a correlation between the MMP-9 release and the production of TNF-${\alpha}$ in response to HIV-1 p24 in the human monocyte cell line THP-1 as a model for microglia. First, it was shown that HIV-l core p24 antigen induced THP-1 to secrete MMP-9 in a dose response manner while it elicited a little effect on MMP-2 release in human astroglial cell line T98G. Next, it was found that p24 induced THP-1 to secrete TNF-${\alpha}$ without prior differentiation into macrophages by phorbol myristate acetate (PMA) treatment. Furthermore, anti-TNF-${\alpha}$ neutralizing antibodies significantly blocked p24-induced MMP-9 release in a dose dependent manner. Our data indicate that p24 antigen induces monocytic MMP-9 release by triggering up-regulation of TNF-${\alpha}$ secretion.

• The Journal of Korean Society of Virology
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• v.26 no.2
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• pp.259-267
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• 1996

In order to evaluate the effect of viral load on the prognosis of human immunodeficiency virus-1 (HIV-1)-infected individuals, immune complex dissociated (ICD) serum p24 antigen (p24) by acid treatment was retrospectively measured for 50 HIV-infected patients for 60 months. Among them, 27 patients were p24 positive (p24+) above 25pg/ml for $40.4{\pm}12$ months and 23 patients were negative (p24-). Follow-up periods from HIV diagnosis were $63.0{\pm}19$ months (range; 40-112) for the p24+ and $68.4{\pm}19$ months (range; 38-106) for the p24-, respectively (P>0.05)Mean CD4+T cell counts in the p24+ group decreased from $473{\pm}$277/ul (median;373) to $157{\pm}150/ul$ (median; 111) for $60{\pm}16$ months (5.3/month P280/ul (median; 476) to $432{\pm}285/ul$ (median;382) for $63{\pm}19$ months (2.5/month, P<0.01). From CD4+T cell count >200/ul, the patient who progressed to AIDS of <200/ul were 13 of 23 (56%) in the p24+ and 4 of 22 (18%) in p24-, respectively (p<0.01). And the number of death in two groups were 6 (22%) and 1 (4%), respectively (p<0.01). Presumed survival in two groups were about 12 and 24.5 years. These data suggest that viral load itself be very important for the prognosis of HIV-infected patients.

• The Journal of Korean Society of Virology
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• v.27 no.1
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• pp.77-86
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• 1997

To examine AZT resistance of HIV-1 isolates from AZT treated or untreated Korean, several biological characteristics such as syncytium formation, HIV-1 reverse transcriptase activity and the p24 antigen production in MT-2 cells infected with 4 HIV-1 isolates were determined. As controls, we tested HIV-1 HTLV-IIIB and pre-drug isolate as AZT susceptible strains, in addition to HIV-1 RTMC/MT-2 and post-drug isolate as AZT resistant strains. When the inoculum size of HIV-1 was 300 $TCID_{50}$/well and 100 $TCID_{50}$/well, the AZT susceptibility of AZT untreated HIV-1 isolates 8806 and 9571 were similar to that of HIV-1 HTLV-IIIB and AZT-susceptible HIV-1 strains. When we evaluated AZT resistance of isolates HIV-1 8812 and 9113 treated with AZT for 36 months by observation of syncytium formation, HIV-1 8812 showed resistance simillar to that of HIV-1 RTMC/MT-2 strain forming syncytium up to AZT $1{\mu}g/ml$, and HIV-1 9113 showed resistance identical with that of AZT-resistant HIV-1 strain which formed syncytium up to AZT $10\;{\mu}g/ml$. Especially, when we evaluated AZT resistance by HIV-1 reverse transcriptase activity and the p24 antigen production, HIV-1 isolates 8812 and 9113 showed much higher resistance (>10 - 200 fold) compared with HIV-1 RTMC/MT-2 and AZT-resistant HIV-1 strain.

• Fisheries and Aquatic Sciences
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• v.19 no.9
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• pp.37.1-37.5
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• 2016

Human immunodeficiency virus (HIV) is the causative agent of acquired immune deficiency syndrome (AIDS). Anti-HIV agents targeting various steps in HIV life cycle have been developed; however, so far, no effective drugs have been found. We show here that a peptide isolated from Spirulina maxima (SM-peptide) inhibits HIV-1 infection in a human T cell line MT4. SM-peptide inhibited $HIV-1_{IIIB}$-induced cell lysis with a half-maximal inhibitory concentration ($IC_{50}$) of 0.691 mM, while its 50 % cytotoxic concentration ($CC_{50}$) was greater than 1.457 mM. Furthermore, the SM-peptide inhibited the HIV-1 reverse transcriptase activity and p24 antigen production. This suggests that SM-peptide is a novel candidate peptide, which may be developed as a therapeutic agent for acquired immunodeficiency syndrome patients.

