The Dietary Inflammatory Index Is Not Associated With Gut Permeability or Biomarkers of Systemic Inflammation in HIV Immunologic Non-responders

Immunologic non-responders (INRs) are a subset of individuals living with HIV who have suboptimal blood CD4+ T cell recovery despite effective antiretroviral therapy (ART). They are at an increased risk of serious non-AIDS co-morbidities and death, and demonstrate enhanced systemic immune activation. In other populations diet has been correlated with markers of systemic inflammation through the Diet Inflammatory Index (DII), but this association has not been studied in persons living with HIV (PLWH). Blood was collected from 28 INR PLWH with a blood CD4+ T cell count <350/μL despite ≥2 years of effective ART. Participants completed a Canadian Diet History Questionnaire, and their responses were used to calculate the DII. Plasma inflammatory markers (IFNγ, TNF, IL-6, sVCAM, D-dimer, sCD14 and CRP) were assayed by ELISA, cellular immune activation (HLA-DR and CD38 on CD4+ and CD8+ T cells) was quantified using flow cytometry, and small bowel permeability assessed by calculation of the urine LacMan ratio after drinking a mix of lactulose and mannitol. Participants were a median age of 57 years, had been on effective ART for 15 years, and the median DII was -1.91 (range of -3.78 to +2.23). No correlation was observed between DII and plasma markers of inflammation, levels of T cell activation, gut permeability, or the biomarker of bacterial translocation sCD14. Self-reported alcohol intake, a potential confounder of the relationship between diet and inflammatory biomarkers, was also not associated with systemic inflammation or gut permeability. Our findings suggest that other mechanisms, rather than diet, are likely to be the major driver of systemic inflammation in INR individuals.

A randomized, blinded, placebo-controlled trial of De Simone formulation probiotic during HIV-associated suboptimal CD4+ T cell recovery

OBJECTIVE

To assess whether probiotic supplementation may reduce disease-linked systemic immune activation in people living with HIV with the immunologic non-responder (INR) phenotype.

DESIGN

Phase 2b, randomized, double-blind, placebo-controlled pilot trial.

METHODS

HIV-positive individuals with blood CD4+ T cell counts <350/mm3 despite viral suppression were randomized 2:1 to receive De Simone Formulation Probiotic (DSFP; "Visbiome" commercially) or placebo for 48 weeks; target enrolment was 36 patients. The primary endpoint was change in blood CD8+ T cell co-expression of HLA-DR and CD38 ("CD8 activation"). Secondary endpoints included biomarkers of inflammation, immune reconstitution, bacterial translocation, and gut permeability. Adjusted linear regression and linear mixed methods regression evaluated the differences between study arms from baseline to week 48. Study monitoring was done by the CIHR Canadian HIV Trials Network Data Safety Monitoring Committee.

RESULTS

Nineteen patients received DSFP, while 10 received placebo. One probiotic-arm patient withdrew early. Blood CD8 activation increased 0.82 percentage points (pp) in the probiotic arm (95% confidence interval [CI];-1.23,2.87;) and decreased by 2.06pp in the placebo arm (-4.81,0.70; between arms p=0.097). CD4+ T cell activation (%HLA-DR+) decreased in the placebo arm (-3.79pp [-7.32,-0.26]) but increased in the probiotic arm (1.64 [-0.98,4.26]; between arms p=0.018). No differences were observed in plasma or urine biomarkers of inflammation or microbial translocation.

CONCLUSIONS

Blood immune activation markers in INR individuals on effective ART were not reduced by supplementation with DSFP; CD4+ T cell activation may have been increased.

