Early Phases Of HIV Infection Research Articles

Predictors for the incidence of pneumonia among HIV-infected children on antiretroviral therapy in Amhara Regional State Comprehensive Specialized Hospitals, Ethiopia: a multicenter retrospective follow-up study

BackgroundHuman Immune deficiency Virus (HIV) infected children are at higher risk of developing pneumonia. Particularly, in the early phase of HIV infection, the risk of acquiring pneumonia is high, and it remains a major public health problem even after the test and treatment strategy. There is no clear evidence of the overall incidence of pneumonia among HIV-infected children in Amhara region. Aimed to assess the incidence of pneumonia and its predictors among HIV-infected children receiving Antiretroviral therapy in Amhara Region Comprehensive Specialized Hospitals, 2022.MethodsA multicenter retrospective follow-up study was conducted from June 10, 2014, to February 28, 2022, among 430 HIV-positive children receiving antiretroviral therapy. A simple random sampling technique was used. The data was taken from the national antiretroviral intake and follow-up forms. The data were collected via the KoBo toolbox and analyzed using Stata version 17. The Kaplan–Meier curve and log-rank test were employed. Bivariable and multivariable Cox regression was carried out to identify predictors of pneumonia and a P-value < 0.05 was considered significant in to multivariable analysis.ResultsA total of 407 children with a record completeness rate of 94.7% were analyzed in the study. The incidence rate of pneumonia was 4.55 (95% CI; 3.5, 5.92) per 100 person-years observation. The mean survival time was 77.67 months and the total times at risk during follow-up period were yielding 1229.33 person-year observations. Having CD4 cell count below threshold [AHR; 2.71 (95% CI: 1.37, 5.35)], WHO stage III and IV [AHR: 2.17 (95% CI: 1.15, 4.08)], ever had fair and poor treatment adherence [AHR: 2.66 (95% CI: 1.45, 4.89)], and not initiated antiretroviral therapy within seven days [AHR: 2.35 (95% CI: 1.15, 4.78)] were the positive predictors for incidence of Pneumonia.ConclusionsIn this study, the incidence of pneumonia was lower than the previous studies. CD4 cells below the threshold, ever had fair and poor adherence to antiretroviral therapy, WHO stage III and IV, and not initiated antiretroviral therapy within seven days were significant predictors. Therefore,, it is crucial to detect baseline assessment and give attention to those identified predictors promptly, and timely initiation of antiretroviral therapy need special attention.

Substantial induction of non-apoptotic CD4 T-cell death during the early phase of HIV-1 infection in a humanized mouse model

Several mechanisms underline induction of CD4 T-cell death by human immunodeficiency virus (HIV) infection. For a long time, apoptosis was considered central to cell death involved in the depletion of CD4 T cells during HIV infection. However, which types of cell death are induced during the early phase of HIV infection in vivo remains unclear. In this study, CD4 T-cell death induced in early HIV infection was characterized using humanized mice challenged with CCR5-tropic (R5) or CXCR4-tropic (X4) HIV-1. Results showed that CD4 T-cell death was induced in the spleen 3 days post-challenge with both R5 and X4 HIV-1. Although cell death without caspase-1 and caspase-3/7 activation was preferentially observed, caspase-1+ pyroptosis was also significantly induced within the memory subpopulation by R5 or X4 HIV-1 and the naïve subpopulation by X4 HIV-1. In contrast, caspase-3/7+ apoptosis was not enhanced by either R5 or X4 HIV-1. Furthermore, phosphorylated mixed lineage kinase domain-like protein+ necroptosis was induced by only X4 HIV-1. These findings indicate that various types of non-apoptotic CD4 T-cell death, such as pyroptosis and necroptosis, are induced during the early phase of HIV infection in vivo.

Increased Expression of sST2 in Early HIV Infected Patients Attenuated the IL-33 Induced T Cell Responses.

