Predictors of viral suppression and rebound among HIV-positive men who have sex with men in a large multi-site Canadian cohort.

PubMed

Tanner, Zachary; Lachowsky, Nathan; Ding, Erin; Samji, Hasina; Hull, Mark; Cescon, Angela; Patterson, Sophie; Chia, Jason; Leslie, Alia; Raboud, Janet; Loutfy, Mona; Cooper, Curtis; Klein, Marina; Machouf, Nima; Tsoukas, Christos; Montaner, Julio; Hogg, Robert S

2016-10-21

Gay, bisexual and other men who have sex with men (MSM) are disproportionately affected by HIV in Canada. Combination antiretroviral therapy has been shown to dramatically decrease progression to AIDS, premature death and HIV transmission. However, there are no comprehensive data regarding combination antiretroviral therapy outcomes among this population. We sought to identify socio-demographic and clinical correlates of viral suppression and rebound. Our analysis included MSM participants in the Canadian Observational Cohort, a multi-site cohort of HIV-positive adults from Canada's three most populous provinces, aged ≥18 years who first initiated combination antiretroviral therapy between 2000 and 2011. We used accelerated failure time models to identify factors predicting time to suppression (2 measures <50 copies/mL ≥30 days apart) and subsequent rebound (2 measures >200 copies/mL ≥30 days apart). Of 2,858 participants, 2,448 (86 %) achieved viral suppression in a median time of 5 months (Q1-Q3: 3-7 months). Viral suppression was significantly associated with later calendar year of antiretroviral therapy initiation, no history of injection drug use, lower baseline viral load, being on an initial regimen consisting of non-nucleoside reverse-transcriptase inhibitors, and older age. Among those who suppressed, 295 (12 %) experienced viral rebound. This was associated with earlier calendar year of antiretroviral therapy initiation, injection drug use history, younger age, higher baseline CD4 cell count, and living in British Columbia. Further strategies are required to optimize combination antiretroviral therapy outcomes in men who have sex with men in Canada, specifically targeting younger MSM and those with a history of injection drug use.

Early antiretroviral treatment (eART) limits viral diversity over time in a long-term HIV viral suppressed perinatally infected child.

PubMed

Palma, Paolo; Zangari, Paola; Alteri, Claudia; Tchidjou, Hyppolite K; Manno, Emma Concetta; Liuzzi, Giuseppina; Perno, Carlo Federico; Rossi, Paolo; Bertoli, Ada; Bernardi, Stefania

2016-12-09

HIV genetic diversity implicates major challenges for the control of viral infection by the immune system and for the identification of an effective immunotherapeutic strategy. With the present case report we underline as HIV evolution could be effectively halted by early antiretroviral treatment (eART). Few cases supported this evidence due to the difficulty of performing amplification and sequencing analysis in long-term viral suppressed patients. Here, we reported the case of limited HIV-1 viral evolution over time in a successful early treated child. A perinatally HIV-1 infected infant was treated within 7 weeks of age with zidovudine, lamivudine, nevirapine and lopinavir/ritonavir. At antiretroviral treatment (ART) initiation HIV-1 viral load (VL) and CD4 percentage were >500,000 copies/ml and 35%, respectively. Plasma genotypic resistance test showed a wild-type virus. The child reached VL undetectability after 33 weeks of combination antiretroviral therapy (cART) since he maintained a stable VL <40copies/ml. After 116 weeks on ART we were able to perform amplification and sequencing assay on the plasma virus. At this time VL was <40 copies/ml and CD4 percentage was 40%. Again the genotypic resistance test revealed a wild-type virus. The phylogenetic analysis performed on the HIV-1 pol sequences of the mother and the child revealed that sequences clustered with C subtype reference strains and formed a monophyletic cluster distinct from the other C sequences included in the analysis (bootstrap value >90%). Any major evolutionary divergence was detected. eART limits the viral evolution avoiding the emergence of new viral variants. This result may have important implications in host immune control and may sustain the challenge search of new personalized immunotherapeutic approaches to achieve a prolonged viral remission.

Effect of Patient Navigation With or Without Financial Incentives on Viral Suppression Among Hospitalized Patients With HIV Infection and Substance Use

PubMed Central

Metsch, Lisa R.; Feaster, Daniel J.; Gooden, Lauren; Matheson, Tim; Stitzer, Maxine; Das, Moupali; Jain, Mamta K.; Rodriguez, Allan E.; Armstrong, Wendy S.; Lucas, Gregory M.; Nijhawan, Ank E.; Drainoni, Mari-Lynn; Herrera, Patricia; Vergara-Rodriguez, Pamela; Jacobson, Jeffrey M.; Mugavero, Michael J.; Sullivan, Meg; Daar, Eric S.; McMahon, Deborah K.; Ferris, David C.; Lindblad, Robert; VanVeldhuisen, Paul; Oden, Neal; Castellón, Pedro C.; Tross, Susan; Haynes, Louise F.; Douaihy, Antoine; Sorensen, James L.; Metzger, David S.; Mandler, Raul N.; Colfax, Grant N.; del Rio, Carlos

2017-01-01

IMPORTANCE Substance use is a major driver of the HIV epidemic and is associated with poor HIV care outcomes. Patient navigation (care coordination with case management) and the use of financial incentives for achieving predetermined outcomes are interventions increasingly promoted to engage patients in substance use disorders treatment and HIV care, but there is little evidence for their efficacy in improving HIV-1 viral suppression rates. OBJECTIVE To assess the effect of a structured patient navigation intervention with or without financial incentives to improve HIV-1 viral suppression rates among patients with elevated HIV-1 viral loads and substance use recruited as hospital inpatients. DESIGN, SETTING, AND PARTICIPANTS From July 2012 through January 2014, 801 patients with HIV infection and substance use from 11 hospitals across the United States were randomly assigned to receive patient navigation alone (n = 266), patient navigation plus financial incentives (n = 271), or treatment as usual (n = 264). HIV-1 plasma viral load was measured at baseline and at 6 and 12 months. INTERVENTIONS Patient navigation included up to 11 sessions of care coordination with case management and motivational interviewing techniques over 6 months. Financial incentives (up to $1160) were provided for achieving targeted behaviors aimed at reducing substance use, increasing engagement in HIV care, and improving HIV outcomes. Treatment as usual was the standard practice at each hospital for linking hospitalized patients to outpatient HIV care and substance use disorders treatment. MAIN OUTCOMES AND MEASURES The primary outcome was HIV viral suppression (≤200 copies/mL) relative to viral nonsuppression or death at the 12-month follow-up. RESULTS Of 801 patients randomized, 261 (32.6%) were women (mean [SD] age, 44.6 years [10.0 years]). There were no differences in rates of HIV viral suppression versus nonsuppression or death among the 3 groups at 12 months. Eighty-five of 249

Affordable Care Act Qualified Health Plan Coverage: Association With Improved HIV Viral Suppression for AIDS Drug Assistance Program Clients in a Medicaid Nonexpansion State

PubMed Central

McManus, Kathleen A.; Rhodes, Anne; Bailey, Steven; Yerkes, Lauren; Engelhard, Carolyn L.; Ingersoll, Karen S.; Stukenborg, George J.; Dillingham, Rebecca

2016-01-01

Background. With the Patient Protection and Affordable Care Act, many state AIDS Drug Assistance Programs (ADAPs) shifted their healthcare delivery model from direct medication provision to purchasing qualified health plans (QHPs). The objective of this study was to characterize the demographic and healthcare delivery factors associated with Virginia ADAP clients' QHP enrollment and to assess the relationship between QHP coverage and human immunodeficiency virus (HIV) viral suppression. Methods. The cohort included persons living with HIV who were enrolled in the Virginia ADAP (n = 3933). Data were collected from 1 January 2013 through 31 December 2014. Multivariable binary logistic regression was conducted to assess for associations with QHP enrollment and between QHP coverage and viral load (VL) suppression. Results. In the cohort, 47.1% enrolled in QHPs, and enrollment varied significantly based on demographic and healthcare delivery factors. In multivariable binary logistic regression, controlling for time, age, sex, race/ethnicity, and region, factors significantly associated with achieving HIV viral suppression included QHP coverage (adjusted odds ratio, 1.346; 95% confidence interval, 1.041–1.740; P = .02), an initially undetectable VL (2.809; 2.174–3.636; P < .001), HIV rather than AIDS disease status (1.377; 1.049–1.808; P = .02), and HIV clinic (P < .001). Conclusions. QHP coverage was associated with viral suppression, an essential outcome for individuals and for public health. Promoting QHP coverage in clinics that provide care to persons living with HIV may offer a new opportunity to increase rates of viral suppression. PMID:27143661

Viral Suppression and Retention in Care up to 5 Years after Initiation of Lifelong ART during Pregnancy (Option B+) in Rural Uganda

PubMed Central

Koss, Catherine A.; Natureeba, Paul; Kwarisiima, Dalsone; Ogena, Mike; Clark, Tamara D.; Olwoch, Peter; Cohan, Deborah; Okiring, Jaffer; Charlebois, Edwin D.; Kamya, Moses R.; Havlir, Diane V.

2016-01-01

Background Lifelong antiretroviral therapy (ART) is recommended for all HIV-infected pregnant women, but early studies suggest women often drop out of care postpartum and data are limited on virologic outcomes. Methods We evaluated viral suppression (primary outcome) and retention in care up to 5 years after ART initiation among HIV-infected women who started lifelong ART during pregnancy, irrespective of CD4 count, in a study in rural Uganda (NCT00993031). Participants were followed in the study for up to 1 year postpartum, then referred to clinics in surrounding communities. A random sample (N=200) was invited to participate in a cross-sectional follow-up study after completing the trial, involving one visit for a questionnaire and pregnancy and HIV RNA testing. Retention in care was defined as having attended an HIV clinic in the last 90 days. Logistic regression models were used to examine factors associated with viral suppression (HIV-1 RNA ≤400 copies/ml) at follow-up. Results One hundred fifty women (75%) were successfully contacted for follow-up at a median of 4.2 years after starting ART; 135 were retained in care (90%, 95% CI 84.0%–94.3%) and 121 demonstrated viral suppression (80.7%, 95% CI 73.4% –86.7%). Women who had disclosed their HIV status to their primary partner had greater odds of viral suppression (aOR 4.51, 95% CI 1.02–19.8). Conclusions High rates of viral suppression can be achieved up to 5 years after initiating ART during pregnancy among women retained in care. Interventions to facilitate disclosure may improve long-term outcomes among women who initiate ART during pregnancy under universal treatment. PMID:27828878

Viral Suppression and Resistance in a Cohort of Perinatally-HIV Infected (PHIV+) Pregnant Women

PubMed Central

Cruz, Maria Letícia; Santos, Edwiges; Benamor Teixeira, Maria de Lourdes; Poletti, Monica; Sousa, Carolina; Gouvea, Maria Isabel; Nielsen-Saines, Karin; João, Esaú

2016-01-01

Our objective was to describe viral suppression and antiretroviral (ARV) resistance mutations in an ongoing cohort of perinatally-infected HIV+ (PHIV+) pregnant women. Descriptive analysis was performed using SPSS 18.0. From 2011 to 2014, we followed 22 PHIV+ pregnant women. Median age at prenatal entry was 19 years (Interquartile range (IQR) 17.6–21.0); 86% had an AIDS diagnosis; 81% had disclosed their HIV status to partner 11. The median age at HIV diagnosis was 8.3 y (IQR 4.0–13.6), the median age at sexual debut was 16 years (IQR 14–18). At the time of prenatal care initiation, four (18%) were on their first antiretroviral treatment (ART), eight (36%) in their second regimen and nine (41%) in their third regimen or beyond, and one had no data. Seventeen of 22 (77%) had HIV-viral load (VL) > 50 copies/mL at prenatal care entry, 16 had a genotyping exam performed. Seventeen of 22 PHIV+ had VL results near delivery: 7/17 (41%) had VL < 50 copies/mL. Among those who had genotyping at prenatal entry, 11/16 (69%) had mutations associated with ARV resistance. The most frequent major mutations were K103N, M184V, T215, M41L, D67N at reverse transcriptase gene and M46, I54V and V82A at protease gene. No vertical transmissions occurred. Management of pregnancy among PHIV+ is challenging. Individualized ART are needed to achieve viral suppression in a highly ART-exposed subpopulation. PMID:27338425

Viral Suppression and Resistance in a Cohort of Perinatally-HIV Infected (PHIV+) Pregnant Women.

PubMed

Cruz, Maria Letícia; Santos, Edwiges; Benamor Teixeira, Maria de Lourdes; Poletti, Monica; Sousa, Carolina; Gouvea, Maria Isabel; Nielsen-Saines, Karin; João, Esaú

2016-06-07

Our objective was to describe viral suppression and antiretroviral (ARV) resistance mutations in an ongoing cohort of perinatally-infected HIV+ (PHIV+) pregnant women. Descriptive analysis was performed using SPSS 18.0. From 2011 to 2014, we followed 22 PHIV+ pregnant women. Median age at prenatal entry was 19 years (Interquartile range (IQR) 17.6-21.0); 86% had an AIDS diagnosis; 81% had disclosed their HIV status to partner 11. The median age at HIV diagnosis was 8.3 y (IQR 4.0-13.6), the median age at sexual debut was 16 years (IQR 14-18). At the time of prenatal care initiation, four (18%) were on their first antiretroviral treatment (ART), eight (36%) in their second regimen and nine (41%) in their third regimen or beyond, and one had no data. Seventeen of 22 (77%) had HIV-viral load (VL) > 50 copies/mL at prenatal care entry, 16 had a genotyping exam performed. Seventeen of 22 PHIV+ had VL results near delivery: 7/17 (41%) had VL < 50 copies/mL. Among those who had genotyping at prenatal entry, 11/16 (69%) had mutations associated with ARV resistance. The most frequent major mutations were K103N, M184V, T215, M41L, D67N at reverse transcriptase gene and M46, I54V and V82A at protease gene. No vertical transmissions occurred. Management of pregnancy among PHIV+ is challenging. Individualized ART are needed to achieve viral suppression in a highly ART-exposed subpopulation.

Viral blips during suppressive antiretroviral treatment are associated with high baseline HIV-1 RNA levels.

PubMed

Sörstedt, Erik; Nilsson, Staffan; Blaxhult, Anders; Gisslén, Magnus; Flamholc, Leo; Sönnerborg, Anders; Yilmaz, Aylin

2016-06-21

Many HIV-1-infected patients on suppressive antiretroviral therapy (ART) have transiently elevated HIV RNA levels. The clinical significance of these viral blips is uncertain. We have determined the incidence of blips and investigated important associations in the Swedish HIV-cohort. HIV-1-infected ART naïve adults who commenced ART 2007-2013 were retrospectively included. Viral blips were defined as a transient viral load between 50 and 500 copies/mL Subjects not suppressed after six months on ART were excluded. Viral blips were found in 76/735 included subjects (10.3 %) and in 90/4449 samples (2.0 %). Median blip viral load was 76 copies/mL (range 56-138). Median follow-up time was 170 weeks (range 97-240). Baseline viral load was higher in subjects with viral blips (median log10 4.85 copies/mL) compared with subjects without blips (median log10 4.55 copies/mL) (p < 0.01). There was a significant association between viral blips and risk for subsequent virological failure (p < 0.001). The Swedish national HIV-cohort has a low incidence of viral blips (10 %). Blips were associated with high baseline viral load and an increased risk of subsequent virological failure.

Postpartum Engagement in HIV Care: An Important Predictor of Long-term Retention in Care and Viral Suppression.

PubMed

Adams, Joëlla W; Brady, Kathleen A; Michael, Yvonne L; Yehia, Baligh R; Momplaisir, Florence M

2015-12-15

Human immunodeficiency virus (HIV)-infected women are at risk of virologic failure postpartum. We evaluated factors influencing retention in care and viral suppression in postpartum HIV-infected women. We conducted a retrospective cohort analysis (2005-2011) of 695 deliveries involving 561 HIV-infected women in Philadelphia. Multivariable logistic regression evaluated factors, including maternal age, race/ethnicity, substance use, antiretroviral therapy during pregnancy, timing of HIV diagnosis, previous pregnancy with HIV, adequacy of prenatal care, and postpartum HIV care engagement (≥ 1 CD4 count or viral load [VL] test within 90 days of delivery), associated with retention in care (≥ 1 CD4 count or VL test in each 6-month interval of the period with ≥ 60 days between tests) and viral suppression (VL ≤ 200 copies/mL at the last measure in the period) at 1 and 2 years postpartum. Overall, 38% of women engaged in HIV care within 90 days postpartum; with 39% and 31% retained in care and virally suppressed, respectively, at 1 year postpartum, and 25% and 34% retained in care and virally suppressed, respectively, at 2 years postpartum. In multivariable analyses, women who engaged in HIV care within 90 days of delivery were more likely to be retained (adjusted odds ratio [AOR], 11.38; 95% confidence interval [CI], 7.74-16.68) and suppressed (AOR, 2.60 [95% CI, 1.82-3.73]) at 1 year postpartum. This association persisted in the second year postpartum for both retention (AOR, 6.19 [95% CI, 4.04-9.50]) and suppression (AOR, 1.40 [95% CI, 1.01-1.95]). The prevalence of postpartum HIV-infected women retained in care and maintaining viral suppression is low. Interventions seeking to engage women in care shortly after delivery have the potential to improve clinical outcomes. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Long-term viral suppression and immune recovery during first-line antiretroviral therapy: a study of an HIV-infected adult cohort in Hanoi, Vietnam.

PubMed

Tanuma, Junko; Matsumoto, Shoko; Haneuse, Sebastien; Cuong, Do Duy; Vu, Tuong Van; Thuy, Pham Thi Thanh; Dung, Nguyen Thi; Dung, Nguyen Thi Hoai; Trung, Nguyen Vu; Kinh, Nguyen Van; Oka, Shinichi

2017-12-01

Achieving viral suppression is key in the global strategy to end the HIV epidemic. However, the levels of viral suppression have yet to be described in many resource-limited settings. We investigated the time to virologic failure (VF; defined as a viral load of ≥1000 copies/ml) and changes in CD4 counts since starting antiretroviral therapy (ART) in a cohort of HIV-infected adults in Hanoi, Vietnam. Factors related to the time to VF and impaired early immune recovery (defined as not attaining an increase in 100 cells/mm 3 in CD4 counts at 24 months) were further analysed. From 1806 participants, 225 were identified as having VF at a median of 50 months of first-line ART. The viral suppression rate at 12 months was 95.5% and survival without VF was maintained above 90% until 42 months. An increase in CD4 counts from the baseline was greater in groups with lower baseline CD4 counts. A younger age (multivariate hazard ratio (HR) 0.75, vs. <30), hepatitis C (HCV)-antibody positivity (HR 1.43), and stavudine (d4T)-containing regimens (HR 1.4, vs. zidovudine (AZT)) were associated with earlier VF. Factors associated with impaired early immune recovery included the male sex (odds ratio (OR) 1.78), HCV-antibody positivity (OR 1.72), d4T-based regimens (OR 0.51, vs. AZT), and nevirapine-based regimens (OR 0.53, vs. efavirenz) after controlling for baseline CD4 counts. Durable high-rate viral suppression was observed in the cohort of patients on first-line ART in Vietnam. Our results highlight the need to increase adherence support among injection drug users and HCV co-infected patients. © 2017 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

Antiretroviral Prescription and Viral Suppression in a Representative Sample of HIV-Infected Persons in Care in 4 Large Metropolitan Areas of the United States, Medical Monitoring Project, 2011-2013.

PubMed

Wohl, Amy Rock; Benbow, Nanette; Tejero, Judith; Johnson, Christopher; Scheer, Susan; Brady, Kathleen; Gagner, Alexandra; Hughes, Alison; Eberhart, Michael; Mattson, Christine; Skarbinski, Jacek

2017-10-01

Comparisons of antiretroviral therapy (ART) prescription and viral suppression among people in HIV care across US metropolitan areas are limited. Medical Monitoring Project, 2011-2013, data were used to describe and compare associations between sociodemographics and ART prescription and viral suppression for persons receiving HIV care. Chicago, Los Angeles County (LAC), Philadelphia, and San Francisco in the United States. Bivariate and multivariable methods were used. The proportion of patients prescribed ART (91%-93%) and virally suppressed (79%-88%) was consistent although more persons were virally suppressed in San Francisco compared with the other areas, and a smaller proportion was virally suppressed in Philadelphia compared with Chicago. In the combined cohort, persons aged 30-49 years were less likely than persons 50+ (adjusted prevalence ratio (aPR) -0.97, confidence interval (CI): 0.94 to 0.99); persons reporting non-injection drug use were less likely than non-users (aPR = 0.94, CI: 0.90 to 0.98); and Hispanics were more likely than whites (aPR - 1.04, CI: 1.01 to 1.08) to be prescribed ART. Blacks (aPR = 0.93; CI: 0.87 to 0.99) and homeless persons (aPR = 0.87; CI: 0.80 to 0.95) were less likely to be virally suppressed in the combined cohort. In LAC, persons aged 30-49 years were less likely than those 50+ to be prescribed ART (aPR = 0.94, CI: 0.90 to 0.98). Younger persons (18-29) (aPR = 0.77; CI: 0.60 to 0.99) and persons with less than a high school education (aPR = 0.80; CI: 0.67 to 0.95) in Philadelphia, blacks (aPR = 0.90; CI: 0.83 to 0.99) and men who have sex with women only (aPR = 0.89; CI: 0.80 to 0.99) in Chicago, and homeless individuals in LAC (aPR = 0.80; CI: 0.67 to 0.94) were less likely to be virally suppressed. Data highlight the need to increase ART prescription to achieve viral suppression among younger persons, noninjection drug users, blacks, and homeless persons in US metropolitan areas and underscores the importance of region

Effect of Patient Navigation With or Without Financial Incentives on Viral Suppression Among Hospitalized Patients With HIV Infection and Substance Use: A Randomized Clinical Trial.

PubMed

Metsch, Lisa R; Feaster, Daniel J; Gooden, Lauren; Matheson, Tim; Stitzer, Maxine; Das, Moupali; Jain, Mamta K; Rodriguez, Allan E; Armstrong, Wendy S; Lucas, Gregory M; Nijhawan, Ank E; Drainoni, Mari-Lynn; Herrera, Patricia; Vergara-Rodriguez, Pamela; Jacobson, Jeffrey M; Mugavero, Michael J; Sullivan, Meg; Daar, Eric S; McMahon, Deborah K; Ferris, David C; Lindblad, Robert; VanVeldhuisen, Paul; Oden, Neal; Castellón, Pedro C; Tross, Susan; Haynes, Louise F; Douaihy, Antoine; Sorensen, James L; Metzger, David S; Mandler, Raul N; Colfax, Grant N; del Rio, Carlos

2016-07-12

Substance use is a major driver of the HIV epidemic and is associated with poor HIV care outcomes. Patient navigation (care coordination with case management) and the use of financial incentives for achieving predetermined outcomes are interventions increasingly promoted to engage patients in substance use disorders treatment and HIV care, but there is little evidence for their efficacy in improving HIV-1 viral suppression rates. To assess the effect of a structured patient navigation intervention with or without financial incentives to improve HIV-1 viral suppression rates among patients with elevated HIV-1 viral loads and substance use recruited as hospital inpatients. From July 2012 through January 2014, 801 patients with HIV infection and substance use from 11 hospitals across the United States were randomly assigned to receive patient navigation alone (n = 266), patient navigation plus financial incentives (n = 271), or treatment as usual (n = 264). HIV-1 plasma viral load was measured at baseline and at 6 and 12 months. Patient navigation included up to 11 sessions of care coordination with case management and motivational interviewing techniques over 6 months. Financial incentives (up to $1160) were provided for achieving targeted behaviors aimed at reducing substance use, increasing engagement in HIV care, and improving HIV outcomes. Treatment as usual was the standard practice at each hospital for linking hospitalized patients to outpatient HIV care and substance use disorders treatment. The primary outcome was HIV viral suppression (≤200 copies/mL) relative to viral nonsuppression or death at the 12-month follow-up. Of 801 patients randomized, 261 (32.6%) were women (mean [SD] age, 44.6 years [10.0 years]). There were no differences in rates of HIV viral suppression versus nonsuppression or death among the 3 groups at 12 months. Eighty-five of 249 patients (34.1%) in the usual-treatment group experienced treatment success compared with 89 of

JP-8 jet fuel exposure suppresses the immune response to viral infections.

PubMed

Harris, D T; Sakiestewa, D; Titone, D; He, X; Hyde, J; Witten, M

2008-05-01

The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. Exposure of mice to JP-8 for 1A h/day resulted in immediate secretion of two immunosuppressive agents, namely, interleukin-10 and prostaglandin E2. Thus, it was of interest to determine if jet fuel exposure might alter the immune response to infectious agents. The Hong Kong influenza model was used for these studies. Mice were exposed to 1000A mg/m(3) JP-8 (1A h/day) for 7A days before influenza viral infection. Animals were infected intra-nasally with virus and followed in terms of overall survival as well as immune responses. All surviving animals were killed 14A days after viral infection. In the present study, JP-8 exposure increased the severity of the viral infection by suppressing the anti-viral immune responses. That is, exposure of mice to JP-8 for 1A h/day for 7A days before infection resulted in decreased immune cell viability after exposure and infection, a greater than fourfold decrease in immune proliferative responses to mitogens, as well as an overall loss of CD3(+), CD4(+), and CD8(+) T cells from the lymph nodes, but not the spleens, of infected animals. These changes resulted in decreased survival of the exposed and infected mice, with only 33% of animals surviving as compared with 50% of mice infected but not jet fuel-exposed (and 100% of mice exposed only to JP-8). Thus, short-term, low-concentration JP-8 jet fuel exposures have significant suppressive effects on the immune system which can result in increased severity of viral infections.

Substance abuse, violence, and HIV/AIDS (SAVA) syndemic effects on viral suppression among HIV positive women of color.

PubMed

Sullivan, Kristen A; Messer, Lynne C; Quinlivan, E Byrd

2015-01-01

The combined epidemics of substance abuse, violence, and HIV/AIDS, known as the SAVA syndemic, contribute to the disproportionate burden of disease among people of color in the US. To examine the association between HIV viral load suppression and SAVA syndemic variables, we used baseline data from 563 HIV+ women of color treated at nine HIV medical and ancillary care sites participating in HRSA's Special Project of National Significance Women of Color (WOC) Initiative. Just under half the women (n=260) were virally suppressed. Five psychosocial factors contributing to the SAVA syndemic were examined in this study: substance abuse, binge drinking, intimate partner violence, poor mental health, and sexual risk taking. Associations among the psychosocial factors were assessed and clustering confirmed. A SAVA score was created by summing the dichotomous (present/absent) psychosocial measures. Using generalized estimating equation (GEE) models to account for site-level clustering and individual-covariates, a higher SAVA score (0 to 5) was associated with reduced viral suppression; OR (adjusted)=0.81, 95% CI: 0.66, 0.99. The syndemic approach represents a viable framework for understanding viral suppression among HIV positive WOC, and suggests the need for comprehensive interventions that address the social/environmental contexts of patients' lives.

Viral degradasome hijacks mitochondria to suppress innate immunity

PubMed Central

Goswami, Ramansu; Majumdar, Tanmay; Dhar, Jayeeta; Chattopadhyay, Saurabh; Bandyopadhyay, Sudip K; Verbovetskaya, Valentina; Sen, Ganes C; Barik, Sailen

2013-01-01

The balance between the innate immunity of the host and the ability of a pathogen to evade it strongly influences pathogenesis and virulence. The two nonstructural (NS) proteins, NS1 and NS2, of respiratory syncytial virus (RSV) are critically required for RSV virulence. Together, they strongly suppress the type I interferon (IFN)-mediated innate immunity of the host cells by degrading or inhibiting multiple cellular factors required for either IFN induction or response pathways, including RIG-I, IRF3, IRF7, TBK1 and STAT2. Here, we provide evidence for the existence of a large and heterogeneous degradative complex assembled by the NS proteins, which we named “NS-degradasome” (NSD). The NSD is roughly ∼300-750 kD in size, and its degradative activity was enhanced by the addition of purified mitochondria in vitro. Inside the cell, the majority of the NS proteins and the substrates of the NSD translocated to the mitochondria upon RSV infection. Genetic and pharmacological evidence shows that optimal suppression of innate immunity requires mitochondrial MAVS and mitochondrial motility. Together, we propose a novel paradigm in which the mitochondria, known to be important for the innate immune activation of the host, are also important for viral suppression of the innate immunity. PMID:23877405

Effects of CD4 monitoring frequency on clinical endpoints in clinically stable HIV-infected patients with viral suppression

PubMed Central

Ahn, Jin Young; Boettiger, David; Law, Matthew; Kumarasamy, Nagalingeswaran; Yunihastuti, Evy; Chaiwarith, Romanee; Lee, Man Po; Sim, Benedict LH; Oka, Shinichi; Wong, Wingwai; Kamarulzaman, Adeeba; Kantipong, Pacharee; Phanuphak, Praphan; Ng, Oon Tek; Kiertiburanakul, Sasisopin; Zhang, Fujie; Pujari, Sanjay; Ditangco, Rossana; Ratanasuwan, Winai; Merati, Tuti Parwati; Saphonn, Vonthanak; Sohn, Annette H.; Choi, Jun Yong

2015-01-01

Background Current treatment guidelines for HIV infection recommend routine CD4+ lymphocyte (CD4) count monitoring in patients with viral suppression. This may have a limited impact on influencing care as clinically meaningful CD4 decline rarely occurs during viral suppression. Methods In a regional HIV observational cohort in the Asia-Pacific, patients with viral suppression (2 consecutive viral loads <400 copies/mL) and a CD4 count ≥200 cells/μL who had CD4 testing 6 monthly were analyzed. Main study endpoints were occurrence of one CD4 count <200 cells/μL (single CD4<200) and two CD4 counts <200 cells/μL within a 6-month period (confirmed CD4<200). A comparison of time to single and confirmed CD4<200 with biannual or annual CD4 assessment was performed by generating a hypothetical group comprised of the same patients with annual CD4 testing by removing every second CD4 count. Results Among 1538 patients, the rate of single CD4<200 was 3.45/100 patient-years, and of confirmed CD4<200 was 0.77/100 patient-years. During 5 years of viral suppression, patients with baseline CD4 200-249 cells/μL were significantly more likely to experience confirmed CD4<200 compared with patients with higher baseline CD4 (hazard ratio 55.47 [95% confidence interval 7.36–418.20], p<0.001 versus baseline CD4 ≥500 cells/μL). Cumulative probabilities of confirmed CD4<200 was also higher in patients with baseline CD4 200-249 cells/μL compared with patients with higher baseline CD4. There was no significant difference in time to confirmed CD4<200 between biannual and annual CD4 measurement (p=0.336). Conclusions Annual CD4 monitoring in virally suppressed HIV patients with a baseline CD4 ≥250 cells/μL may be sufficient for clinical management. PMID:25850606

Optimizing prevention of HIV mother to child transmission: Duration of antiretroviral therapy and viral suppression at delivery among pregnant Malawian women

PubMed Central

Miller, William C.; Tang, Jennifer H.; Hoffman, Irving F.; Mthiko, Bryan C.; Phulusa, Jacob; John, Mathias; Jumbe, Allan; Hosseinipour, Mina C.

2018-01-01

Background Effective antiretroviral therapy during pregnancy minimizes the risk of vertical HIV transmission. Some women present late in their pregnancy for first antenatal visit; whether these women achieve viral suppression by delivery and how suppression varies with time on ART is unclear. Methods We conducted a prospective cohort study of HIV-infected pregnant women initiating antiretroviral therapy for the first time at Bwaila Hospital in Lilongwe, Malawi from June 2015 to November 2016. Multivariable Poisson models with robust variance estimators were used to estimate risk ratios (RR) and 95% confidence intervals (CI) of the association between duration of ART and both viral load (VL) ≥1000 copies/ml and VL ≥40 copies/ml at delivery. Results Of the 252 women who had viral load testing at delivery, 40 (16%) and 78 (31%) had VL ≥1000 copies/ml and VL ≥40 copies/ml, respectively. The proportion of women with poor adherence to ART was higher among women who were on ART for ≤12 weeks (9/50 = 18.0%) than among those who were on ART for 13–35 weeks (18/194 = 9.3%). Compared to women who were on ART for ≤12 weeks, women who were on ART for 13–20 weeks (RR = 0.52; 95% CI: 0.36–0.74) or 21–35 weeks (RR = 0.26; 95% CI: 0.14–0.48) had a lower risk of VL ≥40 copies/ml at delivery. Similar comparisons for VL ≥1000 copies/ml at delivery showed decrease in risk although not significant for those on ART 13–20 weeks. Conclusion Longer duration of ART during pregnancy was associated with suppressed viral load at delivery. Early ANC attendance in pregnancy to facilitate prompt ART initiation for HIV-positive women is essential in the effort to eliminate HIV vertical transmission. PMID:29614083

The Molecular Prevalence of Viral Infections in Transplant Candidates with Bone Marrow Suppression, Shiraz, Southern Iran, 2010

PubMed Central

Mohammadi, B.; Yaghobi, R.; Dehghani, M.; Behzad Behbahani, A.

2013-01-01

Background: Transient bone marrow suppression, characterized by acute inability of the bone marrow to produce circulating blood cells, may strongly relate to the pathogenesis of some viral infections. Objective: To study the prevalence of some DNA and RNA viruses in patients with transient bone marrow suppression. Methods: EDTA-treated blood samples were collected from 27 patients with clinically- and laboratory-confirmed transient bone marrow suppression. The genomic DNA of hepatitis B virus, adenovirus, polyomavirus BK, and parvovirus B19, and genomic RNA of hepatitis C and G viruses were extracted and amplified by sensitive and specific in-house simple and nested PCR and RT-PCR protocols, respectively. The risk factors that might be related to the studied viral infections were analyzed. Results: Hepatitis B virus infection was diagnosed in 9 (33%) of 27 patients; adenovirus infection in 2 (7%); and parvovirus B19 infection in 7 (26%) of 27 patients. The genomic DNA of polyomovirus BK was not detected in any patients. Both hepatitis C and G viruses were found in 3 (11%) of 27 patients. Conclusion: Diagnosis of the high prevalence of hepatitis B virus, and parvovirus B19 in patients with transient bone marrow suppression, reflects the importance of these viral infections in introducing bone marrow suppression. This hypothesis should be confirmed in further studies. PMID:25013658

A Host Susceptibility Gene, DR1, Facilitates Influenza A Virus Replication by Suppressing Host Innate Immunity and Enhancing Viral RNA Replication

PubMed Central

Hsu, Shih-Feng; Su, Wen-Chi; Jeng, King-Song

2015-01-01

ABSTRACT Influenza A virus (IAV) depends on cellular factors to complete its replication cycle; thus, investigation of the factors utilized by IAV may facilitate antiviral drug development. To this end, a cellular transcriptional repressor, DR1, was identified from a genome-wide RNA interference (RNAi) screen. Knockdown (KD) of DR1 resulted in reductions of viral RNA and protein production, demonstrating that DR1 acts as a positive host factor in IAV replication. Genome-wide transcriptomic analysis showed that there was a strong induction of interferon-stimulated gene (ISG) expression after prolonged DR1 KD. We found that beta interferon (IFN-β) was induced by DR1 KD, thereby activating the JAK-STAT pathway to turn on ISG expression, which led to a strong inhibition of IAV replication. This result suggests that DR1 in normal cells suppresses IFN induction, probably to prevent undesired cytokine production, but that this suppression may create a milieu that favors IAV replication once cells are infected. Furthermore, biochemical assays of viral RNA replication showed that DR1 KD suppressed viral RNA replication. We also showed that DR1 associated with all three subunits of the viral RNA-dependent RNA polymerase (RdRp) complex, indicating that DR1 may interact with individual components of the viral RdRp complex to enhance viral RNA replication. Thus, DR1 may be considered a novel host susceptibility gene for IAV replication via a dual mechanism, not only suppressing the host defense to indirectly favor IAV replication but also directly facilitating viral RNA replication. IMPORTANCE Investigations of virus-host interactions involved in influenza A virus (IAV) replication are important for understanding viral pathogenesis and host defenses, which may manipulate influenza virus infection or prevent the emergence of drug resistance caused by a high error rate during viral RNA replication. For this purpose, a cellular transcriptional repressor, DR1, was identified from

The Effect of Viral Suppression on Cross Sectional Incidence Testing in the Johns Hopkins Hospital Emergency Department

PubMed Central

Laeyendecker, Oliver; Rothman, Richard E.; Henson, Charlamaine; Jo Horne, Bobbi; Ketlogetswe, Kerunne S.; Kraus, Chadd K.; Shahan, Judy; Kelen, Gabor. D.; Quinn, Thomas C.

2009-01-01

Objective(s) To determine the effect of viral suppression on cross sectional incidence testing. Methods In 2001 and 2003, patients entering the Johns Hopkins Hospital Emergency Department (JHHED) were enrolled into an interview based, identity unlinked serosurvey. All HIV positive samples were tested by the Vironostika-less sensitive (LS) EIA and an avidity assay to determine recent HIV infection. Additionally 16 samples from 8 previously characterized elite suppressors (ES) were tested by cross sectional incidence assays. Results HIV prevalence was 12% for the 2001 survey and 11% for the 2003 survey. Of the HIV infected subjects 18% did not know they were infected. Vironostika-LS EIA determined that 6% (11/183) and 7% (17/243) of HIV+ individuals in 2001and 2003, respectively, were recently infected. Avidity testing confirmed 6 of 11 in 2001, and 5 of 17 in 2003 were newly infected, leaving 17 discrepant samples. All 17 discrepant samples were western blot positive, viral load undetectable and 7/17 had antiretroviral drugs (ARVs) in their serum. Ten individuals were virally suppressed without ARVs, appeared incident by Vironostika-LS EIA but chronic by avidity. These 10 subjects had similar testing profiles to the known 16 ES samples, as 9 of 16 were incident by Vironostika-LS EIA, and 0/16 were incident by avidity. Conclusions By removing the viral load negative individuals and by confirming the initial Vironostika-LS EIA results by avidity, the incidence estimate was lowered from 1.73 to 0.94 percent/year in 2001 and from 1.90 to 0.56 percent/year in 2003. Viral suppression affects the performance of the cross sectional incidence tests which rely on antibody titer. In additional 2% (10/426) of all HIV infected individuals who use the JHHED for medical care appear to suppress HIV to undetectable levels without ARVs. PMID:18520680

Curcumin suppression of cytokine release and cytokine storm. A potential therapy for patients with Ebola and other severe viral infections.

