Staphylococcus aureus peptidoglycan (PGN) induces pathogenic autoantibody production via autoreactive B cell receptor clonal selection, implications in systemic lupus erythematosus.

OBJECTIVES: There is an intricate interplay between the microbiome and the immune response impacting development of normal immunity and autoimmunity. However, we do not fully understand how the microbiome affects production of natural-like and pathogenic autoantibodies. Peptidoglycan (PGN) is a component of the bacterial cell wall which is highly antigenic. PGNs from different bacteria can differ in their immune regulatory activities. METHODS: C57BL/6 and MRL/lpr mice were intraperitoneally injected with saline or PGN from Staphylococcus aureus or Bacillus subtilis. Spleen anti-double-stranded DNA (dsDNA) IgG + B cells were sorted for B-cell receptor sequencing. Serum autoantibody levels and kidney damage were analyzed. Further, the association between plasma S. aureus translocation and systemic lupus erythematosus (SLE) pathogenesis was assessed in women. RESULTS: Administration of B. subtilis PGN induced natural-like anti-dsDNA autoantibodies (e.g., IgM, short lived IgG response, and no tissue damage), whereas S. aureus PGN induced pathogenic anti-dsDNA autoantibodies (e.g., prolonged IgG production, low IgM, autoantibody-mediated kidney damage) in C57BL/6 and/or MRL/lpr mice. However, serum total IgG did not differ. S. aureus PGN induced antibodies with reduced clonality and greater hypermutation of IGHV3-74 in splenic anti-dsDNA IgG + B cells from C57BL/6 mice. Further, S. aureus PGN promoted IgG class switch recombination via toll-like receptor 2. Plasma S. aureus DNA levels were increased in women with SLE versus control women and correlated with levels of lupus-related autoantibodies and renal involvement. CONCLUSIONS: S. aureus PGN induces pathogenic autoantibody production, whereas B. subtilis PGN drives production of natural nonpathogenic autoantibodies.

An innovative compound bed of EDI device with enhancing ion-exchange resins regeneration efficiency.

Electrodeionization (EDI) technology is limited by low regeneration efficiency of ion exchange resins, requirements of high-quality influent water, fouling of the ion exchange membrane and electrode, etc. In this work, a novel bed type called a compound bed in which cation and anion exchange resins were near the cation and anion exchange membrane and placed in layers, was proposed to implement high-efficiency regeneration of ion exchange resins. The influence of different operating conditions on the regeneration efficiency of ion exchange resins was elucidated as well. The regeneration efficiency of ion exchange resins could reach 73.1%, when the device was operated for 5 h under current density of 9 mA/cm2, with a cation and anion exchange resins ratio of 2: 3, influent water conductivity of 1,360 µS/cm and hardness of 400 mg/L. Therefore, the proposed compound bed structure not only widened the inlet water conditions, but also achieved the high-efficiency regeneration of ion exchange resins and anti-fouling of membranes and electrodes.

Effect of laser power on cleaning mechanism and surface properties.

In this paper, the mechanism of laser dry cleaning was introduced, and the influence of different power on laser cleaning effect and surface performance after cleaning were investigated. The cleaning effect of 60-120 W cleaning power on the oxidized layer of a Q235 surface was analyzed by experiment and simulation. The results showed that the cleaning power of 70 W makes the surface performance after cleaning of the samples relatively optimized. The best cleaning power is 90 W. The sample surface of 100 W is the smoothest, but it causes slight damage to the matrix. The cleaning power of 120 W has the maximum friction coefficient, but it has the maximum damage to the matrix.

Epidemiological characteristics of asymptomatic Norovirus infection in a population from oyster (Ostrea rivularis Gould) farms in southern China.

