Dendritic cells potently purge latent HIV-1 beyond TCR-stimulation, activating the PI3K-Akt-mTOR pathway.

BACKGROUND: The latent HIV-1 reservoir in treated patients primarily consists of resting memory CD4+ T cells. Stimulating the T-cell receptor (TCR), which facilitates transition of resting into effector T cells, is the most effective strategy to purge these latently infected cells. Here we supply evidence that TCR-stimulated effector T cells still frequently harbor latent HIV-1. METHODS: Primary HIV-1 infected cells were used in a latency assay with or without dendritic cells (DCs) and reversion of HIV-1 latency was determined, in the presence or absence of specific pathway inhibitors. FINDINGS: Renewed TCR-stimulation or subsequent activation with latency reversing agents (LRAs) did not overcome latency. However, interaction of infected effector cells with DCs triggered further activation of latent HIV-1. When compared to TCR-stimulation only, CD4+ T cells from aviremic patients receiving TCR + DC-stimulation reversed latency more frequently. Such a "one-two punch" strategy seems ideal for purging the reservoir. We determined that DC contact activates the PI3K-Akt-mTOR pathway in CD4+ T cells. INTERPRETATION: This insight could facilitate the development of a novel class of potent LRAs that purge latent HIV beyond levels reached by T-cell activation.

Lactobacillus-dominated cervicovaginal microbiota associated with reduced HIV/STI prevalence and genital HIV viral load in African women.

Cervicovaginal microbiota not dominated by lactobacilli may facilitate transmission of HIV and other sexually transmitted infections (STIs), as well as miscarriages, preterm births and sepsis in pregnant women. However, little is known about the exact nature of the microbiological changes that cause these adverse outcomes. In this study, cervical samples of 174 Rwandan female sex workers were analyzed cross-sectionally using a phylogenetic microarray. Furthermore, HIV-1 RNA concentrations were measured in cervicovaginal lavages of 58 HIV-positive women among them. We identified six microbiome clusters, representing a gradient from low semi-quantitative abundance and diversity dominated by Lactobacillus crispatus (cluster R-I, with R denoting 'Rwanda') and L. iners (R-II) to intermediate (R-V) and high abundance and diversity (R-III, R-IV and R-VI) dominated by a mixture of anaerobes, including Gardnerella, Atopobium and Prevotella species. Women in cluster R-I were less likely to have HIV (P=0.03), herpes simplex virus type 2 (HSV-2; P<0.01), and high-risk human papillomavirus (HPV; P<0.01) and had no bacterial STIs (P=0.15). Statistically significant trends in prevalence of viral STIs were found from low prevalence in cluster R-I, to higher prevalence in clusters R-II and R-V, and highest prevalence in clusters R-III/R-IV/R-VI. Furthermore, only 10% of HIV-positive women in clusters R-I/R-II, compared with 40% in cluster R-V, and 42% in clusters R-III/R-IV/R-VI had detectable cervicovaginal HIV-1 RNA (Ptrend=0.03). We conclude that L. crispatus-dominated, and to a lesser extent L. iners-dominated, cervicovaginal microbiota are associated with a lower prevalence of HIV/STIs and a lower likelihood of genital HIV-1 RNA shedding.

Triple infection with HIV-1, HTLV-1 and Strongyloides stercoralis, rendering CD4+ T-cell counts a misleading entity.

We report the case of a Gabonese HIV-patient who presented with haemoptysis, weight loss, fulminant diarrhoea and subsequent ileus and elevated CD4+ T-cell counts. He was diagnosed with Strongyloides stercoralis and human T-lymphotrophic virus type-1 infection. After treatment of the strongyloides hyperinfection syndrome, his CD4+ T-cell counts dropped greatly. The initially elevated CD4+ T-cell counts were misleading to the clinicians with regard to decision-making on antiretroviral therapy initiation.

Ten years of HIV testing with fourth generation assays: the Amsterdam experience.

Serological HIV assays combining detection of HIV antigen and antibodies are referred to as fourth generation assays. Fourth generation assays were implemented in Europe for routine patient testing about 10 years ago. The Academic Medical Center is one of the main HIV treatment centers in the Netherlands and has now 10 years experience with fourth generation testing, which is summarized here.

Lack of detection of XMRV in seminal plasma from HIV-1 infected men in The Netherlands.

