Weak HIV Antibody Responses in Perinatally Infected Young Adults: Weak HIV Antibody Responses in Perinatally Infected Adults.

We compared the antibody response to HIV using 2 serologic cross-sectional incidence assays in adults with perinatally acquired HIV, to elite controllers and individuals exposed to antiretroviral therapy who were all infected as adults. Low antibody responses were seen more frequently in adults with perinatally acquired HIV, both overall and when stratified by viral suppression status.

Multimethod Longitudinal HIV Drug Resistance Analysis in Antiretroviral-Therapy-Naive Patients.

The global intensification of antiretroviral therapy (ART) can lead to increased rates of HIV drug resistance (HIVDR) mutations in treated and also in ART-naive patients. ART-naive HIV-1-infected patients from Cameroon were subjected to a multimethod HIVDR analysis using amplification-refractory mutation system (ARMS)-PCR, Sanger sequencing, and longitudinal next-generation sequencing (NGS) to determine their profiles for the mutations K103N, Y181C, K65R, M184V, and T215F/Y. We processed 66 ART-naive HIV-1-positive patients with highly diverse subtypes that underlined the predominance of CRF02_AG and the increasing rate of F2 and other recombinant forms in Cameroon. We compared three resistance testing methods for 5 major mutation sites. Using Sanger sequencing, the overall prevalence of HIVDR mutations was 7.6% (5/66) and included all studied mutations except K65R. Comparing ARMS-PCR with Sanger sequencing as a reference, we obtained a sensitivity of 100% (5/5) and a specificity of 95% (58/61), caused by three false-positive calls with ARMS-PCR. For 32/66 samples, we obtained NGS data and we observed two additional mismatches made up of minority variants (7% and 18%) that might not be clinically relevant. Longitudinal NGS analyses revealed changes in HIVDR mutations in all five positive subjects that could not be attributed to treatment. In one of these cases, superinfection led to the temporary masking of a resistant virus. HIVDR mutations can be sensitively detected by ARMS-PCR and sequencing methods with comparable performances. Longitudinal changes in HIVDR mutations have to be considered even in the absence of treatment.

Short Communication: Comparison of Maxim and Sedia Limiting Antigen Assay Performance for Measuring HIV Incidence.

Accurate methods for cross-sectional incidence estimation are needed for HIV prevention research. The Limiting Antigen Avidity (LAg-Avidity) assay has been marketed by two vendors, Maxim Biomedical and Sedia BioSciences Corporation. Performance differences between the two versions of the assay are unknown. We tested a total 1,410 treatment-naive samples with both versions of the assay. The samples came from 176 seroconverters from the Zimbabwe Hormonal Contraception and HIV Study. The correlation between the two versions of the assay was 0.93 for the optical density (OD) and 0.86 for the normalized OD. As the difference was more pronounced for the normalized OD, the difference in assays can be attributed to the calibrators. The mean duration of recent infection (MDRI), the average time individuals infected <2 years appear recently infected, was determined for both versions using an assay cutoff of 1.5 OD-n alone or in combination with a viral load cutoff of >1,000 copies/ml. The MDRI was 137 days for Sedia and 157 days for Maxim, with a difference of 20 days (95% CI 11-30). The MDRIs decreased to 102 and 120 days with the inclusion of a viral load cutoff of >1,000 copies/ml. These results imply that use of the Sedia LAg-Avidity will result in estimates of incidence ∼13% lower than those using the Maxim LAg-Avidity.

Contrasting antibody responses to intrasubtype superinfection with CRF02_AG.

HIV superinfection describes the sequential infection of an individual with two or more unrelated HIV strains. Intersubtype superinfection has been shown to cause a broader and more potent heterologous neutralizing antibody response when compared to singly infected controls, yet the effects of intrasubtype superinfection remain controversial. Longitudinal samples were analyzed phylogenetically for pol and env regions using Next-Generation Sequencing and envelope cloning. The impact of CRF02_AG intrasubtype superinfection was assessed for heterologous neutralization and antibody binding responses. We compared two cases of CRF02_AG intrasubtype superinfection that revealed complete replacement of the initial virus by superinfecting CRF02_AG variants with signs of recombination. NYU6564, who became superinfected at an early time point, exhibited greater changes in antibody binding profiles and generated a more potent neutralizing antibody response post-superinfection compared to NYU6501. In contrast, superinfection occurred at a later time point in NYU6501 with strains harboring significantly longer V1V2 regions with no observable changes in neutralization patterns. Here we show that CRF02_AG intrasubtype superinfection can induce a cross-subtype neutralizing antibody response, and our data suggest timing and/or superinfecting viral envelope characteristics as contributing factors. These results highlight differential outcomes in intrasubtype superinfection and provide the first insight into cases with CRF02_AG, the fourth most prevalent HIV-1 strain worldwide.

