Current HIV Research - Volume 9, Issue 3, 2011

Human immunodeficiency virus infection is a worldwide health problem and a protective vaccine is desperately needed to control the AIDS pandemics. To address this concern, we previously constructed single-cycle replicable (SCR) HIV-1 virions, which completely maintained the antigenic structures of HIV-1. Herein, to optimize a vaccination strategy, we studied the immunogenicity of produced SCR virions and adjuvant-formulated HIV-1 virus-like particles (VLPs) in homologous and heterologous prime-boosting regimens. Accordingly, BALB/c mice received three doses of immunogens in 3-week intervals and their immune responses were evaluated using ELISA, cytokine and IFN-γ ELISpot assays. These analyses not only indicated the superiority of SCR prime-VLP boosting for strong induction of specific IFN-γ producing cells, but also showed the capability of this strategy over the others for better stimulation of humoral response, which was evidenced with the detection of highest titer of total IgG against HIV ENV glycoprotein. Furthermore, determination of IgG subclasses and IFN-γ/IL4 secretion ratio in cultured splenocytes demonstrated the efficient augmentation of mixed responses with the dominancy of Th1 immunity following SCR/VLP immunization strategy. Our results additionally pointed towards the applicability of Montanide ISA 720 + CpG as a potent Th1-directing adjuvant mixture. Overall, this study suggests SCR prime-VLP boosting as a promising approach in HIV vaccine development.

We investigated the relationship between viral persistence in the gut, microbial translocation, and T cell activation during chronic HIV infection. Plasma levels of LPS, fraction of circulating CD8+CD38+ T cells, and levels of HIV-DNA in rectosigmoid biopsies and peripheral blood mononuclear cells were determined in 22 HIV-infected individuals and 10 healthy controls. We found that in untreated HIV-infected individuals, HIV-DNA load was higher in the gut mucosa than in the blood. Also, ART-treated patients exhibited lower levels of LPS and CD8+CD38+ T cells than untreated patients, but higher levels than controls. In ART-treated individuals, the level of HIV-DNA in the gut correlated with levels of LPS and fraction of CD8+CD38+ T cells. We concluded that in ART-treated individuals, higher levels of gut-associated HIV-DNA are associated with persistent immune activation and microbial translocation.

Information concerning structured treatment interruptions (STI) of the Highly Active Antiretroviral Therapy (HAART) and the associated risk of this strategy for selecting antiretroviral resistance in children is scarce. In this study, we have searched for antiretroviral resistance mutations at the end of five viral rebounds of two HIV-1-infected children who underwent an STI program. The HAART of two children with HIV and a chronically undetectable viral load (VL) was interrupted for 4 weeks and then restarted and continued for 12 weeks for three cycles. VL, CD4+/CD8+ lymphocytes, and clinical status were evaluated at the end of each STI and at 6 and 12 weeks after HAART was resumed. Treatment of both the patients based on AZT+3TC+RTV remained identical during the study. The reverse transcriptase (RT)- and protease (PR)-coding regions were sequenced searching for antiretroviral resistance mutations at the end of each viral rebound. Genotyping analysis was performed using the Stanford University HIV Drug Resistance Database (HIV-DB). One patient experienced progressively lower viral rebounds (269000-31300 at the first and third rebounds, respectively), while the other patient did not experience such a reduction, and the VL of both the patients fell to undetectable levels during therapy. In the five viral rebounds examined, no mutations for major or minor resistance to protease inhibitors (PIs) were found and the analysis indicated susceptibility to all PIs currently in clinical use. Although the mutation K103R associated with non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance was found in two viral rebounds of one patient, the analysis indicated the absence of resistance to reverse transcriptase inhibitors in all the sequences evaluated. As no mutation related to antiretroviral resistance was found, our results suggest that the STI program used in this study may have a low risk of selecting antiretroviral resistance. Nevertheless, further studies evaluating larger cohorts over longer periods, and above all, controlled clinical trials, are required before definitive conclusions about the safety of STI of HAART in children may be drawn.