The following paper investigates the prevalence and characteristics of asymptomatic norovirus infection in the population living around oyster farm sites. Two consecutive surveys were conducted from January 2014 to December 2014 and 4549 stool samples were screened during the same time period. The total asymptomatic infection rate was 4.04% (184/4549). Norovirus infection rate was 5.20% in oyster farming population which was significantly higher compared with non-farming population where the infection rate was 3.65% (χ2 = 5.49, P < 0.05). A total of 184 NoV positive samples were identified by real time-quantitative polymerase chain reaction (RT-qPCR) and semi-nested RT-PCR and 136 sequences were obtained. The sequences were clustered into 14 genotypes. GI strains were clustered into six genotypes, including GI.2, GI.3, GI.5, GI.6, GI.8 and GI.9; while GII strains were clustered into GII.2, GII.3, GII.4, GII.5, GII.6, GII.8 and GII.13. GI.9 and GII.17 were the predominant and most prevalent genotypes, respectively. The GII.17 genotype replaced GII.4 becoming the dominant genotype in the oyster farming area in 2014. To sum up, long-term monitoring of asymptomatic infection is crucial for the detection of new variant strains and for identifying outbreaks during the early stage.

Pathological Role of Anti-CD4 Antibodies in HIV-Infected Immunologic Nonresponders Receiving Virus-Suppressive Antiretroviral Therapy.

Increased mortality and morbidity occur among human immunodeficiency virus (HIV)-infected patients in whom CD4+ T-cell counts do not increase despite viral suppression with antiretroviral therapy (ART). Here we identified an underlying mechanism. Significantly elevated plasma levels of anti-CD4 immunoglobulin G (IgG) were found in HIV-positive immunologic nonresponders (ie, HIV-positive individuals with CD4+ T-cell counts of ≤350 cells/µL), compared with levels in HIV-positive immunologic responders (ie, HIV-positive individuals with CD4+ T-cell counts of ≥500 cells/µL) and healthy controls. Higher plasma level of anti-CD4 IgG correlated with blunted CD4+ T-cell recovery. Furthermore, purified anti-CD4 IgG from HIV-positive immunologic nonresponders induced natural killer (NK) cell-dependent CD4+ T-cell cytolysis and apoptosis through antibody-dependent cell-mediated cytotoxicity (ADCC) in vitro. We also found that anti-CD4 IgG-mediated ADCC exerts greater apoptosis of naive CD4+ T cells relative to memory CD4+ T cells. Consistently, increased frequencies of CD107a+ NK cells and profound decreases of naive CD4+ T cells were observed in immunologic nonresponders as compared to responders and healthy controls ex vivo. These data indicate that autoreactive anti-CD4 IgG may play an important role in blunted CD4+ T-cell reconstitution despite effective ART.

Inhibition of sphingosine kinase 2 downregulates the expression of c-Myc and Mcl-1 and induces apoptosis in multiple myeloma.

Sphingolipid metabolism is being increasingly recognized as a key pathway in regulating cancer cell survival and proliferation. However, very little is known about its role in multiple myeloma (MM). We investigated the potential of targeting sphingosine kinase 2 (SK2) for the treatment of MM. We found that SK2 was overexpressed in MM cell lines and in primary human bone marrow (BM) CD1381 myeloma cells. Inhibition of SK2 by SK2- specific short hairpin RNA or ABC294640 (a SK2 specific inhibitor) effectively inhibited myeloma cell proliferation and induced caspase 3­mediated apoptosis. ABC294640 inhibited primary human CD1381 myeloma cells with the same efficacy as with MM cell lines. ABC294640 effectively induced apoptosis of myeloma cells, even in the presence of BM stromal cells. Furthermore, we found that ABC294640 downregulated the expression of pS6 and directed c-Myc and myeloid cell leukemia 1 (Mcl-1) for proteasome degradation. In addition, ABC294640 increased Noxa gene transcription and protein expression. ABC294640, per se, did not affect the expression of B-cell lymphoma 2 (Bcl-2), but acted synergistically with ABT-737 (a Bcl-2 inhibitor) in inducing myeloma cell death. ABC294640 suppressed myeloma tumor growth in vivo in mouse myeloma xenograft models. Our data demonstrated that SK2 provides a novel therapeutic target for the treatment of MM.This trial was registered at www.clinicaltrials.gov as #NCT01410981.