Factors Associated With the Control of Viral Replication and Virologic Breakthrough in a Recently Infected HIV-1 Controller.

HIV-1 controllers are patients who control HIV-1 viral replication without antiretroviral therapy. Control is achieved very early in the course of infection, but the mechanisms through which viral replication is restricted are not fully understood. We describe a patient who presented with acute HIV-1 infection and was found to have an HIV-1 RNA level of <100copies/mL. She did not have any known protective HLA alleles, but significant immune activation of CD8+ T cells and natural killer (NK) cells was present, and both cell types inhibited viral replication. Virus cultured from this patient replicated as well in vitro as virus isolated from her partner, a patient with AIDS who was the source of transmission. Virologic breakthrough occurred 9months after her initial presentation and was associated with an increase in CD4+ T cell activation levels and a significant decrease in NK cell inhibitory capacity. Remarkably, CD8+ T cell inhibitory capacity was preserved and there were no new escape mutations in targeted Gag epitopes. These findings suggest that fully replication-competent virus can be controlled in acute HIV-1 infection in some patients without protective HLA alleles and that NK cell responses may contribute to this early control of viral replication.

Elevated cytomegalovirus IgG antibody levels are associated with HIV-1 disease progression and immune activation.

OBJECTIVE: To assess the association between cytomegalovirus (CMV) IgG antibody levels, HIV disease progression, and immune activation markers. DESIGN: A prospective cohort study was conducted among women enrolled in a trial that was designed to determine the effect of acyclovir on HIV disease progression in Rakai, Uganda. METHODS: The primary endpoints were progression to a CD4 T-cell count less than 250 cells/µl, nontraumatic death, or initiation of antiretroviral therapy (ART). CD4 T-cell counts, HIV viral load, C-reactive protein (CRP), and soluble CD14 levels were assessed biannually for 24 months. CMV IgG antibodies were measured at baseline among all women and annually among a subset of women who initiated ART. RESULTS: There were 300 HIV/CMV-coinfected participants who contributed a total of 426.4 person-years with a median follow-up time of 1.81 years. Compared with the lowest CMV IgG tertile group at baseline, the highest CMV IgG tertile group was associated with an increased risk to reach a primary endpoint independent of acyclovir use, age, CD4 T-cell count, and HIV viral load at baseline [adjusted hazard ratio = 1.59; (95% CI = 1.05-2.39); P = 0.027]. Among pre-ART visits (n = 1200), women in the highest baseline CMV IgG tertile had increasing annual rates of soluble CD14 and CRP levels, which was not observed for the low CMV IgG tertile group. Compared with pre-ART visits, CMV IgG antibody levels were higher post-ART initiation, and concurrent levels remained associated with soluble CD14 and CRP during suppressive ART (n = 88 person-visits). CONCLUSION: The magnitude of the immune response to CMV was associated with HIV disease progression and immune activation in sub-Saharan Africa.

Penile Immune Activation and Risk of HIV Shedding: A Prospective Cohort Study.

Background: Genital immune activation is suspected to modulate local human immunodeficiency virus (HIV) RNA levels and the risk of sexual HIV transmission. Methods: A prospective, observational cohort study of 221 HIV-infected men undergoing male circumcision (MC) was conducted in Rakai, Uganda. Penile lavage samples collected from the coronal sulcus at baseline and 4 weekly visits after MC were assayed for pro-inflammatory cytokines and HIV RNA. The main analysis was limited to 175 men with detectable HIV plasma viral load (VL > 400 copies/mL; n = 808 visits). The primary exposures of interest were individual and total cytokine detection at the previous postoperative visit. Adjusted prevalence risk ratios (adjPRR) of detectable HIV shedding (VL > 40 copies/mL) were estimated by Poisson regression models with generalized estimating equations and robust variance estimators and included adjustment for plasma HIV VL. Findings: Among men with a detectable plasma VL, penile HIV shedding was detected at 136 visits (16.8%). Detectable interleukin (IL)-1ß (adjPRR = 2.14; 95% confidence interval (CI) = 1.02-4.48), IL-6 (adjPRR = 2.24; 95% CI = 1.28-3.90), IL-8 (adjPRR = 2.42; 95% CI = 1.15-5.08), IL-10 (adjPRR = 2.51; 95% CI = 1.67-3.80), and IL-13 (adjPRR = 1.87; 95% CI = 1.15-3.03) were associated with penile HIV shedding at the subsequent visit. Men with 2-4 (adjPRR = 2.36; 95% CI = 1.08-5.14) and 5-7 (adjPRR = 3.00; 95% CI = 1.28-7.01) detectable cytokines had a greater likelihood of detectable penile HIV shedding at the subsequent visit, compared to men with ≤ 1 detectable cytokine. The total number of detectable cytokines was also associated with a higher penile log10 HIV VL at the subsequent visit among HIV shedders. Interpretation: Pro-inflammatory cytokine production had a dose-dependent and temporal association with penile HIV shedding, suggesting that genital immune activation may increase the risk of sexual HIV transmission by driving local HIV replication.