BCL-2 antagonism sensitizes cytotoxic T cell-resistant HIV reservoirs to elimination ex vivo

Curing HIV infection will require the elimination of a reservoir of infected CD4+ T cells that persists despite HIV-specific cytotoxic T cell (CTL) responses. Although viral latency is a critical factor in this persistence, recent evidence also suggests a role for intrinsic resistance of reservoir-harboring cells to CTL killing. This resistance may have contributed to negative outcomes of clinical trials, where pharmacologic latency reversal has thus far failed to drive reductions in HIV reservoirs. Through transcriptional profiling, we herein identified overexpression of the prosurvival factor B cell lymphoma 2 (BCL-2) as a distinguishing feature of CD4+ T cells that survived CTL killing. We show that the inducible HIV reservoir was disproportionately present in BCL-2hi subsets in ex vivo CD4+ T cells. Treatment with the BCL-2 antagonist ABT-199 was not sufficient to drive reductions in ex vivo viral reservoirs when tested either alone or with a latency-reversing agent (LRA). However, the triple combination of strong LRAs, HIV-specific T cells, and a BCL-2 antagonist uniquely enabled the depletion of ex vivo viral reservoirs. Our results provide rationale for novel therapeutic approaches targeting HIV cure and, more generally, suggest consideration of BCL-2 antagonism as a means of enhancing CTL immunotherapy in other settings, such as cancer.

Integrated Assessment of Viral Transcription, Antigen Presentation, and CD8+ T Cell Function Reveals Multiple Limitations of Class I-Selective Histone Deacetylase Inhibitors during HIV-1 Latency Reversal

Clinical trials investigating histone deacetylase inhibitors (HDACi) to reverse HIV-1 latency aim to expose reservoirs in antiretroviral (ARV)-treated individuals to clearance by immune effectors, yet have not driven measurable reductions in the frequencies of infected cells. We therefore investigated the effects of the class I-selective HDACi nanatinostat and romidepsin on various blocks to latency reversal and elimination, including viral splicing, antigen presentation, and CD8+ T cell function. In ex vivo CD4+ T cells from ARV-suppressed individuals, both HDACi significantly induced viral transcription, but not splicing nor supernatant HIV-1 RNA. In an HIV-1 latency model using autologous CD8+ T cell clones as biosensors of antigen presentation, neither HDACi-treated CD4+ T cell condition induced clone degranulation. Both HDACi also impaired the function of primary CD8+ T cells in viral inhibition assays, with nanatinostat causing less impairment. These findings suggest that spliced or cell-free HIV-1 RNAs are more indicative of antigen expression than unspliced HIV-RNAs and may help to explain the limited abilities of HDACi to generate CD8+ T cell targets in vivoIMPORTANCE Antiretroviral (ARV) drug regimens suppress HIV-1 replication but are unable to cure infection. This leaves people living with HIV-1 burdened by a lifelong commitment to expensive daily medication. Furthermore, it has become clear that ARV therapy does not fully restore health, leaving individuals at elevated risk for cardiovascular disease, certain types of cancers, and neurocognitive disorders, as well as leaving them exposed to stigma. Efforts are therefore under way to develop therapies capable of curing infection. A key focus of these efforts has been on a class of drugs called histone deacetylase inhibitors (HDACi), which have the potential of exposing hidden reservoirs of HIV-1 to elimination by the immune system. Unfortunately, clinical trial results with HDACi have thus far been disappointing. In the current study, we integrate a number of experimental approaches to build a model that provides insights into the limited activity of HDACi in clinical trials and offers direction for future approaches.

Circulating endothelial progenitor cell levels are not reduced in HIV-infected men

Reduced levels of endothelial progenitor cells (EPCs) have been associated with increased cardiovascular (CV) risk, but limited data are available on EPC levels in the human immunodeficiency virus (HIV)-infected population. EPCs (CD45(dim)/CD34(+)/kinase domain receptor(+)) from 36 HIV-uninfected and 30 antiretroviral therapy-naive HIV-infected men without known CV risk factors were enumerated using flow cytometry. The mean EPC levels (± standard error of the mean) were 1.4 ± 0.5 cells/μL in the HIV-infected group and 3.7 ± 2.2 cells/μL in the control group (P = .92). EPC levels were not associated with disease parameters, such as CD4 cell count or viral load. Reductions in EPC levels do not seem to explain the increased risk of CV disease among HIV-infected men.