To prospectively observe the efficacy, tolerability, immune reconstitution and toxicity of long-term highly active antiretroviral therapy (HAART) in Chinese patients infected HIV. 437 cases originally received two nucleoside reverse transcriptase inhibitors (NRTIs) and one non-nucleoside reverse transcriptase inhibitor (NNRTI) during a mean period of 4.3 years (3.1-7.3). Patients were followed up by HIV RNA levels, T lymphocyte subsets, blood routine test, and biochemical parameters. If active opportunistic infections, apparent side effects or virological failure appeared, appropriate treatment would be taken immediately. 30 patients (6.86%) died, most in the first 6 months of HAART. The proportion of subjects with HIV-1 RNA <500 copies/ml was 90.8%, 63.5%, 69.4%, 70.0% and 72.2% at 1, 4, 5, 6 and 7 year. The CD4+ T cell count was 115, 246, 301, 334, 363, 356,386 and 373 cells/ul at 0, 1, 2, 3, 4, 5, 6 and 7 year. 67.9% showed various drug-related side effects, most including gastrointestinal side-effects, nervous disorder, myelotoxicity and abnormal liver function, rashes, serum cholesterol elevation, mostly appearing in the first 12 months. Grade 3 and Grade 4 adverse events occurred in 41 cases. This is the first to report results from the prospectively 7-year follow-up of Chinese patients infected HIV taking HAART. It demonstrates that two NRTIs and one NNRTI regimens may persistently suppress HIV viremia and continuously induce CD4 cell increase, with good safety and tolerance. The majority took firstline regimens effectively. 19.2% changed to other first-line drug due to drug-related side effects, 10.2% switched to second-line regimens due to viral resistance. Some discontinued or got virological failure because of poor compliance.

To assess the efficacy and the tolerability of once-daily (QD) versus twice-daily (BID) nevirapine (NVP)-based highly active antiretroviral therapy (HAART) in virologically suppressed, HIV-positive patients switched from protease inhibitor (PI)-based HAART. Eligible patients were enrolled in the multicenter trial if HIV RNA levels were <50 copies/mL for ≥6 months prior. Patients were switched from a PI to NVP 200 mg BID for 2 months, and then randomized to continue with that regimen (group A) or NVP 400 mg QD (group B) for a further 10 months. Virological efficacy (primary endpoint) and tolerability/toxicity were evaluated according to an intention-to-treat analysis. A total of 126 patients (63 per group) were enrolled. Withdrawals from the study (any reason) numbered 15 in group A and 14 in B, virological failures numbered 5 and 2, respectively, and there were 4 cases of adverse events in each group (all p = NS). Mean alanine aminotransaminase (ALT) and gamma-glutamyl transpeptidase (γ-GT) level increases were significant for the whole cohort (33.2±22.9 to 43.3±29.1, p < 0.001; 57.3±72 to 109±131 U/L, p < 0.0002, respectively), but there were no differences between the two groups. Apparently, no significant differences between the QD and BID NVP groups were found, in terms of virological failures or tolerability/toxicity. The switch to NVP may be safely pursued with a QD schedule.

Raltegravir (RAL) has been shown to be virologically effective in both treatment naive and triple class resistant patients. A more favourable metabolic profile associated with RAL in comparison with other antiretroviral drugs has also been observed. The aim of this study was to investigate the molecular mechanisms that could explain the lack of toxicity of this drug in metabolism. Thus, the effects of RAL on adipogenesis and adipocyte metabolism were analyzed using 3T3- L1 cells, a very adequate and convenient cell culture model for the investigation of adipose differentiation and metabolism. The effects of RAL on adipogenesis were evaluated by the Oil Red O staining after 8 days of induction of differentiation. Several adipogenic genes (C/EBPα, PPARγ, Pref-1 and AP2) were analyzed by Real-Time PCR. Fully differentiated adipocytes were also incubated with RAL for 24 hours and glucose utilization, lactate production and glycerol release were analyzed. Thus, minimal effects of RAL on murine adipocyte differentiation were observed. Basal glucose uptake and lactate production were not affected by RAL at any of the concentrations used. No effects were also found on the percentage of glucose that is metabolized to lactate. Lipolysis was only slightly inhibited by Raltegravir (-10%) at the highest concentration used (50 μM), while no effects were observed with lower doses. Our results suggest that the absence of significant actions of RAL on adipogenesis and glucose and lipid metabolism in adipocytes could explain, at least in part, the neutral metabolic effects of RAL in clinical studies.