T cell responses were less functional and persisted in an exhausted state in chronic HIV infection. Even in early phase of HIV infection, the dysfunction of HIV-specific T cells can be observed in rapid progressors, but the underlying mechanisms are not fully understood. Cytokines play a central role in regulating T cell function. In this study, we sought to elucidate whether IL-33/ST2 axis plays roles in the regulation of T cell function in HIV infection. We found that the level of IL-33 was upregulated in early HIV-infected patients compared with that in healthy controls and has a trend associated with disease progression. In vitro study shows that IL-33 promotes the expression of IFN-γ by Gag stimulated CD4+ and CD8+T cells from HIV-infected patients to a certain extent. However, soluble ST2 (sST2), a decoy receptor of IL-33, was also increased in early HIV infected patients, especially in those with progressive infection. We found that anti-ST2 antibodies attenuated the effect of IL-33 to CD4+ and CD8+T cells. Our data indicates that elevated expression of IL-33 in early HIV infection has the potential to enhance the function of T cells, but the upregulated sST2 weakens the activity of IL-33, which may indirectly contribute to the dysfunction of T cells and rapid disease progression. This data broadens the understanding of HIV pathogenesis and provides critical information for HIV intervention.

Mass Cytometry Analysis Reveals the Landscape and Dynamics of CD32a+ CD4+ T Cells From Early HIV Infection to Effective cART

CD32a has been proposed as a specific marker of latently HIV-infected CD4+ T cells. However, CD32a was recently found to be expressed on CD4+ T cells of healthy donors, leading to controversy on the relevance of this marker in HIV persistence. Here, we used mass cytometry to characterize the landscape and variation in the abundance of CD32a+ CD4+ T cells during HIV infection. To this end, we analyzed CD32a+ CD4+ T cells in primary HIV infection before and after effective combination antiretroviral therapy (cART) and in healthy donors. We found that CD32a+ CD4+ T cells include heterogeneous subsets that are differentially affected by HIV infection. Our analysis revealed that naive (N), central memory (CM), and effector/memory (Eff/Mem) CD32a+ CD4+ T-cell clusters that co-express LILRA2- and CD64-activating receptors were more abundant in primary HIV infection and cART stages. Conversely, LILRA2− CD32a+ CD4+ T-cell clusters of either the TN, TCM, or TEff/Mem phenotype were more abundant in healthy individuals. Finally, an activated CD32a+ CD4+ TEff/Mem cell cluster co-expressing LILRA2, CD57, and NKG2C was more abundant in all HIV stages, particularly during primary HIV infection. Overall, our data show that multiple abundance modifications of CD32a+ CD4+ T-cell subsets occur in the early phase of HIV infection, and some of which are conserved after effective cART. Our study brings a better comprehension of the relationship between CD32a expression and CD4+ T cells during HIV infection.

Monocyte-derived exosomes upon exposure to cigarette smoke condensate alter their characteristics and show protective effect against cytotoxicity and HIV-1 replication

Smoking is known to exacerbate HIV-1 pathogenesis, especially in monocytes, through the oxidative stress pathway. Exosomes are known to alter HIV-1 pathogenesis through inter-cellular communication. However, the role of exosomes in smoking-mediated HIV-1 pathogenesis is unknown. In this study, we investigated the effect of cigarette smoke condensate (CSC) on the characteristics of monocyte-derived exosomes and their influence on HIV-1 replication. Initially, we demonstrated that CSC reduced total protein and antioxidant capacity in exosomes derived from HIV-1-infected and uninfected macrophages. The exosomes from CSC-treated uninfected cells showed a protective effect against cytotoxicity and viral replication in HIV-1-infected macrophages. However, exosomes derived from HIV-1-infected cells lost their protective capacity. The results suggest that the exosomal defense is likely to be more effective during the early phase of HIV-1 infection and diminishes at the latter phase. Furthermore, we showed CSC-mediated upregulation of catalase in exosomes from uninfected cells, with a decrease in the levels of catalase and PRDX6 in exosomes derived from HIV-1-infected cells. These results suggest a potential role of antioxidant enzymes, which are differentially packaged into CSC-exposed HIV-1-infected and uninfected cell-derived exosomes, on HIV-1 replication of recipient cells. Overall, our study suggests a novel role of exosomes in tobacco-mediated HIV-1 pathogenesis.