Loss of the signaling adaptor TRAF1 causes CD8+ T cell dysregulation during human and murine chronic infection

The signaling adaptor TNFR-associated factor 1 (TRAF1) is specifically lost from virus-specific CD8 T cells during the chronic phase of infection with HIV in humans or lymphocytic choriomeningitis virus (LCMV) clone 13 in mice. In contrast, TRAF1 is maintained at higher levels in virus-specific T cells of HIV controllers or after acute LCMV infection. TRAF1 expression negatively correlates with programmed death 1 expression and HIV load and knockdown of TRAF1 in CD8 T cells from viral controllers results in decreased HIV suppression ex vivo. Consistent with the desensitization of the TRAF1-binding co-stimulatory receptor 4-1BB, 4-1BBL-deficient mice have defects in viral control early, but not late, in chronic infection. TGFβ induces the posttranslational loss of TRAF1, whereas IL-7 restores TRAF1 levels. A combination treatment with IL-7 and agonist anti-4-1BB antibody at 3 wk after LCMV clone 13 infection expands T cells and reduces viral load in a TRAF1-dependent manner. Moreover, transfer of TRAF1(+) but not TRAF1(-) memory T cells at the chronic stage of infection reduces viral load. These findings identify TRAF1 as a potential biomarker of HIV-specific CD8 T cell fitness during the chronic phase of disease and a target for therapy.

Perforin expression directly ex vivo by HIV-specific CD8 T-cells is a correlate of HIV elite control

Many immune correlates of CD8⁺ T-cell-mediated control of HIV replication, including polyfunctionality, proliferative ability, and inhibitory receptor expression, have been discovered. However, no functional correlates using ex vivo cells have been identified with the known ability to cause the direct elimination of HIV-infected cells. We have recently discovered the ability of human CD8⁺ T-cells to rapidly upregulate perforin—an essential molecule for cell-mediated cytotoxicity—following antigen-specific stimulation. Here, we examined perforin expression capability in a large cross-sectional cohort of chronically HIV-infected individuals with varying levels of viral load: elite controllers (n = 35), viremic controllers (n = 29), chronic progressors (n = 27), and viremic nonprogressors (n = 6). Using polychromatic flow cytometry and standard intracellular cytokine staining assays, we measured perforin upregulation, cytokine production, and degranulation following stimulation with overlapping peptide pools encompassing all proteins of HIV. We observed that HIV-specific CD8⁺ T-cells from elite controllers consistently display an enhanced ability to express perforin directly ex vivo compared to all other groups. This ability is not restricted to protective HLA-B haplotypes, does not require proliferation or the addition of exogenous factors, is not restored by HAART, and primarily originates from effector CD8⁺ T-cells with otherwise limited functional capability. Notably, we found an inverse relationship between HIV-specific perforin expression and viral load. Thus, the capability of HIV-specific CD8⁺ T-cells to rapidly express perforin defines a novel correlate of control in HIV infection.

While the majority HIV-infected individuals progress to AIDS, a fraction of these individuals—for reasons not completely understood—do not develop AIDS and also display sustained control over viral replication; these subjects are sometimes referred to as elite controllers (EC). Prior evidence has shown that HIV-specific CD8⁺ T-cells, a component of adaptive immunity against intracellular pathogens, from EC exhibit enhanced functionality compared to individuals with progressive disease. Therefore, HIV-specific CD8⁺ T-cells likely play an important role in the favorable clinical outcomes witnessed in EC. We show in this study that the ability to control HIV replication in EC is associated with the expression of a protein called perforin, a critical molecule that enables CD8⁺ T-cells to directly kill infected cells - thereby preventing the spread of HIV to previously uninfected cells. In infected subjects with nonprogressive disease, we show that HIV-specific CD8⁺ T-cells demonstrate a superior ability to express perforin upon antigen-specific stimulation, whereas in progressors this property is diminished. Thus, we identify a functional capability of CD8⁺ T-cells, readily measured by standard intracellular cytokine staining assays, that potentially has a direct impact on HIV replication in vivo. These findings may, therefore, provide an important qualifier for future HIV vaccine research.