PubMed

Sordillo, Peter P; Helson, Lawrence

2015-01-01

The terminal stage of Ebola and other viral diseases is often the onset of a cytokine storm, the massive overproduction of cytokines by the body's immune system. The actions of curcumin in suppressing cytokine release and cytokine storm are discussed. Curcumin blocks cytokine release, most importantly the key pro-inflammatory cytokines, interleukin-1, interleukin-6 and tumor necrosis factor-α. The suppression of cytokine release by curcumin correlates with clinical improvement in experimental models of disease conditions where a cytokine storm plays a significant role in mortality. The use of curcumin should be investigated in patients with Ebola and cytokine storm. Intravenous formulations may allow achievement of therapeutic blood levels of curcumin. Copyright © 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Antiretroviral Therapy Use, Medication Adherence, and Viral Suppression Among PLWHA with Panic Symptoms.

PubMed

Sam, Tanyka Suzanne; Hutton, Heidi E; Lau, Bryan; McCaul, Mary E; Keruly, Jeanne; Moore, Richard; Chander, Geetanjali

2015-11-01

Panic symptoms are prevalent among PLWHAs, yet few studies have examined their relationship with HIV outcomes. Using data from an observational cohort study in Baltimore, MD, we examined the association between panic symptoms and antiretroviral therapy (ART) use, medication adherence, and viral suppression. Data were analyzed using generalized estimating equations and adjusted for age, sex, race/ethnicity, cocaine and/or heroin use, clinic enrollment time, alcohol use, and depressive symptoms. Between June 2010 and September 2012, 1195 individuals participated in 2080 audio computer assisted interviews; 9.9 % (n = 118) of individuals endorsed current panic symptoms. In multivariate analysis, panic symptoms were associated with decreased ART use (IRR 0.94; p = 0.05). Panic symptoms were neither associated with medication adherence nor viral suppression. These findings were independent of depressive symptoms and substance use. Panic symptoms are under-recognized in primary care settings and present an important barrier to ART use. Further studies investigating the reasons for this association are needed.

Antiretroviral Therapy Use, Medication Adherence, and Viral Suppression among PLWHA with Panic Symptoms

PubMed Central

Sam, Tanyka S; Hutton, Heidi E; Lau, Bryan; McCaul, Mary E; Keruly, Jeanne; Moore, Richard; Chander, Geetanjali

2015-01-01

Panic symptoms are prevalent among PLWHAs, yet few studies have examined their relationship with HIV outcomes. Using data from an observational cohort study in Baltimore, MD, we examined the association between panic symptoms and ART use, medication adherence, and viral suppression. Data were analyzed using GEE and adjusted for age, sex, race/ethnicity, cocaine and/or heroin use, clinic enrollment time, alcohol use, and depressive symptoms. Between June 2010 and September 2012, 1195 individuals participated in 2080 audio computer assisted interviews; 9.9% (n=118) of individuals endorsed current panic symptoms. In multivariate analysis, panic symptoms were associated with decreased ART use (IRR 0.94; p = 0.05). Panic symptoms were neither associated with medication adherence nor viral suppression. These findings were independent of depressive symptoms and substance use. Panic symptoms are under-recognized in primary care settings and present an important barrier to ART use. Further studies investigating the reasons for this association are needed. PMID:25903506

Cancer risk in HIV patients with incomplete viral suppression after initiation of antiretroviral therapy.

PubMed

Lee, Jennifer S; Cole, Stephen R; Achenbach, Chad J; Dittmer, Dirk P; Richardson, David B; Miller, William C; Mathews, Christopher; Althoff, Keri N; Moore, Richard D; Eron, Joseph J

2018-01-01

Cancer causes significant morbidity and mortality among HIV patients in the US due to extended life expectancy with access to effective antiretroviral therapy. Low, detectable HIV RNA has been studied as a risk factor for adverse health outcomes, but its clinical impact on cancer risk remains unclear. The objective of this study was to determine whether HIV RNA <1,000 copies/mL six months after starting therapy was associated with 10-year first cancer risk. We followed 7,515 HIV therapy initiators from a US-based multicenter clinical cohort from 1998 to 2014. We used nonparametric multiple imputation to account for viral loads that fell below assay detection limits, and categorized viral loads six months after therapy initiation into four groups: <20, 20-199, 200-999, and >999 copies/mL. We calculated estimates of the cumulative incidence of cancer diagnosis, accounting for death as a competing event. Inverse probability of exposure and censoring weights were used to control for confounding and differential loss to follow up, respectively. Crude 10-year first cancer risk in the study sample was 7.03% (95% CI: 6.08%, 7.98%), with the highest risk observed among patients with viral loads between 200 and 999 copies/mL six months after ART initiation (10.7%). After controlling for baseline confounders, 10-year first cancer risk was 6.90% (95% CI: 5.69%, 8.12%), and was similar across viral load categories. Overall risk of first cancer was not associated with incomplete viral suppression; however, cancer remains a significant threat to HIV patients after treatment initiation. As more HIV patients gain access to treatment in the current "treat all" era, occurrences of incomplete viral suppression will be observed more frequently in clinical practice, which supports continued study of the role of low-level HIV RNA on cancer development.

Adeno-Associated Viral Vector-Induced Overexpression of Neuropeptide Y Y2 Receptors in the Hippocampus Suppresses Seizures

ERIC Educational Resources Information Center

Woldbye, David P. D.; Angehagen, Mikael; Gotzsche, Casper R.; Elbrond-Bek, Heidi; Sorensen, Andreas T.; Christiansen, Soren H.; Olesen, Mikkel V.; Nikitidou, Litsa; Hansen, Thomas v. O.; Kanter-Schlifke, Irene; Kokaia, Merab

2010-01-01

Gene therapy using recombinant adeno-associated viral vectors overexpressing neuropeptide Y in the hippocampus exerts seizure-suppressant effects in rodent epilepsy models and is currently considered for clinical application in patients with intractable mesial temporal lobe epilepsy. Seizure suppression by neuropeptide Y in the hippocampus is…

Role of Viral Hemorrhagic Septicemia Virus (VHSV) Matrix (M) Protein in Suppressing Host Transcription

USDA-ARS?s Scientific Manuscript database

Viral Hemorrhagic Septicemia virus (VHSV) is a pathogenic fish rhabdovirus found in discrete locales throughout the northern hemisphere. VHSV infection of fish cells leads to upregulation of the host's virus detection response, but the virus quickly suppresses interferon (IFN) production and antivir...

HIV-infected patients receiving lopinavir/ritonavir-based antiretroviral therapy achieve high rates of virologic suppression despite adherence rates less than 95%.

PubMed

Shuter, Jonathan; Sarlo, Julie A; Kanmaz, Tina J; Rode, Richard A; Zingman, Barry S

2007-05-01

The observation that extremely high levels of medication adherence are required to achieve complete virologic suppression is based largely on studies of treatment-experienced patients receiving HIV protease inhibitor (PI)-based therapy without ritonavir boosting. This study aims to define the level of adherence needed to achieve virologic suppression in patients receiving boosted PI-based highly active antiretroviral therapy (HAART) with lopinavir/ritonavir. HIV-infected adults receiving a regimen containing lopinavir/ritonavir were recruited into a prospective, observational study of the relation between adherence to lopinavir/ritonavir and virologic outcomes. Adherence was measured using the Medication Event Monitoring System (MEMS; Aardex, Union City, CA). HIV-1 viral load (VL) was measured at week 24. The final study population contained 64 subjects. Eighty percent had AIDS, 97% received lopinavir/ritonavir before enrollment, and most had more than 7 years of HAART experience. Mean adherence overall was 73%. Eighty percent and 59% achieved a VL <400 copies/mL and a VL <75 copies/mL, respectively. Mean adherence was 75% in those achieving a VL <75 copies/mL. High rates of virologic suppression were observed in all adherence quartiles, including the lowest quartile (range of adherence: 23.5%-53.3%). Moderate levels of adherence can lead to virologic suppression in most patients taking lopinavir/ritonavir-based HAART.

Social Capital, Depressive Symptoms, and HIV Viral Suppression Among Young Black, Gay, Bisexual and Other Men Who Have Sex with Men Living with HIV.

PubMed

Hussen, Sophia A; Easley, Kirk A; Smith, Justin C; Shenvi, Neeta; Harper, Gary W; Camacho-Gonzalez, Andres F; Stephenson, Rob; Del Rio, Carlos

2018-04-04

Social capital, the sum of an individual's resource-containing social network connections, has been proposed as a facilitator of successful HIV care engagement. We explored relationships between social capital, psychological covariates (depression, stigma and internalized homonegativity), and viral suppression in a sample of young Black gay, bisexual and other men who have sex with men (YB-GBMSM). We recruited 81 HIV-positive YB-GBMSM 18-24 years of age from a clinic setting. Participants completed a cross-sectional survey, and HIV-1 viral load (VL) measurements were extracted from the medical record. Sixty-five percent (65%) were virally suppressed (HIV-1 VL ≤ 40 copies/ml). Forty-seven percent (47%) had a positive depression screen. Depressive symptoms affected viral suppression differently in YB-GBMSM with lower vs. higher social capital (p = 0.046, test for statistical interaction between depression and social capital). The odds of viral suppression among YB-GBMSM with lower social capital was 93% lower among those with depressive symptoms (OR 0.07, p = 0.002); however, there was no association between depressive symptoms and viral suppression among those with higher social capital. Our results suggest that social capital may buffer the strong negative effects of depressive symptoms on clinical outcomes in YB-GBMSM living with HIV. In addition to treating depression, there is a role for interventions to augment social capital among YB-GBMSM living with HIV as a strategy for enhancing care engagement.

Food insecurity, CD4 counts, and incomplete viral suppression among HIV+ patients from Texas Children's Hospital: A pilot study

USDA-ARS?s Scientific Manuscript database

Our goal was to determine the relationship between food insecurity and CD4 counts and viral suppression among pediatric HIV-positive patients. Food insecurity was assessed by validated survey. CD4 counts and viral load were abstracted from patients’ charts. We used linear regression for the dependen...

Health information technology interventions enhance care completion, engagement in HIV care and treatment, and viral suppression among HIV-infected patients in publicly funded settings.

PubMed

Shade, Starley B; Steward, Wayne T; Koester, Kimberly A; Chakravarty, Deepalika; Myers, Janet J

2015-04-01

The National HIV/AIDS Strategy (NHAS) emphasizes the use of technology to facilitate coordination of comprehensive care for people with HIV. We examined the effect of six health information technology (HIT) interventions in a Ryan White-funded Special Projects of National Significance (SPNS) on care completion services, engagement in HIV care, and viral suppression. Interventions included use of surveillance data to identify out-of-care individuals, extending access to electronic health records to support service providers, use of electronic laboratory ordering and prescribing, and development of a patient portal. Data from a sample of electronic patient records from each site were analyzed to assess changes in utilization of comprehensive care (prevention screening, support service utilization), engagement in primary HIV medical care (receipt of services and use of antiretroviral therapy), and viral suppression. We used weighted generalized estimating equations to estimate outcomes while accounting for the unequal contribution of data and differences in the distribution of patient characteristics across sites and over time. We observed statistically significant changes in the desired direction in comprehensive care utilization and engagement in primary care outcomes targeted by each site. Five of six sites experienced statistically significant increases in viral suppression. These results provide additional support for the use of HIT as a valuable tool for achieving the NHAS goal of providing comprehensive care for all people living with HIV. HIT has the potential to increase utilization of services, improve health outcomes for people with HIV, and reduce community viral load and subsequent transmission of HIV. © The Author 2014. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com For affiliation see end of article.

Roles of Arenavirus Z Protein in Mediating Virion Budding, Viral Transcription-Inhibition and Interferon-Beta Suppression.

PubMed

Shao, Junjie; Liang, Yuying; Ly, Hinh

2018-01-01

The smallest arenaviral protein is the zinc-finger protein (Z) that belongs to the RING finger protein family. Z serves as a main component required for virus budding from the membrane of the infected cells through self-oligomerization, a process that can be aided by the viral nucleoprotein (NP) to form the viral matrix of progeny virus particles. Z has also been shown to be essential for mediating viral transcriptional repression activity by locking the L polymerase onto the viral promoter in a catalytically inactive state, thus limiting viral replication. The Z protein has also recently been shown to inhibit the type I interferon-induction pathway by directly binding to the intracellular pathogen-sensor proteins RIG-I and MDA5, and thus inhibiting their normal functions. This chapter describes several assays used to examine the important roles of the arenaviral Z protein in mediating virus budding (i.e., either Z self-budding or NP-Z budding activities), viral transcriptional inhibition in a viral minigenome (MG) assay, and type I IFN suppression in an IFN-β promoter-mediated luciferase reporter assay.

Understanding Cross-Sectional Racial, Ethnic, and Gender Disparities in Antiretroviral Use and Viral Suppression Among HIV Patients in the United States

PubMed Central

Beer, Linda; Mattson, Christine L.; Bradley, Heather; Skarbinski, Jacek

2016-01-01

Abstract To examine racial/ethnic and gender disparities in antiretroviral (ART) use and viral suppression among HIV-infected persons in care and identify factors that might account for observed disparities. The Medical Monitoring Project (MMP) is a complex sample survey of HIV-infected adults receiving medical care in the United States. We used weighted interview and medical record data collected 06/2009 to 05/2012 to estimate the prevalence of ART use and viral suppression among gender-stratified racial/ethnic groups. We used χ2 tests to identify significant differences in outcomes between white men versus other groups, and logistic regression models to identify the most parsimonious set of factors that could account for each observed difference. We found no significant disparity in ART use between white and Hispanic men, and no disparities between white men and white and Hispanic women after adjustment for disease stage, age, and poverty. Disparities in ART use between white men and black persons persisted after adjusting for other factors, but the observed differences were relatively small. Differences in ART use and adherence, demographic characteristics, and social determinants of health such as poverty, education, and insurance accounted for the observed disparities in viral suppression between white men and all groups except black men. In our model, accounting for these factors reduced the prevalence difference in viral suppression between white and black men by almost half. We found that factors associated with disparities differed among men and women of the same race/ethnicity, lending support to the assertion that gender affects access to care and health status among HIV-infected patients. In addition to supporting efforts to increase ART use and adherence among persons living with HIV, our analysis provides evidence for the importance of social determinants of health in understanding racial/ethnic and gender differences in ART use and viral suppression

West nile virus infections suppress early viral RNA synthesis and avoid inducing the cell stress granule response.

PubMed

Courtney, S C; Scherbik, S V; Stockman, B M; Brinton, M A

2012-04-01

West Nile virus (WNV) recently became endemic in the United States and is a significant cause of human morbidity and mortality. Natural WNV strain infections do not induce stress granules (SGs), while W956IC (a lineage 2/1 chimeric WNV infectious clone) virus infections produce high levels of early viral RNA and efficiently induce SGs through protein kinase R (PKR) activation. Additional WNV chimeric viruses made by replacing one or more W956IC genes with the lineage 1 Eg101 equivalent in the W956IC backbone were analyzed. The Eg-NS4b+5, Eg-NS1+3+4a, and Eg-NS1+4b+5 chimeras produced low levels of viral RNA at early times of infection and inefficiently induced SGs, suggesting the possibility that interactions between viral nonstructural proteins and/or between viral nonstructural proteins and cell proteins are involved in suppressing early viral RNA synthesis and membrane remodeling during natural WNV strain infections. Detection of exposed viral double-stranded RNA (dsRNA) in W956IC-infected cells suggested that the enhanced early viral RNA synthesis surpassed the available virus-induced membrane protection and allowed viral dsRNA to activate PKR.

Same-day antiretroviral therapy (ART) initiation in pregnancy is not associated with viral suppression or engagement in care: A cohort study.

PubMed

Langwenya, Nontokozo; Phillips, Tamsin K; Brittain, Kirsty; Zerbe, Allison; Abrams, Elaine J; Myer, Landon

2018-06-01

Many prevention of mother-to-child HIV transmission programmes across Africa initiate HIV-infected (HIV positive) pregnant women on lifelong antiretroviral therapy (ART) on the first day of antenatal care ("same-day" initiation). However, there are concerns that same-day initiation may limit patient preparation before starting ART and contribute to subsequent non-adherence, disengagement from care and raised viral load. We examined if same-day initiation was associated with viral suppression and engagement in care during pregnancy. Consecutive ART-eligible pregnant women making their first antenatal care (ANC) visit at a primary care facility in Cape Town, South Africa were enrolled into a prospective cohort between March 2013 and June 2014. Before July 2013, ART eligibility was based on CD4 cell count ≤350 cells/μL ("Option A"), with a 1 to 2 week delay from the first ANC visit to ART initiation for patient preparation; thereafter all women were eligible regardless of CD4 cell count ("Option B+") and offered ART on the same day as first ANC visit. Women were followed with viral load testing conducted separately from routine ART services, and engagement in ART services was measured using routinely collected clinic, pharmacy and laboratory records through 12 months postpartum. Among 628 HIV-positive women (median age, 28 years; median gestation at ART start, 21 weeks; 55% newly diagnosed with HIV), 73% initiated ART same-day; this proportion was higher under Option B+ versus Option A (85% vs. 20%). Levels of viral suppression (viral load <50 copies/mL) at delivery (74% vs. 82%) and 12 months postpartum (74% vs. 71%) were similar under same-day versus delayed initiation respectively. Findings were consistent when viral suppression was defined at <1000 copies/mL, after adjustment for demographic/clinical measures and across subgroups of age, CD4 and timing of HIV diagnosis. Time to first viral rebound following initial suppression did not differ by timing

The Herpes Simplex Virus Virion Host Shutoff Protein Enhances Translation of Viral True Late mRNAs Independently of Suppressing Protein Kinase R and Stress Granule Formation.

PubMed

Dauber, Bianca; Poon, David; Dos Santos, Theodore; Duguay, Brett A; Mehta, Ninad; Saffran, Holly A; Smiley, James R

2016-07-01

The herpes simplex virus (HSV) virion host shutoff (vhs) RNase destabilizes cellular and viral mRNAs, suppresses host protein synthesis, dampens antiviral responses, and stimulates translation of viral mRNAs. vhs mutants display a host range phenotype: translation of viral true late mRNAs is severely impaired and stress granules accumulate in HeLa cells, while translation proceeds normally in Vero cells. We found that vhs-deficient virus activates the double-stranded RNA-activated protein kinase R (PKR) much more strongly than the wild-type virus does in HeLa cells, while PKR is not activated in Vero cells, raising the possibility that PKR might play roles in stress granule induction and/or inhibiting translation in restrictive cells. We tested this possibility by evaluating the effects of inactivating PKR. Eliminating PKR in HeLa cells abolished stress granule formation but had only minor effects on viral true late protein levels. These results document an essential role for PKR in stress granule formation by a nuclear DNA virus, indicate that induction of stress granules is the consequence rather than the cause of the translational defect, and are consistent with our previous suggestion that vhs promotes translation of viral true late mRNAs by preventing mRNA overload rather than by suppressing eIF2α phosphorylation. The herpes simplex virus vhs RNase plays multiple roles during infection, including suppressing PKR activation, inhibiting the formation of stress granules, and promoting translation of viral late mRNAs. A key question is the extent to which these activities are mechanistically connected. Our results demonstrate that PKR is essential for stress granule formation in the absence of vhs, but at best, it plays a secondary role in suppressing translation of viral mRNAs. Thus, the ability of vhs to promote translation of viral mRNAs can be largely uncoupled from PKR suppression, demonstrating that this viral RNase modulates at least two distinct aspects

Assessing the Effect of Recent Incarceration in Prison on HIV Care Retention and Viral Suppression in Two States.

PubMed

Costa, Michael; Montague, Brian T; Solomon, Liza; Sammartino, Cara; Gutman, Roee; Zibman, Chava; Rosen, David; Rich, Josiah D

2018-05-01

The prevalence of HIV among people in correctional facilities remains much higher than that of the general population. Numerous studies have demonstrated the effectiveness and acceptability of HIV treatment for individuals incarcerated in US prisons and jails. However, the period following incarceration is characterized by significant disruptions in HIV care. These disruptions include failure to link in a timely manner (or at all) to community care post-release, as well as not being retained in care after linking. We used a retrospective, propensity-matched cohort design to compare retention in care between HIV-positive individuals recently released from prison (releasees) who linked to care in Ryan White HIV/AIDS Program (RWHAP) clinics and RWHAP patients without a recent incarceration history (community controls). We also performed analyses comparing viral load suppression of those retained in both groups. This study shows that even for those who do successfully link to care after prison, they are 24 to 29 percentage points less likely to be retained in care than those already in community care. However, we found that for those who did retain in care, there was no disparity in rates of viral suppression. These findings provide valuable insight regarding how best to address challenges associated with ensuring that HIV-positive individuals leaving prison successfully move through the HIV care continuum to become virally suppressed.

Patterns of HIV Service Use and HIV Viral Suppression Among Patients Treated in an Academic Infectious Diseases Clinic in North Carolina

PubMed Central

Lounsbury, David W.; Messer, Lynne; Quinlivan, Evelyn Byrd

2015-01-01

Irregular participation in HIV medical care hinders HIV RNA suppression and impacts health among people living with HIV. Cluster analysis of clinical data from 1,748 patients attending a large academic medical center yielded three HIV service usage patterns, namely: ‘engaged in care’, ‘sporadic care’, and ‘frequent use’. Patients ‘engaged in care’ exhibited most consistent retention (on average, >88 % of each patient’s observation years had ≥2 visits 90 days apart), annualized visit use (2.9 mean visits/year) and viral suppression (>73 % HIV RNA tests <400 c/mL). Patients in ‘sporadic care’ demonstrated lower retention (46–52 %), visit use (1.7 visits/year) and viral suppression (56 % <400 c/mL). Patients with ‘frequent use’ (5.2 visits/year) had more inpatient and emergency visits. Female, out-of-state residence, low attendance during the first observation year and detectable first-observed HIV RNA were early predictors of subsequent service usage. Patients ‘engaged in care’ were more likely to have HIV RNA <400 than those receiving sporadic care. Results confirm earlier findings that under-utilization of services predicts poorer viral suppression and health out-comes and support recommendations for 2–3 visits/year. PMID:25240628

Alcohol use and depression: link with adherence and viral suppression in adult patients on antiretroviral therapy in rural Lesotho, Southern Africa: a cross-sectional study.

PubMed

Cerutti, Bernard; Broers, Barbara; Masetsibi, Motlomelo; Faturiyele, Olatunbosun; Toti-Mokoteli, Likabelo; Motlatsi, Mokete; Bader, Joelle; Klimkait, Thomas; Labhardt, Niklaus D

2016-09-08

Depression and alcohol use disorder have been shown to be associated with poor adherence to antiretroviral therapy (ART). Studies examining their association with viral suppression in rural Africa are, however, scarce. This study reports prevalence of depressive symptoms and alcohol use disorder, and their potential association with adherence and viral suppression in adult patients on ART in ten clinics in rural Lesotho, Southern Africa. Among 1,388 adult patients (69 % women), 80.7 % were alcohol abstinent, 6.3 % were hazardous drinkers (men: 10.7 %, women: 4.4 %, p < 0.001). The prevalence of depressive symptoms was 28.8 % (men 20.2 %, women 32.7 %, p < 0.001). Both alcohol consumption (adjusted odds-ratio: 2.09, 95 % CI: 1.58-2.77) and alcohol use disorder (2.73, 95 % CI: 1.68-4.42) were significantly associated with poor adherence. There was, however, no significant association with viral suppression. Whereas the results of this study confirm previously reported association of alcohol use disorder with adherence to ART, there was no association with viral suppression. April 28th 2014; NCT02126696 .

Full Viral Suppression, Low-Level Viremia, and Quantifiable Plasma HIV-RNA at the End of Pregnancy in HIV-Infected Women on Antiretroviral Treatment.

PubMed

Baroncelli, Silvia; Pirillo, Maria F; Tamburrini, Enrica; Guaraldi, Giovanni; Pinnetti, Carmela; Degli Antoni, Anna; Galluzzo, Clementina M; Stentarelli, Chiara; Amici, Roberta; Floridia, Marco

2015-07-01

There is limited information on full viral suppression and low-level HIV-RNA viremia in HIV-infected women at the end of pregnancy. We investigated HIV-RNA levels close to delivery in women on antiretroviral treatment in order to define rates of complete suppression, low-level viremia, and quantifiable HIV-RNA, exploring as potential determinants some clinical and viroimmunological variables. Plasma samples from a national study in Italy, collected between 2003 and 2012, were used. According to plasma HIV-RNA levels, three groups were defined: full suppression (target not detected), low-level viremia (target detected but <37 copies/ml), and quantifiable HIV-RNA (≥37 copies/ml). Multivariable logistic regression was used to define determinants of full viral suppression and of quantifiable HIV-RNA. Among 107 women evaluated at a median gestational age of 35 weeks, 90 (84.1%) had HIV-RNA <37 copies/ml. Most of them (59/90, 65.6%) had full suppression, with the remaining (31/90, 34.4%) showing low-level viremia (median: 11.9 copies/ml; IQR 7.4-16.3). Among the 17 women with quantifiable viral load, median HIV-RNA was 109 copies/ml (IQR 46-251), with only one case showing resistance (mutation M184V; rate: 9.1%). In multivariable analyses, women with higher baseline HIV-RNA levels and with hepatitis C virus (HCV) coinfection were significantly more likely to have quantifiable HIV-RNA in late pregnancy. Full viral suppression was significantly more likely with nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimens and significantly less likely with higher HIV-RNA in early pregnancy. No cases of HIV transmission occurred. In conclusion, HIV-infected pregnant women showed a high rate of viral suppression and a low resistance rate before delivery. In most cases no target HIV-RNA was detected in plasma, suggesting a low risk of subsequent virological rebound and development of resistance. Women with high levels of HIV-RNA in early pregnancy and those who have

Persistence of Viral Reservoirs in Multiple Tissues after Antiretroviral Therapy Suppression in a Macaque RT-SHIV Model

PubMed Central

Franks, Tamera; Kiser, Rebecca; Coalter, Vicky; Smedley, Jeremy; Piatak, Michael; Mellors, John W.; Lifson, Jeffrey D.; Ambrose, Zandrea

2013-01-01

Although antiretroviral therapy (ART) can suppress HIV-1 replication sufficiently to eliminate measurable plasma viremia, infected cells remain and ensure viral recrudescence after discontinuation of ART. We used a macaque model of HIV-1/AIDS to evaluate the location of infected cells during ART. Twelve macaques were infected with RT-SHIVmne, a SIV containing HIV-1 reverse transcriptase, conferring sensitivity to non-nucleoside reverse transcriptase inhibitors (NNRTIs). Ten to fourteen weeks post-infection, 6 animals were treated with 3 or 4 antiretroviral drugs for 17-20 weeks; 6 control animals remained untreated. Viral DNA (vDNA) and RNA (vRNA) were measured in peripheral blood mononuclear cells (PBMC) and at necropsy in multiple tissues by quantitative PCR and RT-PCR. The majority of virally infected cells were located in lymphoid tissues with variable levels in the gastrointestinal tract of both treated and untreated animals. Tissue viral DNA levels correlated with week 1 plasma viremia, suggesting that tissues that harbor proviral DNA are established within the first week of infection. PBMC vDNA levels did not correlate with plasma viremia or tissue levels of vDNA. vRNA levels were high in lymphoid and gastrointestinal tissues of the untreated animals; animals on ART had little vRNA expressed in tissues and virus could not be cultured from lymph node resting CD4+ cells after 17-20 weeks on ART, indicating little or no ongoing viral replication. Strategies for eradication of HIV-1 will need to target residual virus in ART suppressed individuals, which may not be accurately reflected by frequencies of infected cells in blood. PMID:24367650

HIV-1 tropism testing in subjects achieving undetectable HIV-1 RNA: diagnostic accuracy, viral evolution and compartmentalization.

PubMed

Pou, Christian; Codoñer, Francisco M; Thielen, Alexander; Bellido, Rocío; Pérez-Álvarez, Susana; Cabrera, Cecilia; Dalmau, Judith; Curriu, Marta; Lie, Yolanda; Noguera-Julian, Marc; Puig, Jordi; Martínez-Picado, Javier; Blanco, Julià; Coakley, Eoin; Däumer, Martin; Clotet, Bonaventura; Paredes, Roger

2013-01-01

Technically, HIV-1 tropism can be evaluated in plasma or peripheral blood mononuclear cells (PBMCs). However, only tropism testing of plasma HIV-1 has been validated as a tool to predict virological response to CCR5 antagonists in clinical trials. The preferable tropism testing strategy in subjects with undetectable HIV-1 viremia, in whom plasma tropism testing is not feasible, remains uncertain. We designed a proof-of-concept study including 30 chronically HIV-1-infected individuals who achieved HIV-1 RNA <50 copies/mL during at least 2 years after first-line ART initiation. First, we determined the diagnostic accuracy of 454 and population sequencing of gp120 V3-loops in plasma and PBMCs, as well as of MT-2 assays before ART initiation. The Enhanced Sensitivity Trofile Assay (ESTA) was used as the technical reference standard. 454 sequencing of plasma viruses provided the highest agreement with ESTA. The accuracy of 454 sequencing decreased in PBMCs due to reduced specificity. Population sequencing in plasma and PBMCs was slightly less accurate than plasma 454 sequencing, being less sensitive but more specific. MT-2 assays had low sensitivity but 100% specificity. Then, we used optimized 454 sequence data to investigate viral evolution in PBMCs during viremia suppression and only found evolution of R5 viruses in one subject. No de novo CXCR4-using HIV-1 production was observed over time. Finally, Slatkin-Maddison tests suggested that plasma and cell-associated V3 forms were sometimes compartmentalized. The absence of tropism shifts during viremia suppression suggests that, when available, testing of stored plasma samples is generally safe and informative, provided that HIV-1 suppression is maintained. Tropism testing in PBMCs may not necessarily produce equivalent biological results to plasma, because the structure of viral populations and the diagnostic performance of tropism assays may sometimes vary between compartments. Thereby, proviral DNA tropism testing

Lucidone suppresses dengue viral replication through the induction of heme oxygenase-1.

PubMed

Chen, Wei-Chun; Tseng, Chin-Kai; Lin, Chun-Kuang; Wang, Shen-Nien; Wang, Wen-Hung; Hsu, Shih-Hsien; Wu, Yu-Hsuan; Hung, Ling-Chien; Chen, Yen-Hsu; Lee, Jin-Ching

2018-01-01

Dengue virus (DENV) infection causes life-threatening diseases such as dengue hemorrhagic fever and dengue shock syndrome. Currently, there is no effective therapeutic agent or vaccine against DENV infection; hence, there is an urgent need to discover anti-DENV agents. The potential therapeutic efficacy of lucidone was first evaluated in vivo using a DENV-infected Institute of Cancer Research (ICR) suckling mouse model by monitoring body weight, clinical score, survival rate, and viral titer. We found that lucidone effectively protected mice from DENV infection by sustaining survival rate and reducing viral titers in DENV-infected ICR suckling mice. Then, the anti-DENV activity of lucidone was confirmed by western blotting and quantitative-reverse-transcription-polymerase chain reaction analysis, with an EC 50 value of 25 ± 3 μM. Lucidone significantly induced heme oxygenase-1 (HO-1) production against DENV replication by inhibiting DENV NS2B/3 protease activity to induce the DENV-suppressed antiviral interferon response. The inhibitory effect of lucidone on DENV replication was attenuated by silencing of HO-1 gene expression or blocking HO-1 activity. In addition, lucidone-stimulated nuclear factor erythroid 2-related factor 2 (Nrf2), which is involved in transactivation of HO-1 expression for its anti-DENV activity. Taken together, the mechanistic investigations revealed that lucidone exhibits significant anti-DENV activity in in vivo and in vitro by inducing Nrf2-mediated HO-1 expression, leading to blockage of viral protease activity to induce the anti-viral interferon (IFN) response. These results suggest that lucidone is a promising candidate for drug development.

Someone to count on: social support as an effect modifier of viral load suppression in a prospective cohort study

PubMed Central

Friedman, M. Reuel; Coulter, Robert W.S.; Silvestre, Anthony J.; Stall, Ron; Teplin, Linda; Shoptaw, Steve; Surkan, Pamela J.; Plankey, Michael W.

2017-01-01

Though functional social support has been shown to serve as a protective factor for HIV viral load suppression in other populations, scant research has examined this relationship among men who have sex with men (MSM) in the United States. We assessed characteristics of social support; effects of social support on HIV viral load; and moderation by social support of the relationship between psychosocial indicators of a synergistic epidemic (syndemic) and HIV viral load. We analyzed longitudinal data from HIV-positive MSM using antiretroviral therapy (ART) who were enrolled in the Multicenter AIDS Cohort Study between 2002—2009 (n=712). First, we conducted reliability assessments of a one-item social support measure. Then, we conducted a series of generalized longitudinal mixed models to assess our research questions. Moderation was assessed using an interaction term. A three-level (low/medium/high) social support variable demonstrated high reliability (ICC=0.72; 95% CI: 0.70, 0.75). Black and Hispanic MSM reported lower social support than their White counterparts (p<.0001). Recent sero-conversion was associated with higher social support (p<.05). Higher numbers of concomitant syndemic indicators (depression, polysubstance use, and condomless anal sex) were associated with lower social support (p<.0001). Medium and high social support levels were associated with greater viral load suppression and lower viral load means (p<.0001). Social support moderated the relationships between syndemic and HIV viral load (p<.05). HIV-positive MSM, particularly those of color, may benefit greatly from interventions that can successfully boost functional social support. Creating strengths-based interventions may also have particularly high impact among HIV-positive MSM with the highest psychosocial burdens. PMID:27456040

Type I and Type II Interferon Coordinately Regulate Suppressive Dendritic Cell Fate and Function during Viral Persistence

PubMed Central

Cunningham, Cameron R.; Champhekar, Ameya; Tullius, Michael V.; Dillon, Barbara Jane; Zhen, Anjie; de la Fuente, Justin Rafael; Herskovitz, Jonathan; Elsaesser, Heidi; Snell, Laura M.; Wilson, Elizabeth B.; de la Torre, Juan Carlos; Kitchen, Scott G.; Horwitz, Marcus A.; Bensinger, Steven J.; Smale, Stephen T.; Brooks, David G.

2016-01-01

Persistent viral infections are simultaneously associated with chronic inflammation and highly potent immunosuppressive programs mediated by IL-10 and PDL1 that attenuate antiviral T cell responses. Inhibiting these suppressive signals enhances T cell function to control persistent infection; yet, the underlying signals and mechanisms that program immunosuppressive cell fates and functions are not well understood. Herein, we use lymphocytic choriomeningitis virus infection (LCMV) to demonstrate that the induction and functional programming of immunosuppressive dendritic cells (DCs) during viral persistence are separable mechanisms programmed by factors primarily considered pro-inflammatory. IFNγ first induces the de novo development of naive monocytes into DCs with immunosuppressive potential. Type I interferon (IFN-I) then directly targets these newly generated DCs to program their potent T cell immunosuppressive functions while simultaneously inhibiting conventional DCs with T cell stimulating capacity. These mechanisms of monocyte conversion are constant throughout persistent infection, establishing a system to continuously interpret and shape the immunologic environment. MyD88 signaling was required for the differentiation of suppressive DCs, whereas inhibition of stimulatory DCs was dependent on MAVS signaling, demonstrating a bifurcation in the pathogen recognition pathways that promote distinct elements of IFN-I mediated immunosuppression. Further, a similar suppressive DC origin and differentiation was also observed in Mycobacterium tuberculosis infection, HIV infection and cancer. Ultimately, targeting the underlying mechanisms that induce immunosuppression could simultaneously prevent multiple suppressive signals to further restore T cell function and control persistent infections. PMID:26808628

CD4+ cell count recovery in naïve patients initiating cART, who achieved and maintained plasma HIV-RNA suppression.

PubMed

Costagliola, Dominique; Lacombe, Jean-Marc; Ghosn, Jade; Delaugerre, Constance; Pialoux, Gilles; Cuzin, Lise; Launay, Odile; Ménard, Amélie; de Truchis, Pierre; Mary-Krause, Murielle; Weiss, Laurence; Delfraissy, Jean-François

2014-01-01

A key objective of combined antiretroviral therapy (cART) is to reach and maintain high CD4 cell counts to provide long-term protection against AIDS-defining opportunistic infections and malignancies, as well as other comorbidities. However, a high proportion of patients present late for care. Our objective was to assess CD4 cell count recovery up to seven years in naïve patients initiating cART with at least three drugs in usual clinical care. From the French Hospital Database on HIV, we selected naïve individuals initiating cART from 2000 with at least two years of follow-up. Participants were further required to have achieved viral load suppression by six months after initiating cART and were censored in case of virological failure. We calculated the proportion of patients (Kaplan-Meier estimates) who achieved CD4 recovery to >500/mm(3) according to baseline CD4 cell count. A total of 15,025 patients were analyzed with a median follow-up on ART of 65.5 months (IQR: 42.3-96.0). At cART initiation, the median age was 38.6 years (IQR: 32.2-46.0), 9734 (64.8%) were men, median CD4 cell count was 239 (IQR: 130-336) and 2668 (17.8%) had a prior AIDS event. RESULTS are presented in the Table 1. This study shows that CD4 cell counts continue to increase seven years after cART initiation, whatever the baseline CD4 cell count. Failing to achieve CD4 recovery with continuous viral load suppression is rare for naïve patients initiating cART in routine clinical practice, but takes substantially longer in patients who initiate antiretroviral therapy at low CD4 cell counts.