BACKGROUND: Xenotropic murine leukaemia virus-related virus (XMRV) is a recently discovered human gammaretrovirus with yet unknown prevalence and transmission route(s). Its presence in prostate stromal fibroblasts and prostatic secretions suggests that XMRV might be sexually transmitted. We chose to study a compartment closely connected to the prostate, a location where XMRV was detected in independent studies. Seminal plasma samples from HIV-1 infected men were examined as they have an increased probability of acquiring sexually transmitted pathogens. METHODOLOGY/PRINCIPAL FINDINGS: We studied the prevalence of XMRV in 93 seminal plasma samples of 54 HIV-1 infected men living in The Netherlands with a nested PCR amplification specifically targeting the XMRV gag gene. As a control for the presence and integrity of retrovirus particles, HIV-1 was amplified from the same samples with a PCR amplification targeting the env gene of the virus, or HIV-1 was quantified with a real-time PCR amplifying part of the pol gene. CONCLUSIONS/SIGNIFICANCE: Although HIV-1 was amplified from 25% of the seminal plasma samples, no XMRV was detected, suggesting that either the prevalence of XMRV is very low in The Netherlands, or that XMRV is not naturally present in the seminal plasma.

High incidence of asymptomatic syphilis in HIV-infected MSM justifies routine screening.

BACKGROUND: Recently, the incidence of syphilis has risen, mainly among men having sex with men (MSM), many of whom are coinfected with HIV. Current guidelines recommend at least yearly syphilis testing in this group. In this study, we assessed the yield of routine syphilis screening in outpatient HIV-patients. METHODS: From March through June 2003, syphilis serology was routinely performed in HIV-infected patients visiting our outpatient clinic. Serology was repeated six months later. Positive test results of the first episode were compared to historical test results (retrospective analysis). Test results of the second episode were compared to test results from the first episode (prospective analysis). Case records of all patients with a new infection were reviewed for symptomatic disease or testing because of syphilis contacts, versus asymptomatic disease. RESULTS: In the retrospective analysis, 1,105 patients were included. In 68 patients, 81 syphilis infections were identified, of which 33% asymptomatic. 77/81 infections were acquired between 2000 and 2003, resulting in a total incidence of 2.7/100 person years (PY) of follow-up, and 0.9/100 PY for asymptomatic disease. In MSM, the incidence rate was 4.6/100 and 1.5/100 PY respectively. In the prospective analysis, 1,010 patients were included. Seventeen patients, all MSM, had a new or recurrent syphilis infection, of whom 4 asymptomatic, accounting for a total event rate of 3.5/100 PY. In MSM, the event rate was 6.2/100 PY, with an incidence of asymptomatic disease of 1.4/100 PY. CONCLUSION: Routine screening for syphilis identifies significant numbers of asymptomatic syphilis infection in HIV-infected MSM.

Routine HIV-1 genotyping as a tool to identify dual infections.

OBJECTIVES: The incidence of HIV-1 dual infections is generally thought to be low, but as dual infections have been associated with accelerated disease progression, its recognition is clinically important. Methods to identify HIV-1 dual infections are time consuming and are not routinely performed. DESIGN: Genotyping of the HIV-1 protease and reverse transcriptase (prot/RT) genes is commonly performed in the western world to detect drug-resistance mutations in clinical isolates. In our hospital, prot/RT baseline sequencing is part of the patient care for all newly infected patients in the Amsterdam region since 2003. We reasoned that degenerate base codes in this sequence could indicate either extensive viral evolution or infection with multiple HIV-1 strains. METHODS: We amplified, cloned and sequenced multiple HIV-1 envelope (env)-V3 and gag sequences from patients with 34 or more (range 34-99) degenerate base codes in the ViroSeq genotyping RT sequence (37 out of 1661 available records) to estimate the number of HIV-1 dual infections in this group. RESULTS: Of the 37 patients included in this study, 16 (43.2%, equal to 1% of the 1661 total records) had an HIV-1 dual infection based on phylogenetic analysis of env-V3/gag sequences. If only sequences with 45 or more degenerate base codes were taken into account, 73.3% of patients showed evidence of a dual infection. CONCLUSION: We describe an additional use of routinely performed HIV-1 genotyping. In patients with a high number of degenerate bases (> or = 34) in RT it is important to consider the possibility of a dual HIV-1 infection.

Epstein-Barr virus infects B and non-B lymphocytes in HIV-1-infected children and adolescents.