• YAKHAK HOEJI
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• v.49 no.3
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• pp.217-224
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• 2005

Human Immunodeficiency Virus type 1 (HIV-l) based lentivirus vector has demonstrated great potential as gene therapy vectors mediating efficient gene delivery and long-term transgene expression in both dividing and nondividing cells. However, for clinical studies it must be confirmed that vector preparations are safe and not contaminated by replication competent lentivirus (RCL) related to the parental pathogenic virus, HIV-l. In this study, we would like to establish the method for titration and RCL detection of lentivirus vector. The titration was determined by vector expression containing the green fluorescent protein, GFP in transduced cells. The titer was $1{\times}10^7$ Transducing Unit/ml in the GFP expression assay and $8.9{\times}10^7$ molecules/ml in the real-time PCR. Also, for the detection of RCL, we have used a combination method of PCR and p24 antigen detection. First, PBS/psi and VSV-G region in the genomic DNA of transduced cells was detected by PCR assay. Second, transfer and expression of the HIV-1 gag gene was detected by p24 ELISA. In an attempt to amplify any RCL, the transduced cells were cultured for 3 weeks (amplification phase) and the supernatant of amplified transduced cell was used for the second transduction to determine whether a true RCL was present (indicator phase). Analysis of cells and supernatant at day 6 in indicator phase were negative for PBS/psi, VSV-G, and p24 antigen. These results suggest that they are not mobilized and therefore there are no RCL in amplification phase. Thus, real-time PCR is a reliable and sensitive method for titration and RCL detection of lentivirus vector.

• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.21-30
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• 1998

Synthetic genes encoding the gag p24 and the part of the envelope protein gp41 of the human immunodeficiency virus (HIV-1) were cloned and overexpressed as fusion proteins in Escherichia coli, using an expression vector carrying T7 promoter and the poly-histidine leader, sequence. The overexpressed p24 fusion protein was purified by centrifugation, Ni-affinity chromatography and CM-sepharose chromatography. The overexpressed gp41 fusion protein was purified by centrifugation, $C_4$ chromatography and DEAE-sepharose chromatography. The purified fusion proteins showed a high level of purity and immunoreactivity in SDS-polyacrylamide gel electrophoresis and western blot analysis. These results suggest that this prokaryotic - expression purification method is suitable for obtaining a large amount of the viral antigen which may be useful for screening of antibodies to HIV-1 in human blood samples.

• The Journal of Korean Society of Virology
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• v.28 no.4
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• pp.347-358
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• 1998

To analyze the correlation between biological phenotypes of HIV-1 isolates and disease progression, we selected 9 long-term non-progressors (LTNP) and 12 rapid progressors (RP) from HIV-1 infected Korean. We isolated HIV-1 isolates by culture of PBMC of LTNP and RP with normal PBMC and measured HIV-1 p24 antigen production. The HIV-1 isolation rate from LTNP was 55.6% (5/9). And 4 HIV-1 LTNP isolates were non-syncytium inducing (NSI) phenotype and showed slow/low replication. The HIV-1 isolation rate from RP was 91.7% (11/12) which was higher than that from LTNP. Besides 3 RP HIV-1 isolates which showed syncytium inducing (SI) phenotype, 8 RP HIV-1 isolates showed NSI phenotype in normal PBMC and MT-2 cell line. All RP HIV-1 isolates replicated more rapidly than LTNP HIV-1 isolates. Comparing the replication kinetics and syncytium forming capacity of HIV-1 isolates from LTNP and RP, we suggest that the difference of biological phenotype of HIV-1 isolates could be related with disease progression of HIV-1 infected persons.

• Proceedings of the Microbiological Society of Korea Conference
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• 2008.05a
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• pp.62-64
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• 2008

A major hurdle to the development of RNA interference as therapy for HIV infection is the delivery of siRNA to T lymphocytes which are difficult cells to transfect even in vitro. We have employed a single chain antibody to the pan T cell surface antigen CD7 was conjugated to an oligo-9-arginine peptide (scFvCD7-9R) for T cell-specific siRNA delivery in NOD/SCIDIL2${\gamma}$-/- mice reconstituted with human peripheral blood lymphocytes (Hu-PBL). Using a novel delivery, we first show that scFvCD7-9R efficiently delivered CD4 siRNA into human T cells in vitro. In vivo administration to Hu-PBL mice resulted in reduced levels of surface CD4 expression on T cells. Mice infected with HIV-1 and treated on a weekly basis with scFvCD7-9R-siRNA complexes targeting a combination of viral genes and the host coreceptor molecule CCR5 successfully maintained CD4/CD3 T cell ratios up to 4 weeks after infection in contrast to control mice that displayed a marked reduction in CD4 T cell numbers. p24 antigen levels were undetectable in 3 of the 4 protected mice. scFvCD7-9R/antiviral siRNA treatment also helped maintain CD4 T cell numbers with reduced plasma viral loads in Hu-PBL mice reconstituted with PBMC from donors seropositive for HIV, indicating that this method can contain viral replication even in established HIV infections. Our results show that scFvCD7-9R could be further developed as a potential therapeutic for HIV-1 infection.