Brief Report: Food Insufficiency Is Associated With Lack of Sustained Viral Suppression Among HIV-Infected Pregnant and Breastfeeding Ugandan Women

PubMed Central

Natureeba, Paul; Nyafwono, Dorcas; Plenty, Albert; Mwesigwa, Julia; Nzarubara, Bridget; Clark, Tamara D.; Ruel, Theodore D.; Achan, Jane; Charlebois, Edwin D.; Cohan, Deborah; Kamya, Moses R.; Havlir, Diane V.; Young, Sera L.

2016-01-01

Abstract: Food insecurity is associated with poor virologic outcomes, but this has not been studied during pregnancy and breastfeeding. We assessed sustained viral suppression from 8 weeks on antiretroviral therapy to 48 weeks postpartum among 171 pregnant and breastfeeding Ugandan women; 74.9% experienced food insufficiency. In multivariable analysis, food insufficiency [adjusted odds ratio (aOR) 0.38, 95% confidence interval (CI): 0.16 to 0.91], higher pretreatment HIV-1 RNA (aOR 0.55 per 10-fold increase, 95% CI: 0.37 to 0.82), and lopinavir/ritonavir versus efavirenz (aOR 0.49, 95% CI: 0.24 to 0.96) were associated with lower odds of sustained viral suppression. Interventions to address food security may improve virologic outcomes among HIV-infected women. PMID:26397935

The Perilous Road from HIV Diagnosis in the Hospital to Viral Suppression in the Outpatient Clinic.

PubMed

Colasanti, Jonathan; Goswami, Neela D; Khoubian, Jonathan J; Pennisi, Eugene; Root, Christin; Ziemer, Dorothy; Armstrong, Wendy S; Del Rio, Carlos

2016-08-01

The HIV care continuum has received considerable attention in recent years, however, few care continua focus on the population of patients who are diagnosed during an inpatient hospital admission. We aimed to describe the HIV care continuum for patients newly diagnosed during hospitalization through 24-month follow-up. A retrospective chart review of HIV patients diagnosed at Grady Memorial Hospital from 2011 to 2012 was performed and records were matched to Georgia Department of Public Health HIV/AIDS surveillance data. Descriptive statistics and statistical tests of independence were utilized. Ninety-four new diagnoses were confirmed during the 2-year study period. Median age was 43 years (interquartile range [IQR] 30-51), 77% were male, 72% were non-Hispanic Black, 31% were men who have sex with men (MSM), and 77% were uninsured. Median CD4 count at diagnosis was 134 cells/μL (IQR 30-307). Eighty-four percent received their diagnosis before hospital discharge, 68% linked to care by 90 days, 73% were retained for 12 months, 48% were virologically suppressed by 12 months, 58% were retained for 24 continuous months, and 38% achieved continuous viral suppression (VS) during the initial 24 months after diagnosis. Late diagnosis is a persistent problem in hospitalized patients. Despite relative success with linkage to care and 12-month retention in care, a minority of patients maintained retention and VS for 24 continuous months.

The proteasomal Rpn11 metalloprotease suppresses tombusvirus RNA recombination and promotes viral replication via facilitating assembly of the viral replicase complex.

PubMed

Prasanth, K Reddisiva; Barajas, Daniel; Nagy, Peter D

2015-03-01

RNA viruses co-opt a large number of cellular proteins that affect virus replication and, in some cases, viral genetic recombination. RNA recombination helps viruses in an evolutionary arms race with the host's antiviral responses and adaptation of viruses to new hosts. Tombusviruses and a yeast model host are used to identify cellular factors affecting RNA virus replication and RNA recombination. In this study, we have examined the role of the conserved Rpn11p metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates, in tombusvirus replication and recombination in Saccharomyces cerevisiae and plants. Depletion or mutations of Rpn11p lead to the rapid formation of viral RNA recombinants in combination with reduced levels of viral RNA replication in yeast or in vitro based on cell extracts. Rpn11p interacts with the viral replication proteins and is recruited to the viral replicase complex (VRC). Analysis of the multifunctional Rpn11p has revealed that the primary role of Rpn11p is to act as a "matchmaker" that brings the viral p92(pol) replication protein and the DDX3-like Ded1p/RH20 DEAD box helicases into VRCs. Overexpression of Ded1p can complement the defect observed in rpn11 mutant yeast by reducing TBSV recombination. This suggests that Rpn11p can suppress tombusvirus recombination via facilitating the recruitment of the cellular Ded1p helicase, which is a strong suppressor of viral recombination, into VRCs. Overall, this work demonstrates that the co-opted Rpn11p, which is involved in the assembly of the functional proteasome, also functions in the proper assembly of the tombusvirus VRCs. RNA viruses evolve rapidly due to genetic changes based on mutations and RNA recombination. Viral genetic recombination helps viruses in an evolutionary arms race with the host's antiviral responses and facilitates adaptation of viruses to new hosts. Cellular factors affect viral RNA recombination, although the role

The Proteasomal Rpn11 Metalloprotease Suppresses Tombusvirus RNA Recombination and Promotes Viral Replication via Facilitating Assembly of the Viral Replicase Complex

PubMed Central

Prasanth, K. Reddisiva; Barajas, Daniel

2014-01-01

ABSTRACT RNA viruses co-opt a large number of cellular proteins that affect virus replication and, in some cases, viral genetic recombination. RNA recombination helps viruses in an evolutionary arms race with the host's antiviral responses and adaptation of viruses to new hosts. Tombusviruses and a yeast model host are used to identify cellular factors affecting RNA virus replication and RNA recombination. In this study, we have examined the role of the conserved Rpn11p metalloprotease subunit of the proteasome, which couples deubiquitination and degradation of proteasome substrates, in tombusvirus replication and recombination in Saccharomyces cerevisiae and plants. Depletion or mutations of Rpn11p lead to the rapid formation of viral RNA recombinants in combination with reduced levels of viral RNA replication in yeast or in vitro based on cell extracts. Rpn11p interacts with the viral replication proteins and is recruited to the viral replicase complex (VRC). Analysis of the multifunctional Rpn11p has revealed that the primary role of Rpn11p is to act as a “matchmaker” that brings the viral p92pol replication protein and the DDX3-like Ded1p/RH20 DEAD box helicases into VRCs. Overexpression of Ded1p can complement the defect observed in rpn11 mutant yeast by reducing TBSV recombination. This suggests that Rpn11p can suppress tombusvirus recombination via facilitating the recruitment of the cellular Ded1p helicase, which is a strong suppressor of viral recombination, into VRCs. Overall, this work demonstrates that the co-opted Rpn11p, which is involved in the assembly of the functional proteasome, also functions in the proper assembly of the tombusvirus VRCs. IMPORTANCE RNA viruses evolve rapidly due to genetic changes based on mutations and RNA recombination. Viral genetic recombination helps viruses in an evolutionary arms race with the host's antiviral responses and facilitates adaptation of viruses to new hosts. Cellular factors affect viral RNA

Inhibition of flavivirus infections by antisense oligomers specifically suppressing viral translation and RNA replication.

PubMed

Deas, Tia S; Binduga-Gajewska, Iwona; Tilgner, Mark; Ren, Ping; Stein, David A; Moulton, Hong M; Iversen, Patrick L; Kauffman, Elizabeth B; Kramer, Laura D; Shi, Pei-Yong

2005-04-01

RNA elements within flavivirus genomes are potential targets for antiviral therapy. A panel of phosphorodiamidate morpholino oligomers (PMOs), whose sequences are complementary to RNA elements located in the 5'- and 3'-termini of the West Nile (WN) virus genome, were designed to anneal to important cis-acting elements and potentially to inhibit WN infection. A novel Arg-rich peptide was conjugated to each PMO for efficient cellular delivery. These PMOs exhibited various degrees of antiviral activity upon incubation with a WN virus luciferase-replicon-containing cell line. Among them, PMOs targeting the 5'-terminal 20 nucleotides (5'End) or targeting the 3'-terminal element involved in a potential genome cyclizing interaction (3'CSI) exhibited the greatest potency. When cells infected with an epidemic strain of WN virus were treated with the 5'End or 3'CSI PMO, virus titers were reduced by approximately 5 to 6 logs at a 5 muM concentration without apparent cytotoxicity. The 3'CSI PMO also inhibited mosquito-borne flaviviruses other than WN virus, and the antiviral potency correlated with the conservation of the targeted 3'CSI sequences of specific viruses. Mode-of-action analyses showed that the 5'End and 3'CSI PMOs suppressed viral infection through two distinct mechanisms. The 5'End PMO inhibited viral translation, whereas the 3'CSI PMO did not significantly affect viral translation but suppressed RNA replication. The results suggest that antisense PMO-mediated blocking of cis-acting elements of flavivirus genomes can potentially be developed into an anti-flavivirus therapy. In addition, we report that although a full-length WN virus containing a luciferase reporter (engineered at the 3' untranslated region of the genome) is not stable, an early passage of this reporting virus can be used to screen for inhibitors against any step of the virus life cycle.

Antiviral activity of double-stranded RNA-binding protein PACT against influenza A virus mediated via suppression of viral RNA polymerase.

PubMed

Chan, Chi-Ping; Yuen, Chun-Kit; Cheung, Pak-Hin Hinson; Fung, Sin-Yee; Lui, Pak-Yin; Chen, Honglin; Kok, Kin-Hang; Jin, Dong-Yan

2018-03-07

PACT is a double-stranded RNA-binding protein that has been implicated in host-influenza A virus (IAV) interaction. PACT facilitates the action of RIG-I in the activation of the type I IFN response, which is suppressed by the viral nonstructural protein NS1. PACT is also known to interact with the IAV RNA polymerase subunit PA. Exactly how PACT exerts its antiviral activity during IAV infection remains to be elucidated. In the current study, we demonstrated the interplay between PACT and IAV polymerase. Induction of IFN-β by the IAV RNP complex was most robust when both RIG-I and PACT were expressed. PACT-dependent activation of IFN-β production was suppressed by the IAV polymerase subunits, polymerase acidic protein, polymerase basic protein 1 (PB1), and PB2. PACT associated with PA, PB1, and PB2. Compromising PACT in IAV-infected A549 cells resulted in the augmentation of viral RNA (vRNA) transcription and replication and IFN-β production. Furthermore, vRNA replication was boosted by knockdown of PACT in both A549 cells and IFN-deficient Vero cells. Thus, the antiviral activity of PACT is mediated primarily via its interaction with and inhibition of IAV polymerase. Taken together, our findings reveal a new facet of the host-IAV interaction in which the interplay between PACT and IAV polymerase affects the outcome of viral infection and antiviral response.-Chan, C.-P., Yuen, C.-K., Cheung, P.-H. H., Fung, S.-Y., Lui, P.-Y., Chen, H., Kok, K.-H., Jin, D.-Y. Antiviral activity of double-stranded RNA-binding protein PACT against influenza A virus mediated via suppression of viral RNA polymerase.

Someone to count on: social support as an effect modifier of viral load suppression in a prospective cohort study.

PubMed

Friedman, M Reuel; Coulter, Robert W S; Silvestre, Anthony J; Stall, Ron; Teplin, Linda; Shoptaw, Steve; Surkan, Pamela J; Plankey, Michael W

2017-04-01

Though functional social support has been shown to serve as a protective factor for HIV viral load suppression in other populations, scant research has examined this relationship among men who have sex with men (MSM) in the United States. We assessed characteristics of social support, effects of social support on HIV viral load, and moderation by social support of the relationship between psychosocial indicators of a synergistic epidemic (syndemic) and HIV viral load. We analyzed longitudinal data from HIV-positive MSM using antiretroviral therapy who were enrolled in the Multicenter AIDS Cohort Study between 2002 and 2009 (n = 712). First, we conducted reliability assessments of a one-item social support measure. Then, we conducted a series of generalized longitudinal mixed models to assess our research questions. Moderation was assessed using an interaction term. A three-level (low/medium/high) social support variable demonstrated high reliability (intraclass correlation coefficients  = 0.72; 95% CI: 0.70, 0.75). Black and Hispanic MSM reported lower social support than their White counterparts (p < .0001). Recent sero-conversion was associated with higher social support (p < .05). Higher numbers of concomitant syndemic indicators (depression, polysubstance use, and condomless anal sex) were associated with lower social support (p < .0001). Medium and high social support levels were associated with greater viral load suppression and lower viral load means (p < .0001). Social support moderated the relationships between syndemic and HIV viral load (p < .05). HIV-positive MSM, particularly those of color, may benefit greatly from interventions that can successfully boost functional social support. Creating strengths-based interventions may also have particularly high impact among HIV-positive MSM with the highest psychosocial burdens.

Gene Expression During the Development of Bacteriophage φ29 III. Analysis of Viral-Specific Protein Synthesis with Suppressible Mutants

PubMed Central

McGuire, Jeffrey C.; Pène, Jacques J.; Barrow-Carraway, Joyce

1974-01-01

Fifty-four suppressible mutants of bacteriophage φ29 have been isolated with a variety of mutagens and assigned to eight complementation groups. Viral-specific protein synthesis in UV light-irradiated, nonsuppressing Bacillus subtilis 60084 was analyzed with exponential acrylamide gels. Four additional φ29 proteins which were undetected on ordinary acrylamide gels are reported in this paper. Five phage φ29 proteins have been unambiguously assigned to specific cistrons. Two cistrons had pleiotropic effects on viral protein synthesis. Mutants in cistrons I or II were unable to synthesize DNA in nonsuppressing bacteria. Mutants in cistron I were unable to attach viral chromosomes to the host cell membrane, and the protein responsible for this function has been identified. The other viral protein playing a role in phage φ29 DNA synthesis is also identified and assigned to cistron II. Mutants in cistron II can attach viral chromosomes to membrane, but cannot synthesize DNA in nonsuppressing bacteria. Images PMID:4362871

Impact of adherence on duration of virological suppression among patients receiving combination antiretroviral therapy.

PubMed

Raboud, J M; Harris, M; Rae, S; Montaner, J S G

2002-04-01

To assess the effect of adherence to antiretroviral therapy on the duration of virological suppression after controlling for whether or not the patient ever attained a plasma viral load below the limit of detection of sensitive HIV-1 RNA assays. Data were combined from three randomized, blinded clinical trials (INCAS, AVANTI-2, and AVANTI-3) that compared the antiviral effects of two- and three-drug antiretroviral regimens. Virological suppression was defined as maintaining a plasma viral load below 1000 copies/mL. Adherence was defined prospectively and measured by patient self-report. Adherence did not have a major impact on the probability of achieving virological suppression for patients receiving dual therapy. However, for patients receiving triple therapy, adherence increased the probability of virological suppression, whether the plasma viral load nadir was above or below the lower limit of quantification. Compared to adherent patients with a plasma viral load nadir below the lower limit of quantification, the relative risk of virological failure was 3.0 for non-adherent patients with a nadir below the limit, 18.1 for adherent patients with a nadir above the limit, and 32.1 for non-adherent patients with a nadir above the limit. For patients receiving current three-drug antiretroviral regimens, adherence to therapy and plasma viral load nadir are important factors determining the duration of virological suppression.

Early age at start of antiretroviral therapy associated with better virologic control after initial suppression in HIV-infected infants.

PubMed

Shiau, Stephanie; Strehlau, Renate; Technau, Karl-Günter; Patel, Faeezah; Arpadi, Stephen M; Coovadia, Ashraf; Abrams, Elaine J; Kuhn, Louise

2017-01-28

The report of the 'Mississippi baby' who was initiated on antiretroviral therapy (ART) within 30 h of birth and maintained viral suppression off ART for 27 months has increased interest in the timing of ART initiation early in life. We examined associations between age at ART initiation and virologic outcomes in five cohorts of HIV-infected infants and young children who initiated ART before 2 years of age in Johannesburg, South Africa. We compared those who initiated ART early (<6 months of age) and those who started ART late (6-24 months of age). Two primary outcomes were examined: initial response to ART in three cohorts and later sustained virologic control after achieving suppression on ART in two cohorts. We did not observe consistent differences in initial viral suppression rates by age at ART initiation. Overall, initial viral suppression rates were low. Only 31, 40.1, and 26.5% of early-treated infants (<6 months of age) in the three cohorts, respectively, were suppressed less than 50 copies/ml of HIV RNA 6 months after starting ART. We did observe better sustained virologic control after achieving suppression on ART among infants starting ART early compared with late. Children who started ART early were less likely to experience viral rebound (>50 copies/ml or >1000 copies/ml) than children who started late in both cohorts. These findings provide additional support for early initiation of ART in HIV-infected infants.

A SELEX-Screened Aptamer of Human Hepatitis B Virus RNA Encapsidation Signal Suppresses Viral Replication

PubMed Central

Feng, Hui; Beck, Jürgen; Nassal, Michael; Hu, Kang-hong

2011-01-01

Background The specific interaction between hepatitis B virus (HBV) polymerase (P protein) and the ε RNA stem-loop on pregenomic (pg) RNA is crucial for viral replication. It triggers both pgRNA packaging and reverse transcription and thus represents an attractive antiviral target. RNA decoys mimicking ε in P protein binding but not supporting replication might represent novel HBV inhibitors. However, because generation of recombinant enzymatically active HBV polymerase is notoriously difficult, such decoys have as yet not been identified. Methodology/Principal Findings Here we used a SELEX approach, based on a new in vitro reconstitution system exploiting a recombinant truncated HBV P protein (miniP), to identify potential ε decoys in two large ε RNA pools with randomized upper stem. Selection of strongly P protein binding RNAs correlated with an unexpected strong enrichment of A residues. Two aptamers, S6 and S9, displayed particularly high affinity and specificity for miniP in vitro, yet did not support viral replication when part of a complete HBV genome. Introducing S9 RNA into transiently HBV producing HepG2 cells strongly suppressed pgRNA packaging and DNA synthesis, indicating the S9 RNA can indeed act as an ε decoy that competitively inhibits P protein binding to the authentic ε signal on pgRNA. Conclusions/Significance This study demonstrates the first successful identification of human HBV ε aptamers by an in vitro SELEX approach. Effective suppression of HBV replication by the S9 aptamer provides proof-of-principle for the ability of ε decoy RNAs to interfere with viral P-ε complex formation and suggests that S9-like RNAs may further be developed into useful therapeutics against chronic hepatitis B. PMID:22125633

Adeno-Associated Viral-Mediated Catalase Expression Suppresses Optic Neuritis in Experimental Allergic Encephalomyelitis

NASA Astrophysics Data System (ADS)

Guy, John; Qi, Xiaoping; Hauswirth, William W.

1998-11-01

Suppression of oxidative injury by viral-mediated transfer of the human catalase gene was tested in the optic nerves of animals with experimental allergic encephalomyelitis (EAE). EAE is an inflammatory autoimmune disorder of primary central nervous system demyelination that has been frequently used as an animal model for the human disease multiple sclerosis (MS). The optic nerve is a frequent site of involvement common to both EAE and MS. Recombinant adeno-associated virus containing the human gene for catalase was injected over the right optic nerve heads of SJL/J mice that were simultaneously sensitized for EAE. After 1 month, cell-specific catalase activity, evaluated by quantitation of catalase immunogold, was increased approximately 2-fold each in endothelia, oligodendroglia, astrocytes, and axons of the optic nerve. Effects of catalase on the histologic lesions of EAE were measured by computerized analysis of the myelin sheath area (for demyelination), optic disc area (for optic nerve head swelling), extent of the cellular infiltrate, extravasated serum albumin labeled by immunogold (for blood-brain barrier disruption), and in vivo H2O2 reaction product. Relative to control, contralateral optic nerves injected with the recombinant virus without a therapeutic gene, catalase gene inoculation reduced demyelination by 38%, optic nerve head swelling by 29%, cellular infiltration by 34%, disruption of the blood-brain barrier by 64%, and in vivo levels of H2O2 by 61%. Because the efficacy of potential treatments for MS are usually initially tested in the EAE animal model, this study suggests that catalase gene delivery by using viral vectors may be a therapeutic strategy for suppression of MS.

Suppression of HTLV-1 replication by Tax-mediated rerouting of the p13 viral protein to nuclear speckles

PubMed Central

Andresen, Vibeke; Pise-Masison, Cynthia A.; Sinha-Datta, Uma; Bellon, Marcia; Valeri, Valerio; Washington Parks, Robyn; Cecchinato, Valentina; Fukumoto, Risaku; Nicot, Christophe

2011-01-01

Disease development in human T-cell leukemia virus type 1 (HTLV-1)–infected individuals is positively correlated with the level of integrated viral DNA in T cells. HTLV-1 replication is positively regulated by Tax and Rex and negatively regulated by the p30 and HBZ proteins. In the present study, we demonstrate that HTLV-1 encodes another negative regulator of virus expression, the p13 protein. Expressed separately, p13 localizes to the mitochondria, whereas in the presence of Tax, part of it is ubiquitinated, stabilized, and rerouted to the nuclear speckles. The p13 protein directly binds Tax, decreases Tax binding to the CBP/p300 transcriptional coactivator, and, by reducing Tax transcriptional activity, suppresses viral expression. Because Tax stabilizes its own repressor, these findings suggest that HTLV-1 has evolved a complex mechanism to control its own replication. Further, these results highlight the importance of studying the function of the HTLV-1 viral proteins, not only in isolation, but also in the context of full viral replication. PMID:21677314

HIV-1 Viral Escape in Cerebrospinal Fluid of Subjects on Suppressive Antiretroviral Treatment

PubMed Central

Edén, Arvid; Fuchs, Dietmar; Hagberg, Lars; Nilsson, Staffan; Spudich, Serena; Svennerholm, Bo; Price, Richard W.; Gisslén, Magnus

2010-01-01

Background. Occasional cases of viral escape in cerebrospinal fluid (CSF) despite suppression of plasma human immunodeficiency virus type 1 (HIV-1) RNA have been reported. We investigated CSF viral escape in subjects treated with commonly used antiretroviral therapy regimens in relation to intrathecal immune activation and central nervous system penetration effectiveness (CPE) rank. Methods. Sixty-nine neurologically asymptomatic subjects treated with antiretroviral therapy >6 months and plasma HIV-1 RNA <50 copies/mL were cross-sectionally included in the analysis. Antiretroviral therapy regimens included efavirenz, lopinavir/ritonavir or atazanavir/ritonavir combined with tenofovir, abacavir, or zidovudine and emtricitabine or lamivudine. HIV-1 RNA was analyzed with real-time polymerase chain reaction assays. Neopterin was analyzed by enzyme-linked immunosorbent assay. Results. Seven (10%) of the 69 subjects had detectable CSF HIV-1 RNA, in median 121 copies/mL (interquartile range, 54–213 copies/mL). Subjects with detectable CSF virus had significantly higher CSF neopterin and longer duration of treatment. Previous treatment interruptions were more common in subjects with CSF escape. Central nervous system penetration effectiveness rank was not a significant predictor of detectable CSF virus or CSF neopterin levels. Conclusions. Viral escape in CSF is more common than previously reported, suggesting that low-grade central nervous system infection may continue in treated patients. Although these findings need extension in longitudinal studies, they suggest the utility of monitoring CSF responses, as new treatment combinations and strategies modify clinical practice. PMID:21050119

HIV-1 viral escape in cerebrospinal fluid of subjects on suppressive antiretroviral treatment.

PubMed

Edén, Arvid; Fuchs, Dietmar; Hagberg, Lars; Nilsson, Staffan; Spudich, Serena; Svennerholm, Bo; Price, Richard W; Gisslén, Magnus

2010-12-15

Occasional cases of viral escape in cerebrospinal fluid (CSF) despite suppression of plasma human immunodeficiency virus type 1 (HIV-1) RNA have been reported. We investigated CSF viral escape in subjects treated with commonly used antiretroviral therapy regimens in relation to intrathecal immune activation and central nervous system penetration effectiveness (CPE) rank. Sixty-nine neurologically asymptomatic subjects treated with antiretroviral therapy >6 months and plasma HIV-1 RNA <50 copies/mL were cross-sectionally included in the analysis. Antiretroviral therapy regimens included efavirenz, lopinavir/ritonavir or atazanavir/ritonavir combined with tenofovir, abacavir, or zidovudine and emtricitabine or lamivudine. HIV-1 RNA was analyzed with real-time polymerase chain reaction assays. Neopterin was analyzed by enzyme-linked immunosorbent assay. Seven (10%) of the 69 subjects had detectable CSF HIV-1 RNA, in median 121 copies/mL (interquartile range, 54-213 copies/mL). Subjects with detectable CSF virus had significantly higher CSF neopterin and longer duration of treatment. Previous treatment interruptions were more common in subjects with CSF escape. Central nervous system penetration effectiveness rank was not a significant predictor of detectable CSF virus or CSF neopterin levels. Viral escape in CSF is more common than previously reported, suggesting that low-grade central nervous system infection may continue in treated patients. Although these findings need extension in longitudinal studies, they suggest the utility of monitoring CSF responses, as new treatment combinations and strategies modify clinical practice.

HIV-1-encoded antisense RNA suppresses viral replication for a prolonged period

PubMed Central

2012-01-01

Background Recent evidence proposes a novel concept that mammalian natural antisense RNAs play important roles in cellular homeostasis by regulating the expression of several genes. Identification and characterization of retroviral antisense RNA would provide new insights into mechanisms of replication and pathogenesis. HIV-1 encoded-antisense RNAs have been reported, although their structures and functions remain to be studied. We have tried to identify and characterize antisense RNAs of HIV-1 and their function in viral infection. Results Characterization of transcripts of HEK293T cells that were transiently transfected with an expression plasmid with HIV-1NL4–3 DNA in the antisense orientation showed that various antisense transcripts can be expressed. By screening and characterizing antisense RNAs in HIV-1NL4–3-infected cells, we defined the primary structure of a major form of HIV-1 antisense RNAs, which corresponds to a variant of previously reported ASP mRNA. This 2.6 kb RNA was transcribed from the U3 region of the 3′ LTR and terminated at the env region in acutely or chronically infected cell lines and acutely infected human peripheral blood mononuclear cells. Reporter assays clearly demonstrated that the HIV-1 LTR harbours promoter activity in the reverse orientation. Mutation analyses suggested the involvement of NF-κΒ binding sites in the regulation of antisense transcription. The antisense RNA was localized in the nuclei of the infected cells. The expression of this antisense RNA suppressed HIV-1 replication for more than one month. Furthermore, the specific knockdown of this antisense RNA enhanced HIV-1 gene expression and replication. Conclusions The results of the present study identified an accurate structure of the major form of antisense RNAs expressed from the HIV-1NL4–3 provirus and demonstrated its nuclear localization. Functional studies collectively demonstrated a new role of the antisense RNA in viral replication. Thus, we suggest

CD4 decline is associated with increased risk of cardiovascular disease, cancer, and death in virally suppressed patients with HIV.

PubMed

Helleberg, Marie; Kronborg, Gitte; Larsen, Carsten S; Pedersen, Gitte; Pedersen, Court; Obel, Niels; Gerstoft, Jan

2013-07-01

The clinical implications of a considerable CD4 decline despite antiretroviral treatment and viral suppression are unknown. We aimed to test the hypothesis that a major CD4 decline could be a marker of cardiovascular disease or undiagnosed cancer. Patients with human immunodeficiency virus (HIV) were followed in the Danish nationwide, population-based cohort study in the period 1995-2010 with quarterly CD4 measurements. Associations between a CD4 decline of ≥30% and cardiovascular disease, cancer, and death were analyzed using Poisson regression with date of CD4 decline as a time-updated variable. We followed 2584 virally suppressed HIV patients for 13 369 person-years (PY; median observation time, 4.7 years). Fifty-six patients developed CD4 decline (incidence rate, 4.2/1000 PY [95% confidence interval {CI}, 3.2-5.4]). CD4 counts dropped from a median of 492 cells/µL to 240 cells/µL. CD8, CD3, and total lymphocyte counts dropped concomitantly. No HIV-related factors, apart from treatment with didanosine, were associated with CD4 decline. The risk of cardiovascular disease, cancer, and death increased markedly ≤6 months after CD4 decline (incidence rate ratio, 11.7 [95% CI, 3.6-37.4] and 13.7 [95% CI, 4.3-43.6], respectively, and mortality rate ratio 4.3 [95% CI, 1.1-17.6]). A major decline in CD4 count is associated with a marked increased risk of cardiovascular disease, cancer, and death among virally suppressed HIV patients.

Improvements in HIV Care Engagement and Viral Load Suppression Following Enrollment in a Comprehensive HIV Care Coordination Program

PubMed Central

Irvine, Mary K.; Chamberlin, Stephanie A.; Robbins, Rebekkah S.; Myers, Julie E.; Braunstein, Sarah L.; Mitts, Beau J.; Harriman, Graham A.; Nash, Denis

2015-01-01

Background. Substantial evidence gaps remain regarding human immunodeficiency virus (HIV) intervention strategies that improve engagement in care (EiC) and viral load suppression (VLS). We assessed EiC and VLS before and after enrollment in a comprehensive intervention for persons at risk of poor HIV care outcomes. Methods. New York City's Ryan White Part A HIV Care Coordination Program (CCP), launched at 28 agencies in 2009, applies multiple strategies to promote optimal utilization of medical and social services. Using laboratory test records from an HIV surveillance registry, we examined pre–post outcomes among 3641 CCP clients enrolled before April 2011. For the year before and after enrollment, we assessed EiC (defined as ≥2 tests, ≥90 days apart, with ≥1 in each half-year) and VLS (defined as viral load [VL] ≤200 copies/mL on latest VL test in the second half of the year). We estimated relative risks (RRs), comparing pre- and postenrollment proportions achieving EiC and VLS. Results. Among newly diagnosed clients, 90.5% (95% confidence interval [CI], 87.9%–93.2%) and 66.2% (95% CI, 61.9%–70.6%) achieved EiC and VLS, respectively. Among previously diagnosed clients, EiC increased from 73.7% to 91.3% (RR = 1.24; 95% CI, 1.21–1.27) and VLS increased from 32.3% to 50.9% (RR = 1.58; 95% CI, 1.50–1.66). Clients without evidence of HIV care during the 6 months preenrollment contributed most to overall improvements. Pre–post improvements were robust, retaining statistical significance within most sociodemographic and clinical subgroups, and in 89% (EiC) and 75% (VLS) of CCP agencies. Conclusions. Clients in comprehensive HIV care coordination for persons with evident barriers to care showed substantial and consistent improvement in short-term outcomes. PMID:25301208

SAMHD1 suppresses innate immune responses to viral infections and inflammatory stimuli by inhibiting the NF-κB and interferon pathways.

PubMed

Chen, Shuliang; Bonifati, Serena; Qin, Zhihua; St Gelais, Corine; Kodigepalli, Karthik M; Barrett, Bradley S; Kim, Sun Hee; Antonucci, Jenna M; Ladner, Katherine J; Buzovetsky, Olga; Knecht, Kirsten M; Xiong, Yong; Yount, Jacob S; Guttridge, Denis C; Santiago, Mario L; Wu, Li

2018-04-17

Sterile alpha motif and HD-domain-containing protein 1 (SAMHD1) blocks replication of retroviruses and certain DNA viruses by reducing the intracellular dNTP pool. SAMHD1 has been suggested to down-regulate IFN and inflammatory responses to viral infections, although the functions and mechanisms of SAMHD1 in modulating innate immunity remain unclear. Here, we show that SAMHD1 suppresses the innate immune responses to viral infections and inflammatory stimuli by inhibiting nuclear factor-κB (NF-κB) activation and type I interferon (IFN-I) induction. Compared with control cells, infection of SAMHD1-silenced human monocytic cells or primary macrophages with Sendai virus (SeV) or HIV-1, or treatment with inflammatory stimuli, induces significantly higher levels of NF-κB activation and IFN-I induction. Exogenous SAMHD1 expression in cells or SAMHD1 reconstitution in knockout cells suppresses NF-κB activation and IFN-I induction by SeV infection or inflammatory stimuli. Mechanistically, SAMHD1 inhibits NF-κB activation by interacting with NF-κB1/2 and reducing phosphorylation of the NF-κB inhibitory protein IκBα. SAMHD1 also interacts with the inhibitor-κB kinase ε (IKKε) and IFN regulatory factor 7 (IRF7), leading to the suppression of the IFN-I induction pathway by reducing IKKε-mediated IRF7 phosphorylation. Interactions of endogenous SAMHD1 with NF-κB and IFN-I pathway proteins were validated in human monocytic cells and primary macrophages. Comparing splenocytes from SAMHD1 knockout and heterozygous mice, we further confirmed SAMHD1-mediated suppression of NF-κB activation, suggesting an evolutionarily conserved property of SAMHD1. Our findings reveal functions of SAMHD1 in down-regulating innate immune responses to viral infections and inflammatory stimuli, highlighting the importance of SAMHD1 in modulating antiviral immunity.

Enhancing patient navigation to improve intervention session attendance and viral load suppression of persons with HIV and substance use: a secondary post hoc analysis of the Project HOPE study.

PubMed

Stitzer, Maxine; Matheson, Tim; Cunningham, Colin; Sorensen, James L; Feaster, Daniel J; Gooden, Lauren; Hammond, Alexis S; Fitzsimons, Heather; Metsch, Lisa R

2017-06-27

Interventions are needed to improve viral suppression rates among persons with HIV and substance use. A 3-arm randomized multi-site study (Metsch et al. in JAMA 316:156-70, 2016) was conducted to evaluate the effect on HIV outcomes of usual care referral to HIV and substance use services (N = 253) versus patient navigation delivered alone (PN: N = 266) or together with contingency management (PN + CM; N = 271) that provided financial incentives targeting potential behavioral mediators of viral load suppression. This secondary analysis evaluates the effects of financial incentives on attendance at PN sessions and the relationship between session attendance and viral load suppression at end of the intervention. Frequency of sessions attended was analyzed over time and by distribution of individual session attendance frequency (PN vs PN + CM). Percent virally suppressed (≤200 copies/mL) at 6 months was compared for low, medium and high rate attenders. In PN + CM a total of $220 could be earned for attendance at 11 PN sessions over the 6-month intervention with payments ranging from $10 to $30 under an escalating schedule. The majority (74%) of PN-only participants attended 6 or more sessions but only 28% attended 10 or more and 16% attended all eleven sessions. In contrast, 90% of PN + CM attended 6 or more visits, 69% attended 10 or more and 57% attended all eleven sessions (attendance distribution χ 2 [11] = 105.81; p < .0001). Overall (PN and PN + CM participants combined) percent with viral load suppression at 6-months was 15, 38 and 54% among those who attended 0-5, 6-9 and 10-11 visits, respectively (χ 2 (2) = 39.07, p < .001). In this secondary post hoc analysis, contact with patient navigators was increased by attendance incentives. Higher rates of attendance at patient navigation sessions was associated with viral suppression at the 6-month follow-up assessment. Study results support use of attendance incentives to improve rates

PARP12 suppresses Zika virus infection through PARP-dependent degradation of NS1 and NS3 viral proteins.

PubMed

Li, Lili; Zhao, Hui; Liu, Ping; Li, Chunfeng; Quanquin, Natalie; Ji, Xue; Sun, Nina; Du, Peishuang; Qin, Cheng-Feng; Lu, Ning; Cheng, Genhong

2018-06-19

Zika virus infection stimulates a type I interferon (IFN) response in host cells, which suppresses viral replication. Type I IFNs exert antiviral effects by inducing the expression of hundreds of IFN-stimulated genes (ISGs). To screen for antiviral ISGs that restricted Zika virus replication, we individually knocked out 21 ISGs in A549 lung cancer cells and identified PARP12 as a strong inhibitor of Zika virus replication. Our findings suggest that PARP12 mediated the ADP-ribosylation of NS1 and NS3, nonstructural viral proteins that are involved in viral replication and modulating host defense responses. This modification of NS1 and NS3 triggered their proteasome-mediated degradation. These data increase our understanding of the antiviral activity of PARP12 and suggest a molecular basis for the potential development of therapeutics against Zika virus. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Current status and strategies for viral hepatitis control in Korea.

PubMed

Sinn, Dong Hyun; Cho, Eun Ju; Kim, Ji Hoon; Kim, Do Young; Kim, Yoon Jun; Choi, Moon Seok

2017-09-01

Viral hepatitis is one of major global health challenges with increasing disease burden worldwide. Hepatitis B virus and hepatitis C virus infections are major causes of chronic liver diseases. They can lead to cirrhosis, hepatocellular carcinoma, and death in significant portion of affected people. Transmission of hepatitis B virus can be blocked by vaccination. Progression of hepatitis B virus-related liver diseases can be prevented by long-term viral suppression with effective drugs. Although vaccine for hepatitis C virus is currently unavailable, hepatitis C virus infection can be eradicated by oral direct antiviral agents. To eliminate viral hepatitis, World Health Organization (WHO) has urged countries to develop national goals and targets through reducing 90% of new infections and providing universal access to key treatment services up to 80%. This can lead to 65% reduction of viral hepatitis-related mortality. Here, we discuss some key features of viral hepatitis, strategies to control viral hepatitis suggested by WHO, and current status and strategies for viral hepatitis control in South Korea. To achieve the goal of viral hepatitis elimination by 2030 in South Korea, an independent 'viral hepatitis sector' in Centers for Disease Control & Prevention (CDC) needs to be established to organize and execute comprehensive strategy for the management of viral hepatitis in South Korea.

Human Antiviral Protein IFIX Suppresses Viral Gene Expression during Herpes Simplex Virus 1 (HSV-1) Infection and Is Counteracted by Virus-induced Proteasomal Degradation.

