Delayed gastrointestinal-associated lymphoid tissue reconstitution in duodenum compared with rectum in HIV-infected patients initiating antiretroviral therapy.

BACKGROUND: We aimed to characterize the impact of antiretroviral therapy (ART) initiation on gastrointestinal-associated lymphoid tissue at various sites along the gastrointestinal site. METHODOLOGY: Peripheral blood and duodenal and rectal biopsies were obtained from 12 HIV to 33 treatment-naive HIV participants at baseline and after 9 months ART. Tissue was digested for immunophenotyping. Inflammatory, bacterial translocation and intestinal damage markers were measured in plasma. RESULTS: Twenty-six HIV patients completed follow-up. The lowest reconstitution of CD4 T cells and the lowest CD4/CD8 ratio during ART compared with blood were observed in the duodenum with the rectum being either intermediate or approaching blood levels. Regulatory T cells were in higher proportions in the duodenum than the rectum and neither declined significantly during ART. Several correlations with biomarkers of microbial translocation were observed including increases in lipoteichoic acid levels, which reflects Gram-positive bacterial translocation, correlated with increases in %CD4 T cells in the duodenum (Rho 0.773, P = 0.033), and with decreases in duodenal regulatory T-cell populations (Rho -0.40, P = 0.045). CONCLUSION: HIV-mediated immunological disruption is greater in the duodenum than rectum and blood before and during ART. Small intestine damage may represent a unique environment for T-cell depletion, which might be attenuated by interaction with Gram-positive bacteria.

Hydroxypropyl-Beta-Cyclodextrin Reduces Inflammatory Signaling from Monocytes: Possible Implications for Suppression of HIV Chronic Immune Activation.

Monocytes from HIV-infected patients produce increased levels of inflammatory cytokines, which are associated with chronic immune activation and AIDS progression. Chronic immune activation is often not restored even in patients showing viral suppression under ART. Therefore, new therapeutic strategies to control inflammation and modulate immune activation are required. Hydroxypropyl-beta-cyclodextrin (HP-BCD) is a cholesterol-sequestering agent that has been reported to be safe for human use in numerous pharmaceutical applications and that has been shown to inactivate HIV in vitro and to control SIV infection in vivo Since cellular cholesterol content or metabolism has been related to altered cellular activation, we evaluated whether HP-BCD treatment could modulate monocyte response to inflammatory stimuli. Treatment of monocytes isolated from HIV-positive and HIV-negative donors with HP-BCD inhibited the expression of CD36 and TNF-α after LPS stimulation, independent of raft disruption. Accordingly, HP-BCD-treated cells showed significant reduction of TNF-α and IL-10 secretion, which was associated with lower mRNA expression. LPS-induced p38MAPK phosphorylation was dampened by HP-BCD treatment, indicating this pathway as a target for HP-BCD-mediated anti-inflammatory response. The expression of HLA-DR was also reduced in monocytes and dendritic cells treated with HP-BCD, which could hinder T cell activation by these cells. Our data suggest that, besides its well-known antiviral activity, HP-BCD could have an immunomodulatory effect, leading to decreased inflammatory responses mediated by antigen-presenting cells, which may impact HIV pathogenesis and AIDS progression.IMPORTANCE Chronic immune activation is a hallmark of HIV infection and is often not controlled even in patients under antiretroviral therapy. Indeed, chronic diseases with inflammatory pathogenesis are being reported as major causes of death for HIV-infected persons. Hydroxypropyl-beta cyclodextrin (HP-BCD) is a cholesterol-sequestering drug that inhibits HIV replication and infectivity in vitro and in vivo Recent studies have demonstrated the importance of cholesterol metabolism and content in different inflammatory conditions; therefore, we investigated the potential of HP-BCD as an immunomodulatory drug, regulating the activation of cells from HIV-infected patients. Treatment of monocytes with HP-BCD inhibited the expression and secretion of receptors and mediators that are usually enhanced in HIV patients. Furthermore, we investigated the molecular mechanisms associated with the immunomodulatory effect of HP-BCD. Our results indicate that, besides reducing viral replication, HP-BCD treatment may contribute to modulation of chronic immune activation associated with AIDS.