Respiratory-swallow training in patients with head and neck cancer.

OBJECTIVE: To test a novel intervention to train swallowing to occur in the midexpiratory to low expiratory phase of quiet breathing to improve swallowing safety and efficiency. DESIGN: Safety and efficacy nonrandomized controlled trial with 1-month follow-up. SETTING: Ambulatory clinics. PARTICIPANTS: Patients (N=30) with head and neck cancer (HNC) and chronic dysphagia completed the intervention. Fifteen of these patients participated in a 1-month follow-up visit. INTERVENTIONS: Training protocol based on hierarchy of motor skill acquisition to encourage autonomous and optimal respiratory-swallowing coordination. Visual feedback of respiratory phase and volume for swallowing initiation was provided by nasal airflow and rib cage/abdomen signals. MAIN OUTCOME MEASURES: Respiratory-swallow phase pattern, Modified Barium Swallow Impairment Profile (MBSImP) scores, Penetration-Aspiration Scale (PAS) scores, and MD Anderson Dysphagia Inventory scores. RESULTS: Using visual feedback, patients were trained to initiate swallows during the midexpiratory phase of quiet breathing and continue to expire after swallowing. This optimal phase patterning increased significantly after treatment (P<.0001). Changes in respiratory-swallowing coordination were associated with improvements in 3 MBSImP component scores: laryngeal vestibular closure (P=.0004), tongue base retraction (P<.0001), and pharyngeal residue (P=.01). Significant improvements were also seen in PAS scores (P<.0001). Relative to pretreatment values, patients participating in 1-month follow-up had increased optimal phase patterning (P<.0001), improved laryngeal vestibular closure (P=.01), tongue base retraction (P=.003), and pharyngeal residue (P=.006) MBSImP scores and improved PAS scores (P<.0001). CONCLUSIONS: Improvements in respiratory-swallowing coordination can be trained using a systematic protocol and respiratory phase-lung volume-related biofeedback in patients with HNC and chronic dysphagia, with favorable effects on airway protection and bolus clearance.

Racial Differences in Plasma Microbial Translocation and Plasma Microbiome, Implications in Systemic Lupus Erythematosus Disease Pathogenesis.

OBJECTIVE: Black groups have increased prevalence and accelerated pathogenicity of systemic lupus erythematosus (SLE) compared to other ethnic/racial groups. The microbiome and systemic microbial translocation are considered contributing factors to SLE disease pathogenesis. However, racial differences in the plasma microbiome and microbial translocation in lupus remain unknown. METHODS: In the current study, we investigated plasma levels of microbial translocation (lipopolysaccharide [LPS] and zonulin) and the plasma microbiome using microbial 16S RNA sequencing of Black and White patients with SLE and Black and White healthy controls. RESULTS: Plasma microbial translocation was increased in Black patients versus in White patients and in patients with SLE versus healthy controls regardless of race. Compared to sex, age, and disease status, race had the strongest association with plasma microbiome differences. Black groups (Black controls and Black patients) had lower α-diversity than White groups (White controls and White patients) and more distinct ß-diversity. Black and White patients demonstrated differences in plasma bacterial presence, including Staphylococcus and Burkholderia. Compared to White patients, Black patients had higher SLE Disease Activity Index (SLEDAI) scores and urinary protein levels as well as a trend for increased anti-double-stranded DNA (dsDNA) antibody levels consistent with the known increased severity of lupus in Black patients overall. Certain plasma bacteria at the genus level were identified that were associated with the SLEDAI score, urinary protein, and anti-dsDNA antibody levels. CONCLUSION: This study reveals racial differences in both quality and quantity of plasma microbial translocation and identified specific plasma microbiome differences associated with SLE disease pathogenesis. Thus, this study may provide new insights into future potential microbiome therapies on SLE pathogenesis.

