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Prasert Thongcharoen

Publications and source records attributed to Prasert Thongcharoen.

6 recordsLinked to original sources

Antibody-dependent cell-mediated cytotoxic responses in participants enrolled in a phase I/II ALVAC-HIV/AIDSVAX B/E prime-boost HIV-1 vaccine trial in Thailand.

Antibody-dependent cell-mediated cytotoxicity (ADCC) was assessed in volunteers participating in an ALVAC-HIV (vCP1521)/AIDSVAX B/E gp120 prime-boost vaccine trial in Thailand. ADCC activity was measured using chromium release from gp120 subtype B- and CRF01_AE-coated targets in 95 vaccinees and 28 placebo recipients. There was a significant difference in the magnitude of the ADCC response to both targets between vaccinees and placebo recipients. The frequency of responders to subtype B and to CRF01_AE was 96% and 84% in the vaccine group versus 11% and 7% in the placebo group. The results demonstrate that this HIV vaccine is a potent inducer of ADCC activity and may be an additional protection of this prime-boost vaccine in preventing HIV disease.

AIDS Vaccines↗

Enhanced sensitivity of detection of cytotoxic T lymphocyte responses to HIV type 1 proteins using an extended in vitro stimulation period for measuring effector function in volunteers enrolled in an ALVAC-HIV phase I/II prime boost vaccine trial in Thailand.

A phase I/II prime-boost vaccine trial in HIV-1-seronegative adults was conducted in Thailand using ALVAC-HIV (vCP1521) as a prime, boosting with either oligomeric gp160 TH023/LAI or Chiron HIV Thai subtype E (CM235) plus U. S. subtype B (SF2) gp120. Cytotoxic T lymphocyte (CTL) assays were conducted at one of the vaccine trial sites (Siriraj Hospital) at a single time point following the completion of immunization demonstrated that 8 of 50 (16%) vaccine recipients showed HIV-specific CTL by standard chromium release assay (CRA) after in vitro stimulation (IVS) for 2 weeks. Five additional vaccinees (13/50 = 26%) showed CTL responses after IVS for up to 4 weeks. Moreover, one volunteer with a positive CTL response to a single HIV antigen at Day 14 demonstrated a response to an additional HIV-1 antigen(s) after the longer IVS period. CTL activity was CD8+ restricted. Despite extension of the IVS up to 4 weeks, no CTL responses were detected in placebo recipients. These results imply that extension of the IVS period may increase the sensitivity of the CRA when measuring HIV-specific CTL in ALVAC-HIV prime-boost recipients without compromising specificity.

AIDS Vaccines↗

V-1 immunitor.

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AIDS Vaccines↗

Safety and immunogenicity of combinations of recombinant subtype E and B human immunodeficiency virus type 1 envelope glycoprotein 120 vaccines in healthy Thai adults.

Safety and immunogenicity of 2 recombinant human immunodeficiency virus (HIV) type 1 envelope glycoprotein (gp) 120 vaccines derived from SF2 (subtype B) and CM235 (CRF01_AE, Thai E) were evaluated in 370 Thai adults at low risk of HIV infection. Various doses of CM235 (25, 50, or 100 microg) and SF2 (0, 25, or 50 microg) gp120 were used. Eighty volunteers received placebo. There were no serious adverse events related to vaccination. Binding antibody developed in all vaccine recipients. There was no dose response to CM235 gp120, but a dose response to gp120 SF2 was present. Neutralizing antibodies to subtype E HIV-1 NPO3 and subtype B HIV-1 SF2 developed in 84% and 82% of vaccine recipients, respectively. Lymphoproliferative responses were detected in >95% of vaccine recipients. There was no evidence of antigenic interference in HIV-specific humoral or cellular responses. The gp120 Thai E and SF2 vaccines were safe and immunogenic in combination and could be advanced into phase 3 testing.

AIDS Vaccines↗

Prevalence of rabies virus and Hantaan virus infections in commensal rodents and shrews trapped in Bangkok.

Five hundred rodents and shrews (Rattus norvegicus: 458, Rattus rattus: 28, Rattus exulans: 5, Mus musculus: 4 and Suncus murine: 5) trapped from the fresh food markets around Bangkok area were investigated for rabies virus and Hantaan virus infections. No rabies viral antigens in the animals' brains were detected by direct immunofluorescence. On the other hand, antibodies to Hantaan virus were demonstrated in the sera of 7 (1.53%) R. norvegicus caught in various markets using a particle agglutination technique. Further determination of the viral genome in rat lung tissue was performed by reverse transcriptase-polymerase chain reaction (RT-PCR) and nested PCR, 3 (0.66%) out of 7 were positive. HindIII and HifI restriction enzyme analyses showed the pattern of the Hantaan virus genome in 2 samples and that of the Seoul virus genome in the other. The results of the present study suggest that rodents from Bangkok's fresh food markets did not carry rabies. Thus, getting rid of rabies in dogs or cats in the Bangkok area may be easier than anticipated because there are no sources of asymptomatic reservoirs. This may result in the low incidence of rabies patients observed in Bangkok. On the contrary, the presence of antibodies and the Hantaan virus genome and Seoul virus genome in R. norvegicus will definitely provide evidence for physicians to be aware of hemorrhagic fever with renal syndrome (HFRS) and other clinical settings of Hantaan/Seoul virus disease in patients with a history of having contact with rats or their excreta.

Animals↗