Immunological Signaling During Herpes Simplex Virus-2 and Cytomegalovirus Vaginal Shedding After Initiation of Antiretroviral Treatment.

Vaginal proinflammatory cytokine expression during herpes virus reactivation was examined in human immunodeficiency virus-infected women before and after initiation of antiretroviral therapy (ART). Vaginal swabs were screened for levels of cytokines interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, tumor necrosis factor (TNF)-α, and interferon-γ. The relative risk (RR) of herpes simplex virus-2 or cytomegalovirus (CMV) shedding being associated with cytokine levels above the median were estimated. Herpes simplex virus-2 shedding was significantly associated with higher levels of IL-6 (RR = 1.4, P = .003) and TNF-α (RR = 1.3, P = .010), whereas CMV shedding was associated with higher IL-6 (RR = 1.3, P = .006) and IL-2 (RR = 1.4, P = .01). The association of viral shedding with higher IL-6 levels suggests that herpes virus reactivation may be playing a role in immune activation after ART initiation.

Development and Evaluation of a Modified Fourth-Generation Human Immunodeficiency Virus Enzyme Immunoassay for Cross-Sectional Incidence Estimation in Clade B Populations.

BACKGROUND: Accurate methods for cross-sectional incidence estimation are needed for HIV surveillance and prevention research. We developed an avidity assay based on the fourth-generation Genetic Systems HIV Combo Ag/Ab EIA (Bio-Rad Combo assay) and evaluated its performance. MATERIALS AND METHODS: The Bio-Rad Combo assay was modified incubating samples with and without 0.025 M diethylamine (DEA). The avidity index (AI) was calculated as the ratio of the DEA-treated to untreated result for a specific sample. We analyzed 2,140 samples from 808 individuals from the United States with known duration of HIV infection. The mean duration of recent infection (MDRI) and the false-recent rate (FRR, fraction of samples from individuals known to be infected >2 years misclassified as recent) were calculated for AI cutoffs of 20%-90% for the avidity assay alone and in combination with a viral load assay (VL, limit of detection 400 copies/ml). Factors associated with misclassification of samples collected ≥2 years after infections were also evaluated. RESULTS: The MDRI for the Bio-Rad Combo Avidity assay ranged from 50 days using an AI cutoff of 20% to 276 days using an AI cutoff of 90%; the FRR ranged from 0% to 9%. When samples with a VL <400 copies/ml were classified as nonrecent, the FRRs were reduced approximately twofold and the MDRI estimates were reduced by ∼20%. An AI cutoff of 50% provided an MDRI of 135 days with an FRR of 2.1%. All samples from elite suppressors had an AI >80%. In adjusted analysis, viral suppression and low CD4 cell count were significantly associated with misclassification among individuals infected >2 years. CONCLUSIONS: This modified Bio-Rad Combo Avidity assay may be a useful tool for cross-sectional HIV incidence estimation. Further research is needed to evaluate use of this assay in combination with other assays to accurately estimate population-level HIV incidence.

Characteristics of seroconversion and implications for diagnosis of post-treatment Lyme disease syndrome: acute and convalescent serology among a prospective cohort of early Lyme disease patients.

Two-tier serology is often used to confirm a diagnosis of Lyme disease. One hundred and four patients with physician diagnosed erythema migrans rashes had blood samples taken before and after 3 weeks of doxycycline treatment for early Lyme disease. Acute and convalescent serologies for Borrelia burgdorferi were interpreted according to the 2-tier antibody testing criteria proposed by the Centers for Disease Control and Prevention. Serostatus was compared across several clinical and demographic variables both pre- and post-treatment. Forty-one patients (39.4%) were seronegative both before and after treatment. The majority of seropositive individuals on both acute and convalescent serology had a positive IgM western blot and a negative IgG western blot. IgG seroconversion on western blot was infrequent. Among the baseline variables included in the analysis, disseminated lesions (p < 0.0001), a longer duration of illness (p < 0.0001), and a higher number of reported symptoms (p = 0.004) were highly significantly associated with positive final serostatus, while male sex (p = 0.05) was borderline significant. This variability, and the lack of seroconversion in a subset of patients, highlights the limitations of using serology alone in identifying early Lyme disease. Furthermore, these findings underline the difficulty for rheumatologists in identifying a prior exposure to Lyme disease in caring for patients with medically unexplained symptoms or fibromyalgia-like syndromes.