PubMed

Crow, Marni S; Cristea, Ileana M

2017-04-01

The interferon-inducible protein X (IFIX), a member of the PYHIN family, was recently recognized as an antiviral factor against infection with herpes simplex virus 1 (HSV-1). IFIX binds viral DNA upon infection and promotes expression of antiviral cytokines. How IFIX exerts its host defense functions and whether it is inhibited by the virus remain unknown. Here, we integrated live cell microscopy, proteomics, IFIX domain characterization, and molecular virology to investigate IFIX regulation and antiviral functions during HSV-1 infection. We find that IFIX has a dynamic localization during infection that changes from diffuse nuclear and nucleoli distribution in uninfected cells to discrete nuclear puncta early in infection. This is rapidly followed by a reduction in IFIX protein levels. Indeed, using immunoaffinity purification and mass spectrometry, we define IFIX interactions during HSV-1 infection, finding an association with a proteasome subunit and proteins involved in ubiquitin-proteasome processes. Using synchronized HSV-1 infection, microscopy, and proteasome-inhibition experiments, we demonstrate that IFIX co-localizes with nuclear proteasome puncta shortly after 3 h of infection and that its pyrin domain is rapidly degraded in a proteasome-dependent manner. We further demonstrate that, in contrast to several other host defense factors, IFIX degradation is not dependent on the E3 ubiquitin ligase activity of the viral protein ICP0. However, we show IFIX degradation requires immediate-early viral gene expression, suggesting a viral host suppression mechanism. The IFIX interactome also demonstrated its association with transcriptional regulatory proteins, including the 5FMC complex. We validate this interaction using microscopy and reciprocal isolations and determine it is mediated by the IFIX HIN domain. Finally, we show IFIX suppresses immediate-early and early viral gene expression during infection. Altogether, our study demonstrates that IFIX antiviral

Rates of Initial Virological Suppression and Subsequent Virological Failure After Initiating Highly Active Antiretroviral Therapy: The Impact of Aboriginal Ethnicity and Injection Drug Use

PubMed Central

Martin, L.J.; Houston, S.; Yasui, Y.; Wild, T.C.; Saunders, L.D.

2010-01-01

Objectives: To compare rates of initial virological suppression and subsequent virological failure by Aboriginal ethnicity after starting highly active antiretroviral therapy (HAART). Methods: We conducted a retrospective cohort study of antiretroviral-naïve HIV-patients starting HAART in January 1999-June 2005 (baseline), followed until December 31, 2005 in Alberta, Canada. We compared the odds of achieving initial virological suppression (viral load <500 copies/mL) by Aboriginal ethnicity using logistic regression and, among those achieving suppression, rates of virological failure (the first of two consecutive viral loads > 1000 copies/mL) by Aboriginal ethnicity using cumulative incidence curves and Cox proportional hazards models. Sex, injection drug use as an HIV exposure category (IDU), baseline age, CD4 cell count, viral load, calendar year, and HAART regimen were considered as potential confounders. Results: Of 461 study patients, 37% were Aboriginal and 48% were IDUs; 71% achieved initial virological suppression and were followed for 730.4 person-years. After adjusting for confounding variables, compared to non-Aboriginals with other exposures, the odds of achieving initial virological suppression were lower for Aboriginal IDUs (odds ratio (OR)=0.33, 95% CI=0.19-0.60, p=0.0002), non-Aboriginal IDUs (OR=0.30, 95% CI=0.15-0.60, p=0.0006), and Aboriginals with other exposures (OR=0.38, 95% CI=0.21-0.67, p=0.0009). Among those achieving suppression, Aboriginals experienced higher virological failure rates ≥1 year after suppression (hazard ratio=3.35, 95% CI=1.68-6.65, p=0.0006). Conclusions: Future research should investigate adherence among Aboriginals and IDUs treated with HAART and explore their treatment experiences to assess ways to improve outcomes. PMID:21187007

Improving laboratory efficiencies to scale-up HIV viral load testing.

PubMed

Alemnji, George; Onyebujoh, Philip; Nkengasong, John N

2017-03-01

Viral load measurement is a key indicator that determines patients' response to treatment and risk for disease progression. Efforts are ongoing in different countries to scale-up access to viral load testing to meet the Joint United Nations Programme on HIV and AIDS target of achieving 90% viral suppression among HIV-infected patients receiving antiretroviral therapy. However, the impact of these initiatives may be challenged by increased inefficiencies along the viral load testing spectrum. This will translate to increased costs and ineffectiveness of scale-up approaches. This review describes different parameters that could be addressed across the viral load testing spectrum aimed at improving efficiencies and utilizing test results for patient management. Though progress is being made in some countries to scale-up viral load, many others still face numerous challenges that may affect scale-up efficiencies: weak demand creation, ineffective supply chain management systems; poor specimen referral systems; inadequate data and quality management systems; and weak laboratory-clinical interface leading to diminished uptake of test results. In scaling up access to viral load testing, there should be a renewed focus to address efficiencies across the entire spectrum, including factors related to access, uptake, and impact of test results.

Structural Determinants of Antiretroviral Therapy Use, HIV Care Attendance, and Viral Suppression among Adolescents and Young Adults Living with HIV

PubMed Central

Kahana, Shoshana Y.; Jenkins, Richard A.; Bruce, Douglas; Fernandez, Maria I.; Hightow-Weidman, Lisa B.; Bauermeister, Jose A.

2016-01-01

Background The authors examined associations between structural characteristics and HIV disease management among a geographically diverse sample of behaviorally and perinatally HIV-infected adolescents and young adults in the United States. Methods The sample included 1891 adolescents and young adults living with HIV (27.8% perinatally infected; 72.2% behaviorally infected) who were linked to care through 20 Adolescent Medicine Trials Network for HIV/AIDS Interventions Units. All completed audio computer–assisted self-interview surveys. Chart abstraction or blood draw provided viral load data. Geographic-level variables were extracted from the United States Census Bureau (e.g., socioeconomic disadvantage, percent of Black and Latino households, percent rural) and Esri Crime (e.g., global crime index) databases as Zip Code Tabulation Areas. AIDSVu data (e.g., prevalence of HIV among youth) were extracted at the county-level. Using HLM v.7, the authors conducted means-as-outcomes random effects multi-level models to examine the association between structural-level and individual-level factors and (1) being on antiretroviral therapy (ART) currently; (2) being on ART for at least 6 months; (3) missed HIV care appointments (not having missed any vs. having missed one or more appointments) over the past 12 months; and (4) viral suppression (defined by the corresponding assay cutoff for the lower limit of viral load at each participating site which denoted nondetectability vs. detectability). Results Frequencies for the 4 primary outcomes were as follows: current ART use (n = 1120, 59.23%); ART use for ≥6 months (n = 861, 45.53%); at least one missed HIV care appointment (n = 936, 49.50); and viral suppression (n = 577, 30.51%). After adjusting for individual-level factors, youth living in more disadvantaged areas (defined by a composite score derived from 2010 Census indicators including percent poverty, percent receiving public assistance, percent of female, single

A Peer-Led HIV Mediation Adherence Intervention Targeting Adults Linked to Medical Care but without a Suppressed Viral Load

PubMed Central

Enriquez, Maithe; Cheng, An-Lin; Banderas, Julie; Farnan, Rose; Chertoff, Keyna; Hayes, Deana; Ortego, Gerry; Moreno, Jose; Peterson, Jane; McKinsey, David

2017-01-01

Background Non-adherence to antiretroviral (ART) treatment remains a prevalent problem even among the segment of the U.S. HIV population that is ‘linked’ to medical care. Methods Controlled pilot feasibility study with ART experienced adult patients (n=20) linked to HIV medical care without suppressed viral load. Patients were randomized to a peer-led HIV medication adherence intervention named ‘Ready’ or a time equivalent ‘healthy eating’ control arm. Lay individuals living with HIV were trained to facilitate ‘Ready’. Results Patients had been prescribed a mean of three prior ART regimens. The group randomized to ‘Ready’ had significantly improved adherence. MEMS and pharmacy refill data correlated with viral load log drop. Higher readiness for healthful behavior change correlated with viral load drop and approached significance. Conclusion A peer-led medication adherence intervention had a positive impact among adults who had experienced repeated non-adherence to HIV treatment. A larger study is needed to examine intervention dissemination and efficacy. PMID:25412724

Time to viral load suppression in antiretroviral-naive and -experienced HIV-infected pregnant women on highly active antiretroviral therapy: implications for pregnant women presenting late in gestation.

PubMed

Aziz, N; Sokoloff, A; Kornak, J; Leva, N V; Mendiola, M L; Levison, J; Feakins, C; Shannon, M; Cohan, D

2013-11-01

To compare time to achieve viral load <400 copies/ml and <1000 copies/ml in HIV-infected antiretroviral (ARV) -naive versus ARV-experienced pregnant women on highly active antiretroviral therapy (HAART). Retrospective cohort study. Three university medical centers, USA. HIV-infected pregnant women initiated or restarted on HAART during pregnancy. We calculated time to viral load <400 copies/ml and <1000 copies/ml in HIV-infected pregnant women on HAART who reported at least 50% adherence, stratifying based on previous ARV exposure history. Time to HIV viral load <400 copies/ml and <1000 copies/ml. We evaluated 138 HIV-infected pregnant women, comprising 76 ARV-naive and 62 ARV-experienced. Ninety-three percent of ARV-naive women achieved a viral load < 400 copies/ml during pregnancy compared with 92% of ARV-experienced women (P = 0.82). The median number of days to achieve a viral load < 400 copies/ml in the ARV-naive cohort was 25.0 (range 3.5-133; interquartile range 16-34) days compared with 27.0 (range 8-162.5; interquartile range 18.5-54.3) days in the ARV-experienced cohort (P = 0.02). In a multiple predictor analysis, women with higher adherence (adjusted relative hazard [aRH] per 10% increase in adherence 1.29, 95% confidence interval [CI] 1.08-1.54, P = 0.01) and receiving a non-nucleotide reverse transcriptase inhibitor (NNRTI) -based regimen (aRH 2.48, 95% CI 1.33-4.63, P = 0.01) were more likely to achieve viral load <400 copies/ml earlier. Increased baseline HIV log10 viral load was associated with a later time of achieving viral load <400 copies/ml (aRH 0.60, 95% CI 0.39-0.92, P = 0.02). In a corresponding model of time to achieve viral load <1000 copies/ml, adherence (aRH per 10% increase in adherence 1.79, 95% CI 1.34-2.39, P < 0.001), receipt of NNRTI (aRH 2.95, 95% CI 1.23-7.06, P = 0.02), and CD4 cell count (aRH per 50 count increase in CD4 1.12, 95% CI 1.03-1.22, P = 0.01) were associated with an earlier time to achieve viral load below this

Envelope co-receptor tropism, drug resistance, and viral evolution among subtype C HIV-1 infected individuals receiving non-suppressive antiretroviral therapy

PubMed Central

Kassaye, Seble; Johnston, Elizabeth; McColgan, Bryan; Kantor, Rami; Zijenah, Lynn; Katzenstein, David

2009-01-01

In resource-constrained settings, antiretroviral treatment (ART) is often continued based on clinical and CD4 responses, without virologic monitoring. ART with incomplete viral suppression was assessed in 27 subjects with subtype C HIV-1 by measuring plasma HIV-1 RNA, drug resistance, viral tropism, and evolution in polymerase (pol) and envelope (env) genes. The association between these viral parameters and CD4 cell change over time was analyzed using linear regression models. Increased area under the curve of HIV-1 RNA replication was a predictor of lower CD4 cell gains (p <0.007), while less drug resistance measured as a genotypic susceptibility score (GSS) (p=0.065), and lower rates of evolution in pol and env genes (p= 0.08 and 0.097, respectively) measured as genetic distance were modestly associated with increasing CD4 cell counts. Evolution of pol and env were correlated (R2 = 0.48, p=0.005), however, greater evolution was identified in env vs. pol (p <0.05). CXCR4-usage (X4) was detected in 14/27 (52%) but no differences in CD4 cell change or plasma viremia were associated with X4-usage. Among subtype C HIV-1 infected patients in Zimbabwe receiving incompletely suppressive ART, higher virus replication and lower CD4 cell gains were associated with drug resistance and evolution of polymerase and envelope. PMID:19295330

Viral Suppression and HIV Drug Resistance at 6 Months Among Women in Malawi's Option B+ Program: Results From the PURE Malawi Study.

PubMed

Hosseinipour, Mina; Nelson, Julie A E; Trapence, Clement; Rutstein, Sarah E; Kasende, Florence; Kayoyo, Virginia; Kaunda-Khangamwa, Blessings; Compliment, Kara; Stanley, Christopher; Cataldo, Fabian; van Lettow, Monique; Rosenberg, Nora E; Tweya, Hannock; Gugsa, Salem; Sampathkumar, Veena; Schouten, Erik; Eliya, Michael; Chimbwandira, Frank; Chiwaula, Levison; Kapito-Tembo, Atupele; Phiri, Sam

2017-06-01

In 2011, Malawi launched Option B+, a program of universal antiretroviral therapy (ART) treatment for pregnant and lactating women to optimize maternal health and prevent pediatric HIV infection. For optimal outcomes, women need to achieve HIVRNA suppression. We report 6-month HIVRNA suppression and HIV drug resistance in the PURE study. PURE study was a cluster-randomized controlled trial evaluating 3 strategies for promoting uptake and retention; arm 1: Standard of Care, arm 2: Facility Peer Support, and arm 3: Community Peer support. Pregnant and breastfeeding mothers were enrolled and followed according to Malawi ART guidelines. Dried blood spots for HIVRNA testing were collected at 6 months. Samples with ART failure (HIVRNA ≥1000 copies/ml) had resistance testing. We calculated odds ratios for ART failure using generalized estimating equations with a logit link and binomial distribution. We enrolled 1269 women across 21 sites in Southern and Central Malawi. Most enrolled while pregnant (86%) and were WHO stage 1 (95%). At 6 months, 950/1269 (75%) were retained; 833/950 (88%) had HIVRNA testing conducted, and 699/833 (84%) were suppressed. Among those with HIVRNA ≥1000 copies/ml with successful amplification (N = 55, 41% of all viral loads > 1000 copies/ml), confirmed HIV resistance was found in 35% (19/55), primarily to the nonnucleoside reverse transcriptase inhibitor class of drugs. ART failure was associated with treatment default but not study arm, age, WHO stage, or breastfeeding status. Virologic suppression at 6 months was <90% target, but the observed confirmed resistance rates suggest that adherence support should be the primary approach for early failure in option B+.

Postpartum Loss to HIV Care and HIV Viral Suppression among Previously Diagnosed HIV-Infected Women with a Live Birth in New York State

PubMed Central

2016-01-01

Mother-to-child-transmission of HIV in the United States has been greatly reduced, with clear benefits for the child. However, little is known about factors that predict maternal loss to HIV care in the postpartum year. This retrospective cohort study included 980 HIV-positive women, diagnosed with HIV at least one year before pregnancy, who had a live birth during 2008–2010 in New York State. Women who did not meet the following criterion in the 12 months after the delivery-related hospital discharge were considered to be lost to HIV care: two or more laboratory tests (CD4 or HIV viral load), separated by at least 90 days. Adjusted relative risks (aRR) and 95% confidence intervals (CI) for predictors of postpartum loss to HIV care were identified with Poisson regression, solved using generalized estimating equations. Having an unsuppressed (>200 copies/mL) HIV viral load in the postpartum year was also evaluated. Overall, 24% of women were loss to HIV care during the postpartum year. Women with low participation in HIV care during preconception were more likely to be lost to HIV care during the postpartum year (aRR: 2.70; 95% CI: 2.09–3.49). In contrast, having a low birth weight infant was significantly associated with a decreased likelihood of loss to HIV care (aRR: 0.72; 95% CI: 0.53–0.98). While 75% of women were virally suppressed at the last viral load before delivery only 44% were continuously suppressed in the postpartum year; 12% had no viral load test reported in the postpartum year and 44% had at least one unsuppressed viral load test. Lack of engagement in preconception HIV-related health care predicts postpartum loss to HIV care for HIV-positive parturient women. Many women had poor viral control during the postpartum period, increasing the risk of disease progression and infectivity. PMID:27513953

Association between depressive symptoms, CD4 count and HIV viral suppression among HIV-HCV co-infected people.

PubMed

Aibibula, Wusiman; Cox, Joseph; Hamelin, Anne-Marie; Moodie, Erica E M; Anema, Aranka; Klein, Marina B; Brassard, Paul

2018-05-01

Depressive symptoms are associated with poor HIV viral control and immune recovery among people living with HIV. However, no prior studies assessed this association exclusively among people co-infected with HIV-hepatitis C virus (HCV). While people with HIV only and those with HIV-HCV co-infection share many characteristics, co-infected people may become more susceptible to the effects of depressive symptoms on health outcomes. We assessed this association exclusively among people co-infected with HIV-HCV in Canada using data from the Food Security & HIV-HCV Sub-Study (FS Sub-Study) of the Canadian Co-Infection Cohort (CCC). Stabilized inverse probability weighted marginal structural model was used to account for potential time-varying confounders. A total of 725 participants were enrolled between 2012 and 2015. At baseline, 52% of participants reported depressive symptoms, 75% had undetectable HIV viral load, and median CD4 count was 466 (IQR 300-665). People experiencing depressive symptoms had 1.32 times (95% CI: 1.07, 1.63) the risk of having detectable HIV viral load, but had comparable CD4 count to people who did not experience depressive symptoms (fold change of CD4 = 0.96, 95% CI: 0.91, 1.03). Presence of depressive symptoms is a risk factor for incomplete short-term HIV viral suppression among people co-infected with HIV-HCV. Therefore, depressive symptoms screening and related counseling may improve HIV related health outcomes and reduce HIV transmission.

Suppression of injuries caused by a lytic RNA virus (mengovirus) and their uncoupling from viral reproduction by mutual cell/virus disarmament.

PubMed

Mikitas, Olga V; Ivin, Yuri Y; Golyshev, Sergey A; Povarova, Natalia V; Galkina, Svetlana I; Pletjushkina, Olga Y; Nadezhdina, Elena S; Gmyl, Anatoly P; Agol, Vadim I

2012-05-01

Viruses often elicit cell injury (cytopathic effect [CPE]), a major cause of viral diseases. CPE is usually considered to be a prerequisite for and/or consequence of efficient viral growth. Recently, we proposed that viral CPE may largely be due to host defensive and viral antidefensive activities. This study aimed to check the validity of this proposal by using as a model HeLa cells infected with mengovirus (MV). As we showed previously, infection of these cells with wild-type MV resulted in necrosis, whereas a mutant with incapacitated antidefensive ("security") viral leader (L) protein induced apoptosis. Here, we showed that several major morphological and biochemical signs of CPE (e.g., alterations in cellular and nuclear shape, plasma membrane, cytoskeleton, chromatin, and metabolic activity) in cells infected with L(-) mutants in the presence of an apoptosis inhibitor were strongly suppressed or delayed for long after completion of viral reproduction. These facts demonstrate that the efficient reproduction of a lytic virus may not directly require development of at least some pathological alterations normally accompanying infection. They also imply that L protein is involved in the control of many apparently unrelated functions. The results also suggest that the virus-activated program with competing necrotic and apoptotic branches is host encoded, with the choice between apoptosis and necrosis depending on a variety of intrinsic and extrinsic conditions. Implementation of this defensive suicidal program could be uncoupled from the viral reproduction. The possibility of such uncoupling has significant implications for the pathogenesis and treatment of viral diseases.

Suppression of Injuries Caused by a Lytic RNA Virus (Mengovirus) and Their Uncoupling from Viral Reproduction by Mutual Cell/Virus Disarmament

PubMed Central

Mikitas, Olga V.; Ivin, Yuri Y.; Golyshev, Sergey A.; Povarova, Natalia V.; Galkina, Svetlana I.; Pletjushkina, Olga Y.; Nadezhdina, Elena S.; Gmyl, Anatoly P.

2012-01-01

Viruses often elicit cell injury (cytopathic effect [CPE]), a major cause of viral diseases. CPE is usually considered to be a prerequisite for and/or consequence of efficient viral growth. Recently, we proposed that viral CPE may largely be due to host defensive and viral antidefensive activities. This study aimed to check the validity of this proposal by using as a model HeLa cells infected with mengovirus (MV). As we showed previously, infection of these cells with wild-type MV resulted in necrosis, whereas a mutant with incapacitated antidefensive (“security”) viral leader (L) protein induced apoptosis. Here, we showed that several major morphological and biochemical signs of CPE (e.g., alterations in cellular and nuclear shape, plasma membrane, cytoskeleton, chromatin, and metabolic activity) in cells infected with L− mutants in the presence of an apoptosis inhibitor were strongly suppressed or delayed for long after completion of viral reproduction. These facts demonstrate that the efficient reproduction of a lytic virus may not directly require development of at least some pathological alterations normally accompanying infection. They also imply that L protein is involved in the control of many apparently unrelated functions. The results also suggest that the virus-activated program with competing necrotic and apoptotic branches is host encoded, with the choice between apoptosis and necrosis depending on a variety of intrinsic and extrinsic conditions. Implementation of this defensive suicidal program could be uncoupled from the viral reproduction. The possibility of such uncoupling has significant implications for the pathogenesis and treatment of viral diseases. PMID:22438537

Characterizing Class‐Specific Exposure‐Viral Load Suppression Response of HIV Antiretrovirals Using A Model‐Based Meta‐Analysis

PubMed Central

Xu, Y; Li, YF; Zhang, D; Dockendorf, M; Tetteh, E; Rizk, ML; Grobler, JA; Lai, M‐T; Gobburu, J

2016-01-01

We applied model‐based meta‐analysis of viral suppression as a function of drug exposure and in vitro potency for short‐term monotherapy in human immunodeficiency virus type 1 (HIV‐1)‐infected treatment‐naïve patients to set pharmacokinetic targets for development of nonnucleoside reverse transcriptase inhibitors (NNRTIs) and integrase strand transfer inhibitors (InSTIs). We developed class‐specific models relating viral load kinetics from monotherapy studies to potency normalized steady‐state trough plasma concentrations. These models were integrated with a literature assessment of doses which demonstrated to have long‐term efficacy in combination therapy, in order to set steady‐state trough concentration targets of 6.17‐ and 2.15‐fold above potency for NNRTIs and InSTIs, respectively. Both the models developed and the pharmacokinetic targets derived can be used to guide compound selection during preclinical development and to predict the dose–response of new antiretrovirals to inform early clinical trial design. PMID:27171172

Hepatitis C Virus Induces Regulatory T Cells by Naturally Occurring Viral Variants to Suppress T Cell Responses

PubMed Central

Cusick, Matthew F.; Schiller, Jennifer J.; Gill, Joan C.; Eckels, David D.

2011-01-01

Regulatory T cell markers are increased in chronically infected individuals with the hepatitis C virus (HCV), but to date, the induction and maintenance of Tregs in HCV infection has not been clearly defined. In this paper, we demonstrate that naturally occurring viral variants suppress T cell responses to cognate NS3358-375 in an antigen-specific manner. Of four archetypal variants, S370P induced regulatory T cell markers in comparison to NS3358-375-stimulated CD4 T cells. Further, the addition of variant-specific CD4 T cells back into a polyclonal culture in a dose-dependent manner inhibited the T cell response. These results suggest that HCV is able to induce antigen-specific regulatory T cells to suppress the antiviral T cell response in an antigen-specific manner, thus contributing to a niche within the host that could be conducive to HCV persistence. PMID:21197453

Suppression of synthesis of an IgG subclass in a persistent viral infection.

PubMed Central

McGuire, T C

1976-01-01

Comparison of immunoglobulin levels of nine horses before and after infection with equine infectious anaemia (EIA) virus demonstrated a significant depression of serum IgG(T) at 2 months (P less than 0-001) and at 1 year (P less than 0-01) after infection. In contrast, the levels of IgGa were significantly increased at both times after infection. Another sixteen horses with EIA for 1-4 months were examined and there was also significant depression (P less than 0-001) of IgG(T) when compared to pre-infection levels. No significant changes in IgG(T), IgGa and IgM were noted in fourteen normal horses housed for 2-7 months in the same manner as infected horses. Following DNP immunization there was a significant (P less than 0-02) decrease in the amount of IgG(T) antibody produced in five horses with EIA when compared to five normal horses. Metabolism studies with iodinated IgG(T) showed a significant (P less than 0-001) decrease in synthesis of this immunoglobulin in EIA-infected horses when compared to normal horses. Amounts of IgGa synthesized were similar in the two groups. Thus, persistent EIA viral infection suppresses the synthesis of IgG(T), an IgG subclass, without suppressing IgGa. PMID:814077

Reducing Viral Load Measurements to Once a Year in Patients on Stable, Virologically Suppressive Cart Regimen: Findings from the Australian HIV Observational Database

PubMed Central

Rafiee, Mahshid; Kariminia, Azar; Wright, Stephen; Mills, Graham; Woolley, Ian; Smith, Don; Templeton, David J.; Law, Matthew G.; Petoumenos, Kathy

2015-01-01

Reducing viral-load measurements to annual testing in virologically suppressed patients increases the estimated mean time those patients remain on a failing regimen by 6 months. This translates to an increase in the proportion of patients with at least one Thymidine Analogue Mutation from 10% to 32% over one year. PMID:26618053

Neutrophil subset responses in infants with severe viral respiratory infection.

PubMed

Cortjens, Bart; Ingelse, Sarah A; Calis, Job C; Vlaar, Alexander P; Koenderman, Leo; Bem, Reinout A; van Woensel, Job B

2017-03-01

Neutrophils are the predominant inflammatory cells recruited to the respiratory tract as part of the innate immune response to viral infections. Recent reports indicate the existence of distinct functional neutrophil subsets in the circulatory compartment of adults, following severe inflammatory conditions. Here, we evaluated the occurrence of neutrophil subsets in blood and broncho-alveolar lavage fluid during severe viral respiratory infection in infants based on CD16/CD62L expression. We show that during the course of severe respiratory infection infants may develop four heterogeneous neutrophil subsets in blood (mature, immature, progenitor, and suppressive neutrophils), each with distinct activation states. However, while isolated viral respiratory infection was characterized by a relative absence of suppressive neutrophils in both blood and lungs, only patients with bacterial co-infection were shown to produce suppressive neutrophils. These data suggest the occurrence of distinct and unique neutrophil subset responses during severe viral and (secondary) bacterial respiratory infection in infants. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Characterizing Class-Specific Exposure-Viral Load Suppression Response of HIV Antiretrovirals Using A Model-Based Meta-Analysis.

PubMed

Xu, Y; Li, Y F; Zhang, D; Dockendorf, M; Tetteh, E; Rizk, M L; Grobler, J A; Lai, M-T; Gobburu, J; Ankrom, W

2016-08-01

We applied model-based meta-analysis of viral suppression as a function of drug exposure and in vitro potency for short-term monotherapy in human immunodeficiency virus type 1 (HIV-1)-infected treatment-naïve patients to set pharmacokinetic targets for development of nonnucleoside reverse transcriptase inhibitors (NNRTIs) and integrase strand transfer inhibitors (InSTIs). We developed class-specific models relating viral load kinetics from monotherapy studies to potency normalized steady-state trough plasma concentrations. These models were integrated with a literature assessment of doses which demonstrated to have long-term efficacy in combination therapy, in order to set steady-state trough concentration targets of 6.17- and 2.15-fold above potency for NNRTIs and InSTIs, respectively. Both the models developed and the pharmacokinetic targets derived can be used to guide compound selection during preclinical development and to predict the dose-response of new antiretrovirals to inform early clinical trial design. © 2016 The Authors. Clinical and Translational Science published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

HIV-1 Rev protein specifies the viral RNA export pathway by suppressing TAP/NXF1 recruitment

PubMed Central

Taniguchi, Ichiro; Mabuchi, Naoto; Ohno, Mutsuhito

2014-01-01

Nuclear RNA export pathways in eukaryotes are often linked to the fate of a given RNA. Therefore, the choice of export pathway should be well-controlled to avoid an unfavorable effect on gene expression. Although some RNAs could be exported by more than one pathway, little is known about how the choice is regulated. This issue is highlighted when the human immunodeficiency virus type 1 (HIV-1) Rev protein induces the export of singly spliced and unspliced HIV-1 transcripts. How these RNAs are exported is not well understood because such transcripts should have the possibility of utilizing CRM1-dependent export via Rev or cellular TAP/NXF1-dependent export via the transcription/export (TREX) complex, or both. Here we found that Rev suppressed TAP/NXF1-dependent export of model RNA substrates that recapitulated viral transcripts. In this effect, Rev interacted with the cap-binding complex and inhibited the recruitment of the TREX complex. Thus, Rev controls the identity of the factor occupying the cap-proximal region that determines the RNA export pathway. This ribonucleoprotein remodeling activity of Rev may favor viral gene expression. PMID:24753416

Cerebrospinal fluid viral breakthrough in two HIV-infected subjects on darunavir/ritonavir monotherapy

PubMed Central

2012-01-01

Darunavir/ritonavir monotherapy maintains HIV suppression in most patients who have achieved an undetectable viral load on combination antiretroviral treatment, and is increasingly used in the clinic. However, concerns have been raised about the effectiveness of ritonavir-boosted protease inhibitor (PI/r) monotherapy in the prevention of HIV replication in the central nervous system (CNS). Here we report the cases of 2 patients on darunavir/r maintenance monotherapy with cerebrospinal fluid viral breakthrough together with increased immunoactivation and biomarker signs of neuronal injury. These 2 cases raise concerns about the effectiveness of darunavir/ritonavir monotherapy in HIV CNS infection. Thus, we recommend caution with protease inhibitor monotherapy until CNS results have been obtained from clinical studies. PMID:22776013

Cerebrospinal fluid viral breakthrough in two HIV-infected subjects on darunavir/ritonavir monotherapy.

PubMed

Gisslén, Magnus; Fuchs, Dietmar; Hagberg, Lars; Svennerholm, Bo; Zetterberg, Henrik

2012-12-01

Darunavir/ritonavir monotherapy maintains HIV suppression in most patients who have achieved an undetectable viral load on combination antiretroviral treatment, and is increasingly used in the clinic. However, concerns have been raised about the effectiveness of ritonavir-boosted protease inhibitor (PI/r) monotherapy in the prevention of HIV replication in the central nervous system (CNS). Here we report the cases of 2 patients on darunavir/r maintenance monotherapy with cerebrospinal fluid viral breakthrough together with increased immunoactivation and biomarker signs of neuronal injury. These 2 cases raise concerns about the effectiveness of darunavir/ritonavir monotherapy in HIV CNS infection. Thus, we recommend caution with protease inhibitor monotherapy until CNS results have been obtained from clinical studies.

Brief Report: Racial Comparison of D-Dimer Levels in US Male Military Personnel Before and After HIV Infection and Viral Suppression.

PubMed

OʼBryan, Thomas A; Agan, Brian K; Tracy, Russell P; Freiberg, Matthew S; Okulicz, Jason F; So-Armah, Kaku; Ganesan, Anuradha; Rimland, David; Lalani, Tahaniyat; Deiss, Robert G; Tramont, Edmund C

2018-04-15

D-dimer blood levels in persons with HIV infection are associated with risk of serious non-AIDS conditions and death. Black race has been correlated with higher D-dimer levels in several studies. We examined the effects of race and HIV on D-dimer over time and the impact of viral load suppression by longitudinally comparing changes in levels among healthy young adult male African Americans and whites before HIV seroconversion and before and after initiation of antiretroviral therapy (ART). We analyzed D-dimer levels and clinical and laboratory data of 192 participants enrolled in the US Military HIV Natural History Study, a 30-year cohort of military personnel infected with HIV. D-dimer levels were measured on stored sera from each participant at 3 time points: (1) before HIV seroconversion (Pre-SC), (2) ≥6 months after HIV seroconversion but before ART initiation (Post-SC), and (3) ≥6 months after ART with documented viral suppression (Post-ART). Levels were compared at each time point using nonparametric and logistic regression analysis. Compared with whites (n = 106), African Americans (n = 86) had higher D-dimer levels post-SC (P = 0.007), but in the same individuals, pre-SC baseline and post-ART levels were similar (P = 0.40 and P = 0.99, respectively). There were no racial differences in CD4 cell counts, HIV RNA viral load, time from estimated seroconversion to ART initiation, and duration on ART. Observed longitudinally, racial differences in D-dimer levels were seen only during HIV viremia. Higher levels of D-dimer commonly observed in African Americans are likely due to factors in addition to race.

Increased Intrathecal Immune Activation in Virally Suppressed HIV-1 Infected Patients with Neurocognitive Impairment

PubMed Central

Edén, Arvid; Marcotte, Thomas D.; Heaton, Robert K.; Nilsson, Staffan; Zetterberg, Henrik; Fuchs, Dietmar; Franklin, Donald; Price, Richard W.; Grant, Igor; Letendre, Scott L.; Gisslén, Magnus

2016-01-01

Objective Although milder forms of HIV-associated neurocognitive disorder (HAND) remain prevalent, a correlation to neuronal injury has not been established in patients on antiretroviral therapy (ART). We examined the relationship between mild HAND and CSF neurofilament light protein (NFL), a biomarker of neuronal injury; and CSF neopterin, a biomarker of CNS immunoactivation, in virally suppressed patients on antiretroviral therapy (ART). Design and Methods We selected 99 subjects on suppressive ART followed longitudinally from the CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) study. Based on standardized comprehensive neurocognitive performance (NP) testing, subjects were classified as neurocognitively normal (NCN; n = 29) or impaired (NCI; n = 70). The NCI group included subjects with asymptomatic (ANI; n = 37) or mild (MND; n = 33) HAND. CSF biomarkers were analyzed on two occasions. Results Geometric mean CSF neopterin was 25% higher in the NCI group (p = 0.04) and NFL and neopterin were significantly correlated within the NCI group (r = 0.30; p<0.001) but not in the NCN group (r = -0.13; p = 0.3). Additionally, a trend towards higher NFL was seen in the NCI group (p = 0.06). Conclusions Mild HAND was associated with increased intrathecal immune activation, and the correlation between neopterin and NFL found in NCI subjects indicates an association between neurocognitive impairment, CNS inflammation and neuronal damage. Together these findings suggest that NCI despite ART may represent an active pathological process within the CNS that needs further characterization in prospective studies. PMID:27295036

Increased Intrathecal Immune Activation in Virally Suppressed HIV-1 Infected Patients with Neurocognitive Impairment.

PubMed

Edén, Arvid; Marcotte, Thomas D; Heaton, Robert K; Nilsson, Staffan; Zetterberg, Henrik; Fuchs, Dietmar; Franklin, Donald; Price, Richard W; Grant, Igor; Letendre, Scott L; Gisslén, Magnus

2016-01-01

Although milder forms of HIV-associated neurocognitive disorder (HAND) remain prevalent, a correlation to neuronal injury has not been established in patients on antiretroviral therapy (ART). We examined the relationship between mild HAND and CSF neurofilament light protein (NFL), a biomarker of neuronal injury; and CSF neopterin, a biomarker of CNS immunoactivation, in virally suppressed patients on antiretroviral therapy (ART). We selected 99 subjects on suppressive ART followed longitudinally from the CNS HIV Anti-Retroviral Therapy Effects Research (CHARTER) study. Based on standardized comprehensive neurocognitive performance (NP) testing, subjects were classified as neurocognitively normal (NCN; n = 29) or impaired (NCI; n = 70). The NCI group included subjects with asymptomatic (ANI; n = 37) or mild (MND; n = 33) HAND. CSF biomarkers were analyzed on two occasions. Geometric mean CSF neopterin was 25% higher in the NCI group (p = 0.04) and NFL and neopterin were significantly correlated within the NCI group (r = 0.30; p<0.001) but not in the NCN group (r = -0.13; p = 0.3). Additionally, a trend towards higher NFL was seen in the NCI group (p = 0.06). Mild HAND was associated with increased intrathecal immune activation, and the correlation between neopterin and NFL found in NCI subjects indicates an association between neurocognitive impairment, CNS inflammation and neuronal damage. Together these findings suggest that NCI despite ART may represent an active pathological process within the CNS that needs further characterization in prospective studies.

“It Makes You Feel Like Someone Cares” acceptability of a financial incentive intervention for HIV viral suppression in the HPTN 065 (TLC-Plus) study

PubMed Central

Greene, Elizabeth; Pack, Allison; Stanton, Jill; Shelus, Victoria; Tolley, Elizabeth E.; Taylor, Jamilah; El Sadr, Wafaa M.; Branson, Bernard M.; Leider, Jason; Rakhmanina, Natella; Gamble, Theresa

2017-01-01

Background HPTN 065 (TLC-Plus) evaluated the feasibility and effectiveness of providing quarterly $70 gift card financial incentives to HIV-infected patients on antiretroviral therapy (ART) to encourage ART adherence and viral suppression, and represents the largest study to-date of a financial incentive intervention for HIV viral suppression. A post-trial qualitative substudy was undertaken to examine acceptability of the financial incentives among those receiving and implementing the intervention. Methods Between July and October 2013, semi-structured interviews were conducted with 72 patients and 12 investigators from 14 sites; three focus groups were conducted with 12 staff from 10 sites. Qualitative data collection elicited experiences with and attitudes about the intervention, including philosophical viewpoints and implementation experiences. Transcripts were analyzed in NVivo 10. Memos and matrices were developed to explore themes from different participant group perspectives. Results Patients, investigators, and staff found the intervention highly acceptable, primarily due to the emotional benefits gained through giving or receiving the incentive. Feeling rewarded or cared for was a main value perceived by patients; this was closely tied to the financial benefit for some. Other factors influencing acceptability for all included perceived effectiveness and health-related benefits, philosophical concerns about the use of incentives for health behavior change, and implementation issues. The termination of the incentive at the end of the study was disappointing to participants and unexpected by some, but generally accepted. Conclusion Positive experiences with the financial incentive intervention and strategies used to facilitate implementation led to high acceptability of the intervention, despite some reluctance in principle to the use of incentives. The findings of this analysis provide encouraging evidence in support of the acceptability of a large

Silencing and innate immunity in plant defense against viral and non-viral pathogens.