Tissue Pharmacologic and Virologic Determinants of Duodenal and Rectal Gastrointestinal-Associated Lymphoid Tissue Immune Reconstitution in HIV-Infected Patients Initiating Antiretroviral Therapy.

Plasma, duodenal, and rectal tissue antiretroviral therapy (ART) drug concentrations, human immunodeficiency virus (HIV) RNA and HIV DNA copy numbers, and recovery of mucosal immunity were measured before and 9 months after initiation of 3 different ART regimens in 26 subjects. Plasma and tissue HIV RNA correlated at baseline and when 9-month declines were compared, suggesting that these compartments are tightly associated. Antiretroviral tissue:blood penetration ratios were above the 50% inhibitory concentration values in almost 100% of cases. There were no correlations between drug concentrations and HIV DNA/RNA. Importantly, no evidence was found for residual viral replication or deficient tissue drug penetration to account for delayed gastrointestinal-associated lymphoid tissue immune recovery.

Associations of Plasma Cytokine and Microbial Translocation Biomarkers With Immune Reconstitution Inflammatory Syndrome.

A nested case-cohort study was performed in participants of a clinical trial of first-line human immunodeficiency virus treatments to investigate plasma biomarkers of inflammation and microbial translocation for their association with immune reconstitution inflammatory syndrome (IRIS). Fifty-one of 1452 participants with baseline CD4 count <350 cells/µL developed IRIS. Plasma from 51 IRIS cases, including 6 stratified by preenrollment CD4 count ≤200 cells/µL, were analyzed and compared to 94 non-IRIS controls. At baseline, CXCL10, lipopolysaccharide, soluble CD14, 16S ribosomal DNA, and interferon-α2 were associated with greater risk of IRIS. Systemic inflammation through persistent monocyte activation and microbial translocation appear to be important in IRIS pathogenesis.

Correction: Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial.

[This corrects the article DOI: 10.1371/journal.ppat.1005381.].

Effects of Combined CCR5/Integrase Inhibitors-Based Regimen on Mucosal Immunity in HIV-Infected Patients Naïve to Antiretroviral Therapy: A Pilot Randomized Trial.

Whether initiation of antiretroviral therapy (ART) regimens aimed at achieving greater concentrations within gut associated lymphoid tissue (GALT) impacts the level of mucosal immune reconstitution, inflammatory markers and the viral reservoir remains unknown. We included 12 HIV- controls and 32 ART-naïve HIV patients who were randomized to efavirenz, maraviroc or maraviroc+raltegravir, each with fixed-dose tenofovir disoproxil fumarate/emtricitabine. Rectal and duodenal biopsies were obtained at baseline and at 9 months of ART. We performed a comprehensive assay of T-cell subsets by flow cytometry, T-cell density in intestinal biopsies, plasma and tissue concentrations of antiretroviral drugs by high-performance liquid chromatography/mass spectroscopy, and plasma interleukin-6 (IL-6), lipoteichoic acid (LTA), soluble CD14 (sCD14) and zonulin-1 each measured by ELISA. Total cell-associated HIV DNA was measured in PBMC and rectal and duodenal mononuclear cells. Twenty-six HIV-infected patients completed the follow-up. In the duodenum, the quadruple regimen resulted in greater CD8+ T-cell density decline, greater normalization of mucosal CCR5+CD4+ T-cells and increase of the naïve/memory CD8+ T-cell ratio, and a greater decline of sCD14 levels and duodenal HIV DNA levels (P = 0.004 and P = 0.067, respectively), with no changes in HIV RNA in plasma or tissue. Maraviroc showed the highest drug distribution to the gut tissue, and duodenal concentrations correlated well with other T-cell markers in duodenum, i.e., the CD4/CD8 ratio, %CD4+ and %CD8+ HLA-DR+CD38+ T-cells. Maraviroc use elicited greater activation of the mucosal naïve CD8+ T-cell subset, ameliorated the distribution of the CD8+ T-cell maturational subsets and induced higher improvement of zonulin-1 levels. These data suggest that combined CCR5 and integrase inhibitor based combination therapy in ART treatment naïve patients might more effectively reconstitute duodenal immunity, decrease inflammatory markers and impact on HIV persistence by cell-dependent mechanisms, and show unique effects of MVC in duodenal immunity driven by higher drug tissue penetration and possibly by class-dependent effects.