Granulocytic Myeloid-Derived Suppressor Cells Increased in Early Phases of Primary HIV Infection Depending on TRAIL Plasma Level.

It has been demonstrated that myeloid-derived suppressor cells (MDSC) are expanded in HIV-1-infected individuals and correlated with disease progression. The phase of HIV infection during which MDSC expansion occurs, and the mechanisms that regulate this expansion remain to be established. In this study, we evaluated the frequency of MDSC in patients during primary HIV infection (PHI) and factors involved in MDSC control. Patients with PHI and chronic HIV infection (CHI) were enrolled. PHI staging was performed according to Fiebig classification, and circulating MDSC frequency and function were evaluated by flow cytometry. Cytokine levels were evaluated by Luminex technology. We found that granulocytic MDSC (Gr-MDSC) frequency was higher in patients with PHI compared with healthy donors, but lower than that in patients with CHI. Interestingly, Gr-MDSC expansion was observed in the early phases of HIV infection (Fiebig II/III), but it was not associated with HIV viral load and CD4 T-cell count. Interestingly, in PHI, Gr-MDSC frequency was inversely correlated with plasmatic level of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), although a direct correlation was observed in CHI. Furthermore, lower level of Granulocyte Macrophage Colony Stimulating Factor (GM-CSF) was observed in PHI compared with that in CHI. In vitro experiments demonstrated that, differently from CHI, recombinant TRAIL-induced apoptosis of Gr-MDSC from PHI, an effect that can be abrogated by GM-CSF. We found that Gr-MDSC are expanded early during PHI and may be regulated by TRAIL and GM-CSF levels. These findings shed light on the fine mechanisms regulating the immune system during HIV infection and open new perspectives for immune-based strategies.

Characterization of two distinct early post-entry blocks to HIV-1 in common marmoset lymphocytes.

In nature, primate lentiviruses infect humans and several Old World monkeys and apes. However, to date, lentiviruses infecting New World monkeys have not been described. We studied the susceptibility of common marmoset cells to HIV-1 infection and observed the presence of post-entry blocks to the early phase of HIV-1 infection in peripheral blood lymphocytes (PBLs) and a B lymphocytic cell line (B-LCL). The blocks present in these cells are dominant and phenotypically different from each other. In PBLs, the block occurs at the level of reverse transcription, reducing the accumulation of early and late transcripts, similar to the block imposed by TRIM5α. However, we have found that marmoset TRIM5α does not block HIV-1. In contrast, the restriction factor present in B-LCLs blocks HIV-1 replication at a later step, after nuclear entry, and inhibits integration. Additionally, we have identified an HIV-1 capsid mutant, N74D, that is able to escape the restriction in the marmoset B-LCLs. Our results suggest that the factors responsible for the blocks present in marmoset PBLs and B-LCLs are different. We propose the existence of at least two new restriction factors able to block HIV-1 infection in marmoset lymphocytes.

Anti-HIV-1 potency of the CRISPR/Cas9 system insufficient to fully inhibit viral replication.

The range of genome-editing tools has recently been expanded. In particular, an RNA-guided genome-editing tool, the clustered regularly interspaced short palindromic repeat (CRISPR)-associated 9 (Cas9) system, has many applications for human diseases. In this study, guide RNA (gRNA) to target gag, pol and a long terminal repeat of HIV-1 was designed and used to generate gRNA-expressing lentiviral vectors. An HIV-1-specific gRNA and Cas9 were stably dually transduced into a highly HIV-1-susceptible human T-cell line and the inhibitory ability of the anti-HIV-1 CRISPR/Cas9 lentiviral vector assessed. Although clear inhibition of the early phase of HIV-1 infection was observed, as evaluated by a VSV-G-pseudotyped HIV-1 reporter system, the anti-HIV-1 potency in multiple rounds of wild type (WT) viral replication was insufficient, either because of generation of resistant viruses or overcoming of the activity of the WT virus. Thus, there are potential difficulties that must be addressed when considering anti-HIV-1 treatment with the CRISPR/Cas9 system alone.