A massive galaxy in its core formation phase three billion years after the Big Bang.

Most massive galaxies are thought to have formed their dense stellar cores in early cosmic epochs. Previous studies have found galaxies with high gas velocity dispersions or small apparent sizes, but so far no objects have been identified with both the stellar structure and the gas dynamics of a forming core. Here we report a candidate core in the process of formation 11 billion years ago, at redshift z = 2.3. This galaxy, GOODS-N-774, has a stellar mass of 100 billion solar masses, a half-light radius of 1.0 kiloparsecs and a star formation rate of solar masses per year. The star-forming gas has a velocity dispersion of 317 ± 30 kilometres per second. This is similar to the stellar velocity dispersions of the putative descendants of GOODS-N-774, which are compact quiescent galaxies at z ≈ 2 (refs 8-11) and giant elliptical galaxies in the nearby Universe. Galaxies such as GOODS-N-774 seem to be rare; however, from the star formation rate and size of this galaxy we infer that many star-forming cores may be heavily obscured, and could be missed in optical and near-infrared surveys.

Linoleic acid increases monocyte deformation and adhesion to endothelium.

Fatty acids have been implicated in having both anti- or pro-inflammatory actions, which may contribute to the progression and severity of atherosclerosis. Linoleic acid has been shown by others to decrease CD18 expression and leukocyte adhesion under static conditions. We investigated the effect of steric acid (18:0), oleic acid (18:1), and linoleic acid (18:2) on the cortical tension (a measure of cell membrane deformability) and adhesion characteristics of the monocytic cell line Mono Mac 6 (MM6) cells to TNF-alpha activated HUVEC under fluid flow. Linoleic acid concentrations up to 23 microM decreased cortical tension and increased adhesion frequencies. Increased adhesion was not due to altered cell morphology or adhesion kinetics and occurred despite decreases in receptor expression (CD18 and CD11a). At higher levels of linoleic acid (> or = 46 microM), cell dissociation constants significantly increased. Results show that decreasing cortical tension increased the probability that contact between MM6 cells and endothelium would produce an adhesive interaction, possibly due to increased deformation of the microvilli and the cell membrane cortex. However, more deformable cells rolled more erratically at low shear rates. The different behavior during initial contact and rolling suggest that adhesion is influenced by two force-dependent mechanisms, deformation of microvilli and a steric barrier. Incubation of MM6 with 23 microM steric or oleic acid did not significantly affect cortical tension. However, cells incubated with steric acid greatly increased their adherence to HUVEC and cells incubated with oleic acid showed no significant effect, indicating factors other than deformability may dominate.

TGF-beta and TNF-a affect cell surface proteoglycan and sialic acid expression on vascular endothelial cells.

Atherosclerosis is the formation of plaques in the arterial wall brought about by numerous events including the accumulation of oxidized low density lipoprotein (LDL), stimulation of inflammatory responses, the release of cytokines, and the attachment of monocytes to the arterial wall. Proteoglycans are implicated in many aspects of atherosclerosis including the metabolism of lipoproteins, regulation of cytokine activity, cell adhesion, and modification of the extracellular matrix. Due to their complex role in molecular recognition and cellular adhesion, the glycosaminoglycan (GAG) chains attached to the proteoglycan core and sialic acids on the terminal ends of the glycan chains are of interest. This study investigated the effects of exposure to transforming growth factor-beta 1 (TGF-beta 1) and tumor necrosis factor-a (TNF-a) on the expression of cell surface GAGs and sialic acids on human umbilical vein endothelial cells (HUVECs). Initial results show that TGF-beta 1 affected GAG expression compared to a control condition. Results also show that the combination of TGF-beta 1 and TNF-a affected GAG expression differently than does TGF-beta 1 alone. Additionally, TNF-a decreased the number of sialic acid residues per cell and TGF-beta 1 slightly upregulated sialic acid expression as compared to the control. The combination of the two cytokines showed a larger upward trend in this value. These data indicate that TNF-a and TGF-beta 1 play a role in the expression of GAG chains and sialic acids on the cell surface. Further study may clarify the implications of these findings for atherosclerosis.