Impact of HIV on cell survival and antiviral activity of plasmacytoid dendritic cells

Plasmacytoid dendritic cells (pDCs) are important mediators of innate immunity that act mainly through secretion of interferon (IFN)-α. Previous studies have found that these cells can suppress HIV in vitro; additionally, pDCs have been shown to be severely reduced in the peripheral blood of HIV-infected individuals. In the present study, we sought to determine the ability of pDCs to directly suppress viral replication ex vivo and to delineate the potential mechanisms whereby pDCs are depleted in HIV-infected individuals. We demonstrate that activated pDCs strongly suppress HIV replication in autologous CD4⁺ T cells via a mechanism involving IFN-α as well as other antiviral factors. Of note, unstimulated pDCs from infected individuals who maintain low levels of plasma viremia without antiretroviral therapy were able to suppress HIV ex vivo via a mechanism requiring cell-to-cell contact. Our data also demonstrate that death of pDCs by both apoptosis and necrosis is induced by fusion of HIV with pDCs. Taken together, our data suggest that pDCs play an important role in the control of HIV replication and that high levels of viral replication in vivo are associated with pDC cell death via apoptosis and necrosis. Elucidation of the mechanism by which pDCs suppress HIV replication in vivo may have clinically relevant implications for future therapeutic strategies.

Human immunodeficiency virus type 1 protease cleaves procaspase 8 in vivo

Human immunodeficiency virus type 1 (HIV-1) infection causes apoptosis of infected CD4 T cells as well as uninfected (bystander) CD4 and CD8 T cells. It remains unknown what signals cause infected cells to die. We demonstrate that HIV-1 protease specifically cleaves procaspase 8 to create a novel fragment termed casp8p41, which independently induces apoptosis. casp8p41 is specific to HIV-1 protease-induced death but not other caspase 8-dependent death stimuli. In HIV-1-infected patients, casp8p41 is detected only in CD4(+) T cells, predominantly in the CD27(+) memory subset, its presence increases with increasing viral load, and it colocalizes with both infected and apoptotic cells. These data indicate that casp8p41 independently induces apoptosis and is a specific product of HIV-1 protease which may contribute to death of HIV-1-infected cells.

The role of cytokines which signal through the common gamma chain cytokine receptor in the reversal of HIV specific CD4(+) and CD8(+) T cell anergy

Background

HIV specific T cells are putatively anergic in vivo. IL-2, a member of a class of cytokines that binds to receptors containing the common gamma chain (γc) has been shown to reverse anergy. We examined the role of γc cytokines in reversing HIV specific T cell anergy.

Methods

PBMC from untreated HIV-infected individuals were briefly exposed to a panel of γc cytokines, and frequencies of gag specific T cells were enumerated by intracellular IFN-γ flow cytometry.

Results

Of the γc cytokines, brief exposure to IL-2, IL-15, or combined IL-15/IL-7 significantly enhanced (range 2–7 fold) the CD4⁺ and CD8⁺ T cell IFN-γ responses to HIV gag, with IL-15 giving the greatest enhancement. The effects of cytokines were not due to enhanced proliferation of pre-existing antigen specific cells, but were due to a combination of enhanced cytokine production from antigen specific T cells plus activation of non-epitope specific T cells.

Conclusions

These observations support the notion that a significant number of HIV specific T cells are circulating in an anergic state. IL-2, IL-7 and particularly IL-15 as an immune modulator to reverse HIV-1 specific T cell anergy should be investigated, with the caveat that non-specific activation of T cells may also be induced.