PubMed

Zvereva, Anna S; Pooggin, Mikhail M

2012-10-29

The frontline of plant defense against non-viral pathogens such as bacteria, fungi and oomycetes is provided by transmembrane pattern recognition receptors that detect conserved pathogen-associated molecular patterns (PAMPs), leading to pattern-triggered immunity (PTI). To counteract this innate defense, pathogens deploy effector proteins with a primary function to suppress PTI. In specific cases, plants have evolved intracellular resistance (R) proteins detecting isolate-specific pathogen effectors, leading to effector-triggered immunity (ETI), an amplified version of PTI, often associated with hypersensitive response (HR) and programmed cell death (PCD). In the case of plant viruses, no conserved PAMP was identified so far and the primary plant defense is thought to be based mainly on RNA silencing, an evolutionary conserved, sequence-specific mechanism that regulates gene expression and chromatin states and represses invasive nucleic acids such as transposons. Endogenous silencing pathways generate 21-24 nt small (s)RNAs, miRNAs and short interfering (si)RNAs, that repress genes post-transcriptionally and/or transcriptionally. Four distinct Dicer-like (DCL) proteins, which normally produce endogenous miRNAs and siRNAs, all contribute to the biogenesis of viral siRNAs in infected plants. Growing evidence indicates that RNA silencing also contributes to plant defense against non-viral pathogens. Conversely, PTI-based innate responses may contribute to antiviral defense. Intracellular R proteins of the same NB-LRR family are able to recognize both non-viral effectors and avirulence (Avr) proteins of RNA viruses, and, as a result, trigger HR and PCD in virus-resistant hosts. In some cases, viral Avr proteins also function as silencing suppressors. We hypothesize that RNA silencing and innate immunity (PTI and ETI) function in concert to fight plant viruses. Viruses counteract this dual defense by effectors that suppress both PTI-/ETI-based innate responses and RNA

Effect of Offering Same-Day ART vs Usual Health Facility Referral During Home-Based HIV Testing on Linkage to Care and Viral Suppression Among Adults With HIV in Lesotho: The CASCADE Randomized Clinical Trial.

PubMed

Labhardt, Niklaus D; Ringera, Isaac; Lejone, Thabo I; Klimkait, Thomas; Muhairwe, Josephine; Amstutz, Alain; Glass, Tracy R

2018-03-20

(absolute difference, 25.6%; 95% CI, 13.8% to 36.3%; P < .001). At 12 months, 50.4% (69) in the same-day group vs 34.3% (47) in usual care group achieved viral suppression (absolute difference, 16.0%; 4.4%-27.2%; P = .007). Two deaths (1.5%) were reported in the same-day group, none in usual care group. Among adults in rural Lesotho, a setting of high HIV prevalence, offering same-day home-based ART initiation to individuals who tested positive during home-based HIV testing, compared with usual care and standard clinic referral, significantly increased linkage to care at 3 months and HIV viral suppression at 12 months. These findings support the practice of offering same-day ART initiation during home-based HIV testing. clinicaltrials.gov Identifier: NCT02692027.

Impact on life expectancy of HIV-1 positive individuals of CD4+ cell count and viral load response to antiretroviral therapy

PubMed Central

May, Margaret T.; Gompels, Mark; Delpech, Valerie; Porter, Kholoud; Orkin, Chloe; Kegg, Stephen; Hay, Phillip; Johnson, Margaret; Palfreeman, Adrian; Gilson, Richard; Chadwick, David; Martin, Fabiola; Hill, Teresa; Walsh, John; Post, Frank; Fisher, Martin; Ainsworth, Jonathan; Jose, Sophie; Leen, Clifford; Nelson, Mark; Anderson, Jane; Sabin, Caroline

2014-01-01

Objective: The objective of this study is to estimate life expectancies of HIV-positive patients conditional on response to antiretroviral therapy (ART). Methods: Patients aged more than 20 years who started ART during 2000–2010 (excluding IDU) in HIV clinics contributing to the UK CHIC Study were followed for mortality until 2012. We determined the latest CD4+ cell count and viral load before ART and in each of years 1–5 of ART. For each duration of ART, life tables based on estimated mortality rates by sex, age, latest CD4+ cell count and viral suppression (HIV-1 RNA <400 copies/ml), were used to estimate expected age at death for ages 20–85 years. Results: Of 21 388 patients who started ART, 961 (4.5%) died during 110 697 person-years. At start of ART, expected age at death [95% confidence interval (CI)] of 35-year-old men with CD4+ cell count less than 200, 200–349, at least 350 cells/μl was 71 (68–73), 78 (74–82) and 77 (72–81) years, respectively, compared with 78 years for men in the general UK population. Thirty-five-year-old men who increased their CD4+ cell count in the first year of ART from less than 200 to 200–349 or at least 350 cells/μl and achieved viral suppression gained 7 and 10 years, respectively. After 5 years on ART, expected age at death of 35-year-old men varied from 54 (48–61) (CD4+ cell count <200 cells/μl and no viral suppression) to 80 (76–83) years (CD4+ cell count ≥350 cells/μl and viral suppression). Conclusion: Successfully treated HIV-positive individuals have a normal life expectancy. Patients who started ART with a low CD4+ cell count significantly improve their life expectancy if they have a good CD4+ cell count response and undetectable viral load. PMID:24556869

Effect of Suberoylanilide Hydroxamic Acid (SAHA) Administration on the Residual Virus Pool in a Model of Combination Antiretroviral Therapy-Mediated Suppression in SIVmac239-Infected Indian Rhesus Macaques

PubMed Central

Del Prete, Gregory Q.; Shoemaker, Rebecca; Oswald, Kelli; Lara, Abigail; Trubey, Charles M.; Fast, Randy; Schneider, Douglas K.; Kiser, Rebecca; Coalter, Vicky; Wiles, Adam; Wiles, Rodney; Freemire, Brandi; Keele, Brandon F.; Estes, Jacob D.; Quiñones, Octavio A.; Smedley, Jeremy; Macallister, Rhonda; Sanchez, Rosa I.; Wai, John S.; Tan, Christopher M.; Alvord, W. Gregory; Hazuda, Daria J.; Piatak, Michael

2014-01-01

Nonhuman primate models are needed for evaluations of proposed strategies targeting residual virus that persists in HIV-1-infected individuals receiving suppressive combination antiretroviral therapy (cART). However, relevant nonhuman primate (NHP) models of cART-mediated suppression have proven challenging to develop. We used a novel three-class, six-drug cART regimen to achieve durable 4.0- to 5.5-log reductions in plasma viremia levels and declines in cell-associated viral RNA and DNA in blood and tissues of simian immunodeficiency virus SIVmac239-infected Indian-origin rhesus macaques, then evaluated the impact of treatment with the histone deacetylase inhibitor (HDACi) suberoylanilide hydroxamic acid (SAHA; Vorinostat) on the residual virus pool. Ex vivo SAHA treatment of CD4+ T cells obtained from cART-suppressed animals increased histone acetylation and viral RNA levels in culture supernatants. cART-suppressed animals each received 84 total doses of oral SAHA. We observed SAHA dose-dependent increases in acetylated histones with evidence for sustained modulation as well as refractoriness following prolonged administration. In vivo virologic activity was demonstrated based on the ratio of viral RNA to viral DNA in peripheral blood mononuclear cells, a presumptive measure of viral transcription, which significantly increased in SAHA-treated animals. However, residual virus was readily detected at the end of treatment, suggesting that SAHA alone may be insufficient for viral eradication in the setting of suppressive cART. The effects observed were similar to emerging data for repeat-dose SAHA treatment of HIV-infected individuals on cART, demonstrating the feasibility, utility, and relevance of NHP models of cART-mediated suppression for in vivo assessments of AIDS virus functional cure/eradication approaches. PMID:25182644

Pregnant and breastfeeding women: A priority population for HIV viral load monitoring.

PubMed

Myer, Landon; Essajee, Shaffiq; Broyles, Laura N; Watts, D Heather; Lesosky, Maia; El-Sadr, Wafaa M; Abrams, Elaine J

2017-08-01

Landon Myer and colleagues discuss viral load monitoring for pregnant HIV-positive women and those breastfeeding; ART treatments can suppress viral load and are key to preventing transmission to the child.

Impact of intimate partner violence on clinic attendance, viral suppression and CD4 cell count of women living with HIV in an urban clinic setting.

PubMed

Anderson, Jocelyn C; Campbell, Jacquelyn C; Glass, Nancy E; Decker, Michele R; Perrin, Nancy; Farley, Jason

2018-04-01

The substance abuse, violence and HIV/AIDS (SAVA) syndemic represents a complex set of social determinants of health that impacts the lives of women. Specifically, there is growing evidence that intimate partner violence (IPV) places women at risk for both HIV acquisition and poorer HIV-related outcomes. This study assessed prevalence of IPV in an HIV clinic setting, as well as the associations between IPV, symptoms of depression and PTSD on three HIV-related outcomes-CD4 count, viral load, and missed clinic visits. In total, 239 adult women attending an HIV-specialty clinic were included. Fifty-one percent (95% CI: 45%-58%) reported past year psychological, physical, or sexual intimate partner abuse. In unadjusted models, IPV was associated with having a CD4 count <200 (OR: 3.284, 95% CI: 1.251-8.619, p = 0.016) and having a detectable viral load (OR: 1.842, 95% CI: 1.006-3.371, p = 0.048). IPV was not associated with missing >33% of past year all type clinic visits (OR: 1.535, 95% CI: 0.920-2.560, p = 0.101) or HIV specialty clinic visits (OR: 1.251, 95% CI: 0.732-2.140). In multivariable regression, controlling for substance use, mental health symptoms and demographic covariates, IPV remained associated with CD4 count <200 (OR: 3.536, 95% CI: 1.114-11.224, p = 0.032), but not viral suppression. The association between IPV and lower CD4 counts, but not adherence markers such as viral suppression and missed visits, indicates a need to examine potential physiologic impacts of trauma that may alter the immune functioning of women living with HIV. Incorporating trauma-informed approaches into current HIV care settings is one opportunity that begins to address IPV in this patient population.

Absence of kynurenine 3-monooxygenase reduces mortality of acute viral myocarditis in mice.

PubMed

Kubo, Hisako; Hoshi, Masato; Mouri, Akihiro; Tashita, Chieko; Yamamoto, Yasuko; Nabeshima, Toshitaka; Saito, Kuniaki

2017-01-01

Infection of the encephalomyocarditis virus (EMCV) in mice is an established model for viral myocarditis. Previously, we have demonstrated that indoleamine 2,3-dioxygenase (IDO), an L-tryptophan - kynurenine pathway (KP) enzyme, affects acute viral myocarditis. However, the roles of KP metabolites in EMCV infection remain unclear. Kynurenine 3-monooxygenase (KMO) is one of the key regulatory enzymes, which metabolizes kynurenine to 3-hydroxykynurenine in the KP. Therefore, we examined the role of KMO in acute viral infection by comparing between KMO -/- mice and KMO +/+ mice. KMO deficiency resulted in suppressed mortality after EMCV infection. The number of infiltrating cells and F4/80 + cells in KMO -/- mice was suppressed compared with those in KMO +/+ mice. KMO -/- mice showed significantly increased levels of serum KP metabolites, and induction of KMO expression upon EMCV infection was involved in its effect on mortality through EMCV suppression. Furthermore, KMO -/- mice showed significantly suppression of CCL2, CCL3 and CCL4 on day 2 and CXCL1 on day 4 after infection. These results suggest that increased KP metabolites reduced chemokine production, resulting in suppressed mortality upon KMO knockdown in EMCV infection. KP metabolites may thus provide an effective strategy for treating acute viral myocarditis. Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

Correlates of Self-Reported Viral Suppression Among HIV-Positive, Young, Black Men Who Have Sex With Men Participating in a Randomized Controlled Trial of An Internet-Based HIV Prevention Intervention.

PubMed

Menza, Timothy William; Choi, Seul-Ki; LeGrand, Sara; Muessig, Kate; Hightow-Weidman, Lisa

2018-02-01

Young, black men who have sex with men are disproportionately impacted by the US HIV epidemic, and HIV-positive, young, black men who have sex with men face stark disparities in HIV clinical outcomes. We performed an observational analysis of the 199 HIV-positive black men aged 18 to 30 years followed up for 12 months in healthMpowerment, a randomized controlled trial of an Internet-based HIV prevention intervention, to identify time-varying correlates of self-reported viral suppression using relative risk (RR) regression. Retention at the 12-month visit was 84%. One hundred five (65%) of 162 participants reported being undetectable at baseline. At 3, 6, and 12 months, 83 (72%) of 115, 84 (82%) of 103, and 101 (86%) of 117 reported an undetectable viral load, respectively. In a multivariable model, participants who reported homelessness (RR, 0.85; 95% confidence interval [CI], 0.72-0.99), who had clinically significant depressive symptoms (RR, 0.88; 95% CI, 0.79-0.98), and who used methamphetamine or crack (RR, 0.61; 95% CI, 0.38-0.96) were less likely to report an undetectable viral load. Young men who engaged in condomless insertive anal intercourse were more likely to report viral suppression (RR, 1.14; 95% CI, 1.04-1.24). HIV care for young, black men who have sex with men must be multidimensional to address medical needs in the context of mental health, substance use, and housing insecurity.

Substituting Abacavir for Stavudine in Children Who Are Virally Suppressed Without Lipodystrophy: Randomized Clinical Trial in Johannesburg, South Africa.

PubMed

Strehlau, Renate; Shiau, Stephanie; Arpadi, Stephen; Patel, Faeezah; Pinillos, Francoise; Tsai, Wei-Yann; Coovadia, Ashraf; Abrams, Elaine; Kuhn, Louise

2018-01-24

Abacavir has replaced stavudine in antiretroviral therapy (ART) regimens because it has largely been phased out as a result of toxicity concerns; this loss has reduced further the already-limited drug options for children. Few data regarding virologic and metabolic outcomes among children who undergo substitution of stavudine exist. We evaluated the effects of preemptive substitution of abacavir for stavudine in children initially without lipodystrophy and virally suppressed on a stavudine-containing regimen. At Rahima Moosa Mother and Child Hospital in Johannesburg, South Africa, virally suppressed human immunodeficiency virus (HIV)-infected children ≥36 months of age without lipodystrophy were randomly assigned to continue taking stavudine as part of their ART regimen (n = 106) or to have abacavir substituted for stavudine (n = 107). The children were followed for 56 weeks after randomization in the context of a larger trial of treatment options for ART-experienced children. The mean age of the children was 4.3 years, and the mean duration of ART before random assignment was 3.5 years. No differences in virological outcomes, CD4 response, growth, or dyslipidemia were noted between the stavudine and abacavir groups. By 56 weeks, children in the abacavir group had less clinically detected lipodystrophy (4.7% vs 16%, respectively), a higher proportion of leg fat relative to total fat (0.243 vs 0.230, respectively; P = .006), and a lower trunk/leg-skinfold ratio (0.547 vs 0.569, respectively; P = .003) than the children in the stavudine group. Substituting abacavir for stavudine did not compromise virological response to treatment and was associated with significantly less lipodystrophy. These results support recommendations that favor abacavir in this population. © The Author(s) 2018. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Validating a self-report measure of HIV viral suppression: an analysis of linked questionnaire and clinical data from the Canadian HIV Women's Sexual and Reproductive Health Cohort Study.

PubMed

Carter, Allison; de Pokomandy, Alexandra; Loutfy, Mona; Ding, Erin; Sereda, Paul; Webster, Kath; Nicholson, Valerie; Beaver, Kerrigan; Hogg, Robert S; Kaida, Angela

2017-03-24

We assessed the validity of a self-report measure of undetectable viral load (VL) among women with HIV in British Columbia (BC), Canada. Questionnaire data from the Canadian HIV Women's Sexual and Reproductive Health Cohort Study was linked with population-based clinical data from the BC Centre for Excellence in HIV/AIDS. Self-reported undetectable VL was assessed by the question: "What was your most recent VL, undetectable (i.e. <50 copies/mL) or detectable (i.e. ≥50 copies/mL)?" Laboratory measurements of VL <50 copies/mL (closest to/before study visit) were the criterion for validity analyses. We measured positive and negative predictive values (PPV, NPV) and likelihood ratios (LR+, LR-). Of 356 participants, 99% were linked to clinical data. Those unlinked (n = 1), missing self-report VL (n = 18), or missing self-report and laboratory VL (n = 1) were excluded. Among the remaining 336: median age was 44 (IQR 37-51); 96% identified as cis-gender; 84% identified as heterosexual; and 45% identified as Indigenous, 40% White, 8% African, Caribbean, or Black, and 8% other/multiple ethnicities. Overall, 85% self-reported having an undetectable VL while 82% had clinical data indicating viral suppression. The PPV was 93.7 (95% CI 90.2-96.2) indicating that 94% of women who self-reported being undetectable truly were. The NPV was 80.4 (95% CI 66.9-90.2). LR+ was 3.2 (2.1-4.6) and LR- was 0.05 (0.03-0.10). Our self-report measure assessing undetectable VL strongly predicted true viral suppression among Canadian women with HIV. This measure can be used in research settings without laboratory data in regions with high rates of VL testing and suppression.

Impact and Programmatic Implications of Routine Viral Load Monitoring in Swaziland

PubMed Central

Parker, Lucy Anne; Azih, Charles; Okello, Velephi; Maphalala, Gugu; Jouquet, Guillaume; Kerschberger, Bernhard; Mekeidje, Calorine; Cyr, Joanne; Mafikudze, Arnold; Han, Win; Lujan, Johnny; Teck, Roger; Antierens, Annick; van Griensven, Johan; Reid, Tony

2014-01-01

Objective: To assess the programmatic quality (coverage of testing, counseling, and retesting), cost, and outcomes (viral suppression, treatment decisions) of routine viral load (VL) monitoring in Swaziland. Design: Retrospective cohort study of patients undergoing routine VL monitoring in Swaziland (October 1, 2012 to March 31, 2013). Results: Of 5563 patients eligible for routine VL testing monitoring in the period of study, an estimated 4767 patients (86%) underwent testing that year. Of 288 patients with detectable VL, 210 (73%) underwent enhanced adherence counseling and 202 (70%) had a follow-up VL within 6 months. Testing coverage was slightly lower in children, but coverage of retesting was similar between and age groups and sexes. Of those with a follow-up test, 126 (62%) showed viral suppression. The remaining 78 patients had World Health Organization–defined virologic failure; 41 (53%) were referred by the doctor for more adherence counseling, and 13 (15%) were changed to second-line therapy, equating to an estimated rate of 1.2 switches per 100 patient-years. Twenty-four patients (32%) were transferred out, lost to follow-up, or not reviewed by doctor. The “fully loaded” cost of VL monitoring was $35 per patient-year. Conclusions: Achieving good quality VL monitoring is feasible and affordable in resource-limited settings, although close supervision is needed to ensure good coverage of testing and counseling. The low rate of switch to second-line therapy in patients with World Health Organization–defined virologic failure seems to reflect clinician suspicion of ongoing adherence problems. In our study, the main impact of routine VL monitoring was reinforcing adherence rather than increasing use of second-line therapy. PMID:24872139

Viral evasion of intracellular DNA and RNA sensing

PubMed Central

Chan, Ying Kai; Gack, Michaela U.

2016-01-01

The co-evolution of viruses with their hosts has led to the emergence of viral pathogens that are adept at evading or actively suppressing host immunity. Pattern recognition receptors (PRRs) are key components of antiviral immunity that detect conserved molecular features of viral pathogens and initiate signalling that results in the expression of antiviral genes. In this Review, we discuss the strategies that viruses use to escape immune surveillance by key intracellular sensors of viral RNA or DNA, with a focus on RIG-I-like receptors (RLRs), cyclic GMP–AMP synthase (cGAS) and interferon-γ (IFNγ)-inducible protein 16 (IFI16). Such viral strategies include the sequestration or modification of viral nucleic acids, interference with specific post-translational modifications of PRRs or their adaptor proteins, the degradation or cleavage of PRRs or their adaptors, and the sequestration or relocalization of PRRs. An understanding of viral immune-evasion mechanisms at the molecular level may guide the development of vaccines and antivirals. PMID:27174148

IFITM Proteins Restrict Viral Membrane Hemifusion

PubMed Central

Golfetto, Ottavia; Bungart, Brittani; Li, Minghua; Ding, Shilei; He, Yuxian; Liang, Chen; Lee, James C.; Gratton, Enrico; Cohen, Fredric S.; Liu, Shan-Lu

2013-01-01

The interferon-inducible transmembrane (IFITM) protein family represents a new class of cellular restriction factors that block early stages of viral replication; the underlying mechanism is currently not known. Here we provide evidence that IFITM proteins restrict membrane fusion induced by representatives of all three classes of viral membrane fusion proteins. IFITM1 profoundly suppressed syncytia formation and cell-cell fusion induced by almost all viral fusion proteins examined; IFITM2 and IFITM3 also strongly inhibited their fusion, with efficiency somewhat dependent on cell types. Furthermore, treatment of cells with IFN also markedly inhibited viral membrane fusion and entry. By using the Jaagsiekte sheep retrovirus envelope and influenza A virus hemagglutinin as models for study, we showed that IFITM-mediated restriction on membrane fusion is not at the steps of receptor- and/or low pH-mediated triggering; instead, the creation of hemifusion was essentially blocked by IFITMs. Chlorpromazine (CPZ), a chemical known to promote the transition from hemifusion to full fusion, was unable to rescue the IFITM-mediated restriction on fusion. In contrast, oleic acid (OA), a lipid analog that generates negative spontaneous curvature and thereby promotes hemifusion, virtually overcame the restriction. To explore the possible effect of IFITM proteins on membrane molecular order and fluidity, we performed fluorescence labeling with Laurdan, in conjunction with two-photon laser scanning and fluorescence-lifetime imaging microscopy (FLIM). We observed that the generalized polarizations (GPs) and fluorescence lifetimes of cell membranes expressing IFITM proteins were greatly enhanced, indicating higher molecularly ordered and less fluidized membranes. Collectively, our data demonstrated that IFITM proteins suppress viral membrane fusion before the creation of hemifusion, and suggested that they may do so by reducing membrane fluidity and conferring a positive spontaneous

Viral haemorrhagic fever and vascular alterations.

PubMed

Aleksandrowicz, P; Wolf, K; Falzarano, D; Feldmann, H; Seebach, J; Schnittler, H

2008-02-01

Pathogenesis of viral haemorrhagic fever (VHF) is closely associated with alterations of the vascular system. Among the virus families causing VHF, filoviruses (Marburg and Ebola) are the most fatal, and will be focused on here. After entering the body, Ebola primarily targets monocytes/macrophages and dendritic cells. Infected dendritic cells are largely impaired in their activation potency, likely contributing to the immune suppression that occurs during filovirus infection. Monocytes/macrophages, however, immediately activate after viral contact and release reasonable amounts of cytokines that target the vascular system, particularly the endothelial cells. Some underlying molecular mechanisms such as alteration of the vascular endothelial cadherin/catenin complex, tyrosine phosphorylation, expression of cell adhesion molecules, tissue factor and the effect of soluble viral proteins released from infected cells to the blood stream will be discussed.

Brain Macrophages in Simian Immunodeficiency Virus-Infected, Antiretroviral-Suppressed Macaques: a Functional Latent Reservoir

PubMed Central

Avalos, Claudia R.; Abreu, Celina M.; Queen, Suzanne E.; Li, Ming; Price, Sarah; Shirk, Erin N.; Engle, Elizabeth L.; Forsyth, Ellen; Bullock, Brandon T.; Mac Gabhann, Feilim; Wietgrefe, Stephen W.; Haase, Ashley T.; Zink, M. Christine; Mankowski, Joseph L.; Clements, Janice E.

2017-01-01

ABSTRACT A human immunodeficiency virus (HIV) infection cure requires an understanding of the cellular and anatomical sites harboring virus that contribute to viral rebound upon treatment interruption. Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are reported in HIV-infected individuals on ART. Biomarkers for macrophage activation and neuronal damage in cerebrospinal fluid (CSF) of HIV-infected individuals demonstrate continued effects of HIV in brain and suggest that the central nervous system (CNS) may serve as a viral reservoir. Using a simian immunodeficiency virus (SIV)/macaque model for HIV encephalitis and AIDS, we evaluated whether infected cells persist in brain despite ART. Eight SIV-infected pig-tailed macaques were virally suppressed with ART, and plasma and CSF viremia levels were analyzed longitudinally. To assess whether virus persisted in brain macrophages (BrMΦ) in these macaques, we used a macrophage quantitative viral outgrowth assay (MΦ-QVOA), PCR, and in situ hybridization (ISH) to measure the frequency of infected cells and the levels of viral RNA and DNA in brain. Viral RNA in brain tissue of suppressed macaques was undetectable, although viral DNA was detected in all animals. The MΦ-QVOA demonstrated that the majority of suppressed animals contained latently infected BrMΦ. We also showed that virus produced in the MΦ-QVOAs was replication competent, suggesting that latently infected BrMΦ are capable of reestablishing productive infection upon treatment interruption. This report provides the first confirmation of the presence of replication-competent SIV in BrMΦ of ART-suppressed macaques and suggests that the highly debated issue of viral latency in macrophages, at least in brain, has been addressed in SIV-infected macaques treated with ART. PMID:28811349

Human β-D-3 Exacerbates MDA5 but Suppresses TLR3 Responses to the Viral Molecular Pattern Mimic Polyinosinic:Polycytidylic Acid

PubMed Central

Semple, Fiona; MacPherson, Heather; Webb, Sheila; Kilanowski, Fiona; Lettice, Laura; McGlasson, Sarah L.; Wheeler, Ann P.; Chen, Valerie; Millhauser, Glenn L.; Melrose, Lauren; Davidson, Donald J.; Dorin, Julia R.

2015-01-01

Human β-defensin 3 (hBD3) is a cationic host defence peptide and is part of the innate immune response. HBD3 is present on a highly copy number variable block of six β-defensin genes, and increased copy number is associated with the autoimmune disease psoriasis. It is not known how this increase influences disease development, but psoriasis is a T cell-mediated disease and activation of the innate immune system is required for the initial trigger that leads to the amplification stage. We investigated the effect of hBD3 on the response of primary macrophages to various TLR agonists. HBD3 exacerbated the production of type I Interferon-β in response to the viral ligand mimic polyinosinic:polycytidylic acid (polyI:C) in both human and mouse primary cells, although production of the chemokine CXCL10 was suppressed. Compared to polyI:C alone, mice injected with both hBD3 peptide and polyI:C also showed an enhanced increase in Interferon-β. Mice expressing a transgene encoding hBD3 had elevated basal levels of Interferon-β, and challenge with polyI:C further increased this response. HBD3 peptide increased uptake of polyI:C by macrophages, however the cellular response and localisation of polyI:C in cells treated contemporaneously with hBD3 or cationic liposome differed. Immunohistochemistry showed that hBD3 and polyI:C do not co-localise, but in the presence of hBD3 less polyI:C localises to the early endosome. Using bone marrow derived macrophages from knockout mice we demonstrate that hBD3 suppresses the polyI:C-induced TLR3 response mediated by TICAM1 (TRIF), while exacerbating the cytoplasmic response through MDA5 (IFIH1) and MAVS (IPS1/CARDIF). Thus, hBD3, a highly copy number variable gene in human, influences cellular responses to the viral mimic polyI:C implying that copy number may have a significant phenotypic effect on the response to viral infection and development of autoimmunity in humans. PMID:26646717

Ten Year Trends in Community HIV Viral Load in Barbados: Implications for Treatment as Prevention

PubMed Central

Landis, R. Clive; Branch-Beckles, Songee Lynn; Crichlow, Shawna; Hambleton, Ian R.; Best, Anton

2013-01-01

Background Treatment as prevention is a paradigm in HIV medicine which describes the public health benefit of antiretroviral therapy (ART). It is based on research showing substantial reductions in the risk of HIV transmission in persons with optimally suppressed HIV-1 Viral Loads (VL). The present study describes ten year VL trends at the national HIV treatment unit and estimates VL suppression at a population level in Barbados, a Caribbean island with a population of 277,000, an estimated adult HIV prevalence of 1.2%, and served by a single treatment unit. Methods The national HIV treatment centre of the Barbados Ministry of Health has a client VL database extending back to inception of the clinic in 2002 (n = 1,462 clients, n = 17,067 VL measurements). Optimal VL suppression was defined at a threshold value of ≤200 viral copies/mL. Results Analysis of VL trends showed a statistically significant improvement in VL suppression between 2002 to 2011, from 33.6% of clients achieving the 200 copies/mL threshold in 2002 to 70.3% in 2011 (P<0.001). Taking into account the proportion of clients alive and in care and on ART, the known diagnosed HIV population in Barbados, and estimates of unknown HIV infections, this translates into an estimated 26.2% VL suppression at a population level at the end of 2010. Conclusions We have demonstrated a significant trend towards optimal VL suppression in clients utilizing the services of the national HIV treatment program in Barbados over a 10-year period. Estimates of VL suppression at a population level are similar to reports in developed countries that applied similar methodologies and this could suggest a public health benefit of ART in minimizing the risk of sexual transmission of HIV. Continued efforts are warranted to extend HIV testing to hidden populations in Barbados and linking infected persons to care earlier in their disease. PMID:23520523

Structure and Function of Viral Deubiquitinating Enzymes.

PubMed

Bailey-Elkin, Ben A; Knaap, Robert C M; Kikkert, Marjolein; Mark, Brian L

2017-11-10

Post-translational modification of cellular proteins by ubiquitin regulates numerous cellular processes, including innate and adaptive immune responses. Ubiquitin-mediated control over these processes can be reversed by cellular deubiquitinating enzymes (DUBs), which remove ubiquitin from cellular targets and depolymerize polyubiquitin chains. The importance of protein ubiquitination to host immunity has been underscored by the discovery of viruses that encode proteases with deubiquitinating activity, many of which have been demonstrated to actively corrupt cellular ubiquitin-dependent processes to suppress innate antiviral responses and promote viral replication. DUBs have now been identified in diverse viral lineages, and their characterization is providing valuable insights into virus biology and the role of the ubiquitin system in host antiviral mechanisms. Here, we provide an overview of the structural biology of these fascinating viral enzymes and their role innate immune evasion and viral replication. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuclear Imprisonment: Viral Strategies to Arrest Host mRNA Nuclear Export

PubMed Central

Kuss, Sharon K.; Mata, Miguel A.; Zhang, Liang; Fontoura, Beatriz M. A.

2013-01-01

Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA) that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses. PMID:23872491

High rates of viral suppression in adults and children with high CD4+ counts using a streamlined ART delivery model in the SEARCH trial in rural Uganda and Kenya

PubMed Central

Kwarisiima, Dalsone; Kamya, Moses R.; Owaraganise, Asiphas; Mwangwa, Florence; Byonanebye, Dathan M.; Ayieko, James; Plenty, Albert; Black, Doug; Clark, Tamara D.; Nzarubara, Bridget; Snyman, Katherine; Brown, Lillian; Bukusi, Elizabeth; Cohen, Craig R.; Geng, Elvin H.; Charlebois, Edwin D.; Ruel, Theodore D.; Petersen, Maya L.; Havlir, Diane; Jain, Vivek

2017-01-01

Abstract Introduction: The 2015 WHO recommendation of antiretroviral therapy (ART) for all HIV-positive persons calls for treatment initiation in millions of persons newly eligible with high CD4+ counts. Efficient and effective care models are urgently needed for this population. We evaluated clinical outcomes of asymptomatic HIV-positive adults and children starting ART with high CD4+ counts using a novel streamlined care model in rural Uganda and Kenya. Methods: In the 16 intervention communities of the HIV test-and-treat Sustainable East Africa Research for Community Health Study (NCT01864603), all HIV-positive individuals irrespective of CD4 were offered ART (efavirenz [EFV]/tenofovir disoproxil fumarate + emtricitabine (FTC) or lamivudine (3TC). We studied adults (≥fifteen years) with CD4 ≥ 350/μL and children (two to fourteen years) with CD4 > 500/μL otherwise ineligible for ART by country guidelines. Clinics implemented a patient-centred streamlined care model designed to reduce patient-level barriers and maximize health system efficiency. It included (1) nurse-conducted visits with physician referral of complex cases, (2) multi-disease chronic care (including for hypertension/diabetes), (3) patient-centred, friendly staff, (4) viral load (VL) testing and counselling, (5) three-month return visits and ART refills, (6) appointment reminders, (7) tiered tracking for missed appointments, (8) flexible clinic hours (outside routine schedule) and (9) telephone access to clinicians. Primary outcomes were 48-week retention in care, viral suppression (% with measured week 48 VL ≤ 500 copies/mL) and adverse events. Results: Overall, 972 HIV-positive adults with CD4+ ≥ 350/μL initiated ART with streamlined care. Patients were 66% female and had median age thirty-four years (IQR, 28–42), CD4+ 608/μL (IQR, 487–788/μL) and VL 6775 copies/mL (IQR, <500–37,003 c/mL). At week 48, retention was 92% (897/972; 2 died/40 moved/8 withdrew/4

Achieving the Goals of the National HIV/AIDS Strategy: Declining HIV Diagnoses, Improving Clinical Outcomes, and Diminishing Racial/Ethnic Disparities in King County, WA (2004-2013).

PubMed

Golden, Matthew R; Bennett, Amy B; Dombrowski, Julia C; Buskin, Susan E

2016-05-01

The US National HIV/AIDS Strategy defines national objectives related to HIV prevention and care. The extent to which US cities are meeting those objectives is uncertain. We analyzed King County, WA, HIV surveillance data collected between 2004 and 2013. The study population included 9539 persons diagnosed as having and living with HIV infection and 3779 persons with newly diagnosed HIV infection. Between 2004 and 2013, the rate of new HIV diagnosis decreased from 18.4 to 13.2 per 100,000 residents (decline of 28%); AIDS diagnosis rates declined 42% from 12 to 7 per 100,000; and age-adjusted death rates decreased from 27 to 15 per 1000 persons living with HIV/AIDS (decline of 42%; P<0.0001 for all 3 trends). The rate of new HIV diagnosis declined 26% among men who have sex with men (MSM; P=0.0002), with the largest decline occurring in black MSM (44%). Among 8679 individuals with laboratory results reported to National HIV Surveillance System from 2006 through 2013, viral suppression (viral load<200 copies/mL) increased from 45% to 86% (P<0.0001), with all racial/ethnic groups achieving greater than 80% viral suppression in 2013. The rates of new HIV diagnosis, AIDS diagnoses, and mortality in persons living with HIV in King County, WA, have significantly declined over the last decade. These changes have occurred concurrent with a dramatic increase in HIV viral suppression and have affected diverse populations, including MSM and African American MSM. These findings demonstrate substantial local success in achieving the goals of the National HIV/AIDS Strategy.

Role of zinc-finger anti-viral protein in host defense against Sindbis virus

PubMed Central

Kozaki, Tatsuya; Takahama, Michihiro; Misawa, Takuma; Matsuura, Yoshiharu; Saitoh, Tatsuya

2015-01-01

Accumulating evidence indicates that type I interferon (IFN) mediates the host protective response to RNA viruses. However, the anti-viral effector molecules involved in this response have not been fully identified. Here, we show that zinc-finger anti-viral protein (ZAP), an IFN-inducible gene, plays a critical role in the elimination of Sindbis virus (SINV) in vitro and in vivo. The loss of ZAP greatly enhances the replication of SINV but does not inhibit type I IFN production in primary mouse embryonic fibroblasts (MEFs). ZAP binds and destabilizes SINV RNA, thereby suppressing the replication of SINV. Type I IFN fails to suppress SINV replication in ZAP-deficient MEFs, whereas the ectopic expression of ZAP is sufficient to suppress the replication of SINV in MEFs lacking the expression of type I IFN and the IFN-inducible genes. ZAP-deficient mice are highly susceptible to SINV infection, although they produce sufficient amounts of type I IFN. Therefore, ZAP is an RNA-sensing anti-viral effector molecule that mediates the type-I-IFN-dependent host defense against SINV. PMID:25758257

Human β-Defensin 3 [corrected] Exacerbates MDA5 but Suppresses TLR3 Responses to the Viral Molecular Pattern Mimic Polyinosinic:Polycytidylic Acid.

PubMed

Semple, Fiona; MacPherson, Heather; Webb, Sheila; Kilanowski, Fiona; Lettice, Laura; McGlasson, Sarah L; Wheeler, Ann P; Chen, Valerie; Millhauser, Glenn L; Melrose, Lauren; Davidson, Donald J; Dorin, Julia R

2015-12-01

Human β-defensin 3 (hBD3) is a cationic host defence peptide and is part of the innate immune response. HBD3 is present on a highly copy number variable block of six β-defensin genes, and increased copy number is associated with the autoimmune disease psoriasis. It is not known how this increase influences disease development, but psoriasis is a T cell-mediated disease and activation of the innate immune system is required for the initial trigger that leads to the amplification stage. We investigated the effect of hBD3 on the response of primary macrophages to various TLR agonists. HBD3 exacerbated the production of type I Interferon-β in response to the viral ligand mimic polyinosinic:polycytidylic acid (polyI:C) in both human and mouse primary cells, although production of the chemokine CXCL10 was suppressed. Compared to polyI:C alone, mice injected with both hBD3 peptide and polyI:C also showed an enhanced increase in Interferon-β. Mice expressing a transgene encoding hBD3 had elevated basal levels of Interferon-β, and challenge with polyI:C further increased this response. HBD3 peptide increased uptake of polyI:C by macrophages, however the cellular response and localisation of polyI:C in cells treated contemporaneously with hBD3 or cationic liposome differed. Immunohistochemistry showed that hBD3 and polyI:C do not co-localise, but in the presence of hBD3 less polyI:C localises to the early endosome. Using bone marrow derived macrophages from knockout mice we demonstrate that hBD3 suppresses the polyI:C-induced TLR3 response mediated by TICAM1 (TRIF), while exacerbating the cytoplasmic response through MDA5 (IFIH1) and MAVS (IPS1/CARDIF). Thus, hBD3, a highly copy number variable gene in human, influences cellular responses to the viral mimic polyI:C implying that copy number may have a significant phenotypic effect on the response to viral infection and development of autoimmunity in humans.