Sheep Face Recognition Model Based on Deep Learning and Bilinear Feature Fusion.

A key prerequisite for the establishment of digitalized sheep farms and precision animal husbandry is the accurate identification of each sheep's identity. Due to the uncertainty in recognizing sheep faces, the differences in sheep posture and shooting angle in the recognition process have an impact on the recognition accuracy. In this study, we propose a deep learning model based on the RepVGG algorithm and bilinear feature extraction and fusion for the recognition of sheep faces. The model training and testing datasets consist of photos of sheep faces at different distances and angles. We first design a feature extraction channel with an attention mechanism and RepVGG blocks. The RepVGG block reparameterization mechanism is used to achieve lossless compression of the model, thus improving its recognition efficiency. Second, two feature extraction channels are used to form a bilinear feature extraction network, which extracts important features for different poses and angles of the sheep face. Finally, features at the same scale from different images are fused to enhance the feature information, improving the recognition ability and robustness of the network. The test results demonstrate that the proposed model can effectively reduce the effect of sheep face pose on the recognition accuracy, with recognition rates reaching 95.95%, 97.64%, and 99.43% for the sheep side-, front-, and full-face datasets, respectively, outperforming several state-of-the-art sheep face recognition models.

A Distinct Plasma Microbiome But Not Gut Microbiome in Patients With Systemic Lupus Erythematosus Compared to Healthy Individuals.

OBJECTIVE: Blood microbiome has been analyzed in cancer patients using machine learning. We aimed to study whether the plasma microbiome represents the microbial community in the gut among patients with systemic lupus erythematosus (SLE) and healthy controls (HCs). METHODS: Paired plasma and stool samples from female patients with SLE and female HCs were assessed for microbiome composition by microbial 16S ribosomal RNA sequencing. RESULTS: Decreased microbial alpha diversity in stool compared to plasma and distinct plasma and gut beta diversity were found in both HCs and patients with SLE. No difference in gut microbial diversity was found; however, plasma alpha diversity was decreased in patients with SLE compared to HCs. The predominant bacteria differed between plasma and stool in both groups. Although the predominant plasma and stool genus bacteria were similar in patients with SLE and HCs, some were clearly different. CONCLUSION: Compared to the gut, the plasma microbiome contained distinct community and greater heterogeneity, indicating that the predominant circulating microbiome may originate from sites (eg, oral or skin) other than the gastrointestinal tract. The decreased plasma but not gut alpha diversity in patients with SLE compared to HCs implies an altered plasma microbiome in SLE, which may be important for systemic immune perturbations and SLE disease pathogenesis.

[Spatiotemporal variation and obstacle factor diagnosis of resource and environment carrying capacity of Lanzhou-Xining urban agglomeration in the upper Yellow River, Nothwest China]. / é»„æ²³ä¸Šæ¸¸å °å·ž-è¥¿å®åŸŽå¸‚ç¾¤èµ„æºçŽ¯å¢ƒæ‰¿è½½åŠ›æ—¶ç©ºåˆ†å¼‚åŠéšœç¢å› å­è¯Šæ–­.

Based on the PSR model, we built an evaluation system for resource and environment carrying capacity. We used the entropy weight method, the comprehensive index model and the spatial analysis function of GIS to explore the spatial-temporal dynamic of the resource and environment carrying capacity of the Lanzhou-Xining urban agglomeration, and used the obstacle degree model to identify the obstacle factors. The results showed that resource and environment carrying capacity of the Lanzhou-Xining urban agglomeration from 2005 to 2018 showed a fluctuating upward trend, which was generally at good condition. The coefficient of variation of resource and environment carrying capacity had a fluctuating upward trend, while regional differences were gradually expanding. Spatially, resource and environment carrying capacity presented a "dual-core" structure centered on the main urban areas of Lanzhou and Xining. The high-level areas were mainly concentrated in the Hehuang Valley with Lanzhou and Xining as the center and some surrounding counties, while the low-level areas were distributed in the central and southern regions of the urban agglomeration. Among them, there were spatiotemporal variations of the subsystem index. The pressure index showed a fluctuating and decreasing trend, and spatially showed a decreasing distribution characteristic from Lanzhou and Xining urban areas to the peripheral areas. The state index showed a fluctuating upward trend, and spatially showed the evolution characteristics of high in the east and west wings and low in the middle. The response index showed an upward trend, and spatially showed distribution patterns high in the east and middle, and low in the west and outside. The urbanization rate, per capita industrial wastewater discharge, domestic waste harmless treatment rate, water consumption index, and the proportion of environmental protection investment in GDP are the main obstacles restricting the improvement of resource and environment carrying capacity of Lanhzhou-Xining urban agglomeration.