Peginterferon α-2a for the treatment of HIV infection.

INTRODUCTION: Novel approaches are urgently needed to achieve the next level of control of HIV infection beyond antiretroviral medications that will lead to the ultimate goal of curing HIV infection. Exploiting the innate immune system control of HIV is one possible component of that strategy with pegylated interferon α representing a well-characterized agent that is being applied to this effort. AREAS COVERED: In this review, the authors summarize the history of interferon α treatment in the setting of HIV infection with a focus on clinical trials that examined the downstream effects on innate immune responses. More recently, clinical trials that administered pegylated interferon α-2a have demonstrated which interferon-stimulated genes are associated with its antiviral effects and which of these host-restriction factors may play a role in limiting the magnitude of the HIV reservoir. EXPERT OPINION: The potential to exploit interferon α as part of a cure strategy is provocative. Whether key interferon-induced antiviral factors can be upregulated sufficiently to affect the reservoir is unknown. Additional research employing pegylated interferon α-2a is needed to identify which innate immune pathways are candidate targets for novel biological therapies for the potential cure of HIV infection.

Pre-cART Elevation of CRP and CD4+ T-Cell Immune Activation Associated With HIV Clinical Progression in a Multinational Case-Cohort Study.

BACKGROUND: Despite the success of combination antiretroviral therapy (cART), a subset of HIV-infected patients who initiate cART develop early clinical progression to AIDS; therefore, some cART initiators are not fully benefitted by cART. Immune activation pre-cART may predict clinical progression in cART initiators. METHODS: A case-cohort study (n = 470) within the multinational Prospective Evaluation of Antiretrovirals in Resource-Limited Settings clinical trial (1571 HIV treatment-naive adults who initiated cART; CD4 T-cell count <300 cells/mm; 9 countries) was conducted. A subcohort of 30 participants per country was randomly selected; additional cases were added from the main cohort. Cases [n = 236 (random subcohort 36; main cohort 200)] had clinical progression (incident WHO stage 3/4 event or death) within 96 weeks after cART initiation. Immune activation biomarkers were quantified pre-cART. Associations between biomarkers and clinical progression were examined using weighted multivariable Cox-proportional hazards models. RESULTS: Median age was 35 years, 45% were women, 49% black, 31% Asian, and 9% white. Median CD4 T-cell count was 167 cells per cubic millimeter. In multivariate analysis, highest quartile C-reactive protein concentration [adjusted hazard ratio (aHR), 2.53; 95% confidence interval (CI): 1.02 to 6.28] and CD4 T-cell activation (aHR, 5.18; 95% CI: 1.09 to 24.47) were associated with primary outcomes, compared with lowest quartiles. sCD14 had a trend toward association with clinical failure (aHR, 2.24; 95% CI: 0.96 to 5.21). CONCLUSIONS: Measuring C-reactive protein and CD4 T-cell activation may identify patients with CD4 T-cell counts <300 cells per cubic millimeter at risk for early clinical progression when initiating cART. Additional vigilance and symptom-based screening may be required in this subset of patients even after beginning cART.

C-reactive protein (CRP), interferon gamma-inducible protein 10 (IP-10), and lipopolysaccharide (LPS) are associated with risk of tuberculosis after initiation of antiretroviral therapy in resource-limited settings.