Replication of Human Herpesviruses Is Associated with Higher HIV DNA Levels during Antiretroviral Therapy Started at Early Phases of HIV Infection.

Asymptomatic replication of human herpesviruses (HHV) is frequent in HIV-infected men and is associated with increased T-cell activation and HIV disease progression. We hypothesized that the presence of replication of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) (the most frequently detected HHV) might influence HIV DNA decay during antiretroviral therapy (ART). We investigated 607 peripheral blood mononuclear cell (PBMC) samples from 107 CMV-seropositive, HIV-infected men who have sex with men, who started ART within a median of 3 months from their estimated date of infection (EDI) and were monitored for a median of 19 months thereafter. Levels of HIV, CMV, and EBV DNA and cellular HIV RNA were measured by droplet digital PCR (ddPCR) for each time point. Using a general linear mixed-effect regression model, we evaluated associations between the presence of detectable CMV DNA and EBV DNA levels and HIV DNA decay and cellular HIV RNA levels, while adjusting for peak HIV RNA, nadir CD4(+)count, CD4/CD8 ratio, CMV IgG levels, time from EDI to ART initiation, time from ART initiation to virologic suppression, detectable CMV DNA pre-ART, and age. The presence of intermittent CMV DNA in PBMC during ART was significantly associated with slower decay of HIV DNA (P= 0.011) but not with increased cellular HIV RNA transcription or more detectable 2-long terminal repeat circles. Higher levels of EBV DNA were also associated with higher levels of HIV DNA (P< 0.001) and increased unspliced cellular HIV RNA transcription (P= 0.010). These observations suggest that replication of HHV may help maintain a larger HIV DNA reservoir, but the underlying mechanisms remain unclear. Over three-fourths of HIV-infected men have at least one actively replicating human herpesvirus (HHV) in their mucosal secretions at any one time. Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) are the most common, and although it is often asymptomatic, such CMV and EBV replication is associated with higher levels of immune activation and HIV disease progression. We hypothesized that HHV-associated activation of HIV-infected CD4(+)T cells might lead to increased HIV DNA. This study found that detectable CMV in blood cells of HIV-infected men was associated with slower decay of HIV DNA even during antiretroviral therapy (ART) that was started during early HIV infection. Similarly, levels of EBV DNA were associated with higher levels of HIV DNA during ART. If this observation points to a causal pathway, interventions that control CMV and EBV replication may be able to reduce the HIV reservoir, which might be relevant to current HIV cure efforts.

BMI and Risk Factors of Underweight and Obesity in HIV Subjects in Eastern Nigeria

Background and Objectives: Human immunodeficiency virus infection (HIV) is a global healthcare problem. Progression of HIV infection is commonly associated with decreasing weight. In the early phases of HIV infection, factors associated with weight changes are not completely known. This study evaluated the body mass index (BMI) and its potential risk factors in drug-naive HIV subjects in Owerri, Eastern Nigeria. Methodology: This was a cross-sectional study of HIV subjects. BMI was determined. Relevant investigations were performed. Potential risk factors of BMI were analyzed at different BMI categories. Association of variables with BMI and the strength of variables to predict BMI, underweight and obesity were determined. Results: The mean BMI of the HIV subjects was 26.2 ± 5.4 kg/m2. Underweight was present in 24 (6.1%), overweight in 150 (38.4%) and obesity in 84 (21.5%) of the HIV subjects. High spot urine creatinine (SUCr), high 24-hour urine osmolality (24HUOsm), high serum cholesterol and high hemoglobin predicted BMI in HIV subjects. Low 24HUOsm predicted under weight, whereas low 24-hour urine protein (24 HUP) and high 24HUOsm predicted obesity in HIV subjects. Conclusion: The prevalence of underweight was low (6.1%), overweight high (38.4%) and obesity high (21.5%) in HIV subjects. High SUCr, high 24HUOsm, high serum cholesterol and high hemoglobin were predictors of BMI in HIV subjects. Low 24HUOsm was a predictor of underweight, while low 24HUP and high 24HUOsm were predictors of obesity in HIV subjects. Abnormalities of serum lipids, renal function, and anemia were common in HIV subjects who were underweight and in those obese. Underweight HIV subjects should be evaluated at the early stages for dyslipidemia, renal damage and anemia.