Oral Enrichment of Streptococcus and its Role in Systemic Inflammation Related to Monocyte Activation in Humans with Cocaine Use Disorder.

Cocaine use is commonly associated with increased chronic systemic inflammation. However, the drivers for cocaine use-mediated systemic inflammation are not fully understood. In the current study, we recruited individuals with cocaine use disorder and healthy individuals who did not use cocaine and collected paired saliva and blood samples. The saliva samples were used to assess the oral microbiome, and the plasma samples were evaluated for 33 cytokines and chemokines. Cocaine users exhibited decreased saliva microbial diversities compared to non-users. Streptococcus was the only increased genus in the saliva from cocaine users, whereas several genera were decreased in cocaine users compared to non-users. Notably, cocaine users exhibited increased plasma levels of several monocyte activation markers, including monocyte chemoattractant protein (MCP)-4, macrophage inflammatory protein (MIP)-3α, macrophage-derived chemokine (MDC), and thymus and activation-regulated chemokine (TARC), all of which were correlated with increased saliva levels of three Streptococcus species. Furthermore, treatment with Streptococcus or its lipoteichoic acid preferentially activated primary human monocytes to produce proinflammatory cytokines and chemokines, such as MIP-3α and TARC, in vitro compared to controls. However, monocytes failed to produce these chemokines after exposure to cocaine or cocaine plus bacteria compared to medium or bacteria alone. This study revealed that chronic cocaine use-associated inflammation in the blood may result from increased oral Streptococcus and its effects on myeloid cell activation, but does not result from cocaine directly.

Effects of Early and Delayed Antiretroviral Therapy on Plasma Anti-CD4 Autoreactive IgG and Its Association With CD4+ T-Cell Recovery in Acute HIV-Infected Individuals.

BACKGROUND: Plasma levels of anti-CD4 autoantibodies are increased in chronically HIV-infected patients and inversely correlated with CD4+ T-cell recovery under viral-suppressive antiretroviral therapy (ART). However, it remains unknown the effect of early ART on plasma anti-CD4 autoantibody levels in acute HIV infection (AHI). METHODS: In this cohort study, we evaluated the effect of early and delayed initiation of ART on plasma anti-CD4 autoantibody levels in AHI individuals (n = 90). Blood samples were collected from men who had sex with men (MSM) with acute infection, pre-ART, and 4, 24, 48, and 96 weeks after ART. Plasma levels of anti-CD4 immunoglobulin G (IgG) were measured by ELISA. RESULTS: We found that plasma anti-CD4 IgG levels were significantly increased in AHI individuals compared with healthy controls (HCs) prior to ART. Notably, early ART decreased plasma anti-CD4 IgG to the levels similar to HCs starting at 24 weeks (W). However, delayed initiation of ART did not significantly reduce plasma anti-CD4 IgG levels in AHI individuals. Moreover, the peripheral CD4+ T-cell counts were inversely correlated with plasma anti-CD4 IgG levels in AHI individuals at 48 and 96 W after early ART but not after delayed ART. CONCLUSIONS: Taken together, our findings demonstrate for the first time that early ART, but not delayed initiation of ART, is effective in influencing anti-CD4 autoantibody production and recovering CD4+ T-cell counts in AHI individuals.