Viral persistence, latent reservoir, and blips: a review on HIV-1 dynamics and modeling during HAART and related treatment implications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rong, Libin; Perelson, Alan

2008-01-01

HIV-1 eradication from infected individuals has not been achieved with the use of highly active antiretroviral therapy (HAART) for a prolonged period of time. The cellular reservoir for HIV-1 in resting memory CD4{sup +} T cells remains a major obstacle to viral elimination. The reservoir does not decay significantly over long periods of time as is able to release replication competent HIV-1 upon cell activation. Residual ongoing viral replication may likely occur in many patients because low levels of virus can be detected in plasma by sensitive assays and transient episodes of viremia, or HIV-1 blips, are often observed inmore » patients even with successful viral suppression for many years. Here we review our current knowledge of the factors contributing to viral persistence, the latent reservoir, and blips, and mathematical models developed to explore them and their relationships. We show how mathematical modeling can help improve our understanding of HIV-1 dynamics in patients on HAART and the quantitative events underlying HIV-1 latency, reservoir stability, low-level viremic persistence, and emergence of intermittent viral blips. We also discuss treatment implications related to these studies.« less

Mathematical analysis of antiretroviral therapy aimed at HIV-1 eradication or maintenance of low viral loads.

PubMed

Wein, L M; D'Amato, R M; Perelson, A S

1998-05-07

Motivated by the ability of combinations of antiretroviral agents to sustain viral suppression in HIV-1-infected individuals, we analyse the transient and steady-state behavior of a mathematical model of HIV-1 dynamics in vivo in order to predict whether these drug regimens can eradicate HIV-1 or maintain viral loads at low levels. The model incorporates two cell types (CD4+ T cells and a long-lived pool of cells), two strains of virus (drug-sensitive wild type and drug-resistant mutant) and two types of antiretroviral agents (reverse transcriptase and protease inhibitors). The transient behavior of the cells and virus and the eventual eradication of the virus are determined primarily by the strength of the combination therapy against the mutant strain and the maximum achievable increase in the uninfected CD4+ T cell concentration. We also predict, if the parameters of the model remain constant during therapy, that less intensive maintenance regimens will be unable to maintain low viral loads for extensive periods of time. However, if the reduction in viral load produced by therapy reduces the state of activation of the immune system, the number of cells susceptible for HIV-1 infection may decrease even though total CD4+ T cells increase. Our model predicts that if this occurs strong inductive therapy that reduces viral load followed by weaker maintenance regimes may succeed.

Which adherence measure - self-report, clinician recorded or pharmacy refill - is best able to predict detectable viral load in a public ART programme without routine plasma viral load monitoring?

PubMed

Mekuria, Legese A; Prins, Jan M; Yalew, Alemayehu W; Sprangers, Mirjam A G; Nieuwkerk, Pythia T

2016-07-01

Combination antiretroviral therapy (cART) suppresses viral replication to an undetectable level if a sufficiently high level of adherence is achieved. We investigated which adherence measurement best distinguishes between patients with and without detectable viral load in a public ART programme without routine plasma viral load monitoring. We randomly selected 870 patients who started cART between May 2009 and April 2012 in 10 healthcare facilities in Addis Ababa, Ethiopia. Six hundred and sixty-four (76.3%) patients who were retained in HIV care and were receiving cART for at least 6 months were included and 642 had their plasma HIV-1 RNA concentration measured. Patients' adherence to cART was assessed according to self-report, clinician recorded and pharmacy refill measures. Multivariate logistic regression model was fitted to identify the predictors of detectable viremia. Model accuracy was evaluated by computing the area under the receiver operating characteristic (ROC) curve. A total of 9.2% and 5.5% of the 642 patients had a detectable viral load of ≥40 and ≥400 RNA copies/ml, respectively. In the multivariate analyses, younger age, lower CD4 cell count at cART initiation, being illiterate and widowed, and each of the adherence measures were significantly and independently predictive of having ≥400 RNA copies/ml. The ROC curve showed that these variables altogether had a likelihood of more than 80% to distinguish patients with a plasma viral load of ≥400 RNA copies/ml from those without. Adherence to cART was remarkably high. Self-report, clinician recorded and pharmacy refill non-adherence were all significantly predictive of detectable viremia. The choice for one of these methods to detect non-adherence and predict a detectable viral load can therefore be based on what is most practical in a particular setting. © 2016 John Wiley & Sons Ltd.

Viral Hepatitis Strategic Information to Achieve Elimination by 2030: Key Elements for HIV Program Managers

PubMed Central

Low-Beer, Daniel; Bergeri, Isabel; Hess, Sarah; Garcia-Calleja, Jesus Maria; Hayashi, Chika; Mozalevskis, Antons; Rinder Stengaard, Annemarie; Sabin, Keith; Harmanci, Hande; Bulterys, Marc

2017-01-01

Evidence documenting the global burden of disease from viral hepatitis was essential for the World Health Assembly to endorse the first Global Health Sector Strategy (GHSS) on viral hepatitis in May 2016. The GHSS on viral hepatitis proposes to eliminate viral hepatitis as a public health threat by 2030. The GHSS on viral hepatitis is in line with targets for HIV infection and tuberculosis as part of the Sustainable Development Goals. As coordination between hepatitis and HIV programs aims to optimize the use of resources, guidance is also needed to align the strategic information components of the 2 programs. The World Health Organization monitoring and evaluation framework for viral hepatitis B and C follows an approach similar to the one of HIV, including components on the following: (1) context (prevalence of infection), (2) input, (3) output and outcome, including the cascade of prevention and treatment, and (4) impact (incidence and mortality). Data systems that are needed to inform this framework include (1) surveillance for acute hepatitis, chronic infections, and sequelae and (2) program data documenting prevention and treatment, which for the latter includes a database of patients. Overall, the commonalities between HIV and hepatitis at the strategic, policy, technical, and implementation levels justify coordination, strategic linkage, or integration, depending on the type of HIV and viral hepatitis epidemics. Strategic information is a critical area of this alignment under the principle of what gets measured gets done. It is facilitated because the monitoring and evaluation frameworks for HIV and viral hepatitis were constructed using a similar approach. However, for areas where elimination of viral hepatitis requires data that cannot be collected through the HIV program, collaborations are needed with immunization, communicable disease control, tuberculosis, and hepatology centers to ensure collection of information for the remaining indicators. PMID

Suppression of Antigen-Specific T Cell Responses by the Kaposi's Sarcoma-Associated Herpesvirus Viral OX2 Protein and Its Cellular Orthologue, CD200

PubMed Central

Misstear, Karen; Chanas, Simon A.; Rezaee, S. A. Rahim; Colman, Rachel; Quinn, Laura L.; Long, Heather M.; Goodyear, Oliver; Lord, Janet M.; Hislop, Andrew D.

2012-01-01

Regulating appropriate activation of the immune response in the healthy host despite continual immune surveillance dictates that immune responses must be either self-limiting and therefore negatively regulated following their activation or prevented from developing inappropriately. In the case of antigen-specific T cells, their response is attenuated by several mechanisms, including ligation of CTLA-4 and PD-1. Through the study of the viral OX2 (vOX2) immunoregulator encoded by Kaposi's sarcoma-associated herpesvirus (KSHV), we have identified a T cell-attenuating role both for this protein and for CD200, a cellular orthologue of the viral vOX2 protein. In vitro, antigen-presenting cells (APC) expressing either native vOX2 or CD200 suppressed two functions of cognate antigen-specific T cell clones: gamma interferon (IFN-γ) production and mobilization of CD107a, a cytolytic granule component and measure of target cell killing ability. Mechanistically, vOX2 and CD200 expression on APC suppressed the phosphorylation of ERK1/2 mitogen-activated protein kinase in responding T cells. These data provide the first evidence for a role of both KSHV vOX2 and cellular CD200 in the negative regulation of antigen-specific T cell responses. They suggest that KSHV has evolved to harness the host CD200-based mechanism of attenuation of T cell responses to facilitate virus persistence and dissemination within the infected individual. Moreover, our studies define a new paradigm in immune modulation by viruses: the provision of a negative costimulatory signal to T cells by a virus-encoded orthologue of CD200. PMID:22491458

Improving ART programme retention and viral suppression are key to maximising impact of treatment as prevention - a modelling study.

PubMed

McCreesh, Nicky; Andrianakis, Ioannis; Nsubuga, Rebecca N; Strong, Mark; Vernon, Ian; McKinley, Trevelyan J; Oakley, Jeremy E; Goldstein, Michael; Hayes, Richard; White, Richard G

2017-08-09

UNAIDS calls for fewer than 500,000 new HIV infections/year by 2020, with treatment-as-prevention being a key part of their strategy for achieving the target. A better understanding of the contribution to transmission of people at different stages of the care pathway can help focus intervention services at populations where they may have the greatest effect. We investigate this using Uganda as a case study. An individual-based HIV/ART model was fitted using history matching. 100 model fits were generated to account for uncertainties in sexual behaviour, HIV epidemiology, and ART coverage up to 2015 in Uganda. A number of different ART scale-up intervention scenarios were simulated between 2016 and 2030. The incidence and proportion of transmission over time from people with primary infection, post-primary ART-naïve infection, and people currently or previously on ART was calculated. In all scenarios, the proportion of transmission by ART-naïve people decreases, from 70% (61%-79%) in 2015 to between 23% (15%-40%) and 47% (35%-61%) in 2030. The proportion of transmission by people on ART increases from 7.8% (3.5%-13%) to between 14% (7.0%-24%) and 38% (21%-55%). The proportion of transmission by ART dropouts increases from 22% (15%-33%) to between 31% (23%-43%) and 56% (43%-70%). People who are currently or previously on ART are likely to play an increasingly large role in transmission as ART coverage increases in Uganda. Improving retention on ART, and ensuring that people on ART remain virally suppressed, will be key in reducing HIV incidence in Uganda.

Measles virus-induced suppression of immune responses.

PubMed

Griffin, Diane E

2010-07-01

Measles is an important cause of child mortality that has a seemingly paradoxical interaction with the immune system. In most individuals, the immune response is successful in eventually clearing measles virus (MV) infection and in establishing life-long immunity. However, infection is also associated with persistence of viral RNA and several weeks of immune suppression, including loss of delayed type hypersensitivity responses and increased susceptibility to secondary infections. The initial T-cell response includes CD8+ and T-helper 1 CD4+ T cells important for control of infectious virus. As viral RNA persists, there is a shift to a T-helper 2 CD4+ T-cell response that likely promotes B-cell maturation and durable antibody responses but may suppress macrophage activation and T-helper 1 responses to new infections. Suppression of mitogen-induced lymphocyte proliferation can be induced by lymphocyte infection with MV or by lymphocyte exposure to a complex of the hemagglutinin and fusion surface glycoproteins without infection. Dendritic cells (DCs) are susceptible to infection and can transmit infection to lymphocytes. MV-infected DCs are unable to stimulate a mixed lymphocyte reaction and can induce lymphocyte unresponsiveness through expression of MV glycoproteins. Thus, multiple factors may contribute both to measles-induced immune suppression and to the establishment of durable protective immunity.

[Influence of antisense RNA and sequences of viral transactivators traps on RNA synthesis of HTLV-1 virus].

PubMed

Borisenko, A S; Kotus, E V; Kaloshin, A A

2008-01-01

Significant number of scientific publications devoted to inhibition of viral replication by antisense RNA (asRNA) genes shows that this approach is useful for gene therapy of viral infections. To investigate the possibility of suppression of HTLV-1 virus reproduction by asRNA we constructed recombinant plasmids containing asRNA genes against U3 long terminal repeats region and X gene under the control of promoter of myeloproliferative sarcoma virus (MPSV) or without such promoter. Using stable calcium-phosphate transfection method with subsequent selection in the presence of G-418, RaHOS line-based cell clones carrying both asRNA genes and sequences able to bind HTLV-1 transactivator proteins (i.e. "traps" of viral transactivators, TVT) were obtained. Data from dot-hybridization analysis of viral RNA extracted from RaHOS cell clones showed that TVT sequences are able to suppress the viral RNA synthesis on 90% and asRNA against X gene synthesis--on 50%.

Integrated Evaluation of Latent Viral Reactivation During Spaceflight

NASA Technical Reports Server (NTRS)

Pierson, Duane L.; Paloski, W. H. (Technical Monitor)

2000-01-01

This application proposes a continuation of our current effort, which has provided the first demonstration of viral reactivation during space flight. We have used the herpesvirus EBV as a model for latent viral reactivation and have shown that increased amounts of EBV DNA were shed by astronauts during space flight. Analysis of the Antarctic space flight analog indicated that the frequency of viral shedding may also increase (along with the increased numbers of virus) during long periods of isolation. However, a number of critical questions remain before the findings may be considered a significant health risk during extended space flight. These include: Are other latent viruses (e.g., other herpesviruses and polyornaviruses) in addition to EBV also reactivated and shed more frequently and/or in higher numbers during space flight? Is the viral reactivation observed in space flight and ground-based analogs mediated through the hypothalamus-pituitary-adrenal (HPA) axis resulting in a decreased cell-mediated immune response? How does detection of viral DNA by PCR analysis correlate with infectious virus? How does the amount of virus found during flight compare with viral levels observed in acute/chronic viral illnesses and in control individuals? This expanded study will examine the phenomenon of viral reactivation from the initiating stress through the HPA axis with the accompanying suppression of the immune system resulting in viral reactivation. This information is essential to determine if latent viral reactivation among crewmembers represents a sufficient medical risk to space travel to require the development of suitable countermeasures.

Viral Hepatitis Strategic Information to Achieve Elimination by 2030: Key Elements for HIV Program Managers.

PubMed

Hutin, Yvan; Low-Beer, Daniel; Bergeri, Isabel; Hess, Sarah; Garcia-Calleja, Jesus Maria; Hayashi, Chika; Mozalevskis, Antons; Rinder Stengaard, Annemarie; Sabin, Keith; Harmanci, Hande; Bulterys, Marc

2017-12-15

Evidence documenting the global burden of disease from viral hepatitis was essential for the World Health Assembly to endorse the first Global Health Sector Strategy (GHSS) on viral hepatitis in May 2016. The GHSS on viral hepatitis proposes to eliminate viral hepatitis as a public health threat by 2030. The GHSS on viral hepatitis is in line with targets for HIV infection and tuberculosis as part of the Sustainable Development Goals. As coordination between hepatitis and HIV programs aims to optimize the use of resources, guidance is also needed to align the strategic information components of the 2 programs. The World Health Organization monitoring and evaluation framework for viral hepatitis B and C follows an approach similar to the one of HIV, including components on the following: (1) context (prevalence of infection), (2) input, (3) output and outcome, including the cascade of prevention and treatment, and (4) impact (incidence and mortality). Data systems that are needed to inform this framework include (1) surveillance for acute hepatitis, chronic infections, and sequelae and (2) program data documenting prevention and treatment, which for the latter includes a database of patients. Overall, the commonalities between HIV and hepatitis at the strategic, policy, technical, and implementation levels justify coordination, strategic linkage, or integration, depending on the type of HIV and viral hepatitis epidemics. Strategic information is a critical area of this alignment under the principle of what gets measured gets done. It is facilitated because the monitoring and evaluation frameworks for HIV and viral hepatitis were constructed using a similar approach. However, for areas where elimination of viral hepatitis requires data that cannot be collected through the HIV program, collaborations are needed with immunization, communicable disease control, tuberculosis, and hepatology centers to ensure collection of information for the remaining indicators. �

Serum HBV DNA level at week 12 is superior to viral response at week 24 in predicting long-term treatment outcome of telbivudine for chronic hepatitis B patients.

PubMed

Lü, Wei; Yang, Hai-Hong; Fan, Yun-Ming; Li, Takming; Zhang, Li-Fan; Mui, Chongseong; Fan, Hong-Wei; Zhou, Bao-Tong; Liu, Zheng-Yin; Ng, Hou; Liu, Xiao-Qing

2013-06-01

Telbivudine, one of the five nucleos(t)ide antiviral drugs, was reported to be superior to lamivudine in a better biochemical, virological, and histological response for treatment-naive patients in the GLOBE trial. The aim of this study was to determine the antiviral potency, viral resistance, and the signifcance of early response for long-term telbivudine treatment. We recruited 161 patients of chronic hepatitis B (CHB) on telbivudine between January 2009 and September 2011 in Macau, China. The serum hepatitis B virus DNA levels, hepatitis B e antigen (HBeAg) seroconversion, alanine aminotransferase (ALT) normalization, and viral resistance were analyzed. The median age and follow-up duration were 48 years and 16.9 months. All patients were followed up for at least 6 months, while data were collected for 132, 120, 95, and 53 patients at 12, 24, 48, and 96 weeks respectively. The cumulative HBeAg seroconversion rate was 20.8% and only three patients (1.9%) presented with telbivudine low level resistance. The ALT normalization rates were 76.9% at 48 weeks and 77.6% at 96 weeks. Undetectable HBV DNA was achieved by 1.8%, 31.6%, 60%, and 74.1% in HBeAg positive patients and 29.3%, 60.3%, 84%, and 84.6% in HBeAg negative patients at each time point. Week 12 HBV DNA level < 1000 copies/ml (< 200 IU/ml) was a better predictor of viral suppression at 2-year follow-up (P = 0.001, OR = 27.00) than undetectable HBV DNA level at week 24 (P = 0.120, OR = 4.81). Two-year telbivudine treatment yielded high rates of viral suppression and ALT normalization. Serum HBV DNA level at week 12 is a superior predictor for long-term viral suppression.

Viral-associated lymphoid proliferations☆

PubMed Central

Pittaluga, Stefania

2013-01-01

The histological spectrum of viral-associated lymphoid proliferations is quite broad, ranging from reactive lymphadenitis to atypical proliferations mimicking classical Hodgkin lymphoma or non-Hodgkin lymphoma. Virally associated reactive lesions can appear quite alarming on histological examination, because of direct (cytopathic) and indirect viral-induced changes eliciting a polymorphic cellular host response. In addition, the atypical lymphoid proliferation may show aberrant phenotypic features as well as restricted/clonal gene immunoglobulin or T-cell receptor rearrangements, further complicating the interpretation. In order to achieve an accurate diagnosis, it is important to be aware of the clinical history, including family history and ethnic background, clinical presentation, symptoms, and extent of the disease. Among the clinical data, particular emphasis should be placed on serology and viral load studies, and the use of immunosuppressive drugs. The clinical course and outcome vary greatly, from an indolent, self-limited to aggressive clinical course, blurring at times the distinction between neoplastic and reactive proliferations. It is now recognized that immunosenescence also plays a significant role in the development of these viral-associated lymphoid proliferations, and new entities have been described in recent years. In this review we discuss mostly Epstein–Barr virus-associated viral proliferations that may be confused with lymphomas, which the practicing pathologist may encounter. PMID:23537914

Struggle for space: viral extinction through competition for cells.

PubMed

Cuesta, José A; Aguirre, Jacobo; Capitán, José A; Manrubia, Susanna C

2011-01-14

The design of protocols to suppress the propagation of viral infections is an enduring enterprise, especially hindered by limited knowledge of the mechanisms leading to viral extinction. Here we report on infection extinction due to intraspecific competition to infect susceptible hosts. Beneficial mutations increase the production of viral progeny, while the host cell may develop defenses against infection. For an unlimited number of host cells, a feedback runaway coevolution between host resistance and progeny production occurs. However, physical space limits the advantage that the virus obtains from increasing offspring numbers; thus, infection clearance may result from an increase in host defenses beyond a finite threshold. Our results might be relevant to devise improved control strategies in environments with mobility constraints or different geometrical properties.

D-Dimer Levels before HIV Seroconversion Remain Elevated Even after Viral Suppression and Are Associated with an Increased Risk of Non-AIDS Events.

PubMed

Freiberg, Matthew S; Bebu, Ionut; Tracy, Russell; So-Armah, Kaku; Okulicz, Jason; Ganesan, Anuradha; Armstrong, Adam; O'Bryan, Thomas; Rimland, David; Justice, Amy C; Agan, Brian K

2016-01-01

The mechanism underlying the excess risk of non-AIDS diseases among HIV infected people is unclear. HIV associated inflammation/hypercoagulability likely plays a role. While antiretroviral therapy (ART) may return this process to pre-HIV levels, this has not been directly demonstrated. We analyzed data/specimens on 249 HIV+ participants from the US Military HIV Natural History Study, a prospective, multicenter observational cohort of >5600 active duty military personnel and beneficiaries living with HIV. We used stored blood specimens to measure D-dimer and Interleukin-6 (IL-6) at three time points: pre-HIV seroconversion, ≥6 months post-HIV seroconversion but prior to ART initiation, and ≥6 months post-ART with documented HIV viral suppression on two successive evaluations. We evaluated the changes in biomarker levels between time points, and the association between these biomarker changes and future non-AIDS events. During a median follow-up of 3.7 years, there were 28 incident non-AIDS diseases. At ART initiation, the median CD4 count was 361cells/mm3; median duration of documented HIV infection 392 days; median time on ART was 354 days. Adjusted mean percent increase in D-dimer levels from pre-seroconversion to post-ART was 75.1% (95% confidence interval 24.6-148.0, p = 0.002). This increase in D-dimer was associated with a significant 22% increase risk of future non-AIDS events (p = 0.03). Changes in IL-6 levels across time points were small and not associated with future non-AIDS events. In conclusion, ART initiation and HIV viral suppression does not eliminate HIV associated elevation in D-dimer levels. This residual pathology is associated with an increased risk of future non-AIDS diseases.

Spur-of-the-Moment Modification in National Treatment Policies Leads to a Surprising HCV Viral Suppression in All Treated Patients: Real-Life Egyptian Experience.

PubMed

El Kassas, Mohamed; Omran, Dalia; Elsaeed, Kadry; Alboraie, Mohamed; Elakel, Wafaa; El Tahan, Adel; Abd El Latif, Yasmeen; Nabeel, Mohamed Mahmoud; Korany, Mohamed; Ezzat, Sameera; El-Serafy, Magdy; ElShazly, Yehia; Doss, Wahid; Esmat, Gamal

2018-02-01

The aim of this study was to retrospectively analyze the outcome of an unscheduled change in national Egyptian policies for the treatment of hepatitis C virus (HCV), which was transpired as a result of a reduction in interferon supplies, and to manage patients who already started interferon-based therapy. After completing a priming 4-weeks course of sofosbuvir/pegylated interferon/ribavirin (SOF/PEG IFN/RBV), a 12-weeks course of sofosbuvir/daclatasvir (SOF/DCV) combination was initiated. We evaluated the sustained virologic response at 12 weeks posttreatment (SVR12) for 2 groups of patients; Group 1, which included patients who had the previous regimen with IFN priming, and group 2, which included the first consecutive group of patients who received SOF/DCV for 12 weeks from the start without IFN priming. All group 1 patients (1,214 patients) achieved SVR12 (100%) and this was statistically significant when compared with the overall SVR12 in group 2 [8,869 patients with sustained virologic response [SVR] of 98.9%] (P value <0.001). No serious adverse events were reported in both groups. In this real-life treatment experience, interferon-based directly acting antiviral treatment with SOF/PEG IFN/RBV as a priming for 4 weeks, followed by SOF/DCV combination for 12 weeks, led to HCV viral suppression in all treated patients.

NIK1-mediated translation suppression functions as a plant antiviral immunity mechanism.

PubMed

Zorzatto, Cristiane; Machado, João Paulo B; Lopes, Kênia V G; Nascimento, Kelly J T; Pereira, Welison A; Brustolini, Otávio J B; Reis, Pedro A B; Calil, Iara P; Deguchi, Michihito; Sachetto-Martins, Gilberto; Gouveia, Bianca C; Loriato, Virgílio A P; Silva, Marcos A C; Silva, Fabyano F; Santos, Anésia A; Chory, Joanne; Fontes, Elizabeth P B

2015-04-30

Plants and plant pathogens are subject to continuous co-evolutionary pressure for dominance, and the outcomes of these interactions can substantially impact agriculture and food security. In virus-plant interactions, one of the major mechanisms for plant antiviral immunity relies on RNA silencing, which is often suppressed by co-evolving virus suppressors, thus enhancing viral pathogenicity in susceptible hosts. In addition, plants use the nucleotide-binding and leucine-rich repeat (NB-LRR) domain-containing resistance proteins, which recognize viral effectors to activate effector-triggered immunity in a defence mechanism similar to that employed in non-viral infections. Unlike most eukaryotic organisms, plants are not known to activate mechanisms of host global translation suppression to fight viruses. Here we demonstrate in Arabidopsis that the constitutive activation of NIK1, a leucine-rich repeat receptor-like kinase (LRR-RLK) identified as a virulence target of the begomovirus nuclear shuttle protein (NSP), leads to global translation suppression and translocation of the downstream component RPL10 to the nucleus, where it interacts with a newly identified MYB-like protein, L10-INTERACTING MYB DOMAIN-CONTAINING PROTEIN (LIMYB), to downregulate translational machinery genes fully. LIMYB overexpression represses ribosomal protein genes at the transcriptional level, resulting in protein synthesis inhibition, decreased viral messenger RNA association with polysome fractions and enhanced tolerance to begomovirus. By contrast, the loss of LIMYB function releases the repression of translation-related genes and increases susceptibility to virus infection. Therefore, LIMYB links immune receptor LRR-RLK activation to global translation suppression as an antiviral immunity strategy in plants.

Emotional suppression during personal goal pursuit impedes goal strivings and achievement.

PubMed

Low, Rachel S T; Overall, Nickola C; Hammond, Matthew D; Girme, Yuthika U

2017-03-01

Prior research indicates that emotional suppression exacerbates distress and reduces cognitive performance and self-control. We extend this prior work in the current studies by examining whether emotional suppression in specific goal-relevant contexts impedes people's goal strivings and progress. In Study 1, participants (N = 146) provided reports every 2 weeks across a 2-month period reporting the degree to which they engaged in emotional suppression during goal pursuit and reported important goal-related outcomes, including depressed mood, perceived support/closeness, goal effort, goal-related competence, and goal success. In Study 2, participants reported on the degree to which they engaged in emotional suppression while discussing a personal goal with their romantic partner (N = 100 heterosexual couples) and reported on the same outcomes as in Study 1 prior to, immediately following, and then 1 month after couples' discussions. In both studies, greater use of emotional suppression predicted increased depressed mood, reduced perceived support/closeness, and reduced goal effort, competence, and success across time. Corroborating individuals' self-reports, participants who engaged in emotional suppression were also perceived by their partners to experience greater depressed mood and lower feelings of support and closeness, and be less competent with regard to their goal (Study 2). The effects of emotional suppression were robust when controlling for a range of alternative explanations. These goal hindering effects are likely one important reason emotional suppression is linked with poorer psychological and health outcomes and extend our understanding of the detrimental impact that emotional suppression can have in people's everyday lives. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Increased inflammation in sanctuary sites may explain viral blips in HIV infection

DOE PAGES

Piovoso, Michael J.; Cardozo, E. Fabian; Zurakowski, Ryan

2016-08-01

Here, combined antiretroviral therapy (cART) suppress HIV-1 viral replication, such that viral load in plasma remains below the limit of detection in standard assays. However, intermittent episodes of transient viremia (blips) occur in a set of HIV-patients. Given that follicular hyperplasia occurs during lymphoid inflammation as a normal response to infection, it is hypothesised that when the diameter of the lymph node follicle (LNF) increases and crosses a critical size, a viral blip occurs due to cryptic viremia. To study this hypothesis, a theoretical analysis of a mathematical model is performed to find the conditions for virus suppression in allmore » compartments and different scenarios of LNF size changes are simulated. According to the analysis, blips with duration of around 30 days arise when the diameter rise rate is between 0.02 and 0.03 days –1. Moreover, the final diameter of the site is directly related to the steady states of the virus load after the occurrence of a blip. When the value of R 0 is around 2.1, to have a steady-state below the limit of detection after the viral blip, the maximum final diameters should be greater than 0.7 mm so that there is a relative loss of connection between compartments.« less

Increased inflammation in sanctuary sites may explain viral blips in HIV infection.

PubMed

Cardozo, E Fabian; Piovoso, Michael J; Zurakowski, Ryan

2016-08-01

Combined antiretroviral therapy (cART) suppress HIV-1 viral replication, such that viral load in plasma remains below the limit of detection in standard assays. However, intermittent episodes of transient viremia (blips) occur in a set of HIV-patients. Given that follicular hyperplasia occurs during lymphoid inflammation as a normal response to infection, it is hypothesised that when the diameter of the lymph node follicle (LNF) increases and crosses a critical size, a viral blip occurs due to cryptic viremia. To study this hypothesis, a theoretical analysis of a mathematical model is performed to find the conditions for virus suppression in all compartments and different scenarios of LNF size changes are simulated. According to the analysis, blips with duration of around 30 days arise when the diameter rise rate is between 0.02 and 0.03 days(-1). Moreover, the final diameter of the site is directly related to the steady states of the virus load after the occurrence of a blip. When the value of R0 is around 2.1, to have a steady-state below the limit of detection after the viral blip, the maximum final diameters should be greater than 0.7 mm so that there is a relative loss of connection between compartments.

Increased inflammation in sanctuary sites may explain viral blips in HIV infection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piovoso, Michael J.; Cardozo, E. Fabian; Zurakowski, Ryan

Here, combined antiretroviral therapy (cART) suppress HIV-1 viral replication, such that viral load in plasma remains below the limit of detection in standard assays. However, intermittent episodes of transient viremia (blips) occur in a set of HIV-patients. Given that follicular hyperplasia occurs during lymphoid inflammation as a normal response to infection, it is hypothesised that when the diameter of the lymph node follicle (LNF) increases and crosses a critical size, a viral blip occurs due to cryptic viremia. To study this hypothesis, a theoretical analysis of a mathematical model is performed to find the conditions for virus suppression in allmore » compartments and different scenarios of LNF size changes are simulated. According to the analysis, blips with duration of around 30 days arise when the diameter rise rate is between 0.02 and 0.03 days –1. Moreover, the final diameter of the site is directly related to the steady states of the virus load after the occurrence of a blip. When the value of R 0 is around 2.1, to have a steady-state below the limit of detection after the viral blip, the maximum final diameters should be greater than 0.7 mm so that there is a relative loss of connection between compartments.« less

Antiviral activity and CSF concentrations of 600/100 mg of darunavir/ritonavir once daily in HIV-1 patients with plasma viral suppression.

PubMed

Di Yacovo, Maria S; Moltó, José; Ferrer, Elena; Curran, Adrian; Else, Laura; Gisslén, Magnus; Clotet, Bonaventura; Tiraboschi, Juan M; Niubò, Jordi; Vila, Antonia; Zetterberg, H; Back, David; Podzamczer, Daniel

2015-05-01

The objective of this study was to assess whether a lower dose than the currently used one of darunavir/ritonavir might achieve good CSF concentrations and contribute to inhibition of CNS viral replication. This was a substudy of a randomized, open, multicentre study (eudraCT 2011-006272-39), comparing the efficacy and safety of 800/100 mg of darunavir/ritonavir (darunavir 800) versus 600/100 mg of darunavir/ritonavir (darunavir 600) once daily plus tenofovir/emtricitabine or abacavir/lamivudine in 100 virologically suppressed patients. Paired blood and CSF samples were obtained. Total plasma darunavir concentrations were determined by HPLC, and CSF concentrations by liquid chromatography-tandem MS. Viral load (VL) was determined in plasma and CSF (limit of detection = 40 copies/mL) by PCR. Sixteen patients were enrolled. The median (range) of darunavir CSF concentrations in darunavir 600 (n = 8) and darunavir 800 (n = 8) patients was 17.08 (5.79-30.19) and 13.23 (3.47-32.98) ng/mL, respectively (P = 0.916). The median (range) darunavir CSF:plasma ratio was 0.010 (0.005-0.022) in darunavir 600 patients and 0.008 (0.004-0.017) in the darunavir 800 arm (P = 0.370). All 16 patients had a VL < 40 copies/mL in plasma and 14 had a VL < 40 copies/mL in CSF. Of the two patients with detectable CSF VL (280 copies/mL and 159 copies/mL), one was receiving darunavir 600 and the other darunavir 800 plus tenofovir/emtricitabine. Of note, these patients had the lowest CSF darunavir concentrations in their respective groups: 5.79 ng/mL (802 ng/mL in plasma) and 3.47 ng/mL (958 ng/mL in plasma). Darunavir CSF and plasma concentrations were comparable between the two arms. However, one patient from each group (with the lowest CSF darunavir concentrations in their respective groups) had detectable CSF VL despite undetectable plasma VL. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy

Food Insecurity is Associated with Incomplete HIV RNA Suppression Among Homeless and Marginally Housed HIV-infected Individuals in San Francisco

PubMed Central

Frongillo, Edward A.; Ragland, Kathleen; Hogg, Robert S.; Riley, Elise D.; Bangsberg, David R.

2008-01-01

Background and Objectives There is growing international concern that food insecurity may negatively impact antiretroviral (ARV) treatment outcomes, but no studies have directly evaluated the effect of food insecurity on viral load suppression and antiretroviral adherence. We hypothesized that food insecurity would be associated with poor virologic response among homeless and marginally housed HIV-positive ARV-treated patients. Design This is a cross-sectional study. Participants and Setting Participants were ARV-treated homeless and marginally housed persons receiving adherence monitoring with unannounced pill counts in the Research on Access to Care in the Homeless (REACH) Cohort. Measurements Food insecurity was measured by the Household Food Insecurity Access Scale (HFIAS). The primary outcome was suppression of HIV viral RNA to <50 copies/ml. We used multivariate logistic regression to assess whether food insecurity was associated with viral suppression. Results Among 104 participants, 51% were food secure, 24% were mildly or moderately food insecure and 25% were severely food insecure. Severely food insecure participants were less likely to have adherence >=80%. In adjusted analyses, severe food insecurity was associated with a 77% lower odds of viral suppression (95% CI = 0.06–0.82) when controlling for all covariates. In analyses stratified by adherence level, severe food insecurity was associated with an 85% lower odds of viral suppression (95% CI = 0.02–0.99) among those with <=80% adherence and a 66% lower odds among those with >80% adherence (95% CI = 0.06–1.81). Conclusions Food insecurity is present in half of the HIV-positive urban poor in San Francisco, one of the best resourced settings for HIV-positive individuals in the United States, and is associated with incomplete viral suppression. These findings suggest that ensuring access to food should be an integral component of public health HIV programs serving impoverished

A review of licensed viral vaccines, some of their safety concerns, and the advances in the development of investigational viral vaccines.

PubMed

Huang, David B; Wu, Jashin J; Tyring, Stephen K

2004-10-01

Viral vaccines could be considered among the most important medical achievements of the 20th century. They have prevented much suffering and saved many lives. Although some curative antiviral drugs exist, we desperately depend on efforts by academic, governmental and industrial scientists in the advancement of viral vaccines in the prevention and control of infectious diseases. In the next decade, we hope to see advancement in the development of current and investigational viral vaccines against childhood and adult infections. In this article, we will review the licensed viral vaccines, some of their safety concerns, and the advances in the development of investigational viral vaccines.

Mechanism of protection from primary bovine viral diarrhea virus infection. I. The effects of dexamethasone.

PubMed Central

Shope, R E; Muscoplat, C C; Chen, A W; Johnson, D W

1976-01-01

A series of investigations was designed to study the role of cellular immunity and passive antibody in protecting neonatal calves from primary bovine viral diarrhea virus infection. Administration of corticosteroids (dexamethasone) in doses capable of suppressing cellular immunity markedly potentiated systemic bovine viral diarrhea virus infection in calves which lacked bovine viral diarrhea passive neutralizing antibody. Immunosuppressed calves did not form neutralizing antibody to bovine viral diarrhea virus and developed a fatal viremia. Calves with high levels of passive bovine viral diarrhea neutralizing antibodies were protected from the effect of corticosteroids. The results suggest an essential role for humoral passive antibody, but not for cellular immunity, in protection from primary systemic bovine viral diarrhea virus infection in calves. PMID:187303

Innate immune reconstitution with suppression of HIV-1.

PubMed

Scully, Eileen P; Lockhart, Ainsley; Garcia-Beltran, Wilfredo; Palmer, Christine D; Musante, Chelsey; Rosenberg, Eric; Allen, Todd M; Chang, J Judy; Bosch, Ronald J; Altfeld, Marcus

2016-03-17

Progressive HIV-1 infection leads to both profound immune suppression and pathologic inflammation in the majority of infected individuals. While adaptive immune dysfunction, as evidenced by CD4 + T cell depletion and exhaustion, has been extensively studied, less is known about the functional capacity of innate immune cell populations in the context of HIV-1 infection. Given the broad susceptibility to opportunistic infections and the dysregulated inflammation observed in progressive disease, we hypothesized that there would be significant changes in the innate cellular responses. Using a cohort of patients with multiple samplings before and after antiretroviral therapy (ART) initiation, we demonstrated increased responses to innate immune stimuli following viral suppression, as measured by the production of inflammatory cytokines. Plasma viral load itself had the strongest association with this change in innate functional capacity. We further identified epigenetic modifications in the TNFA promoter locus in monocytes that are associated with viremia, suggesting a molecular mechanism for the observed changes in innate immune function following initiation of ART. These data indicate that suppression of HIV-1 viremia is associated with changes in innate cellular function that may in part determine the restoration of protective immune responses.