Primary and Chronic HIV Infection Differently Modulates Mucosal Vδ1 and Vδ2 T-Cells Differentiation Profile and Effector Functions.

Gut-associated immune system has been identified as a major battlefield during the early phases of HIV infection. γδ T-cells, deeply affected in number and function after HIV infection, are able to act as a first line of defence against invading pathogens by producing antiviral soluble factors and by killing infected cells. Despite the relevant role in mucosal immunity, few data are available on gut-associated γδ T-cells during HIV infection. Aim of this work was to evaluate how primary (P-HIV) and chronic (C-HIV) HIV infection affects differentiation profile and functionality of circulating and gut-associated Vδ1 and Vδ2 T-cells. In particular, circulating and mucosal cells were isolated from respectively whole blood and residual gut samples from HIV-infected subjects with primary and chronic infection and from healthy donors (HD). Differentiation profile and functionality were analyzed by multiparametric flow cytometry. P-HIV and C-HIV were characterized by an increase in the frequency of effector Vδ1-T cells both in circulating and mucosal compartments. Moreover, during P-HIV mucosal Vδ1 T-cells expressed high levels of CD107a, suggesting a good effector cytotoxic capability of these cells in the early phase of infection that was lost in C-HIV. P-HIV induced an increase in circulating effector Vδ2 T-cells in comparison to C-HIV and HD. Notably, P-HIV as well as HD were characterized by the ability of mucosal Vδ2 T-cells to spontaneously produce IFN-γ that was lost in C-HIV. Altogether, our data showed for the first time a functional capability of mucosal Vδ1 and Vδ2 T-cells during P-HIV that was lost in C-HIV, suggesting exhaustion mechanisms induced by persistent stimulation.

Performances of fourth generation HIV antigen/antibody assays on filter paper for detection of early HIV infections

BackgroundPoint-of-care testing and diagnosis of HIV acute infections play important roles in preventing transmission, but HIV rapid diagnosis tests have poor capacity to detect early infections. Filter paper can be used for capillary blood collection and HIV testing using 4th generation immunoassays. ObjectivesAntigen/antibody combined immunoassays were evaluated for their capacity to identify early HIV infections using filter paper in comparison with rapid test. Study designThirty nine serum samples collected from HIV seroconverters were spotted onto filter paper and tested by the Roche Elecsys® HIV Combi PT test and the DiaSorin Liaison XL Murex HIV Ab/Ag assay. ResultsFourth generation immunoassays identified 34 out of 39 HIV early infections using dried serum spot, whereas the Determine™ HIV-1/2 rapid test detected 24 out of 39 HIV positive serum (87.2% vs 61.5% respectively, p=0.009). p24 antigen was detected by the Liaison XL in 19 dried serum samples (48.7%). In the group characterized by a negative western blot, 7 out of 8 (87.5%) and 6 out of 8 (75.0%) samples were found positive for HIV using the Elecsys and the Liaison XL, respectively. None of these eight samples classified in this group of early acute infections were found positive by the rapid test. ConclusionFourth generation Ag/Ab immunoassays performed on dried serum spot had good performance for HIV testing during the early phases of HIV infection. This method may be useful to detect HIV early infections in hard-to-reach populations and individuals living in remote areas before rapid tests become positive.

Treatment outcome in HIV+ patients receiving 3- or 4-drug regimens during PHI.