OBJECTIVE: The association between pre-antiretroviral (ART) inflammation and immune activation and risk for incident tuberculosis (TB) after ART initiation among adults is uncertain. DESIGN: Nested case-control study (n = 332) within ACTG PEARLS trial of three ART regimens among 1571 HIV-infected, treatment-naïve adults in 9 countries. We compared cases (participants with incident TB diagnosed by 96 weeks) to a random sample of controls (participants who did not develop TB, stratified by country and treatment arm). METHODS: We measured pre-ART C-reactive protein (CRP), EndoCab IgM, ferritin, interferon gamma (IFN-γ), interleukin 6 (IL-6), interferon gamma-inducible protein 10 (IP-10), lipopolysaccharide (LPS), soluble CD14 (sCD14), tumor necrosis factor alpha (TNF-α), and CD4/DR+/38+ and CD8/DR+/38+ T cells. Markers were defined according to established cutoff definitions when available, 75th percentile of measured values when not, and detectable versus undetectable for LPS. Using logistic regression, we measured associations between biomarkers and incident TB, adjusting for age, sex, study site, treatment arm, baseline CD4 and log10 viral load. We assessed the discriminatory value of biomarkers using receiver operating characteristic (ROC) analysis. RESULTS: Seventy-seven persons (4.9%) developed incident TB during follow-up. Elevated baseline CRP (aOR 3.25, 95% CI: 1.55-6.81) and IP-10 (aOR 1.89, 95% CI: 1.05-3.39), detectable plasma LPS (aOR 2.39, 95% CI: 1.13-5.06), and the established TB risk factors anemia and hypoalbuminemia were independently associated with incident TB. In ROC analysis, CRP, albumin, and LPS improved discrimination only modestly for TB risk when added to baseline routine patient characteristics including CD4 count, body mass index, and prior TB. CONCLUSION: Incident TB occurs commonly after ART initiation. Although associated with higher post-ART TB risk, baseline CRP, IP-10, and LPS add limited value to routine patient characteristics in discriminating who develops active TB. Besides determining ideal cutoffs for these biomarkers, additional biomarkers should be sought that predict TB disease in ART initiators.

Clinical and immunologic predictors of death after an acute opportunistic infection: results from ACTG A5164.

BACKGROUND: In the pre-antiretroviral therapy (ART) era, markers of increased disease severity during an acute opportunistic infection (OI) were associated with mortality. Even with ART, mortality remains high during the first year after an OI in persons with advanced HIV infection, but it is unclear whether previous predictors of mortality remain valid in the current era. OBJECTIVE: To determine clinical and immunological predictors of death after an OI. METHODS: We used clinical data and stored plasma from ACTG A5164, a multicenter study evaluating the optimal timing of ART during a nontuberculous OI. We developed Cox models evaluating associations between clinical parameters and plasma marker levels at entry and time to death over the first 48 weeks after the diagnosis of OI. We developed multivariable models incorporating only clinical parameters, only plasma marker levels, or both. RESULTS: The median CD4+ T-cell count in study participants at baseline was 29 cells/µL. Sixty-four percent of subjects had Pneumocystis jirovecii pneumonia (PCP). Twenty-three of 282 (8.2%) subjects died. In univariate analyses, entry mycobacterial infection, OI number, hospitalization, low albumin, low hemoglobin, lower CD4, and higher IL-8 and sTNFrII levels and lower IL-17 levels were associated with mortality. In the combined model using both clinical and immunologic parameters, the presence of an entry mycobacterial infection and higher sTNFrII levels were significantly associated with death. CONCLUSIONS: In the ART era, clinical risk factors for death previously identified in the pre-ART era remain predictive. Additionally, activation of the innate immune system is associated with an increased risk of death following an acute OI.

A genotypic HIV-1 proviral DNA coreceptor tropism assay: characterization in viremic subjects.