Systemic translocation of Staphylococcus drives autoantibody production in HIV disease.

BACKGROUND: Increased autoreactive antibodies have been reported in HIV disease; however, the mechanism accounting for autoantibody induction in HIV remains unknown. RESULTS: Herein, we show that seasonal influenza vaccination induces autoantibody production (e.g., IgG anti-nuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA)) in some viral-suppressed antiretroviral therapy (ART)-treated HIV+ subjects, but not in healthy controls. These autoantibodies were not derived from antigen-specific B cells but from activated "bystander" B cells analyzed by single-cell assay and by study of purified polyclonal ANAs from plasma. To explore the mechanism of autoantibody generation in HIV+ subjects, plasma level of microbial products, gene expression profile of B cells, and B cell receptor (BCR) repertoires were analyzed. We found that autoantibody production was associated with increased plasma level of microbial translocation; the patients with high autoantibodies had skewed B cell repertoires and upregulation of genes related to innate immune activation in response to microbial translocation. By analyzing circulating microbial 16S rDNA in plasma, the relative abundance of Staphylococcus was found to be associated with autoantibody production in HIV+ subjects. Finally, we found that injection of heat-killed Staphylococcus aureus promoted germinal center B cell responses and autoantibody production in mice, consistent with the notion that autoantibody production in HIV+ patients is triggered by microbial products. CONCLUSIONS: Our results showed that translocation of Staphylococcus can promote B cell activation through enhancing germinal center response and induces autoantibody production. It uncovers a potential mechanism linking microbial translocation and autoimmunity in HIV+ disease and provides a strong rationale for targeting Staphylococcus to prevent autoantibody production.

Drug Use is Associated with Anti-CD4 IgG-mediated CD4+ T Cell Death and Poor CD4+ T Cell Recovery in Viral-suppressive HIV-infected Individuals Under Antiretroviral Therapy.

BACKGROUND: The role and mechanism of drug use or abuse in Antiretroviral Therapy (ART)-treated HIV disease are not completely known. METHODS: To investigate the impact of drug use on HIV pathogenesis without confounding by HIV replication and ART adherence, we first analyzed the data from our clinical database in 103 HIV+ subjects with viral-suppressed ART treatment by a multiple regression test. RESULTS: We found that HIV+ drug users had lower CD4+ T cell counts but higher CD8+ T cell counts compared to HIV+ non-drug users, and both drug use and nadir CD4+ T cell counts was independently associated with CD4+ T cell recovery after controlling for sex and age. Next, we enrolled individuals from four study groups, HIV-negative and HIV+ subjects without any substance use, HIV-negative and HIV+ subjects with current illicit drug use (either non-injection cocaine or cannabis). All HIV+ subjects were viral-suppressed with ART treatment (≥ 2 years). Notably, HIV+ drug users had increased plasma anti-CD4 IgG levels compared to the other three study groups which were inversely correlated with decreased CD4+ T cell counts only in HIV+ drug users. There was a significant increase in CD4+ T cell recovery following ART in HIV+ non-drug users but not in HIV+ drug users. Anti-CD4 IgGs purified from plasma of HIV+ drug users induced CD4+ T cell death in vitro through Antibody-Dependent Cytotoxicity (ADCC). CONCLUSION: These results suggest that drug use prevents immune reconstitution in HIV-infected individuals despite long-term ART treatment and viral suppression.

Distinct systemic microbiome and microbial translocation are associated with plasma level of anti-CD4 autoantibody in HIV infection.