Innate immune reconstitution with suppression of HIV-1

PubMed Central

Scully, Eileen P.; Garcia-Beltran, Wilfredo; Palmer, Christine D.; Musante, Chelsey; Rosenberg, Eric; Allen, Todd M.; Bosch, Ronald J.

2016-01-01

Progressive HIV-1 infection leads to both profound immune suppression and pathologic inflammation in the majority of infected individuals. While adaptive immune dysfunction, as evidenced by CD4+ T cell depletion and exhaustion, has been extensively studied, less is known about the functional capacity of innate immune cell populations in the context of HIV-1 infection. Given the broad susceptibility to opportunistic infections and the dysregulated inflammation observed in progressive disease, we hypothesized that there would be significant changes in the innate cellular responses. Using a cohort of patients with multiple samplings before and after antiretroviral therapy (ART) initiation, we demonstrated increased responses to innate immune stimuli following viral suppression, as measured by the production of inflammatory cytokines. Plasma viral load itself had the strongest association with this change in innate functional capacity. We further identified epigenetic modifications in the TNFA promoter locus in monocytes that are associated with viremia, suggesting a molecular mechanism for the observed changes in innate immune function following initiation of ART. These data indicate that suppression of HIV-1 viremia is associated with changes in innate cellular function that may in part determine the restoration of protective immune responses. PMID:27158667

Emmprin and KSHV: new partners in viral cancer pathogenesis

PubMed Central

Dai, Lu; Bai, Lihua; Lu, Ying; Xu, Zengguang; Reiss, Krys; Valle, Luis Del; Kaleeba, Johnan; Toole, Bryan P.; Parsons, Chris; Qin, Zhiqiang

2013-01-01

Emmprin (CD147; basigin) is a multifunctional glycoprotein expressed at higher levels by cancer cells and stromal cells in the tumor microenvironment. Through direct effects within tumor cells and promotion of tumor-stroma interactions, emmprin participates in induction of tumor cell invasiveness, angiogenesis, metastasis and chemoresistance. Although its contribution to cancer progression has been widely studied, the role of emmprin in viral oncogenesis still remains largely unclear, and only a small body of available literature implicates emmprin-associated mechanisms in viral pathogenesis and tumorigenesis. We summarize these data in this review, focusing on the role of emmprin in pathogenesis associated with the Kaposi sarcoma-associated herpesvirus (KSHV), a common etiology for cancers arising in the setting of immune suppression. We also discuss future directions for mechanistic studies exploring roles for emmprin in viral cancer pathogenesis. PMID:23743354

The emerging role of nuclear viral DNA sensors.

PubMed

Diner, Benjamin A; Lum, Krystal K; Cristea, Ileana M

2015-10-30

Detecting pathogenic DNA by intracellular receptors termed "sensors" is critical toward galvanizing host immune responses and eliminating microbial infections. Emerging evidence has challenged the dogma that sensing of viral DNA occurs exclusively in sub-cellular compartments normally devoid of cellular DNA. The interferon-inducible protein IFI16 was shown to bind nuclear viral DNA and initiate immune signaling, culminating in antiviral cytokine secretion. Here, we review the newly characterized nucleus-originating immune signaling pathways, their links to other crucial host defenses, and unique mechanisms by which viruses suppress their functions. We frame these findings in the context of human pathologies associated with nuclear replicating DNA viruses. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Immunological features underlying viral hemorrhagic fevers.

PubMed

Messaoudi, Ilhem; Basler, Christopher F

2015-10-01

Several enveloped RNA viruses of the arenavirus, bunyavirus, filovirus and flavivirus families are associated with a syndrome known as viral hemorrhagic fever (VHF). VHF is characterized by fever, vascular leakage, coagulation defects and multi organ system failure. VHF is currently viewed as a disease precipitated by viral suppression of innate immunity, which promotes systemic virus replication and excessive proinflammatory cytokine responses that trigger the manifestations of severe disease. However, the mechanisms by which immune dysregulation contributes to disease remain poorly understood. Infection of nonhuman primates closely recapitulates human VHF, notably Ebola and yellow fever, thereby providing excellent models to better define the immunological basis for this syndrome. Here we review the current state of our knowledge and suggest future directions that will better define the immunological mechanisms underlying VHF. Copyright © 2015 Elsevier Ltd. All rights reserved.

TGF-β Suppression of HBV RNA through AID-Dependent Recruitment of an RNA Exosome Complex

PubMed Central

Kitamura, Kouichi; Wang, Zhe; Chowdhury, Sajeda; Monjurul, Ahasan Md; Wakae, Kousho; Koura, Miki; Shimadu, Miyuki; Kinoshita, Kazuo; Muramatsu, Masamichi

2015-01-01

Transforming growth factor (TGF)-β inhibits hepatitis B virus (HBV) replication although the intracellular effectors involved are not determined. Here, we report that reduction of HBV transcripts by TGF-β is dependent on AID expression, which significantly decreases both HBV transcripts and viral DNA, resulting in inhibition of viral replication. Immunoprecipitation reveals that AID physically associates with viral P protein that binds to specific virus RNA sequence called epsilon. AID also binds to an RNA degradation complex (RNA exosome proteins), indicating that AID, RNA exosome, and P protein form an RNP complex. Suppression of HBV transcripts by TGF-β was abrogated by depletion of either AID or RNA exosome components, suggesting that AID and the RNA exosome involve in TGF-β mediated suppression of HBV RNA. Moreover, AID-mediated HBV reduction does not occur when P protein is disrupted or when viral transcription is inhibited. These results suggest that induced expression of AID by TGF-β causes recruitment of the RNA exosome to viral RNP complex and the RNA exosome degrades HBV RNA in a transcription-coupled manner. PMID:25836330

TRIM proteins: another class of viral victims.

PubMed

Munir, Muhammad

2010-04-20

TRIM (tripartite motif) proteins are a family of RING (really interesting new gene) domain-containing proteins comprising more than 70 human members, with new members still being described. In addition to their involvement in cell proliferation, differentiation, development, morphogenesis, and apoptosis, roles in immune signaling and antiviral functions are emerging. In response to viral infection, TRIM25 ubiquitinates the N terminus of the viral RNA receptor retinoic acid-inducible gene-I (RIG-I), and this modification is essential for RIG-I to interact with its downstream partner mitochondrial antiviral signaling (MAVS). TRIM25 activity thus leads to activation of the RIG-I signaling pathway, which results in type I interferon production to limit viral replication. Recently, it has been demonstrated that influenza A viruses target TRIM25 and disable its antiviral function, thereby suppressing the host interferon response. This Journal Club article highlights the emerging roles of TRIM proteins in antiviral defense mechanisms and an immune evasion strategy in which influenza viruses target a member of the TRIM family.

An International Collaboration To Standardize HIV-2 Viral Load Assays: Results from the 2009 ACHIEV2E Quality Control Study▿

PubMed Central

Damond, F.; Benard, A.; Balotta, Claudia; Böni, Jürg; Cotten, Matthew; Duque, Vitor; Ferns, Bridget; Garson, Jeremy; Gomes, Perpetua; Gonçalves, Fátima; Gottlieb, Geoffrey; Kupfer, Bernd; Ruelle, Jean; Rodes, Berta; Soriano, Vicente; Wainberg, Mark; Taieb, Audrey; Matheron, Sophie; Chene, Genevieve; Brun-Vezinet, Francoise

2011-01-01

Accurate HIV-2 plasma viral load quantification is crucial for adequate HIV-2 patient management and for the proper conduct of clinical trials and international cohort collaborations. This study compared the homogeneity of HIV-2 RNA quantification when using HIV-2 assays from ACHIEV2E study sites and either in-house PCR calibration standards or common viral load standards supplied to all collaborators. Each of the 12 participating laboratories quantified blinded HIV-2 samples, using its own HIV-2 viral load assay and standard as well as centrally validated and distributed common HIV-2 group A and B standards (http://www.hiv.lanl.gov/content/sequence/HelpDocs/subtypes-more.html). Aliquots of HIV-2 group A and B strains, each at 2 theoretical concentrations (2.7 and 3.7 log10 copies/ml), were tested. Intralaboratory, interlaboratory, and overall variances of quantification results obtained with both standards were compared using F tests. For HIV-2 group A quantifications, overall and interlaboratory and/or intralaboratory variances were significantly lower when using the common standard than when using in-house standards at the concentration levels of 2.7 log10 copies/ml and 3.7 log10 copies/ml, respectively. For HIV-2 group B, a high heterogeneity was observed and the variances did not differ according to the type of standard used. In this international collaboration, the use of a common standard improved the homogeneity of HIV-2 group A RNA quantification only. The diversity of HIV-2 group B, particularly in PCR primer-binding regions, may explain the heterogeneity in quantification of this strain. Development of a validated HIV-2 viral load assay that accurately quantifies distinct circulating strains is needed. PMID:21813718

Viral/Nonviral Chimeric Nanoparticles to Synergistically Suppress Leukemia Proliferation via Simultaneous Gene Transduction and Silencing

PubMed Central

Hong, Cheol Am; Cho, Soo Kyung; Edson, Julius A.; Kim, Jane; Ingato, Dominique; Pham, Bryan; Chuang, Anthony; Fruman, David; Kwon, Young Jik

2017-01-01

Single modal cancer therapy that targets one pathological pathway often turns out to be inefficient. For example, relapse of Chronic Myelogenous Leukemia (CML) after inhibiting BCR-ABL fusion protein using tyrosine kinase inhibitors (TKI) (e.g., Imatinib) is of significant clinical concern. This study developed a dual modal gene therapy that simultaneously tackles two key BCR-ABL-linked pathways using viral/nonviral chimeric nanoparticles (ChNPs). Consisting of an adeno-associated virus (AAV) core and an acid-degradable polymeric shell, the ChNPs were designed to simultaneously induce pro-apoptotic BIM expression by the AAV core and silence pro-survival MCL-1 by the small interfering RNA (siRNA) encapsulated in the shell. The resulting BIM/MCL-1 ChNPs were able to efficiently suppress the proliferation of BCR-ABL+ K562 and FL5.12/p190 cells in vitro and in vivo via simultaneously expressing BIM and silencing MCL-1. Interestingly, the synergistic anti-leukemic effects generated by BIM/MCL-1 ChNPs were specific to BCR-ABL+ cells and independent of a proliferative cytokine, IL-3. The AAV core of ChNPs was efficiently shielded from inactivation by anti-AAV serum and avoided the generation of anti-AAV serum, without acute toxicity. This study demonstrates the development of a synergistically efficient, specific, and safe therapy for leukemia using gene carriers that simultaneously manipulate multiple and inter-linked pathological pathways. PMID:27472284

Brain Macrophages in Simian Immunodeficiency Virus-Infected, Antiretroviral-Suppressed Macaques: a Functional Latent Reservoir.

PubMed

Avalos, Claudia R; Abreu, Celina M; Queen, Suzanne E; Li, Ming; Price, Sarah; Shirk, Erin N; Engle, Elizabeth L; Forsyth, Ellen; Bullock, Brandon T; Mac Gabhann, Feilim; Wietgrefe, Stephen W; Haase, Ashley T; Zink, M Christine; Mankowski, Joseph L; Clements, Janice E; Gama, Lucio

2017-08-15

A human immunodeficiency virus (HIV) infection cure requires an understanding of the cellular and anatomical sites harboring virus that contribute to viral rebound upon treatment interruption. Despite antiretroviral therapy (ART), HIV-associated neurocognitive disorders (HAND) are reported in HIV-infected individuals on ART. Biomarkers for macrophage activation and neuronal damage in cerebrospinal fluid (CSF) of HIV-infected individuals demonstrate continued effects of HIV in brain and suggest that the central nervous system (CNS) may serve as a viral reservoir. Using a simian immunodeficiency virus (SIV)/macaque model for HIV encephalitis and AIDS, we evaluated whether infected cells persist in brain despite ART. Eight SIV-infected pig-tailed macaques were virally suppressed with ART, and plasma and CSF viremia levels were analyzed longitudinally. To assess whether virus persisted in brain macrophages (BrMΦ) in these macaques, we used a macrophage quantitative viral outgrowth assay (MΦ-QVOA), PCR, and in situ hybridization (ISH) to measure the frequency of infected cells and the levels of viral RNA and DNA in brain. Viral RNA in brain tissue of suppressed macaques was undetectable, although viral DNA was detected in all animals. The MΦ-QVOA demonstrated that the majority of suppressed animals contained latently infected BrMΦ. We also showed that virus produced in the MΦ-QVOAs was replication competent, suggesting that latently infected BrMΦ are capable of reestablishing productive infection upon treatment interruption. This report provides the first confirmation of the presence of replication-competent SIV in BrMΦ of ART-suppressed macaques and suggests that the highly debated issue of viral latency in macrophages, at least in brain, has been addressed in SIV-infected macaques treated with ART. IMPORTANCE Resting CD4 + T cells are currently the only cells that fit the definition of a latent reservoir. However, recent evidence suggests that HIV

Emmprin and KSHV: new partners in viral cancer pathogenesis.

PubMed

Dai, Lu; Bai, Lihua; Lu, Ying; Xu, Zengguang; Reiss, Krys; Del Valle, Luis; Kaleeba, Johnan; Toole, Bryan P; Parsons, Chris; Qin, Zhiqiang

2013-09-01

Emmprin (CD147; basigin) is a multifunctional glycoprotein expressed at higher levels by cancer cells and stromal cells in the tumor microenvironment. Through direct effects within tumor cells and promotion of tumor-stroma interactions, emmprin participates in induction of tumor cell invasiveness, angiogenesis, metastasis and chemoresistance. Although its contribution to cancer progression has been widely studied, the role of emmprin in viral oncogenesis still remains largely unclear, and only a small body of available literature implicates emmprin-associated mechanisms in viral pathogenesis and tumorigenesis. We summarize these data in this review, focusing on the role of emmprin in pathogenesis associated with the Kaposi sarcoma-associated herpesvirus (KSHV), a common etiology for cancers arising in the setting of immune suppression. We also discuss future directions for mechanistic studies exploring roles for emmprin in viral cancer pathogenesis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Effects of treatment with suppressive combination antiretroviral drug therapy and the histone deacetylase inhibitor suberoylanilide hydroxamic acid; (SAHA) on SIV-infected Chinese rhesus macaques.

PubMed

Ling, Binhua; Piatak, Michael; Rogers, Linda; Johnson, Ann-Marie; Russell-Lodrigue, Kasi; Hazuda, Daria J; Lifson, Jeffrey D; Veazey, Ronald S

2014-01-01

Viral reservoirs-persistent residual virus despite combination antiretroviral therapy (cART)-remain an obstacle to cure of HIV-1 infection. Difficulty studying reservoirs in patients underscores the need for animal models that mimics HIV infected humans on cART. We studied SIV-infected Chinese-origin rhesus macaques (Ch-RM) treated with intensive combination antiretroviral therapy (cART) and 3 weeks of treatment with the histone deacetyalse inhibitor, suberoylanilide hydroxamic acid (SAHA). SIVmac251 infected Ch-RM received reverse transcriptase inhibitors PMPA and FTC and integrase inhibitor L-870812 beginning 7 weeks post infection. Integrase inhibitor L-900564 and boosted protease inhibitor treatment with Darunavir and Ritonavir were added later. cART was continued for 45 weeks, with daily SAHA administered for the last 3 weeks, followed by euthanasia/necropsy. Plasma viral RNA and cell/tissue-associated SIV gag RNA and DNA were quantified by qRT-PCR/qPCR, with flow cytometry monitoring changes in immune cell populations. Upon cART initiation, plasma viremia declined, remaining <30 SIV RNA copy Eq/ml during cART, with occasional blips. Decreased viral replication was associated with decreased immune activation and partial restoration of intestinal CD4+ T cells. SAHA was well tolerated but did not result in demonstrable treatment-associated changes in plasma or cell associated viral parameters. The ability to achieve and sustain virological suppression makes cART-suppressed, SIV-infected Ch-RM a potentially useful model to evaluate interventions targeting residual virus. However, despite intensive cART over one year, persistent viral DNA and RNA remained in tissues of all three animals. While well tolerated, three weeks of SAHA treatment did not demonstrably impact viral RNA levels in plasma or tissues; perhaps reflecting dosing, sampling and assay limitations.

A CD4+ cell count <200 cells per cubic millimeter at 2 years after initiation of combination antiretroviral therapy is associated with increased mortality in HIV-infected individuals with viral suppression.

PubMed

Loutfy, Mona R; Genebat, Miguel; Moore, David; Raboud, Janet; Chan, Keith; Antoniou, Tony; Milan, David; Shen, Anya; Klein, Marina B; Cooper, Curtis; Machouf, Nima; Rourke, Sean B; Rachlis, Anita; Tsoukas, Chris; Montaner, Julio S G; Walmsley, Sharon L; Smieja, Marek; Bayoumi, Ahmed; Mills, Edward; Hogg, Robert S

2010-12-01

To determine the long-term impact of immunologic discordance (viral load <50 copies/mL and CD4+ count <=200 cells/mm3) in antiretroviral-naive patients initiating combination antiretroviral therapy (cART). Our analysis included antiretroviral-naive individuals from a population-based Canadian Observational Cohort that initiated cART after January 1, 2000, and achieved virologic suppression. Multivariable Cox proportional hazards regression was used to examine the association between 1-year and 2-year immunologic discordance and time to death from all-causes. Correlates of immunologic discordance were assessed with logistic regression. Immunologic discordance was observed in 19.9% (404 of 2028) and 10.2% (176 of 1721) of individuals at 1 and 2 years after cART initiation, respectively. Two-year immunologic discordance was associated with an increased risk of death [adjusted hazard ratio = 2.69; 95% confidence interval (CI): 1.26 to 5.78]. One-year immunologic discordance was not associated with death (adjusted hazard ratio = 1.12; 95% CI: 0.54 to 2.30). Two-year immunologic discordance was associated with older age (aOR per decade = 1.23; 95% CI: 1.03 to 1.48), male gender (aOR = 1.86; 95% CI: 1.09 to 3.16), injection drug use (aOR = 2.75; 95% CI: 1.81 to 4.17), and lower baseline CD4+ count (aOR per 100 cells = 0.24; 95% CI: 0.19 to 0.31) and viral load (aOR per log10 copies/mL = 0.46; 95% CI: 0.33 to 0.65). Immunologic discordance after 2 years of cART in antiretroviral-naive individuals was significantly associated with an increased risk of mortality.

Elimination of antiviral defense by viral RNase III

PubMed Central

Cuellar, Wilmer J.; Kreuze, Jan F.; Rajamäki, Minna-Liisa; Cruzado, Karin R.; Untiveros, Milton; Valkonen, Jari P. T.

2009-01-01

Sweet potato (Ipomoea batatas) is an important subsistence and famine reserve crop grown in developing countries where Sweet potato chlorotic stunt virus (SPCSV; Closteroviridae), a single-stranded RNA (ssRNA) crinivirus, synergizes unrelated viruses in co-infected sweet potato plants. The most severe disease and yield losses are caused by co-infection with SPCSV and a potyvirus, Sweet potato feathery mottle virus (SPFMV; Potyviridae). Potyviruses synergize unrelated viruses by suppression of RNA silencing with the P1/HC-Pro polyprotein; however, the SPCSV-SPFMV synergism is unusual in that the potyvirus is the beneficiary. Our data show that transformation of an SPFMV-resistant sweet potato variety with the double-stranded RNA (dsRNA)-specific class 1 RNA endoribonuclease III (RNase3) of SPCSV broke down resistance to SPFMV, leading to high accumulation of SPFMV antigen and severe disease symptoms similar to the synergism in plants co-infected with SPCSV and SPFMV. RNase3-transgenic sweet potatoes also accumulated higher concentrations of 2 other unrelated viruses and developed more severe symptoms than non-transgenic plants. In leaves, RNase3 suppressed ssRNA-induced gene silencing (RNAi) in an endonuclease activity-dependent manner. It cleaved synthetic double-stranded small interfering RNAs (siRNAs) of 21, 22, and 24 bp in vitro to products of approximately 14 bp that are inactive in RNAi. It also affected total siRNA isolated from SPFMV-infected sweet potato plants, suggesting a viral mechanism for suppression of RNAi by cleavage of siRNA. Results implicate RNase3 in suppression of antiviral defense in sweet potato plants and reveal RNase3 as a protein that mediates viral synergism with several unrelated viruses, a function previously described only for P1/HC-Pro. PMID:19515815

Measles virus induces persistent infection by autoregulation of viral replication.

PubMed

Doi, Tomomitsu; Kwon, Hyun-Jeong; Honda, Tomoyuki; Sato, Hiroki; Yoneda, Misako; Kai, Chieko

2016-11-24

Natural infection with measles virus (MV) establishes lifelong immunity. Persistent infection with MV is likely involved in this phenomenon, as non-replicating protein antigens never induce such long-term immunity. Although MV establishes stable persistent infection in vitro and possibly in vivo, the mechanism by which this occurs is largely unknown. Here, we demonstrate that MV changes the infection mode from lytic to non-lytic and evades the innate immune response to establish persistent infection without viral genome mutation. We found that, in the persistent phase, the viral RNA level declined with the termination of interferon production and cell death. Our analysis of viral protein dynamics shows that during the establishment of persistent infection, the nucleoprotein level was sustained while the phosphoprotein and large protein levels declined. The ectopic expression of nucleoprotein suppressed viral replication, indicating that viral replication is self-regulated by nucleoprotein accumulation during persistent infection. The persistently infected cells were able to produce interferon in response to poly I:C stimulation, suggesting that MV does not interfere with host interferon responses in persistent infection. Our results may provide mechanistic insight into the persistent infection of this cytopathic RNA virus that induces lifelong immunity.

Estimating antiretroviral treatment coverage rates and viral suppression rates for homosexual men in Australia

PubMed Central

De La Mata, Nicole L.; Mao, Limin; De Wit, John; Smith, Don; Holt, Martin; Prestage, Garrett; Wilson, David P.; Petoumenos, Kathy

2016-01-01

Gay and other men who have sex with men (GMSM) are disproportionally affected by the HIV epidemic in Australia. The study objective is to combine a clinical-based cohort with a community-based surveillance system to present a broader representation of the GMSM community to determine estimates of proportions receiving antiretroviral therapy (ART) and/or with an undetectable viral load. Between 2010 and 2012, small increases were shown in ART uptake (to 70.2%) and proportions with undetectable viral load (to 62.4%). The study findings highlight the potential for significantly increasing ART uptake among HIV-positive GMSM to reduce the HIV epidemic in Australia. PMID:26166247

My Cousin, My Enemy: quasispecies suppression of drug resistance

PubMed Central

Kirkegaard, Karla; van Buuren, Nicholas J; Mateo, Roberto

2017-01-01

If a freshly minted genome contains a mutation that confers drug resistance, will it be selected in the presence of the drug? Not necessarily. During viral infections, newly synthesized viral genomes occupy the same cells as parent and other progeny genomes. If the antiviral target is chosen so that the drug-resistant progeny’s growth is dominantly inhibited by the drug-susceptible members of its intracellular family, its outgrowth can be suppressed. Precedent for ‘dominant drug targeting’ as a deliberate approach to suppress the outgrowth of inhibitor-resistant viruses has been established for envelope variants of vesicular stomatitis virus and for capsid variants of poliovirus and dengue virus. Small molecules that stabilize oligomeric assemblages are a promising means to an unfit family to destroy the effectiveness of a newborn drug-resistant relative due to the co-assembly of drug-susceptible and drug-resistant monomers. PMID:27764731

Achieving NHAS 90/90/80 Objectives by 2020: An Interactive Tool Modeling Local HIV Prevalence Projections.

PubMed

Kelly, Jane M; Kelly, Scott D; Wortley, Pascale M; Drenzek, Cherie L

2016-01-01

Tools using local HIV data to help jurisdictions estimate future demand for medical and support services are needed. We present an interactive prevalence projection model using data obtainable from jurisdictional HIV surveillance and publically available data. Using viral load data from Georgia's enhanced HIV/AIDS Reporting System, state level death rates for people living with HIV and the general population, and published estimates for HIV transmission rates, we developed a model for projecting future HIV prevalence. Keeping death rates and HIV transmission rates for undiagnosed, in care/viral load >200, in care/viral load<200, and out of care (no viral load for 12 months) constant, we describe results from simulations with varying inputs projecting HIV incidence and prevalence from 2014 to 2024. In this model, maintaining Georgia's 2014 rates for diagnosis, transitions in care, viral suppression (VS), and mortality by sub-group through 2020, resulted in 85% diagnosed, 59% in care, and 44% VS among diagnosed (85%/58%/44%) with a total of 67 815 PLWH, 33 953 in care, and more than 1000 new cases per year by 2020. Neither doubling the diagnosis rate nor tripling rates of re-engaging out of care PLWH into care alone were adequate to reach 90/90/80 by 2020. We demonstrate a multicomponent scenario that achieved NHAS goals and resulted in 63 989 PLWH, 57 546 in care, and continued annual prevalence increase through 2024. Jurisdictions can use this HIV prevalence prediction tool, accessible at https://dph.georgia.gov/hiv-prevalence-projections to assess local capacity to meet future HIV care and social services needs. In this model, achieving 90/90/80 by 2020 in Georgia slowed but did not reverse increases in HIV prevalence, and the number of HIV-infected persons needing care and support services more than doubled. Improving the HIV care infrastructure is imperative.

Respiratory viral infection in obliterative airway disease after orthotopic tracheal transplantation.

PubMed

Kuo, Elbert; Bharat, Ankit; Goers, Trudie; Chapman, Will; Yan, Le; Street, Tyler; Lu, Wei; Walter, Michael; Patterson, Alexander; Mohanakumar, Thalachallour

2006-09-01

The long-term survival after human lung transplantation is limited by bronchiolitis obliterans syndrome (BOS). Clinically, community-acquired respiratory viral infections have been correlated with an increased incidence of BOS. The goal of this study was to investigate the role of respiratory viral infections in chronic lung allograft rejection using the murine orthotopic tracheal transplantation model. Eighty orthotopic tracheal transplants were performed using BALB/c and C57BL/6 mice. Recipient mice were infected intranasally with Sendai virus (SdV), a murine parainfluenza type I virus. Experiments altering the infectious dose, infection time, harvest time, allogeneic response, and viral response were performed. Tracheal allograft rejection was monitored using percent fibrosis and lamina propria to cartilage ratio measurements. Interferon-gamma ELISPOT analysis against irradiated donor (BALB/c) splenocytes was used as immunologic indicator of alloreactivity after transplantation. Sendai virus infection revealed a dose-dependent transient suppression of alloreactivity with a decrease in tracheal allograft fibrosis and frequency of alloreactive T cells at 30 days. This immunosuppression was reversed by day 60, leading to increased tracheal allograft fibrosis with a concomitant increase in the frequency of interferon-gamma producing alloreactive T cells. Pretransplant sensitization with donor antigens prevented the initial suppression of alloreactivity due to SdV infection. Furthermore, pretransplant immunization against SdV infection resulted in rapid clearing of the infection and reduced the immunopathology of rejection. Respiratory viral infections can cause enhanced tracheal allograft rejection despite the initial phase of transient immunosuppression. Early treatment or vaccination against the respiratory infections may represent a viable intervention to reduce the risk of chronic rejection.

Continuous Retention and Viral Suppression Provide Further Insights Into the HIV Care Continuum Compared to the Cross-sectional HIV Care Cascade.

PubMed

Colasanti, Jonathan; Kelly, Jane; Pennisi, Eugene; Hu, Yi-Juan; Root, Christin; Hughes, Denise; Del Rio, Carlos; Armstrong, Wendy S

2016-03-01

The human immunodeficiency virus (HIV) care continuum has become an important tool for evaluating HIV care. Current depictions of the care continuum are often cross-sectional and evaluate retention and viral suppression (VS) in a single year, yet the National HIV/AIDS Strategy calls for programs with long-lasting outcomes. Retrospective chart review of HIV-infected patients enrolled in a large, urban clinic in 2010 followed longitudinally for 36 months. McNemar comparisons and logistic regression analyses were conducted to evaluate covariate association with continuous retention and VS. Generalized estimating equation log-linear models were used to integrate time into the model. Among 655 patients (77% male, 83% black, 54% men who have sex with men (MSM), 78% uninsured) continuous retention/VS at 12 months (84%/64%), 24 months (60%/48%), and 36 months (49%/39%) showed significant attrition (P < .0001) over time. Continuous retention was associated with prevalent VS at the end of 36 months (adjusted prevalence ratio 3.12; 95% confidence interval [CI], 2.40, 4.07). 12-month retention for black (84%) and nonblack (85%) patients was equivalent, yet fewer blacks (46%) than nonblacks (63%) achieved 36-month continuous retention due to a significant interaction between race and time (aOR 0.75, 95% CI, .59, .95). Continuous retention is a critically important measure of long-term success in HIV treatment and the crucial component of successful treatment-as-prevention but is infrequently evaluated. Single cross-sections may overestimate successful retention and virologic outcomes. A longitudinal HIV care continuum provides greater insight into long-term outcomes and exposes disparities not evident with traditional cross-sectional care continua. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

Sweden, the first country to achieve the Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO) 90-90-90 continuum of HIV care targets.

PubMed

Gisslén, M; Svedhem, V; Lindborg, L; Flamholc, L; Norrgren, H; Wendahl, S; Axelsson, M; Sönnerborg, A

2017-04-01

The Joint United Nations Programme on HIV/AIDS (UNAIDS)/World Health Organization (WHO) 90-90-90 goals propose that 90% of all people living with HIV should know their HIV status, 90% of those diagnosed should receive antiretroviral therapy (ART), and 90% of those should have durable viral suppression. We have estimated the continuum of HIV care for the entire HIV-1-infected population in Sweden. The Swedish InfCare HIV Cohort Study collects viral loads, CD4 counts, and viral sequences, along with demographic and clinical data, through an electronic clinical decision support system. Almost 100% of those diagnosed with HIV infection are included in the database, corresponding to 6946 diagnosed subjects living with HIV-1 in Sweden by 31 December 2015. Using HIV surveillance data reported to the Public Health Agency of Sweden, it was estimated that 10% of all HIV-infected subjects in Sweden remain undiagnosed. Among all diagnosed patients, 99.8% were linked to care and 97.1% of those remained in care. On 31 December 2015, 6605 of 6946 patients (95.1%) were on ART. A total of 6395 had been on treatment for at least 6 months and 6053 of those (94.7%) had a viral load < 50 HIV-1 RNA copies/mL. The 2014 UNAIDS/WHO 90-90-90 goals for HIV care means that > 73% of all patients living with HIV should be virologically suppressed by 2020. Sweden has already achieved this target, with 78% suppression, and is the first country reported to meet all the UNAIDS/WHO 90-90-90 goals. © 2016 The Authors. HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association.

MicroRNA-like viral small RNA from porcine reproductive and respiratory syndrome virus negatively regulates viral replication by targeting the viral nonstructural protein 2.

PubMed

Li, Na; Yan, Yunhuan; Zhang, Angke; Gao, Jiming; Zhang, Chong; Wang, Xue; Hou, Gaopeng; Zhang, Gaiping; Jia, Jinbu; Zhou, En-Min; Xiao, Shuqi

2016-12-13

Many viruses encode microRNAs (miRNAs) that are small non-coding single-stranded RNAs which play critical roles in virus-host interactions. Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically impactful viruses in the swine industry. The present study sought to determine whether PRRSV encodes miRNAs that could regulate PRRSV replication. Four viral small RNAs (vsRNAs) were mapped to the stem-loop structures in the ORF1a, ORF1b and GP2a regions of the PRRSV genome by bioinformatics prediction and experimental verification. Of these, the structures with the lowest minimum free energy (MFE) values predicted for PRRSV-vsRNA1 corresponded to typical stem-loop, hairpin structures. Inhibition of PRRSV-vsRNA1 function led to significant increases in viral replication. Transfection with PRRSV-vsRNA1 mimics significantly inhibited PRRSV replication in primary porcine alveolar macrophages (PAMs). The time-dependent increase in the abundance of PRRSV-vsRNA1 mirrored the gradual upregulation of PRRSV RNA expression. Knockdown of proteins associated with cellular miRNA biogenesis demonstrated that Drosha and Argonaute (Ago2) are involved in PRRSV-vsRNA1 biogenesis. Moreover, PRRSV-vsRNA1 bound specifically to the nonstructural protein 2 (NSP2)-coding sequence of PRRSV genome RNA. Collectively, the results reveal that PRRSV encodes a functional PRRSV-vsRNA1 which auto-regulates PRRSV replication by directly targeting and suppressing viral NSP2 gene expression. These findings not only provide new insights into the mechanism of the pathogenesis of PRRSV, but also explore a potential avenue for controlling PRRSV infection using viral small RNAs.

The RNA Exosome Syncs IAV-RNAPII Transcription to Promote Viral Ribogenesis and Infectivity.

PubMed

Rialdi, Alexander; Hultquist, Judd; Jimenez-Morales, David; Peralta, Zuleyma; Campisi, Laura; Fenouil, Romain; Moshkina, Natasha; Wang, Zhen Zhen; Laffleur, Brice; Kaake, Robyn M; McGregor, Michael J; Haas, Kelsey; Pefanis, Evangelos; Albrecht, Randy A; Pache, Lars; Chanda, Sumit; Jen, Joanna; Ochando, Jordi; Byun, Minji; Basu, Uttiya; García-Sastre, Adolfo; Krogan, Nevan; van Bakel, Harm; Marazzi, Ivan

2017-05-04

The nuclear RNA exosome is an essential multi-subunit complex that controls RNA homeostasis. Congenital mutations in RNA exosome genes are associated with neurodegenerative diseases. Little is known about the role of the RNA exosome in the cellular response to pathogens. Here, using NGS and human and mouse genetics, we show that influenza A virus (IAV) ribogenesis and growth are suppressed by impaired RNA exosome activity. Mechanistically, the nuclear RNA exosome coordinates the initial steps of viral transcription with RNAPII at host promoters. The viral polymerase complex co-opts the nuclear RNA exosome complex and cellular RNAs en route to 3' end degradation. Exosome deficiency uncouples chromatin targeting of the viral polymerase complex and the formation of cellular:viral RNA hybrids, which are essential RNA intermediates that license transcription of antisense genomic viral RNAs. Our results suggest that evolutionary arms races have shaped the cellular RNA quality control machinery. Copyright © 2017 Elsevier Inc. All rights reserved.

Mutagenesis-Mediated Decrease of Pathogenicity as a Feature of the Mutant Spectrum of a Viral Population

PubMed Central

Sanz-Ramos, Marta; Rodríguez-Calvo, Teresa; Sevilla, Noemí

2012-01-01

Background RNA virus populations are heterogeneous ensembles of closely related genomes termed quasispecies. This highly complex distribution of variants confers important properties to RNA viruses and influences their pathogenic behavior. It has been hypothesized that increased mutagenesis of viral populations, by treatment with mutagenic agents, can induce alterations in the pathogenic potential of a virus population. In this work we investigate whether mutagenized foot-and-mouth disease virus (FMDV) populations display changes in their virulence in mice. Methodology and Principal Findings FMDV C-S8c1 was passaged in BHK cells in the presence of the mutagenic agent ribavirin. Decline in viral titer and viral RNA progeny was observed in the first passage, fluctuating around a constant value thereafter. Hence, the specific infectivity remained stable during the passages. The viral population harvested from passage 9 (P9 R) showed decreased virulence in mice, with a lethal dose 50 (LD50) >104 PFU, as compared with LD50 of 50 PFU of the parental population FMDV C-S8c1. This decrease in virulence was associated to a 20-fold increase in the mutation frequency of the P9 R population with respect to C-S8c1. Interestingly, individual biological clones isolated from the attenuated population P9 R were as virulent as the parental virus C-S8c1. Furthermore, a mixed population of C-S8c1 and P9 R was inoculated into mice and showed decreased virulence as compared to C-S8c1, suggesting that population P9 R is able to suppress the virulent phenotype of C-S8c1. Conclusion Ribavirin-mediated mutagenesis of an FMDV population resulted in attenuation in vivo, albeit a large proportion of its biological clones displayed a highly virulent phenotype. These results, together with the suppression of C-S8c1 by mutagenized P9 R population, document a suppressive effect of mutagenized viral quasispecies in vivo, and suggest novel approaches to the treatment and prevention of viral diseases

Suppression of human immunodeficiency virus type 1 activity in vitro by oligonucleotides which form intramolecular tetrads.

PubMed

Rando, R F; Ojwang, J; Elbaggari, A; Reyes, G R; Tinder, R; McGrath, M S; Hogan, M E

1995-01-27

An oligonucleotide (I100-15) composed of only deoxyguanosine and thymidine was able to inhibit human immunodeficiency virus type-1 (HIV-1) in culture assay systems. I100-15 did not block virus entry into cells but did reduce viral-specific transcripts. As assessed by NMR and polyacrylamide gel methods, I100-15 appears to form a structure in which two stacked guanosine tetrads are connected by three two-base long loops. Structure/activity experiments indicated that formation of intramolecular guanosine tetrads was necessary to achieve maximum antiviral activity. The single deoxyguanosine nucleotide present in each loop was found to be extremely important for the overall antiviral activity. The toxicity of I100-15 was determined to be well above the 50% effective dose (ED50) in culture which yielded a high therapeutic index (> 100). The addition of a cholesterol moiety to the 3' terminus of I100-15 (I100-23) reduced the ED50 value to less than 50 nM (from 0.12 microM for I100-15) and increased the duration of viral suppression to greater than 21 days (versus 7-10 days for I100-15) after removal of the drug from infected cell cultures. The favorable therapeutic index of such molecules coupled with the prolonged suppression of HIV-1, suggest that such compounds further warrant investigation as potential therapeutic agents.