IntroductionThe optimal timing and modality of therapeutic intervention during early phases of HIV infection is still debated; in our prospective observational study we evaluated immunological and virological outcome in HIV+ patients treated during acute or recent HIV infection.Materials and MethodsA total of 25 naïve patients with acute (detectable HIV-RNA, immature Western Blot) or recent (documented infection within six months) HIV infection were recruited at the Infectious Diseases Units of the University of Milan and Turin from 2009 to 2014. Patients received treatment with two NRTIs+one NNRTI/bPI, with or without an induction phase with an additional fourth drug (raltegravir or maraviroc) until HIV-RNA undetectability maintained for six months. Blood samples for HIV-RNA, lymphocyte subsets and tropism assessment were obtained at the beginning of the treatment (BL). Patients underwent subsequent six-monthly follow up for clinical outcome, CD4 cell count and HIV-RNA up to 18 months.ResultsMedian increase in CD4 cells from 0 to 12 months was greater in patients treated during acute (n=18) versus recent (n=7) infection [284/µL, IQR (227–456) versus 176/µL, IQR (70–235); Mann-Whitney test, p=0.046]. This higher value was maintained through 18 months, although failing to reach statistical significance. Patients with acute or recent infection did not significantly differ in virological success (83.3% versus 85.7% at 12 months). We considered CD4 cells gains at six months (multivariate analysis, ANCOVA; Figure 1) and detected an inverse correlation with CD4 levels at BL (r=−0.517; p=0.008) and a direct correlation with the status of acute infection (r=0.234, p NS). This last correlation reached statistical significance at 12 months (r=0.418, p=0.035), whereas the inverse correlation with CD4 levels at BL was still present without a statistical significance (r=−0.350; p=0.072). Patients treated with three or four drugs did not show any significant difference in immunological nor virological response (Mann-Whitney and χ2 test). Modification or interruption of therapy for tolerability took place in 4 out of 25 patients, all while receiving four drugs; two patients underwent STI between 12 and 18 months following virological success.ConclusionsTreatment of primary infection appeared to be effective in preserving the pool of CD4 cells in acute more than recent infection. There was no evidence of a different outcome through the addition of a fourth drug to the standard treatment.

Innate sensing of viral infection by pDCs and regulation by IFN-α and HMGB1 of TRAIL expression on pDCs and NK cells

At an early stage of HIV-1 transmission, plasmacytoid dendritic cells (pDCs) and natural killer (NK) cells are recruited into mucosal tissues. pDCs are the major source of type I interferon (IFN-α), a powerful innate antiviral cytokine, and a strong pDC response is associated with spontaneous virus control. The contribution of pDCs to licensing NK cells and inducing antiviral immunity make them a key player in the early phase of HIV-1 infection. In contrast, the chronic expression of IFN-α was found to be a key mediator for HIV pathogenesis. We addressed herein the question of the molecular mechanisms involved in the generation of Interferon-producing Killer pDCs (IKpDCs), and the consequences on viral control.

The Potential Role of CD16+Vγ2Vδ2 T Cell-Mediated Antibody-Dependent Cell-Mediated Cytotoxicity in Control of HIV Type 1 Disease

Increasing evidence has suggested that HIV infection severely damages the Vγ2Vδ2 (Vδ2) T cells that play an important role in the first-line host response to infectious disease. However, little is known about Vδ2 T cell-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) in HIV disease. We found that although the CD16(+) Vδ2 T cell subset hardly participated in phosphoantigen responses dominated by the CD16(-) Vδ2 T cell subset, the potency of the ADCC function of Vδ2 T cells was correlated with the frequency of the CD16(+) subset. Thus, two distinct and complementary Vδ2 T cell subsets discriminated by CD16 were characterized to explore the respective impacts of HIV-1 infection on them. HIV-1 disease progression was not only associated with the phosphoantigen responsiveness of the CD16(-) Vδ2 subset, but also with the ability of the CD16(+) Vδ2 subset to kill antibody-coated target cells. Furthermore, both of the two Vδ2 functional subsets could be partially restored in HIV-infected patients with antiretroviral therapy. Notably, in the context of an overall HIV-mediated Vδ2 T cell depletion, despite the decline of phosphoantigen-responsive CD16(-) Vδ2 cells, CD16(+) Vδ2 cell-mediated ADCC was not compromised but exhibited a functional switch with dramatic promotion of degranulation in the early phase of HIV infection and chronic infection with slower disease progression. Our study reveals functional characterizations of the two Vδ2 T cell subsets with different activation pathways during HIV-1 infection and provides a rational direction for activating the CD16(+) Vδ2 T cells capable of mediating ADCC as a means to control HIV-1 disease.