BACKGROUND: HIV-1 coreceptor tropism testing is used to evaluate eligibility for CCR5 antagonist therapy. However, HIV-1 RNA-based tests are not suitable for virologically suppressed patients, therefore the use of proviral DNA tropism testing has been investigated. We describe a novel proviral DNA-based genotypic tropism assay and compare its performance to that of a sensitive HIV-1 RNA-based genotypic test. METHODS: Tropism was determined using HIV-1 plasma RNA and proviral DNA from 42 paired samples from patients with plasma viral loads ≥1000 HIV-1 RNA copies/mL. Proviral DNA sample types included whole blood, separated peripheral blood mononuclear cells resuspended in phosphate-buffered saline and peripheral blood mononuclear cells resuspended in spun plasma. The HIV-1 envelope V3 region was PCR-amplified, sequenced in triplicate, and analyzed for tropism with the geno2pheno algorithm using a 10% false-positive rate (FPR). RESULTS: Amplicons were obtained from proviral DNA and plasma RNA in 41/42 samples. Tropism predictions were highly concordant (93%-98%) between proviral DNA and plasma RNA, regardless of the proviral DNA isolation method. Non-R5 proviral DNA results were obtained for 100% of patients with detectable non-R5 plasma HIV-1 RNA results. Geno2pheno FPRs for proviral DNA and plasma RNA were highly correlated (Spearman rho = 0.86). CONCLUSIONS: Our findings demonstrate that proviral DNA tropism determinations from whole blood or peripheral blood mononuclear cells were highly concordant with plasma HIV-1 RNA tropism determinations. This assay may be useful for screening virologically suppressed patients for CCR5-antagonist eligibility and for research purposes.

Safety and efficacy of the peptide-based therapeutic vaccine for HIV-1, Vacc-4x: a phase 2 randomised, double-blind, placebo-controlled trial.

BACKGROUND: Present combination antiretroviral therapy (cART) alone does not cure HIV infection and requires lifelong drug treatment. The potential role of HIV therapeutic vaccines as part of an HIV cure is under consideration. Our aim was to assess the efficacy, safety, and immunogenicity of Vacc-4x, a peptide-based HIV-1 therapeutic vaccine targeting conserved domains on p24(Gag), in adults infected with HIV-1. METHODS: Between July, 2008, and June, 2010, we did a multinational double-blind, randomised, phase 2 study comparing Vacc-4x with placebo. Participants were adults infected with HIV-1 who were aged 18-55 years and virologically suppressed on cART (viral load <50 copies per mL) with CD4 cell counts of 400 × 10(6) cells per L or greater. The trial was done at 18 sites in Germany, Italy, Spain, the UK, and the USA. Participants were randomly assigned (2:1) to Vacc-4x or placebo. Group allocation was masked from participants and investigators. Four primary immunisations, weekly for 4 weeks, containing Vacc-4x (or placebo) were given intradermally after administration of adjuvant. Booster immunisations were given at weeks 16 and 18. At week 28, cART was interrupted for up to 24 weeks. The coprimary endpoints were cART resumption and changes in CD4 counts during treatment interruption. Analyses were by modified intention to treat: all participants who received one intervention. Furthermore, safety, viral load, and immunogenicity (as measured by ELISPOT and proliferation assays) were assessed. The 52 week follow-up period was completed in June, 2011. For the coprimary endpoints the proportion of participants who met the criteria for cART resumption was analysed with a logistic regression model with the treatment effect being assessed in a model including country as a covariate. This study is registered with ClinicalTrials.gov, number NCT00659789. FINDINGS: 174 individuals were screened; because of slow recruitment, enrolment stopped with 136 of a planned 345 participants and 93 were randomly assigned to receive Vacc-4x and 43 to receive placebo. There were no differences between the two groups for the primary efficacy endpoints in those participants who stopped cART at week 28. Of the participants who resumed cART, 30 (34%) were in the Vacc-4x group and 11 (29%) in the placebo group, and percentage changes in CD4 counts were not significant (mean treatment difference -5·71, 95% CI -13·01 to 1·59). However, a significant difference in viral load was noted for the Vacc-4x group both at week 48 (median 23,100 copies per mL Vacc-4x vs 71,800 copies per mL placebo; p=0·025) and week 52 (median 19,550 copies per mL vs 51,000 copies per mL; p=0·041). One serious adverse event, exacerbation of multiple sclerosis, was reported as possibly related to study treatment. Vacc-4x was immunogenic, inducing proliferative responses in both CD4 and CD8 T-cell populations. INTERPRETATION: The proportion of participants resuming cART before end of study and change in CD4 counts during the treatment interruption showed no benefit of vaccination. Vacc-4x was safe, well tolerated, immunogenic, seemed to contribute to a viral-load setpoint reduction after cART interruption, and might be worth consideration in future HIV-cure investigative strategies. FUNDING: Norwegian Research Council GLOBVAC Program and Bionor Pharma ASA.