Microbial signals have been linked to autoantibody induction. Recently, we found that purified anti-CD4 autoantibodies from the plasma of chronic HIV-1-infected patients under viral-suppressed antiretroviral therapy (ART) play a pathologic role in poor CD4+ T cell recovery. The purpose of the study was to investigate the association of systemic microbiome and anti-CD4 autoantibody production in HIV. Plasma microbiome from 12 healthy controls and 22 HIV-infected subjects under viral-suppressed ART were analyzed by MiSeq sequencing. Plasma level of autoantibodies and microbial translocation (LPS, total bacterial 16S rDNA, soluble CD14, and LPS binding protein) were analyzed by ELISA, limulus amebocyte assay, and qPCR. We found that plasma level of anti-CD4 IgGs but not anti-CD8 IgGs was increased in HIV+ subjects compared to healthy controls. HIV+ subjects with plasma anti-CD4 IgG > 50 ng/mL (high) had reduced microbial diversity compared to HIV+ subjects with anti-CD4 IgG ≤ 50 ng/mL (low). Moreover, plasma anti-CD4 IgG level was associated with elevated microbial translocation and reduced microbial diversity in HIV+ subjects. The Alphaproteobacteria class was significantly enriched in HIV+ subjects with low anti-CD4 IgG compared to patients with high anti-CD4 IgG even after controlling for false discovery rate (FDR). The microbial components were different from the phylum to genus level in HIV+ subjects with high anti-CD4 IgGs compared to the other two groups, but these differences were not significant after controlling for FDR. These results suggest that systemic microbial translocation and microbiome may associate with anti-CD4 autoantibody production in ART-treated HIV disease.

Increased Natural Killer Cell Activation in HIV-Infected Immunologic Non-Responders Correlates with CD4+ T Cell Recovery after Antiretroviral Therapy and Viral Suppression.

The role of natural killer (NK) cell function in HIV disease especially in the setting of long-term antiretroviral therapy (ART) and viral suppression is not fully understood. In the current study, we have investigated NK cell activation in healthy controls and aviremic ART-treated HIV+ subjects with different degrees of immune restoration. We performed a cross sectional study in 12 healthy controls and 24 aviremic ART-treated HIV-infected subjects including 13 HIV+ subjects with CD4+ T cells above 500 cells/µL defined as "immunologic responders" and 11 HIV+ subjects with CD4+ T cells below 350 cells/µL defined as "immunologic non-responders". We analyzed NK cell number, subset, and activation by expression of CD107a and NKG2D and co-expression of CD38 and HLA-DR. NK cell-mediated cytotoxicity against uninfected CD4+ T cells was tested in vitro. We found that NK cell absolute number, percentage of NK cells, and percentage of NK cell subsets were similar in the three study groups. The increased NK cell activation was found predominantly in CD56dimCD16+ subset of immunologic non-responders but not immunologic responders compared to healthy controls. The activation of NK cells was inversely correlated with the peripheral CD4+ T cell count in HIV+ subjects, even after controlling for chronic T cell activation, sex, and age, potential contributors for CD4+ T cell counts in HIV disease. Interestingly, NK cells from immunologic non-responders mediated cytotoxicity against uninfected CD4+ T cells ex vivo. NK cells may play a role in blunted CD4+ T cell recovery in ART-treated HIV disease.

The induction of CD80 and apoptosis on B cells and CD40L in CD4+ T cells in response to seasonal influenza vaccination distinguishes responders versus non-responders in healthy controls and aviremic ART-treated HIV-infected individuals.

BACKGROUND: Studies have shown that HIV infection is associated with an impaired influenza vaccine response. We examined the role of cellular phenotypes and function in influenza vaccine responsiveness in healthy controls and aviremic HIV-infected subjects on antiretroviral treatment (ART). METHODS: 16 healthy controls and 26 ART+ aviremic HIV+ subjects were enrolled in the current study. Blood was collected at pre-vaccination (D0), and on days 7-10 (D7) and 14-21 (D14) following the 2013-2014 seasonal influenza vaccine administrations. Subjects were classified as responders if neutralizing titers against H1N1 virus increased ⩾4-fold at D14 compared to D0. A serial analysis of B and CD4+ T cell frequencies and activation was performed on D0 and D7 by flow cytometry. RESULTS: 9 of 26 (34.6%) HIV-infected individuals and 7 of 16 (43.8%) healthy controls were classified as responders to influenza vaccines. Total B cell apoptosis (annexin V) was increased on D7 post-vaccination in non-responders but not in responders among both controls and HIV+ subjects. Surface CD80 expression on memory B cells and intracellular CD40L expression on memory CD4+ T cells were induced on D7 in responders of controls but not in non-responders. The CD80 and CD40L induction was not demonstrable in HIV-infected subjects regardless of responders and non-responders. Memory CD4+ T cell cycling tended to increase on D7 in the four study groups but did not achieve significance. All the other parameters were indistinguishable between responders and non-responders, regardless of HIV-infection status. CONCLUSION: The perturbation of activation and apoptotic induction on B cells or CD4+ T cells after seasonal influenza vaccination in non-responders and HIV-infected subjects may help understand the mechanism of impaired vaccine responsiveness.