Antiretroviral Activity, Pharmacokinetics, and Tolerability of MK-0518, a Novel Inhibitor of HIV-1 Integrase, Dosed As Monotherapy for 10 Days in Treatment-Naive HIV-1-Infected Individuals

BACKGROUND

MK-0518 is a novel HIV-1 integrase strand transfer inhibitor with potent in vitro activity against HIV-1 (95% inhibitory concentration [IC95] = 33 nM in 50% human serum) and good bioavailability in uninfected subjects. This study explored the antiretroviral activity and safety of MK-0518 versus placebo for 10 days as monotherapy in antiretroviral therapy-naive HIV-1-infected patients with plasma HIV-1 RNA levels of at least 5000 copies/mL and CD4 T-cell counts of at least 100 cells/mm.

METHODS

This was a multicenter, double-blind, randomized, placebo-controlled 2-part study, with the first part using MK-0518 in 1 of 4 doses (100, 200, 400, and 600 mg) versus placebo (randomized 1:1:1:1:1) given twice daily for 10 days of monotherapy. Patients were monitored for safety, pharmacokinetic parameters, and antiretroviral effect.

RESULTS

Thirty-five patients were enrolled (6-8 patients per treatment group) and completed 10 days of therapy; the mean baseline log10 HIV RNA level ranged from 4.5 to 5.0 copies/mL in each group. On day 10, the mean decrease from baseline in the log10 HIV RNA level was -0.2 copies/mL for the placebo group and -1.9, -2.0, -1.7 and -2.2 log10 copies/mL for the MK-0518 100-, 200-, 400-, and 600-mg treatment groups, respectively. All dose groups had superior antiretroviral activity compared with placebo (P < 0.001 for comparison of each dose with placebo). At least 50% of patients in each MK-0518 dose group achieved an HIV RNA level <400 copies/mL by day 10. Mean trough MK-0518 concentrations at each dose exceeded the IC95 of 33 nM. Study therapy was generally well tolerated. The most common adverse experiences were headache and dizziness; these were similar between active and control groups. There were no discontinuations because of adverse experiences and no serious adverse experiences.

CONCLUSIONS

MK-0518 showed potent antiretroviral activity as short-term monotherapy and was generally well tolerated at all doses. Based on these results, part 2 of the study, a dose-ranging 48-week trial of MK-0518 versus efavirenz in a combination regimen, has been initiated.

Why can't the immune system control HIV-1? Defining HIV-1-specific CD4+ T cell immunity in order to develop strategies to enhance viral immunity

Globally, at least 60 million people have been infected with the human immunodeficiency virus type 1 (HIV-1), the majority of whom will develop the acquired immunodeficiency syndrome (AIDS) leading to tremendous morbidity and the mortality. Understanding the immunopathogenesis of AIDS and the immune correlates of viral protection are necessary to develop effective vaccines and immunotherapies. A major focus of our laboratory has been to understand the CD4+ T cell immune response directed against HIV- 1, and to determine mechanisms of T cell dysfunction that lead to viral escape. In addition, we are interested in evaluating the TNF-TNFR family members as potential molecular adjuvants that could be incorporated into vaccines which could be used to further boost T cell immunogenicity in healthy or HIV-1-infected individuals, as many of these molecules have been shown to replace the functions of CD4+ T cell help.

OX40 ligation of CD4+ T cells enhances virus-specific CD8+ T cell memory responses independently of IL-2 and CD4+ T regulatory cell inhibition

We have previously shown that CD4(+) T cells are required to optimally expand viral-specific memory CD8(+) CTL responses using a human dendritic cell-T cell-based coculture system. OX40 (CD134), a 50-kDa transmembrane protein of the TNFR family, is expressed primarily on activated CD4(+) T cells. In murine models, the OX40/OX40L pathway has been shown to play a critical costimulatory role in dendritic cell/T cell interactions that may be important in promoting long-lived CD4(+) T cells, which subsequently can help CD8(+) T cell responses. The current study examined whether OX40 ligation on ex vivo CD4(+) T cells can enhance their ability to "help" virus-specific CTL responses in HIV-1-infected and -uninfected individuals. OX40 ligation of CD4(+) T cells by human OX40L-IgG1 enhanced the ex vivo expansion of HIV-1-specific and EBV-specific CTL from HIV-1-infected and -uninfected individuals, respectively. The mechanism whereby OX40 ligation enhanced help of CTL was independent of the induction of cytokines such as IL-2 or any inhibitory effect on CD4(+) T regulatory cells, but was associated with a direct effect on proliferation of CD4(+) T cells. Thus, OX40 ligation on CD4(+) T cells represents a potentially novel immunotherapeutic strategy that should be investigated to treat and prevent persistent virus infections, such as HIV-1 infection.