Safety, tolerability, and immunogenicity of repeated doses of dermavir, a candidate therapeutic HIV vaccine, in HIV-infected patients receiving combination antiretroviral therapy: results of the ACTG 5176 trial.

BACKGROUND: HIV-specific cellular immune responses are associated with control of viremia and delayed disease progression. An effective therapeutic vaccine could mimic these effects and reduce the need for continued antiretroviral therapy. DermaVir, a topically administered plasmid DNA-nanomedicine expressing HIV (CladeB) virus-like particles consisting of 15 antigens, induces predominantly central memory T-cell responses. METHODS: Treated HIV-infected adults (HIV RNA <50 and CD4 >350) were randomized to placebo or escalating DermaVir doses (0.1 or 0.4 mg of plasmid DNA at weeks 1, 7, and 13 in the low- and intermediate-dose groups and 0.8 mg at weeks 0, 1, 6, 7, 12, and 13 in the high-dose group), n = 5-6 evaluable subjects per group. Immunogenicity was assessed by a 12-day cultured interferon-γ enzyme-linked immunosorbent spot assay at baseline and at weeks 9, 17, and 37 using 1 Tat/Rev and 3 overlapping Gag peptide pools (p17, p24, and p15). RESULTS: Groups were comparable at baseline. The study intervention was well tolerated, without dose-limiting toxicities. Most responses were highest at week 17 (4 weeks after last vaccination) when Gag p24 responses were significantly greater among intermediate-dose group compared with control subjects [median (IQR): 67,600 (5633-74,368) versus 1194 (9-1667)] net spot-forming units per million cells, P = 0.032. In the intermediate-dose group, there was also a marginal Gag p15 response increase from baseline to week 17 [2859 (1867-56,933), P = 0.06], and this change was significantly greater than in the placebo group [0 (-713 to 297), P = 0.016]. CONCLUSIONS: DermaVir administration was associated with a trend toward greater HIV-specific, predominantly central memory T-cell responses. The intermediate DermaVir dose tended to show the greatest immunogenicity, consistent with previous studies in different HIV-infected patient populations.

Older HIV-infected patients on antiretroviral therapy have B-cell expansion and attenuated CD4 cell increases with immune activation reduction.

BACKGROUND: The contribution of immune activation to accelerated HIV-disease progression in older individuals has not been delineated. METHODS: Prospective multicenter cohort of older (≥45 years) and younger (18-30 years) HIV-infected adults initiating 192 weeks of antiretroviral therapy (ART). Longitudinal models of CD4 cell restoration examined associations with age-group, thymic volume, immune activation, and viral load. RESULTS: Forty-five older and 45 younger adults (median age 50 and 26 years, respectively) were studied. Older patients had fewer naive CD4 cells (P<0.001) and higher HLA-DR/CD38 expression on CD4 (P=0.05) and CD8 cells (P=0.07) than younger patients at any time on ART. The rate of naive and total CD4 cell increase was similar between age groups, but older patients had a faster mean rate of B-cell increase (by +0.7 cells/week; P=0.01), to higher counts than healthy controls after 192 weeks (P=0.003). Naive CD4 increases from baseline were associated with immune activation reductions (as declines from baseline of %CD8 cells expressing HLA-DR/CD38; P<0.0001), but these increases were attenuated in older patients, or in those with small thymuses. A 15% reduction in activation was associated with naive gains of 29.9 and 6.2 cells/µl in younger, versus older patients, or with gains of 25.7, 23.4, and 2.1 cells/µl in patients with the largest, intermediate, and smallest thymuses, respectively (P<0.01 for interactions between activation reduction and age-group or thymic volume). CONCLUSION: Older patients had significant B-cell expansion, higher levels of immune activation markers, and significantly attenuated naive CD4 cell gains associated with activation reduction.