The effect of plasma auto-IgGs on CD4+ T cell apoptosis and recovery in HIV-infected patients under antiretroviral therapy.

Although effective antiretroviral therapy (ART) suppresses HIV viral replication, prevents AIDS-related complications, and prolongs life, a proportion of patients fails to restore the patients' CD4+ T cell number to the level of healthy individuals. Increased mortality and morbidity have been observed in these patients. In the current study, we have investigated the role of auto-IgGs in CD4+ T cell apoptosis and recovery in a cross-sectional study. All HIV+ subjects were on viral-suppressive ART treatment with a different degree of CD4+ T cell reconstitution. Total auto-IgG binding on CD4+ T cell surfaces and its associated apoptosis and CD4+ T cell recovery were analyzed by flow cytometry ex vivo. Total IgGs from plasma were tested for their binding capacities to CD4+ T cell surfaces and their mediation to CD4+ T cell death through NK cell cytotoxicity in vitro. HIV+ subjects had increased surface binding of auto-IgGs on CD4+ T cells compared with healthy controls, and IgG binding was associated with elevated CD4+ T cell apoptosis in HIV+ subjects but not in healthy controls. Plasma IgGs from HIV+ subjects bound to CD4+ T cells and induced cell apoptosis through NK cytotoxicity in vitro. Soluble CD4 (sCD4) preincubation prevented NK cell-mediated CD4+ T cell death. Our results suggest that plasma autoantibodies may play a role in some HIV+ patients with poor CD4+ T cell recovery under viral-suppressive ART.

Key differences in B cell activation patterns and immune correlates among treated HIV-infected patients versus healthy controls following influenza vaccination.

BACKGROUND: There is increasing recognition of the role of B cell dysfunction in HIV pathogenesis, but little is known about how these perturbations may influence responses to vaccinations. METHODS: Healthy controls (n=16) and antiretroviral therapy (ART)-treated aviremic HIV-infected subjects (n=26) receiving standard-of-care annual influenza vaccinations were enrolled in the present study. Total bacterial 16S rDNA levels were assessed by quantitative polymerase chain reactions in plasma. Serologic responses were characterized by ELISA, hemagglutination inhibition assay (HI), and microneutralization, and cell-mediated responses were assessed by ELISPOT (antigen-specific IgG+ antibody-secreting cells (ASCs)) and flow cytometry at pre-vaccination (D0), day 7-10 (D7) and day 14-21 (D14) post-vaccination. RESULTS: Decreased peripheral CD4+ T cell absolute counts and increased frequencies of cycling and apoptotic B cells were found at baseline in HIV-infected subjects relative to healthy controls. In healthy controls, post-vaccination neutralizing activities were related to the frequencies of vaccine-mediated apoptosis and cycling of B cells, but not to CD4+ T cell counts. In patients, both baseline and post-vaccination neutralizing activities were directly correlated with plasma level of bacterial 16S rDNA. However, overall vaccine responses including antibody titers and fold changes were comparable or greater in HIV-infected subjects relative to healthy controls. CONCLUSION: B cell function correlates with measures of recall humoral immunity in response to seasonal influenza vaccination in healthy controls but not in ART-treated patients.