Genotypic characterization of HIV type 1 env gp160 sequences from three regions in Thailand.

We report 25 env gp160 sequences from patients in three geographically distinct districts of Thailand, i.e., Lampang in the north, Trang in the south and Rayong in the east.

Aberrant life cycle of human immunodeficiency virus type 1 CRF15_01B-like clinical isolates from Thailand in human CD4+ T-cell lines.

Human immunodeficiency virus type 1 (HIV-1) is separated into several subtypes and circulating recombinant forms (CRFs). Here, infections of 4 clinical isolates (0-47-1, CU98-26, CU98-28, and CU98-31) from Thailand were examined in human CD4(+) T-cell lines, MT-4 and MOLT-4. The CU98-26 isolates in both cells and 0-47-1 in MT-4 established chronic infections, as in control 2 subtype B isolates from Japan, while 0-47-1 in MOLT-4 caused a latent infection.

Superinfection of human immunodeficiency virus type 1 (HIV-1) to cell clone persistently infected with defective virus induces production of highly cytopathogenic HIV-1.

Superinfection with human immunodeficiency virus type 1 (HIV-1) in human subjects, defined as reinfection with a heterologous strain of HIV-1, has become a topic of great interest. To illustrate the significance of this occurrence, we performed HIV-1 superinfection of L-2 cells, which were isolated from MT-4 cells persistently infected with subtype B HIV-1 as a cell clone continuously producing defective HIV-1 particles. L-2 cells carrying provirus with a one-base insertion in the pol protease were superinfected with HIV-1 derived from primary isolates of subtype B or CRF01_AE.

Establishment of Vero E6 cell clones persistently infected with severe acute respiratory syndrome coronavirus.

Little information is available on persistent infection of severe acute respiratory syndrome (SARS) coronavirus (CoV). In this study, we established persistent infection of SARS-CoV in the Vero E6 cell line. Acute infection of Vero E6 with SARS-CoV produced a lytic infection with characteristic rounding cytopathic effects (CPE) and the production of a large number of infectious particles in the culture fluid within 3 days post-infection.

A novel diagnostic method for human immunodeficiency virus type-1 in plasma by near-infrared spectroscopy.

Presently, the diagnosis of virus infections is based mainly on serological assays. Although polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) have been increasingly used for the diagnosis of such viral infections, the risk of transfusion-transmitted blood-borne viruses remains. Furthermore, PCR and ELISA are expensive and time-consuming, and sometimes cause falsepositive or false-negative results.

Different susceptibility of human immunodeficiency virus type 1 to Env gp41-derived synthetic peptides corresponding to the C-terminal heptad repeat region.

Two functional domains, alpha-helical heptad repeat 1 (HR-1) and HR-2, located in the N-terminal and C-terminal regions of human immunodeficiency virus type 1 (HIV-1) Env gp41, respectively, play an important role in the fusion process. Synthetic 34-amino-acid peptide that contains the HR-2 region, named C34, has been shown to inhibit the HIV-1 fusion process. Here, we prepared six representative peptides (C34-B1, -B2, -A, -C1, -C2, and -E from subtypes B, A, C, and E, respectively) according to the sequences from the HIV sequence database of Los Alamos.

Interleukin-4 up-regulates T-tropic human immunodeficiency virus type 1 transcription in primary CD4+ CD38+ T-lymphocyte subset.

The capacity of human immunodeficiency virus type 1 (HIV-1) to infect resting cells and to produce progeny particles may contribute significantly to its pathogenicity in vivo. We previously reported that primary culture of resting CD4(+) CD38(+) T-lymphocyte subset had higher production rate of CXCR4-using (X4) HIV-1 than CD4(+) CD38(-) subset. Interleukin (IL)-4 highly contributed to the up-regulation of the X4 virus production in the CD38(+) subset.

Enhancement of human immunodeficiency virus type 1 infectivity by replacing the region including Env derived from defective particles with an ability to form particle-mediated syncytia in CD4+T cells.

The infection and subsequent replication rates of human immunodeficiency virus type 1 (HIV-1) affect the pathogenicity. The initial stage of HIV-1 infection is largely regulated by viral envelope sequence. We previously reported that the defective doughnut-shaped particles produced from a persistently infected cell clone, named L-2, obtained from human CD4+ T-cell line MT-4 that was persistently infected with HIV-1 LAI strain, efficiently form particle-mediated syncytia with uninfected human CD4+ T-cell line, MOLT-4.

Preliminary clinical evaluation of a protein chip for tumor marker serodiagnosis of various cancers.

This preliminary study aimed to investigate sensitivity and specificity of a protein chip system for multi-tumor marker serodiagnosis of ten types of cancers, and to understand the possible clinical applications of this protein chip for the Thai population. The specific cancers diagnosed by this protein chip are lung, breast, liver, cervix, colo-rectal, stomach, ovary, esophagus, prostate and pancreas cancers. We analyzed 215 serum samples of which 165 were obtained from clinically confirmed cancer patients and 50 from healthy people with no evidence of cancer.

The vpu protein of human immunodeficiency virus type 1 plays a protective role against virus-induced apoptosis in primary CD4(+) T lymphocytes.

Previous data revealed that primary cultures of peripheral blood mononuclear cells (PBMCs) were killed by apoptosis at higher rates after infection with two CRF01_AE primary isolates of human immunodeficiency virus type 1 (HIV-1) than after infection with five other CRF01_AE primary isolates, five subtype B primary isolates, and two subtype B laboratory strains. Here, we show evidence that mutations at the vpu gene which were exclusively identified only in the two CRF01_AE isolates mentioned above are involved in their abilities to induce massive apoptosis in primary CD4(+) T lymphocytes. The rates of virus production by these two isolates in the culture media of infected PBMCs were lower (the same as those of the other CRF01_AE isolates) than those of the subtype B isolates.