Short communication: HIV+ viremic slow progressors maintain low regulatory T cell numbers in rectal mucosa but exhibit high T cell activation.

Viremic slow progressors (VSP) are a rare subset of HIV-infected persons who exhibit slow immunologic progression despite high viremia. The mechanisms associated with this slow progression remain to be defined. Clinical characteristics of VSP are similar to those of natural hosts for simian immunodeficiency virus (SIV), such as sooty mangabeys (SM) and African green monkeys (AGM), who maintain near-normal CD4 counts despite high-level viremia but maintain low immune activation. Immune activation is a powerful predictor of disease progression, and we hypothesized that low immune activation might also explain the VSP phenotype. Using multiparameter flow cytometry, we assessed levels of T cell activation and regulatory T cells (Treg) in blood and rectal mucosa of VSP, typical progressors, virologic controllers, and seronegative controls. We also assessed Treg function and CD4 T cell proliferative capacity in VSP. Contrary to expectations, we found that VSP subjects have high levels of T cell activation in the gastrointestinal mucosa. The ratio of Treg to CD3+ T cells in the mucosa of VSP was relatively low, potentially contributing to increased immune activation. Nonetheless, CD4+CD25- T cells isolated from these individuals displayed a comparatively weak proliferative response to anti-CD3 stimulation. These data reveal that the VSP phenotype is associated with elevated markers of mucosal immune activation and low numbers of mucosal Treg, suggesting that factors other than immune activation account for this phenotype.

Impact of highly active antiretroviral therapy initiation on CD4(+) T-cell repopulation in duodenal and rectal mucosa.

OBJECTIVE: The objective of this study was to assess the effects of HAART initiation on CD4(+) T-cell repopulation and T-cell immune activation in rectal and duodenal mucosa. DESIGN: The effects of HAART on the gastrointestinal tract remain controversial, and studies have reached different conclusions regarding its effectiveness at restoring mucosal CD4(+) T cells depending upon time of initiation, duration of treatment and gastrointestinal tract region studied. METHODS: We obtained blood, rectal biopsies and duodenal biopsies from 14 chronically infected individuals at baseline and at 4-9 months post-HAART initiation. We examined CD4(+) T-cell frequencies in blood, rectum and duodenum at both time points, and performed a detailed assessment of CD4(+) T-cell phenotype, immune activation marker expression and HIV-specific CD8(+) T-cell responses in blood and rectal mucosa. RESULTS: CD4(+) T-cell percentages increased significantly in blood, rectal and duodenal mucosa after 4-9 months of HAART (P = 0.02, 0.0005, 0.0002), but remained lower than in uninfected controls. HIV-specific CD8(+) T-cell responses in blood and rectal mucosa declined following HAART initiation (P = 0.0015, 0.021). CD8(+) T-cell coexpression of CD38 and HLA-DR in blood and mucosa, as well as plasma sCD14, declined significantly. CD28 expression on blood and mucosal CD8(+) T cells increased, whereas programmed death receptor-1 expression on blood HIV-specific CD4(+) and CD8(+) T cells decreased. CONCLUSION: Within the first months of HAART, limited CD4(+) T-cell reconstitution occurs in small and large intestinal mucosa. Nevertheless, decreased immune activation and increased CD28 expression suggest rapid immunological benefits of HAART despite incomplete CD4(+) T-cell reconstitution.