Enhancement of HIV-Specific CD8 T Cell Responses by Dual Costimulation with CD80 and CD137L

HIV-specific CD8 T cell responses are defective in chronic HIV infection. In this study, we report that costimulation with either CD137L (4-1BBL) or CD80 (B7.1) enhanced the Ag-specific expansion and acquisition of effector function by HIV-specific memory CD8 T cells. Ag-specific T cells from recently infected donors showed maximal expansion with single costimulatory molecules. Dual costimulation of T cells from recently infected donors or from healthy donors responding to influenza epitopes led to enhanced responses when the accumulation of cytokines was measured. However, accumulation of regulatory cytokines, particularly IFN-gamma, led to inhibition of further Ag-specific CD8 T cell expansion in the cultures. This inhibition was relieved by neutralization of IFN-gamma or of IFN-gamma, TNF, and IL-10. Thus, strong costimulation of T cells in vitro can lead to induction of regulatory cytokines at levels that limit further T cell expansion. In marked contrast, T cells from long-term (>4 years) infected HIV+ donors exhibited reduced Ag-specific CD8 T cell expansion, reduced CD4 T cell responses, and minimal cytokine accumulation. Dual costimulation with both 4-1BBL and B7.1 enhanced responses of T cells from long-term infected subjects to a level similar to that obtained with T cells from early in HIV infection. Experiments with purified CD8 T cells showed that B7.1 and 4-1BBL could act directly and synergistically on CD8 T cells. Taken together, these data suggest that 4-1BBL and B7.1 have additive or synergistic effects on HIV-specific CD8 T cell responses and represent a promising combination for therapeutic vaccination for HIV.

Preferential apoptosis of HIV-1-specific CD4+ T cells

In contrast to other viral infections such as CMV, circulating frequencies of HIV-1-specific CD4+ T cells in peripheral blood are quantitatively diminished in the majority of HIV-1-infected individuals. One mechanism for this quantitative defect is preferential infection of HIV-1-specific CD4+ T cells, although <10% of HIV-1-specific CD4+ T cells are infected. Apoptosis has been proposed as an important contributor to the pathogenesis of CD4+ T cell depletion in HIV/AIDS. We show here that, within HIV-1-infected individuals, a greater proportion of ex vivo HIV-1-specific CD4+ T cells undergo apoptosis compared with CMV-specific CD4+ T cells (45 vs 7.4%, respectively, p < 0.05, in chronic progressors). The degree of apoptosis within HIV-1-specific CD4+ T cells correlates with viral load and disease progression, and highly active antiretroviral therapy abrogates these differences. The data support a mechanism for apoptosis in these cells similar to that found in activation-induced apoptosis through the TCR, resulting in oxygen-free radical production, mitochondrial damage, and caspase-9 activation. That HIV-1 proteins can also directly enhance activation-induced apoptosis supports a mechanism for a preferential induction of apoptosis of HIV-1-specific CD4+ T cells, which contributes to a loss of immunological control of HIV-1 replication.

HIV-1-Specific Memory CD4+ T Cells Are Phenotypically Less Mature Than Cytomegalovirus-Specific Memory CD4+ T Cells