Epstein-Barr virus (EBV) is a widespread, persistent herpesvirus that can transform B cells and that is associated with malignant lymphomas. EBV dynamics and specific immunity in human immunodeficiency virus (HIV)-1-infected children are unknown. We found that, in 74% of EBV-seropositive, HIV-1-infected children, EBV DNA loads at the start of highly active antiretroviral therapy (HAART) were comparable with those in acutely EBV-infected, HIV-negative children. EBV DNA load remained elevated in most HIV-1-infected children for months to years of follow-up. Frequencies of interferon-gamma-producing EBV-specific CD8+ T cells were comparable with those in healthy control children, and antibodies to EBV nuclear antigen were detected in 73% of EBV-seropositive children. Detectable EBV DNA load was not correlated with HIV-1 RNA level or with CD4+ T cell count increase after the start of HAART. Because of its resemblance to chronic active EBV, we studied the cellular tropism of EBV in these patients. EBV DNA was found not only in the CD19+ B cell fraction but also--at stable levels--in the CD4+ and CD8+ T cell fractions. Although the reason for the aberrant T cell tropism of EBV remains unclear, these data may provide an explanation for the differential EBV dynamics in the presence of normal serological findings.

Persistent humoral immune defect in highly active antiretroviral therapy-treated children with HIV-1 infection: loss of specific antibodies against attenuated vaccine strains and natural viral infection.

OBJECTIVE: In the pre-highly active antiretroviral therapy era, a loss of specific antibodies was seen. Our objective with this study was to describe the loss of specific antibodies during treatment with highly active antiretroviral therapy. METHODS: In a prospective, single-center, cohort study of 59 children with HIV-1 infection, we investigated the long-term effect of highly active antiretroviral therapy on the titers and course of specific antibodies against measles, mumps, and rubella vaccine strains compared with wild-type varicella zoster virus, cytomegalovirus, and Epstein-Barr virus. RESULTS: During highly active antiretroviral therapy, age-adjusted CD4+ T cells and B cells increased, whereas total immunoglobulin levels declined. Although these children were preimmunized before the start of highly active antiretroviral therapy, only 24 (43%) had antibodies against all 3 measles, mumps, and rubella. Antibodies against measles, mumps, and rubella were lost in 14 (40%), 11 (38%), and 5 (11%) children who were seropositive at baseline. We also observed loss of varicella zoster virus immunoglobulin G in 7 (21%) of 34, cytomegalovirus immunoglobulin G in 3 (7%) of 45, but none of 53 Epstein-Barr virus-seropositive children. During highly active antiretroviral therapy, primary vaccination in 3 patients and 15 revaccinations in those with negative serology demonstrated incomplete seroconversion. CONCLUSIONS: Humoral reactivity in children with HIV-1 infection remains abnormal during highly active antiretroviral therapy. Despite immune reconstitution, antibodies against live-attenuated vaccine and wild-type natural virus strains disappear over time in up to 40% of children with HIV-1 infection.

Cytomegalovirus rather than HIV triggers the outgrowth of effector CD8+CD45RA+CD27- T cells in HIV-1-infected children.

OBJECTIVE: To analyse the effect of viral coinfections on immune reconstitution in HIV-1-infected children (< 18 years) taking highly active antiretroviral therapy (HAART). METHODS: Absolute lymphocyte numbers of various subsets of CD8 T cells were measured. RESULTS: Prior cytomegalovirus (CMV) infection correlated with an increased number of CD8 effector T cells (i.e., CD45RA+CD27-) at baseline (CMV-seropositive versus CMV-seronegative patients; P = 0.009), as well as an increased state of T cell activation as defined by HLA-DR and CD38 expression. The expansion of effector CD8 T cells persisted over time, independent of the HIV response to HAART. Numbers of CD8 effector T cells were significantly higher in patients with CMV replication as reflected by persistent urinary CMV shedding and periodic CMV DNAaemia (P = 0.02). These patients also showed an increase in CMV-specific antibodies compared with those without CMV shedding (P = 0.007). The number of CMV-specific interferon-gamma (IFN-gamma)-producing CD8 T cells was lower in children who persistently shed CMV compared with those who did not (P = 0.02). In contrast, CMV-specific CD4 T cell responses were detected at similar levels in both groups. CONCLUSIONS: In HIV-1-infected children, CMV infection correlated with the outgrowth of CD8+CD45RA+CD27- effector T cells. Activation of the immune system by persistent CMV secretion resulted in increasing CMV-specific IgG and higher numbers of CD8 effector T cells. Despite these increases, the CMV-specific IFN-gamma-producing CD8 T cell response was diminished, which could explain the inability to suppress CMV completely in 41% of HIV-1-infected children.