Dynamic variation of HIV-1 CRF07_BC env gene in early HIV-1 infection

To understand the evolution of HIV-1 CRF07_BC envelope, we performed a longitudinal study on two patients during their early HIV-1 infection. RNA was extracted from the plasma of the individuals and the C2-C5 fragments of the gp120 gene of HIV-1 were amplified by RT-PCR. Purified DNA segments were inserted into T easy vector and transformed into E. coli Top 10 competent cells. Positive clones were identified by blue-white screening, confirmed by PCR and sequenced by ABI 3700. The samples were collected from the patients every 6 months from seroconversion time. The genetic diversity and divergence in env gene showed consistent increases over time. Our sequence analysis also revealed obvious non-synonymous change in env C1, C3 and V4 regions among these samples. The results support the concept that the consistent pattern of viral evolution existed during early phase of HIV-1 infection. C1, C3 and V4 region of env gene may be mainly immunological target during AIDS progression.

Human Polycomb groupEED protein negatively affects HIV-1 assembly and release

BackgroundThe human EED protein, a member of the superfamily of Polycomb group (PcG) proteins with WD-40 repeats, has been found to interact with three HIV-1 components, namely the structural Gag matrix protein (MA), the integrase enzyme (IN) and the Nef protein. The aim of the present study was to analyze the possible biological role of EED in HIV-1 replication, using the HIV-1-based vector HIV-Luc and EED protein expressed by DNA transfection of 293T cells.ResultsDuring the early phase of HIV-1 infection, a slight negative effect on virus infectivity occurred in EED-expressing cells, which appeared to be dependent on EED-MA interaction. At late times post infection, EED caused an important reduction of virus production, from 20- to 25-fold as determined by CAp24 immunoassay, to 10- to 80-fold based on genomic RNA levels, and this decrease was not due to a reduction of Gag protein synthesis. Coexpression of WTNef, or the non-N-myristoylated mutant NefG2A, restored virus yields to levels obtained in the absence of exogenous EED protein. This effect was not observed with mutant NefΔ57 mimicking the Nef core, or with the lipid raft-retargeted fusion protein LAT-Nef. LATAA-Nef, a mutant defective in the lipid raft addressing function, had the same anti-EED effect as WTNef. Cell fractionation and confocal imaging showed that, in the absence of Nef, EED mainly localized in membrane domains different from the lipid rafts. Upon co-expression with WTNef, NefG2A or LATAA-Nef, but not with NefΔ57 or LAT-Nef, EED was found to relocate into an insoluble fraction along with Nef protein. Electron microscopy of HIV-Luc producer cells overexpressing EED showed significant less virus budding at the cell surface compared to control cells, and ectopic assembly and clustering of nuclear pore complexes within the cytoplasm.ConclusionOur data suggested that EED exerted an antiviral activity at the late stage of HIV-1 replication, which included genomic RNA packaging and virus assembly, resulting possibly from a mistrafficking of viral genomic RNA (gRNA) or gRNA/Gag complex. Nef reversed the EED negative effect on virus production, a function which required the integrity of the Nef N-terminal domain, but not its N-myristoyl group. The antagonistic effect of Nef correlated with a cellular redistribution of both EED and Nef.