HIV-1-specific CD4(+) T cells are qualitatively dysfunctional in the majority of HIV-1-infected individuals and are thus unable to effectively control viral replication. The current study extensively details the maturational phenotype of memory CD4(+) T cells directed against HIV-1 and CMV. We find that HIV-1-specific CD4(+) T cells are skewed to an early central memory phenotype, whereas CMV-specific CD4(+) T cells generally display a late effector memory phenotype. These differences hold true for both IFN-gamma- and IL-2-producing virus-specific CD4(+) T cells, are present during all disease stages, and persist even after highly active antiretroviral therapy (HAART). In addition, after HAART, HIV-1-specific CD4(+) T cells are enriched for CD27(+)CD28(-)-expressing cells, a rare phenotype, reflecting an early intermediate stage of differentiation. We found no correlation between differentiation phenotype of HIV-1-specific CD4(+) T cells and HIV-1 plasma viral load or HIV-1 disease progression. Surprisingly, HIV-1 viral load affected the maturational phenotype of CMV-specific CD4(+) T cells toward an earlier, less-differentiated state. In summary, our data indicate that the maturational state of HIV-1-specific CD4(+) T cells cannot be a sole explanation for loss of containment of HIV-1. However, HIV-1 replication can affect the phenotype of CD4(+) T cells of other specificities, which might adversely affect their ability to control those pathogens. The role for HIV-1-specific CD4(+) T cells expressing CD27(+)CD28(-) after HAART remains to be determined.

Improvement of HIV-specific immunity in HIV-infected twins treated with highly active antiretroviral therapy, interleukin 2, and syngeneic adoptively transferred cells

Five HIV-seropositive twins were treated with HAART and given cycles of treatment consisting of adoptive cellular therapy from their HIV-seronegative identical twins followed by a 5-day course of intravenous IL-2. Changes in absolute and percent CD4(+) and CD8(+) cell count were monitored and compared with changes in these parameters occurring in seven age-, sex-, and disease stage-matched HIV-infected patients treated with HAART alone. Increase in the magnitude and breadth of HIV-specific immune responses was monitored in three twin subjects who received multiple treatment cycles. Absolute and percent CD4(+) cell counts rose dramatically and to significantly higher levels in the recipient twins than in control subjects treated with HAART only. The subjects who received multiple cycles of treatment developed new and increased levels of HIV-specific activated and memory cytotoxic T lymphocyte responses, and interferon gamma-secreting effector cells. Treatment consisting of HAART, adoptive cellular therapy, and IL-2 was superior to treatment with HAART alone for improving absolute and percent CD4(+) cell counts and inducing new, or increasing the magnitude of, HIV-specific immune responses in HIV infected patients.

Effects of vitamin E and C supplementation on oxidative stress and viral load in HIV-infected subjects

OBJECTIVES

The HIV-infected population is known to be oxidatively stressed and deficient in antioxidant micronutrients. Since in vitro replication of HIV is increased with oxidative stress, this study assessed the effect of antioxidant vitamin supplementation on lipid peroxidation, a measure of oxidative stress, and viral load in humans.

DESIGN

A randomized placebo-controlled, double-blind study.

METHODS

Forty-nine HIV-positive patients were randomized to receive supplements of both DL-alpha-tocopherol acetate (800 IU daily) and vitamin C (1000 mg daily), or matched placebo, for 3 months. Plasma antioxidant micronutrient status, breath pentane output, plasma lipid peroxides, malondialdehyde and viral load were measured at baseline and at 3 months. New or recurrent infections for the 6-month period after study entry were also recorded.

RESULTS

The vitamin group (n = 26) had an increase in plasma concentrations of alpha-tocopherol (P < 0.0005) and vitamin C (P < 0.005) and a reduction in lipid peroxidation measured by breath pentane (P < 0.025), plasma lipid peroxides (P < 0.01) and malondialdehyde (P < 0.0005) when compared with controls (n = 23). There was also a trend towards a reduction in viral load (mean +/- SD changes over 3 months, -0.45 +/- 0.39 versus +0.50 +/- 0.40 log10 copies/ml; P = 0.1; 95% confidence interval, -0.21 to -2.14). The number of infections reported was nine in the vitamin group and seven in the placebo group.

CONCLUSION

Supplements of vitamin E and C reduce oxidative stress in HIV and produce a trend towards a reduction in viral load. This is worthy of larger clinical trials, especially in HIV-infected persons who cannot afford new combination therapies.