Background: The prevalence of cervical squamous intraepithelial lesions (SIL) among HIV-infected women on antiretroviral therapy in sub-Saharan Africa has not been well described. Methods: HIV-infected women enrolled in an HIV treatment clinic in Nairobi, Kenya were offered free cervical screening with Papanicolaou (Pap) smear testing if they were 30 to 39 years of age and on antiretroviral therapy. Women with SIL were compared to those without SIL with univariate analyses and logistic regression. Results: Of 595 eligible women, 267 accepted Pap testing and had available cytology results, of whom 258 (97%) were on a non-nucleoside reverse transcriptase inhibitor (NNRTI) based regimen. Median duration of antiretroviral therapy was 13 months [interquartile range (IQR), 8-19]. Abnormal cytology was found in 123 women (46%) with 70 women (26%) having low grade squamous intraepithelial lesions (LSIL), 22 (8%) high grade squamous intraepithelial lesions (HSIL), 30 (11%) atypical squamous cells of unknown significance (ASCUS) and 1 (0.4%) atypical glandular cells (AGC). Women with SIL had lower median CD4 cell count (239 vs 287 cells/mm3; P=0.02), lower income (<70 USD per month: 57% vs 38%; P=0.01), and less regular condom use (24% vs 40%; P=0.02) compared to those with no SIL. Duration and type of antiretroviral regimen were not significantly associated with SIL. Conclusion: SIL is prevalent among women on antiretroviral therapy and is associated with immunosuppression, low income, and less frequent condom use. Cervical cancer screening and counseling on condom use should be routinely offered to HIV-infected women in antiretroviral treatment clinics in Africa.

Objectives: Low 25-Hydroxyvitamin D (25[OH]D) was associated with severe fibrosis and low sustained virological response (SVR) after interferon (IFN)-based therapy in chronic hepatitis C. Furthermore, hypovitaminosis D was reported in HIV-infected individuals, but its role in liver disease progression in HIV/HCV coinfection is unknown. Methods: 25(OH)D was retrospectively measured in 237 HIV-infected patients (93 with HCV coinfection) and 76 healthy controls. Multivariate analysis included season, immuno-virological data, combined antiretroviral therapy (cART) and, in a subgroup of 51 HIV/HCV-genotype 1 coinfected patients, factors influencing SVR to pegylated-IFN and ribavirin. In a group of 20 patients, liver expression of cytochrome (CY)-P27A1 and CYP2R1, 25-hydroxylating enzymes, was assessed by immunohistochemistry. Results: Median 25(OH)D levels were 23.4 (interquartile range 16.7-33.7) ng/mL in the HIV-infected population and 24 ng/mL (18.3-29.5) in healthy controls (p=0.9). At multiple regression analysis, only winter/spring measurements correlated with lower 25(OH)D levels. No correlation with HCV coinfection, nor with cART regimens was found. Low 25(OH)D was independently associated with advanced fibrosis in HIV/HCV coinfected patients (p=0.023), whereas no association emerged with SVR to IFN-based therapy. CYP27A1 and CYP2R1 expression was associated neither with 25(OH)D serum levels nor with HCV-infection, liver histology, or cART. Conclusions: In our experience, despite the high prevalence of 25(OH)D insufficiency, HIV and HCV-infection did not seem to influence vitamin D status. The role of HIV, HCV and cART on hypovitaminosis D needs further validation in larger cohorts that account for the vitamin levels in general populations and for seasonal and regional variability.

Background: Canada's international response to HIV may be under threat given CIDA's new aid priorities that appear to exclude health. Drivers of this recent priority shift have included the influence of global aid trends among public sector donors and changes within the global HIV milieu itself. However, this is not the first time Canada has shifted in response to these two global trends. The era from 2000-2004 also witnessed dramatic changes in both the HIV field and in global thinking around international aid. As such, this article presents an evaluation of the Government of Canada's international response to HIV during the first era of transition (2000-2004) in order to derive lessons for decision-making around HIV in the current climate of change. Methods: In-depth, semi-structured interviews were conducted with 23 key informants with expertise regarding Canada's international response to HIV over time. Analysis involved multiple readings of transcripts to identify descriptive codes and establish intimacy with the data. Descriptive codes were then collapsed into thematic categories using a process of inductive reasoning. Results: Canada's international response to HIV was perceived to be exemplary at times (e.g. seminal funding to WHO's “3-by-5” strategy), but also inconsistent (e.g., underutilized technical assistance capacity) and non-strategic (e.g., contradiction between investing in training health providers while poaching professionals to bolster Canada's workforce). Conclusions: Lessons from the 2000-2004 era of transition focus on strategic investments, the inextricable connection between HIV and development, and strategy coherence. These results highlight that it is more constructive to ensure that Canadian development responses in all areas engage with both the upstream drivers of HIV as well as the impacts of the epidemic itself in order to achieve the greatest results from international investment and the most effective contributions to the lives of the people that these endeavours seek to support.