Identification of ongoing human immunodeficiency virus type 1 (HIV-1) replication in residual viremia during recombinant HIV-1 poxvirus immunizations in patients with clinically undetectable viral loads on durable suppressive highly active antiretroviral therapy.

In most human immunodeficiency virus type 1 (HIV-1)-infected individuals who achieve viral loads of <50 copies/ml during highly active antiretroviral therapy (HAART), low levels of plasma virus remain detectable for years by ultrasensitive methods. The relative contributions of ongoing virus replication and virus production from HIV-1 reservoirs to persistent low-level viremia during HAART remain controversial. HIV-1 vaccination of HAART-treated individuals provides a model for examining low-level viremia, as immunizations may facilitate virus replication and sequence evolution. In a phase 1 trial of modified vaccinia virus Ankara/fowlpox virus-based HIV-1 vaccines in 20 HIV-infected young adults receiving HAART, we assessed the prevalence of low-level viremia and sequence evolution, using ultrasensitive viral load (<6.5 copies/ml) and genotyping (five-copy sensitivity) assays. Viral evolution, consisting of new drug resistance mutations and novel amino acid changes within a relevant HLA-restricted allele (e.g., methionine, isoleucine, glutamine, or arginine for leucine at position 205 of RT), was found in 1 and 3 of 20 subjects, respectively. Sequence evolution was significantly correlated with levels of viremia of between 6.5 and <50 copies/ml (P = 0.03) and was more likely to occur within epitopes presented by relevant HLA alleles (P < 0.001). These findings suggest that ongoing virus replication contributes to low-level viremia in patients on HAART and that this ongoing replication is subject to CD8(+) T-cell selective pressures.

Human T-cell lymphotropic virus type I and II seroprevalence among volunteer blood donors in Thailand.

Human T-cell lymphotrophic virus type I and II (HTLV-I/II) are closely related but distinct retroviruses that can infect humans. Both the viruses can be transmitted via transfusion of contaminated blood components. HTLV pre-transfusion screening is not mandatory in Thailand until now. Current epidemiological data for HTLV prevalence is still lacking since the past surveys were done more than a decade ago. The main objective of this study was to determine the seroprevalence of HTLV-I/II among voluntary blood donors in Thailand. 11,057 volunteer blood donors were screened for HTLV-I/II antibodies using the ARCHITECT rHTLV-I/II chemiluminescent immunoassay (CLIA). Initial-reactive (IR)  samples were subjected to repeat duplicate testing and were also sent for confirmatory testing at Korean Red Cross Society (KRC), Seoul or National Serology Reference Laboratories (NRL), Australia using alternate HTLV serological assays and immunoblot and/or specific nucleic acid testing respectively. Out of 11,057 plasma samples, 10,080 were low-risk seronegative donors and 977 were first-time/high-risk donors. Twenty of 24 IR samples were repeatedly reactive (RR) in low-risk seronegative donors group. On confirmatory testing of these 24 IR by immunoblot, 13 indeterminate and 11 negative results were observed. One out of 977 samples from first-time/high-risk donors was RR for anti-HTLV-I/II antibodies. This sample was co-reactive for HBsAg, but negative for HTLV by EIA or in-house HTLV-I qPCR. The ARCHITECT rHTLV-I/II assay exhibited a specificity of 99.93% in low-risk donors and 99.90% among high-risk donors. This study concluded that HTLV-I/II prevalence is low among blood donors in Thailand. But periodic surveillance should be continually conducted to ensure high blood safety standards in the country.

HIV-1 gp120 as well as alcohol affect blood-brain barrier permeability and stress fiber formation: involvement of reactive oxygen species.

BACKGROUND: HIV-1 infection commonly leads to serious HIV-1-associated neurological disorders, such as HIV-1-associated encephalopathy and dementia. In addition, alcohol is commonly used and/or abused among AIDS patients, but it is unclear whether alcohol affects the disease progression and if it affects it, how this occurs. We hypothesized that alcohol could affect the blood-brain barrier (BBB) integrity and thus could affect the onset and/or progression of HIV-associated neurological disorders. METHODS: Human brain microvascular endothelial cells (HBMEC) in a BBB model system were pretreated with alcohol (17 and 68 mM) and subsequently coexposed with HIV-1 gp120. Expression of chemokine receptors CCR3, CCR5, and CXCR4 was assessed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction. Changes in the permeability of the HBMEC monolayer were assessed using paracellular markers [(3)H]inulin or propidium iodide. Actin rearrangements in HBMEC were visualized by fluorescence microscopy and viability assessed using Live/Dead stain. RESULTS: Both gp120 and alcohol increased the permeability of the BBB model by up to 141%, without affecting HBMEC viability. Cotreatment with alcohol and gp120 did not result in a significant synergistic effect. Gp120 permeability involved chemokine receptor CCR5. Alcohol did not affect chemokine receptor expression on brain endothelial cells. Both gp120 and alcohol reorganized the cytoskeleton and induced stress fiber formation. Inhibition of reactive oxygen species (ROS) formation through NADPH blocked the effects of both gp120 and alcohol on permeability and stress fiber formation. CONCLUSION: These results indicate that both HIV-1 gp120 and alcohol induce stress fibers, causing increased permeability of the human BBB endothelium. Alcohol (68 mM)-mediated permeability increase was linked to ROS formation. The alcohol-mediated physiological changes in the HBMEC monolayers may increase diffusion of plasma components and viral penetration across the BBB. This suggests that alcohol, especially at levels attained in heavy drinkers, can potentially contribute in a negative fashion to HIV-1 neuropathogenesis.