Neopterin levels during the early phase of human immunodeficiency virus, hepatitis C virus, or hepatitis B virus infection

A study was conducted to assess the diagnostic sensitivity of neopterin screening of blood donors with regard to the detection of window-phase specimens of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) infection. In total, 1002 diagnostic window-phase specimens from 98 seroconversion panels (29 HIV-1, 52 HCV, and 17 HBV) were analyzed with viral antigen detection, viral nucleic acid amplification testing (NAT), and neopterin quantitation assays. The study was completed by the analysis of 92 anti-hepatitis B core antigen (HBc)-reactive and 103 alanine aminotransferase (ALT)-elevated blood donor specimens. A significant association between elevated neopterin concentrations and the very early phase of HIV-1 infection was found. No significant correlation could be observed between neopterin levels and the early phase of HCV or HBV infection. Neopterin concentration was not increased in specimens from blood donors with anti-HBc reactivity or ALT elevation. Neopterin screening of blood donors may identify window-phase cases of HIV, but not of HCV or HBV infection. The diagnostic sensitivity of neopterin screening during the HIV window phase is similar to that of the p24 antigen test. With the introduction of viral NATs in blood screening, there is no additional benefit of neopterin screening with regard to the three blood-borne viruses HIV, HCV, and HBV. Acute phases of other infectious agents, however, have been reported to be detected by neopterin enzyme-linked immunosorbent assays.

Power Spectral Analysis of Heart Rate Variability in HIV‐Infected and AIDS Patients

In HIV-infected patients the risks for cardiovascular disease are multifactorial. Autonomic dysfunction has been detected in the early phase of HIV infection as well as in AIDS patients with advanced cardiomyopathy. Forty AIDS patients receiving highly active antiretroviral therapy (HAART), 40 HIV+ naïve of HAART, and 40 control subjects were studied. Computerized analysis of heart rate variability was performed using an analog to digital converter. R-R intervals were obtained from a standard ECG, recorded in DII lead in supine rest and after the cold-face and tilt tests. The series of R-R intervals were assessed in time and frequency domains using an autoregressive algorithm. There was no difference regarding to mean values of R-R intervals and variance in baseline. The normalized power of the low-frequency (LF) component and the low-frequency/high-frequency (HF) ratio (LF/HF) was significantly decreased in the HIV group. Responses of normalized HF and LF/HF ratio during the cold-face test were significantly decreased in the HIV group, as compared to the control. During the tilt test, a higher augmentation of normalized LF and the LF/HF ratio was observed in the HIV group compared with the control. The AIDS group was similar to the control in baseline and after cold-face and tilt tests. The HIV group presented in baseline conditions, a shift of cardiac sympathovagal balance, an exacerbated response of the LF component during the tilt test, and an ineffective cardiac vagal response to the cold-face test suggesting sympathetic and parasympathetic dysfunction. AIDS patients receiving HAART did not present these autonomic alterations.

Accumulation of DC-SIGN+CD40+ dendritic cells with reduced CD80 and CD86 expression in lymphoid tissue during acute HIV-1 infection.

Dendritic cells (DC) are target cells for HIV-1 and play a key role in antigen presentation and activation of T cells. To characterize interdigitating DC in lymphoid tissue (LT) with regard to maturation, expression of cytokines and co-stimulatory molecules in HIV-1-positive patients. DC were characterized by immunohistochemistry and in situ imaging in LT from patients with acute HIV-1 infection (aHI), antiretroviral treated patients, long-term non-progressors/slow progressors with HIV-1 infection (LTNP/SLP), patients with AIDS, HIV-1-negative controls and patients with acute Epstein-Barr virus (EBV) infection. A significant increase of interdigitating DC expressing CD1a, S-100b, CD83 and DC-SIGN was found in LT from patients with aHI (P < 0.02). The co-stimulatory molecules CD80 and CD86 were, however, only partially upregulated and the complete parafollicular network found in acute EBV infection was not generated, despite increased expression of interleukins 1alpha, 1beta, 12; interleukin 1alpha receptor antagonist; interferon alpha; and CD40 expression. LTNP/SLP and treated aviremic subjects had increased frequency of interdigitating DC, albeit lower than in aHI, and low expression of CD80 and CD86. In contrast, patients with AIDS had fewer DC and reduced cytokine expression in LT. In the early phase of HIV-1 infection, there was a migration of DC to LT comparable to that found in acute EBV infection. The infiltration of DC in LT in acute EBV infection was accompanied by upregulation of CD80 and CD86 expression, which did not occur in aHI. This co-stimulatory defect in aHI may have an impact on the development of HIV-1-specific T cell immunity.