HIV disease activity as a modulator of lipoprotein(a) and allele-specific apolipoprotein(a) levels.

OBJECTIVE: Mechanisms underlying the cardiovascular risk of lipoprotein(a) are poorly understood. We investigated the relationship of apolipoprotein(a) (apo(a)) size, lipoprotein(a), and allele-specific apo(a) levels with HIV disease activity parameters in a biethnic population. METHODS AND RESULTS: Lipoprotein(a) and allele-specific apo(a) levels were determined in 139 white and 168 black HIV-positive patients. Plasma HIV RNA viral load and CD4+ T-cell count were used as surrogates for disease activity. Lipoprotein(a) and allele-specific apo(a) levels were higher in blacks than whites (for both P<0.001). Apo(a) allele size distribution was similar between the 2 ethnic groups, with a median apo(a) size of 28 kringle 4 repeats. Allele-specific apo(a) levels were positively associated with CD4+ T-cell count (P=0.027) and negatively with plasma HIV RNA viral load (P<0.001). Further, allele-specific apo(a) levels associated with smaller (<28 kringle 4) atherogenic apo(a) sizes were higher in subjects with CD4+ T-cell counts of ≥350 (P=0.002). CONCLUSIONS: Allele-specific apo(a) levels were higher in subjects with high CD4+ T-cell count or low plasma HIV RNA viral load. The findings suggest that HIV disease activity reduced allele-specific apo(a) levels. Higher allele-specific apo(a) levels associated with atherogenic small apo(a) sizes might contribute to increased cardiovascular risk in HIV-positive subjects with improved disease status.

T cell activation markers and African mitochondrial DNA haplogroups among non-Hispanic black participants in AIDS clinical trials group study 384.

INTRODUCTION: Mitochondrial function influences T cell dynamics and is affected by mitochondrial DNA (mtDNA) variation. We previously reported an association between African mtDNA haplogroup L2 and less robust CD4 cell recovery on antiretroviral therapy (ART) in non-Hispanic black ACTG 384 subjects. We explored whether additional T cell parameters in this cohort differed by mtDNA haplogroup. METHODS: ACTG 384 randomized ART-naïve subjects to two different nucleoside regimens with efavirenz, nelfinavir, or both. CD4 and CD8 memory and activation markers were available at baseline and week 48 on most subjects. mtDNA sequencing was performed on whole blood DNA, and haplogroups were determined. We studied non-Hispanic black subjects with HIV RNA <400 copies/mL at week 48. Analyses included Wilcoxon ranksum test and linear regression. RESULTS: Data from 104 subjects were included. Major African mtDNA haplogroups included L1 (N=25), L2 (N=31), and L3 (N=32). Baseline age, HIV RNA, and CD4 cells did not differ between L2 and non-L2 haplogroups. Compared to non-L2 haplogroups, L2 subjects had lower baseline activated CD4 cells (median 12% vs. 17%; p=0.03) and tended toward lower activated CD8 cells (41% vs. 47%; p=0.06). At 48 weeks of ART, L2 subjects had smaller decreases in activated CD4 cells (-4% vs. -11%; p=0.01), and smaller CD4 cell increases (+95 vs. +178; p=0.002). In models adjusting for baseline age, CD4 cells, HIV RNA, and naïve-to-memory CD4 cell ratio, haplogroup L2 was associated with lower baseline (p=0.04) and 48-week change in (p=0.01) activated CD4 cells. CONCLUSIONS: Among ART-naïve non-Hispanic blacks, mtDNA haplogroup L2 was associated with baseline and 48-week change in T cell activation, and poorer CD4 cell recovery. These data suggest mtDNA variation may influence CD4 T cell dynamics by modulating T cell activation. Further study is needed to replicate these associations and identify mechanisms.