Thousands of Viral Populations Recovered from Peatland Soil Metagenomes Reveal Viral Impacts on Carbon Cycling in Thawing Permafrost

NASA Astrophysics Data System (ADS)

Emerson, J. B.; Brum, J. R.; Roux, S.; Bolduc, B.; Woodcroft, B. J.; Singleton, C. M.; Boyd, J. A.; Hodgkins, S. B.; Wilson, R.; Trubl, G. G.; Jang, H. B.; Crill, P. M.; Chanton, J.; Saleska, S. R.; Rich, V. I.; Tyson, G. W.; Sullivan, M. B.

2016-12-01

Methane and carbon dioxide emissions, which are under significant microbial control, provide positive feedbacks to climate change in thawing permafrost peatlands. Although viruses in marine systems have been shown to impact microbial ecology and biogeochemical cycling through host cell lysis, horizontal gene transfer, and auxiliary metabolic gene expression, viral ecology in permafrost and other soils remains virtually unstudied due to methodological challenges. Here, we identified viral sequences in 208 assembled bulk soil metagenomes derived from a permafrost thaw gradient in Stordalen Mire, northern Sweden, from 2010-2012. 2,048 viral populations were recovered, which genome- and network-based classification revealed to be largely novel, increasing known viral genera globally by 40%. Ecologically, viral communities differed significantly across the thaw gradient and by soil depth. Co-occurring microbial community composition, soil moisture, and pH were predictors of viral community composition, indicative of biological and biogeochemical feedbacks as permafrost thaws. Host prediction—achieved through clustered regularly interspaced short palindromic repeats (CRISPRs), tetranucleotide frequency patterns, and other sequence similarities to binned microbial population genomes—was able to link 38% of the viral populations to a microbial host. 5% of the implicated hosts were archaea, predominantly methanogens and ammonia-oxidizing Nitrososphaera, 45% were Acidobacteria or Verrucomicrobia (mostly predicted heterotrophic complex carbon degraders), and 21% were Proteobacteria, including methane oxidizers. Recovered viral genome fragments also contained auxiliary metabolic genes involved in carbon and nitrogen cycling. Together, these data reveal multiple levels of previously unknown viral contributions to biogeochemical cycling, including to carbon gas emissions, in peatland soils undergoing and contributing to climate change. This work represents a significant step

Epidemiological impact of achieving UNAIDS 90-90-90 targets for HIV care in India: a modelling study.

PubMed

Maddali, Manoj V; Gupta, Amita; Shah, Maunank

2016-07-07

Recent UNAIDS '90-90-90' targets propose that to end the HIV epidemic by 2030, 90% of persons living with HIV (PLWH) worldwide should know their diagnosis, 90% of diagnosed PLWH should be on antiretroviral therapy (ART) and 90% of PLWH on ART should be virally suppressed by 2020. We sought to quantify the epidemiological impact of achieving these targets in India. We constructed a dynamic-transmission model of the Indian HIV epidemic to project HIV infections and AIDS-related deaths that would occur in India over 15 years. We considered several scenarios: continuation of current care engagement (with early ART initiation), achieving 90-90-90 targets on time and delaying achievement by 5 or 10 years. In the base case, assuming continuation of current care engagement, we project 794 000 (95% uncertainty range (UR) 571 000-1 104 000) HIV infections and 689 000 (95% UR 468 000-976 000) AIDS-related deaths in India over 15 years. In this scenario, nearly half of PLWH diagnosed would fail to achieve viral suppression by 2030. With achievement of 90-90-90 targets, India could avert 392 000 (95% UR 248 000-559 000) transmissions (48% reduction) and 414 000 (95% UR 260 000-598 000) AIDS-related deaths (59% reduction) compared to the base-case scenario. Furthermore, fewer than 20 000 (95% UR 12 000-30 000) HIV infections would occur in 2030. Delaying achievement of targets resulted in a similar reduction in HIV incidence by 2030 but at the cost of excess overall infections and mortality. India can halve the epidemiological burden of HIV over 15 years with achievement of the UNAIDS 90-90-90 targets. Reaching the targets on time will require comprehensive healthcare strengthening, especially in early diagnosis and treatment, expanded access to second-line and third-line ART and long-term retention in care. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Crimean-Congo Hemorrhagic Fever Virus Suppresses Innate Immune Responses via a Ubiquitin and ISG15 Specific Protease.

PubMed

Scholte, Florine E M; Zivcec, Marko; Dzimianski, John V; Deaton, Michelle K; Spengler, Jessica R; Welch, Stephen R; Nichol, Stuart T; Pegan, Scott D; Spiropoulou, Christina F; Bergeron, Éric

2017-09-05

Antiviral responses are regulated by conjugation of ubiquitin (Ub) and interferon-stimulated gene 15 (ISG15) to proteins. Certain classes of viruses encode Ub- or ISG15-specific proteases belonging to the ovarian tumor (OTU) superfamily. Their activity is thought to suppress cellular immune responses, but studies demonstrating the function of viral OTU proteases during infection are lacking. Crimean-Congo hemorrhagic fever virus (CCHFV, family Nairoviridae) is a highly pathogenic human virus that encodes an OTU with both deubiquitinase and deISGylase activity as part of the viral RNA polymerase. We investigated CCHFV OTU function by inactivating protease catalytic activity or by selectively disrupting its deubiquitinase and deISGylase activity using reverse genetics. CCHFV OTU inactivation blocked viral replication independently of its RNA polymerase activity, while deubiquitinase activity proved critical for suppressing the interferon responses. Our findings provide insights into viral OTU functions and support the development of therapeutics and vaccines. Published by Elsevier Inc.

Mortality of treated HIV-1 positive individuals according to viral subtype in Europe and Canada: collaborative cohort analysis.

PubMed

2016-01-28

To estimate prognosis by viral subtype in HIV-1-infected individuals from start of antiretroviral therapy (ART) and after viral failure. Collaborative analysis of data from eight European and three Canadian cohorts. Adults (N>20 000) who started triple ART between 1996 and 2012 and had data on viral subtype were followed for mortality. We estimated crude and adjusted (for age, sex, regimen, CD4 cell count, and AIDS at baseline, period of starting ART, stratified by cohort, region of origin and risk group) mortality hazard ratios (MHR) by subtype. We estimated MHR subsequent to viral failure defined as two HIV-RNA measurements greater than 500 copies/ml after achieving viral suppression. The most prevalent subtypes were B (15 419; 74%), C (2091; 10%), CRF02AG (1057; 5%), A (873; 4%), CRF01AE (506; 2.4%), G (359; 1.7%), and D (232; 1.1%). Subtypes were strongly patterned by region of origin and risk group. During 104 649 person-years of observation, 1172/20 784 patients died. Compared with subtype B, mortality was higher for subtype A, but similar for all other subtypes. MHR for A versus B were 1.13 (95% confidence interval 0.85,1.50) when stratified by cohort, increased to 1.78 (1.27,2.51) on stratification by region and risk, and attenuated to 1.59 (1.14,2.23) on adjustment for covariates. MHR for A versus B was 2.65 (1.64,4.28) and 0.95 (0.57,1.57) for patients who started ART with CD4 cell count below, or more than, 100 cells/μl, respectively. There was no difference in mortality between subtypes A, B and C after viral failure. Patients with subtype A had worse prognosis, an observation which may be confounded by socio-demographic factors.

Neuropathogenesis of HIV-associated neurocognitive disorders: roles for immune activation, HIV blipping and viral tropism.

PubMed

Chen, Maria F; Gill, Alexander J; Kolson, Dennis L

2014-11-01

The purpose of this study is to discuss why HIV-associated neurocognitive disorders (HAND) persist despite apparently effective HIV suppression by highly active antiretroviral therapy (ART). As many as 50% of HIV-infected individuals suffer from HAND despite ART suppression of HIV replication to apparently undetectable levels in most treated individuals. Prior to ART, HIV-associated dementia (HAD), the severest form of HAND, affected nearly 20% of infected individuals; HAD now affects only nearly 2% of ART-treated persons, although less severe HAND forms persist. Recent studies link persistent immune activation, inflammation and viral escape/blipping in ART-treated individuals, as well as comorbid conditions, to HIV disease progression and increased HAND risk. Despite sustained HIV suppression in most ART-treated individuals, indicated by routine plasma monitoring and occasional cerebrospinal fluid (CSF) monitoring, 'blips' of HIV replication are often detected with more frequent monitoring, thus challenging the concept of viral suppression. Although the causes of HIV blipping are unclear, CSF HIV blipping associates with neuroinflammation and, possibly, central nervous system (CNS) injury. The current theory that macrophage-tropic HIV strains within the CNS predominate in driving HAND and these associated factors is now also challenged. Protection of the CNS by ART is incomplete, probably due to combined effects of incomplete HIV suppression, persistent immune activation and host comorbidity factors. Adjunctive therapies to ART are necessary for more effective protection.

Differential impact of transplantation on peripheral and tissue-associated viral reservoirs: Implications for HIV gene therapy

PubMed Central

Peterson, Christopher W.; Wang, Jianbin; Deleage, Claire; Reddy, Sowmya; Kaur, Jasbir; Polacino, Patricia; Reik, Andreas; Huang, Meei-Li; Holmes, Michael C.; Estes, Jacob D.

2018-01-01

Autologous transplantation and engraftment of HIV-resistant cells in sufficient numbers should recapitulate the functional cure of the Berlin Patient, with applicability to a greater number of infected individuals and with a superior safety profile. A robust preclinical model of suppressed HIV infection is critical in order to test such gene therapy-based cure strategies, both alone and in combination with other cure strategies. Here, we present a nonhuman primate (NHP) model of latent infection using simian/human immunodeficiency virus (SHIV) and combination antiretroviral therapy (cART) in pigtail macaques. We demonstrate that transplantation of CCR5 gene-edited hematopoietic stem/progenitor cells (HSPCs) persist in infected and suppressed animals, and that protected cells expand through virus-dependent positive selection. CCR5 gene-edited cells are readily detectable in tissues, namely those closely associated with viral reservoirs such as lymph nodes and gastrointestinal tract. Following autologous transplantation, tissue-associated SHIV DNA and RNA levels in suppressed animals are significantly reduced (p ≤ 0.05), relative to suppressed, untransplanted control animals. In contrast, the size of the peripheral reservoir, measured by QVOA, is variably impacted by transplantation. Our studies demonstrate that CCR5 gene editing is equally feasible in infected and uninfected animals, that edited cells persist, traffic to, and engraft in tissue reservoirs, and that this approach significantly reduces secondary lymphoid tissue viral reservoir size. Our robust NHP model of HIV gene therapy and viral persistence can be immediately applied to the investigation of combinatorial approaches that incorporate anti-HIV gene therapy, immune modulators, therapeutic vaccination, and latency reversing agents. PMID:29672640

Understanding Image Virality

DTIC Science & Technology

2015-06-07

anno - tations for these 5 attributes we achieve (65.18%) accuracy, better than human performance (60.12%) at predicting rel- ative virality directly...Nature, 2005. 1 [3] A. Berg, T. Berg, H. Daume, J . Dodge, A. Goyal, X. Han, A. Mensch, M. Mitchell, A. Sood, K. Stratos, et al. Understanding and...predicting importance in images. In CVPR, 2012. 2 [4] J . Berger. Arousal increases social transmission of information. Psy- chological science, 2011. 1

Viral Load Criteria and Threshold Optimization to Improve HIV Incidence Assay Characteristics - A CEPHIA Analysis

PubMed Central

Kassanjee, Reshma; Pilcher, Christopher D; Busch, Michael P; Murphy, Gary; Facente, Shelley N; Keating, Sheila M; Mckinney, Elaine; Marson, Kara; Price, Matthew A; Martin, Jeffrey N; Little, Susan J; Hecht, Frederick M; Kallas, Esper G; Welte, Alex

2016-01-01

Objective Assays for classifying HIV infections as ‘recent’ or ‘non-recent’ for incidence surveillance fail to simultaneously achieve large mean durations of ‘recent’ infection (MDRIs) and low ‘false-recent’ rates (FRRs), particularly in virally suppressed persons. The potential for optimizing recent infection testing algorithms (RITAs), by introducing viral load criteria and tuning thresholds used to dichotomize quantitative measures, is explored. Design The Consortium for the Evaluation and Performance of HIV Incidence Assays characterized over 2000 possible RITAs constructed from seven assays (LAg, BED, Less-sensitive Vitros, Vitros Avidity, BioRad Avidity, Architect Avidity and Geenius) applied to 2500 diverse specimens. Methods MDRIs were estimated using regression, and FRRs as observed ‘recent’ proportions, in various specimen sets. Context-specific FRRs were estimated for hypothetical scenarios. FRRs were made directly comparable by constructing RITAs with the same MDRI through the tuning of thresholds. RITA utility was summarized by the precision of incidence estimation. Results All assays produce high FRRs amongst treated subjects and elite controllers (10%-80%). Viral load testing reduces FRRs, but diminishes MDRIs. Context-specific FRRs vary substantially by scenario – BioRad Avidity and LAg provided the lowest FRRs and highest incidence precision in scenarios considered. Conclusions The introduction of a low viral load threshold provides crucial improvements in RITAs. However, it does not eliminate non-zero FRRs, and MDRIs must be consistently estimated. The tuning of thresholds is essential for comparing and optimizing the use of assays. The translation of directly measured FRRs into context-specific FRRs critically affects their magnitudes and our understanding of the utility of assays. PMID:27454561

An aptamer-siRNA chimera suppresses HIV-1 viral loads and protects from helper CD4(+) T cell decline in humanized mice.

PubMed

Neff, Charles Preston; Zhou, Jiehua; Remling, Leila; Kuruvilla, Jes; Zhang, Jane; Li, Haitang; Smith, David D; Swiderski, Piotr; Rossi, John J; Akkina, Ramesh

2011-01-19

Therapeutic strategies designed to treat HIV infection with combinations of antiviral drugs have proven to be the best approach for slowing the progression to AIDS. Despite this progress, there are problems with viral drug resistance and toxicity, necessitating new approaches to combating HIV-1 infection. We have therefore developed a different combination approach for the treatment of HIV infection in which an RNA aptamer, with high binding affinity to the HIV-1 envelope (gp120) protein and virus neutralization properties, is attached to and delivers a small interfering RNA (siRNA) that triggers sequence-specific degradation of HIV RNAs. We have tested the antiviral activities of these chimeric RNAs in a humanized Rag2(-/-)γc(-/-) (RAG-hu) mouse model with multilineage human hematopoiesis. In this animal model, HIV-1 replication and CD4(+) T cell depletion mimic the situation seen in human HIV-infected patients. Our results show that treatment with either the anti-gp120 aptamer or the aptamer-siRNA chimera suppressed HIV-1 replication by several orders of magnitude and prevented the viral-induced helper CD4(+) T cell decline. In comparison to the aptamer alone, the aptamer-siRNA combination provided more extensive inhibition, resulting in a significantly longer antiviral effect that extended several weeks beyond the last injected dose. The aptamer thus acts as a broad-spectrum HIV-neutralizing agent and an siRNA delivery vehicle. The combined aptamer-siRNA agent provides an attractive, nontoxic therapeutic approach for treatment of HIV infection.

Gene delivery with viral vectors for cerebrovascular diseases

PubMed Central

Gan, Yu; Jing, Zheng; Stetler, R. Anne; Cao, Guodong

2017-01-01

Recent achievements in the understanding of molecular events involved in the pathogenesis of central nervous system (CNS) injury have made gene transfer a promising approach for various neurological disorders, including cerebrovascular diseases. However, special obstacles, including the post-mitotic nature of neurons and the blood-brain barrier (BBB), constitute key challenges for gene delivery to the CNS. Despite the various limitations in current gene delivery systems, a spectrum of viral vectors has been successfully used to deliver genes to the CNS. Furthermore, recent advancements in vector engineering have improved the safety and delivery of viral vectors. Numerous viral vector-based clinical trials for neurological disorders have been initiated. This review will summarize the current implementation of viral gene delivery in the context of cerebrovascular diseases including ischemic stroke, hemorrhagic stroke and subarachnoid hemorrhage (SAH). In particular, we will discuss the potentially feasible ways in which viral vectors can be manipulated and exploited for use in neural delivery and therapy. PMID:23276981

Incomplete Recovery of CD4 count, CD4 Percentage, and CD4/CD8 ratio in HIV-Infected Patients on Long-Term Antiretroviral Therapy with Suppressed Viremia.

PubMed

Mutoh, Yoshikazu; Nishijima, Takeshi; Inaba, Yosuke; Tanaka, Noriko; Kikuchi, Yoshimi; Gatanaga, Hiroyuki; Oka, Shinichi

2018-03-02

The extent and duration of long-term recovery of CD4 count, CD4%, and CD4/CD8 ratio after initiation of combination antiretroviral therapy (cART) in patients with suppressed viral load are largely unknown. HIV-1 infected patients who started cART between January 2004 and January 2012 and showed persistent viral suppression (<200 copies/mL) for at least 4 years were followed up at AIDS Clinical Center, Tokyo. Change point analysis was used to determine the time point where CD4 count recovery shows a plateau, and linear mixed model was applied to estimate CD4 count at the change point. Data of 752 patients were analyzed [93% males, median age 38, median baseline CD4 count 172/µL (IQR, 62-253), CD4% 13.8% (IQR, 7.7-18.5), and CD4/8 ratio 0.23 (IQR, 0.12-0.35)]. The median follow-up period was 81.2 months and 91 (12.1%) patients were followed for >10 years. Change point analysis showed that CD4 count, CD4%, and CD4/CD8 ratio, continued to increase until 78.6, 62.2, and 64.3 months, respectively, with adjusted mean of 590 /µL (95%CI 572-608), 29.5% (29-30.1), and 0.89 (0.86-0.93), respectively, at the change point. Although 73.8% of the study patients achieved CD4 count ≥500 /μL, 48.2% of the patients with baseline CD4 count <100 /μL did not achieve CD4 count ≥500 /μL. Neither CD4% nor CD4/CD8 ratio normalized in a majority of patients. The results showed lack of normalization of CD4 count, CD4%, and CD4/CD8 ratio to the levels seen in healthy individuals even after long-term successful cART in patients with suppressed viral load.

An international collaboration to standardize HIV-2 viral load assays: results from the 2009 ACHI(E)V(2E) quality control study.

PubMed

Damond, F; Benard, A; Balotta, Claudia; Böni, Jürg; Cotten, Matthew; Duque, Vitor; Ferns, Bridget; Garson, Jeremy; Gomes, Perpetua; Gonçalves, Fátima; Gottlieb, Geoffrey; Kupfer, Bernd; Ruelle, Jean; Rodes, Berta; Soriano, Vicente; Wainberg, Mark; Taieb, Audrey; Matheron, Sophie; Chene, Genevieve; Brun-Vezinet, Francoise

2011-10-01

Accurate HIV-2 plasma viral load quantification is crucial for adequate HIV-2 patient management and for the proper conduct of clinical trials and international cohort collaborations. This study compared the homogeneity of HIV-2 RNA quantification when using HIV-2 assays from ACHI(E)V(2E) study sites and either in-house PCR calibration standards or common viral load standards supplied to all collaborators. Each of the 12 participating laboratories quantified blinded HIV-2 samples, using its own HIV-2 viral load assay and standard as well as centrally validated and distributed common HIV-2 group A and B standards (http://www.hiv.lanl.gov/content/sequence/HelpDocs/subtypes-more.html). Aliquots of HIV-2 group A and B strains, each at 2 theoretical concentrations (2.7 and 3.7 log(10) copies/ml), were tested. Intralaboratory, interlaboratory, and overall variances of quantification results obtained with both standards were compared using F tests. For HIV-2 group A quantifications, overall and interlaboratory and/or intralaboratory variances were significantly lower when using the common standard than when using in-house standards at the concentration levels of 2.7 log(10) copies/ml and 3.7 log(10) copies/ml, respectively. For HIV-2 group B, a high heterogeneity was observed and the variances did not differ according to the type of standard used. In this international collaboration, the use of a common standard improved the homogeneity of HIV-2 group A RNA quantification only. The diversity of HIV-2 group B, particularly in PCR primer-binding regions, may explain the heterogeneity in quantification of this strain. Development of a validated HIV-2 viral load assay that accurately quantifies distinct circulating strains is needed.

Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Robert Y.L., E-mail: yuwang@mail.cgu.edu.tw; Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan; Kuo, Rei-Lin

2013-09-01

Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted tomore » new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone. - Highlights: • Hsp90β is associated with EV71 virion and is secreted with the release virus. • Hsp90β effects on the correct assembly of viral particles. • Viral titer of cultured medium was reduced in the presence of geldanamycin. • Viral titer was also reduced when Hsp90β was suppressed by siRNA treatment. • The extracellular Hsp90β was also observed in other RNA viruses-infected cells.« less

The link between CD8⁺ T-cell antigen-sensitivity and HIV-suppressive capacity depends on HLA restriction, target epitope and viral isolate.

PubMed

Lissina, Anna; Fastenackels, Solène; Inglesias, Maria C; Ladell, Kristin; McLaren, James E; Briceño, Olivia; Gostick, Emma; Papagno, Laura; Autran, Brigitte; Sauce, Delphine; Price, David A; Saez-Cirion, Asier; Appay, Victor

2014-02-20

Although it is established that CD8 T-cell immunity is critical for the control of HIV replication in vivo, the key factors that determine antiviral efficacy are yet to be fully elucidated. Antigen-sensitivity and T-cell receptor (TCR) avidity have been identified as potential determinants of CD8⁺ T-cell efficacy. However, there is no general consensus in this regard because the relationship between these parameters and the control of HIV infection has been established primarily in the context of immunodominant CD8⁺ T-cell responses against the Gag₂₆₃₋₂₇₂ KK10 epitope restricted by human leukocyte antigen (HLA)-B27. To investigate the relationship between antigen-sensitivity, TCR avidity and HIV-suppressive capacity in vitro across epitope specificities and HLA class I restriction elements, we used a variety of techniques to study CD8⁺ T-cell clones specific for Nef₇₃₋₈₂ QK10 and Gag₂₀₋₂₉ RY10, both restricted by HLA-A3, alongside CD8⁺ T-cell clones specific for Gag₂₆₃₋₂₇₂ KK10. For each targeted epitope, the linked parameters of antigen-sensitivity and TCR avidity correlated directly with antiviral efficacy. However, marked differences in HIV-suppressive capacity were observed between epitope specificities, HLA class I restriction elements and viral isolates. Collectively, these data emphasize the central role of the TCR as a determinant of CD8⁺ T-cell efficacy and demonstrate that the complexities of antigen recognition across epitope and HLA class I boundaries can confound simple relationships between TCR engagement and HIV suppression.

Predictive Factors of Plasma HIV Suppression during Pregnancy: A Prospective Cohort Study in Benin

PubMed Central

Ogouyemi-Hounto, Aurore; Azon-Kouanou, Angèle; d'Almeida, Marcelline; Azondékon, Alain; Alao, Marouf J.; Dossou-Gbété, Véronique; Afangnihoun, Aldric; Girard, Pierre-Marie; Cot, Michel; Zannou, Djimon-Marcel

2013-01-01

Objective To investigate the factors associated with HIV1 RNA plasma viral load (pVL) below 40 copies/mL at the third trimester of pregnancy, as part of prevention of mother-to-child transmission (PMTCT) in Benin. Design Sub study of the PACOME clinical trial of malaria prophylaxis in HIV-infected pregnant women, conducted before and after the implementation of the WHO 2009 revised guidelines for PMTCT. Methods HIV-infected women were enrolled in the second trimester of pregnancy. Socio-economic characteristics, HIV history, clinical and biological characteristics were recorded. Malaria prevention and PMTCT involving antiretroviral therapy (ART) for mothers and infants were provided. Logistic regression helped identifying factors associated with virologic suppression at the end of pregnancy. Results Overall 217 third trimester pVLs were available, and 71% showed undetectability. Virologic suppression was more frequent in women enrolled after the change in PMTCT recommendations, advising to start ART at 14 weeks instead of 28 weeks of pregnancy. In multivariate analysis, Fon ethnic group (the predominant ethnic group in the study area), regular job, first and second pregnancy, higher baseline pVL and impaired adherence to ART were negative factors whereas higher weight, higher antenatal care attendance and longer ART duration were favorable factors to achieve virologic suppression. Conclusions This study provides more evidence that ART has to be initiated before the last trimester of pregnancy to achieve an undetectable pVL before delivery. In Benin, new recommendations supporting early initiation were well implemented and, together with a high antenatal care attendance, led to high rate of virologic control. PMID:23555035

Predictive factors of plasma HIV suppression during pregnancy: a prospective cohort study in Benin.

PubMed

Denoeud-Ndam, Lise; Fourcade, Camille; Ogouyemi-Hounto, Aurore; Azon-Kouanou, Angèle; d'Almeida, Marcelline; Azondékon, Alain; Alao, Marouf J; Dossou-Gbété, Véronique; Afangnihoun, Aldric; Girard, Pierre-Marie; Cot, Michel; Zannou, Djimon-Marcel

2013-01-01

To investigate the factors associated with HIV1 RNA plasma viral load (pVL) below 40 copies/mL at the third trimester of pregnancy, as part of prevention of mother-to-child transmission (PMTCT) in Benin. Sub study of the PACOME clinical trial of malaria prophylaxis in HIV-infected pregnant women, conducted before and after the implementation of the WHO 2009 revised guidelines for PMTCT. HIV-infected women were enrolled in the second trimester of pregnancy. Socio-economic characteristics, HIV history, clinical and biological characteristics were recorded. Malaria prevention and PMTCT involving antiretroviral therapy (ART) for mothers and infants were provided. Logistic regression helped identifying factors associated with virologic suppression at the end of pregnancy. Overall 217 third trimester pVLs were available, and 71% showed undetectability. Virologic suppression was more frequent in women enrolled after the change in PMTCT recommendations, advising to start ART at 14 weeks instead of 28 weeks of pregnancy. In multivariate analysis, Fon ethnic group (the predominant ethnic group in the study area), regular job, first and second pregnancy, higher baseline pVL and impaired adherence to ART were negative factors whereas higher weight, higher antenatal care attendance and longer ART duration were favorable factors to achieve virologic suppression. This study provides more evidence that ART has to be initiated before the last trimester of pregnancy to achieve an undetectable pVL before delivery. In Benin, new recommendations supporting early initiation were well implemented and, together with a high antenatal care attendance, led to high rate of virologic control.

Latency reversal and viral clearance to cure HIV-1

PubMed Central

Margolis, David M.; Garcia, J. Victor; Hazuda, Daria J.; Haynes, Barton F.

2016-01-01

Research toward a cure for human immunodeficiency virus type 1 (HIV-1) infection has joined prevention and treatment efforts in the global public health agenda. A major approach to HIV eradication envisions antiretroviral suppression, paired with targeted therapies to enforce the expression of viral antigen from quiescent HIV-1 genomes, and immunotherapies to clear latent infection. These strategies are targeted to lead to viral eradication—a cure for AIDS. Paired testing of latency reversal and clearance strategies has begun, but additional obstacles to HIV eradication may emerge. Nevertheless, there is reason for optimism that advances in long-acting antiretroviral therapy and HIV prevention strategies will contribute to efforts in HIV cure research and that the implementation of these efforts will synergize to markedly blunt the effect of the HIV pandemic on society. PMID:27463679

Lytic to temperate switching of viral communities

NASA Astrophysics Data System (ADS)

Knowles, B.; Silveira, C. B.; Bailey, B. A.; Barott, K.; Cantu, V. A.; Cobián-Güemes, A. G.; Coutinho, F. H.; Dinsdale, E. A.; Felts, B.; Furby, K. A.; George, E. E.; Green, K. T.; Gregoracci, G. B.; Haas, A. F.; Haggerty, J. M.; Hester, E. R.; Hisakawa, N.; Kelly, L. W.; Lim, Y. W.; Little, M.; Luque, A.; McDole-Somera, T.; McNair, K.; de Oliveira, L. S.; Quistad, S. D.; Robinett, N. L.; Sala, E.; Salamon, P.; Sanchez, S. E.; Sandin, S.; Silva, G. G. Z.; Smith, J.; Sullivan, C.; Thompson, C.; Vermeij, M. J. A.; Youle, M.; Young, C.; Zgliczynski, B.; Brainard, R.; Edwards, R. A.; Nulton, J.; Thompson, F.; Rohwer, F.

2016-03-01

Microbial viruses can control host abundances via density-dependent lytic predator-prey dynamics. Less clear is how temperate viruses, which coexist and replicate with their host, influence microbial communities. Here we show that virus-like particles are relatively less abundant at high host densities. This suggests suppressed lysis where established models predict lytic dynamics are favoured. Meta-analysis of published viral and microbial densities showed that this trend was widespread in diverse ecosystems ranging from soil to freshwater to human lungs. Experimental manipulations showed viral densities more consistent with temperate than lytic life cycles at increasing microbial abundance. An analysis of 24 coral reef viromes showed a relative increase in the abundance of hallmark genes encoded by temperate viruses with increased microbial abundance. Based on these four lines of evidence, we propose the Piggyback-the-Winner model wherein temperate dynamics become increasingly important in ecosystems with high microbial densities; thus ‘more microbes, fewer viruses’.

Influenza A virus-induced degradation of eukaryotic translation initiation factor 4B contributes to viral replication by suppressing IFITM3 protein expression.

PubMed

Wang, Song; Chi, Xiaojuan; Wei, Haitao; Chen, Yuhai; Chen, Zhilong; Huang, Shile; Chen, Ji-Long

2014-08-01

Although alteration in host cellular translation machinery occurs in virus-infected cells, the role of such alteration and the precise pathogenic processes are not well understood. Influenza A virus (IAV) infection shuts off host cell gene expression at transcriptional and translational levels. Here, we found that the protein level of eukaryotic translation initiation factor 4B (eIF4B), an integral component of the translation initiation apparatus, was dramatically reduced in A549 cells as well as in the lung, spleen, and thymus of mice infected with IAV. The decrease in eIF4B level was attributed to lysosomal degradation of eIF4B, which was induced by viral NS1 protein. Silencing eIF4B expression in A549 cells significantly promoted IAV replication, and conversely, overexpression of eIF4B markedly inhibited the viral replication. Importantly, we observed that eIF4B knockdown transgenic mice were more susceptible to IAV infection, exhibiting faster weight loss, shorter survival time, and more-severe organ damage. Furthermore, we demonstrated that eIF4B regulated the expression of interferon-induced transmembrane protein 3 (IFITM3), a critical protein involved in immune defense against a variety of RNA viruses, including influenza virus. Taken together, our findings reveal that eIF4B plays an important role in host defense against IAV infection at least by regulating the expression of IFITM3, which restricts viral entry and thereby blocks early stages of viral production. These data also indicate that influenza virus has evolved a strategy to overcome host innate immunity by downregulating eIF4B protein. Influenza A virus (IAV) infection stimulates the host innate immune system, in part, by inducing interferons (IFNs). Secreted IFNs activate the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway, leading to elevated transcription of a large group of IFN-stimulated genes that have antiviral function. To circumvent the host innate

The suppression of apoptosis by α-herpesvirus

PubMed Central

You, Yu; Cheng, An-Chun; Wang, Ming-Shu; Jia, Ren-Yong; Sun, Kun-Feng; Yang, Qiao; Wu, Ying; Zhu, Dekang; Chen, Shun; Liu, Ma-Feng; Zhao, Xin-Xin; Chen, Xiao-Yue

2017-01-01

Apoptosis, an important innate immune mechanism that eliminates pathogen-infected cells, is primarily triggered by two signalling pathways: the death receptor pathway and the mitochondria-mediated pathway. However, many viruses have evolved various strategies to suppress apoptosis by encoding anti-apoptotic factors or regulating apoptotic signalling pathways, which promote viral propagation and evasion of the host defence. During its life cycle, α-herpesvirus utilizes an elegant multifarious anti-apoptotic strategy to suppress programmed cell death. This progress article primarily focuses on the current understanding of the apoptosis-inhibition mechanisms of α-herpesvirus anti-apoptotic genes and their expression products and discusses future directions, including how the anti-apoptotic function of herpesvirus could be targeted therapeutically. PMID:28406478

HIV-1 Nef protein in the nucleus influences adipogenesis as well as viral transcription through the peroxisome proliferator-activated receptors.

PubMed

Otake, Kaori; Omoto, Shinya; Yamamoto, Takuya; Okuyama, Harumi; Okada, Hidechika; Okada, Noriko; Kawai, Masahiro; Saksena, Nitin K; Fujii, Yoichi R

2004-01-23

Although the HIV-1 Nef protein (27 kDa) localizes primarily in cytoplasm, there is considerable evidence suggesting its occasional localization in the nucleus. Nef is known to play an important role in transcriptional events and viral replication, but the actual target of Nef in the nucleus remains to be identified. To examine the functional roles of Nef in the nucleus and its possible interactions with other unknown factors in the nucleus. High-density microarray analysis was used to screen directly the unique functions of Nef on host gene transcription. The nuclear localization of Nef and its effects on the expression of peroxisome proliferator-activated receptors (PPAR) was examined using PPAR promoter/reporter assay and immunoblotting. A long terminal repeat/reporter assay was used to investigated the effects of Nef and PPAR on viral transcription. Nef in the nucleus suppressed PPAR gamma expression and reduced fatty acid levels in human T and macrophage cell lines. Expression of Nef or PPAR suppressed viral replication; the effect of PPAR gamma or retinoid X receptor-alpha on viral replication were reduced by coexpression of Nef in MT(-)4 T cells. Nef may be involved in both viral replication and the wasting syndrome associated with AIDS.

A viral deubiquitylating enzyme targets viral RNA-dependent RNA polymerase and affects viral infectivity

PubMed Central

Chenon, Mélanie; Camborde, Laurent; Cheminant, Soizic; Jupin, Isabelle

2012-01-01

Selective protein degradation via the ubiquitin-proteasome system (UPS) plays an essential role in many major cellular processes, including host–pathogen interactions. We previously reported that the tightly regulated viral RNA-dependent RNA polymerase (RdRp) of the positive-strand RNA virus Turnip yellow mosaic virus (TYMV) is degraded by the UPS in infected cells, a process that affects viral infectivity. Here, we show that the TYMV 98K replication protein can counteract this degradation process thanks to its proteinase domain. In-vitro assays revealed that the recombinant proteinase domain is a functional ovarian tumour (OTU)-like deubiquitylating enzyme (DUB), as is the 98K produced during viral infection. We also demonstrate that 98K mediates in-vivo deubiquitylation of TYMV RdRp protein—its binding partner within replication complexes—leading to its stabilization. Finally, we show that this DUB activity contributes to viral infectivity in plant cells. The identification of viral RdRp as a specific substrate of the viral DUB enzyme thus reveals the intricate interplay between ubiquitylation, deubiquitylation and the interaction between viral proteins in controlling levels of RdRp and viral infectivity. PMID:22117220

Adapting the Stress Response: Viral Subversion of the mTOR Signaling Pathway.

PubMed

Le Sage, Valerie; Cinti, Alessandro; Amorim, Raquel; Mouland, Andrew J

2016-05-24

The mammalian target of rapamycin (mTOR) is a central regulator of gene expression, translation and various metabolic processes. Multiple extracellular (growth factors) and intracellular (energy status) molecular signals as well as a variety of stressors are integrated into the mTOR pathway. Viral infection is a significant stress that can activate, reduce or even suppress the mTOR signaling pathway. Consequently, viruses have evolved a plethora of different mechanisms to attack and co-opt the mTOR pathway in order to make the host cell a hospitable environment for replication. A more comprehensive knowledge of different viral interactions may provide fruitful targets for new antiviral drugs.

Adapting the Stress Response: Viral Subversion of the mTOR Signaling Pathway

PubMed Central

Le Sage, Valerie; Cinti, Alessandro; Amorim, Raquel; Mouland, Andrew J.

2016-01-01

The mammalian target of rapamycin (mTOR) is a central regulator of gene expression, translation and various metabolic processes. Multiple extracellular (growth factors) and intracellular (energy status) molecular signals as well as a variety of stressors are integrated into the mTOR pathway. Viral infection is a significant stress that can activate, reduce or even suppress the mTOR signaling pathway. Consequently, viruses have evolved a plethora of different mechanisms to attack and co-opt the mTOR pathway in order to make the host cell a hospitable environment for replication. A more comprehensive knowledge of different viral interactions may provide fruitful targets for new antiviral drugs. PMID:27231932

Non-invasive Imaging of Sendai Virus Infection in Pharmacologically Immunocompromised Mice: NK and T Cells, but not Neutrophils, Promote Viral Clearance after Therapy with Cyclophosphamide and Dexamethasone

PubMed Central

Mostafa, Heba H.; Vogel, Peter; Srinivasan, Ashok; Russell, Charles J.

2016-01-01

In immunocompromised patients, parainfluenza virus (PIV) infections have an increased potential to spread to the lower respiratory tract (LRT), resulting in increased morbidity and mortality. Understanding the immunologic defects that facilitate viral spread to the LRT will help in developing better management protocols. In this study, we immunosuppressed mice with dexamethasone and/or cyclophosphamide then monitored the spread of viral infection into the LRT by using a noninvasive bioluminescence imaging system and a reporter Sendai virus (murine PIV type 1). Our results show that immunosuppression led to delayed viral clearance and increased viral loads in the lungs. After cessation of cyclophosphamide treatment, viral clearance occurred before the generation of Sendai-specific antibody responses and coincided with rebounds in neutrophils, T lymphocytes, and natural killer (NK) cells. Neutrophil suppression using anti-Ly6G antibody had no effect on infection clearance, NK-cell suppression using anti-NK antibody delayed clearance, and T-cell suppression using anti-CD3 antibody resulted in no clearance (chronic infection). Therapeutic use of hematopoietic growth factors G-CSF and GM-CSF had no effect on clearance of infection. In contrast, treatment with Sendai virus—specific polysera or a monoclonal antibody limited viral spread into the lungs and accelerated clearance. Overall, noninvasive bioluminescence was shown to be a useful tool to study respiratory viral progression, revealing roles for NK and T cells, but not neutrophils, in Sendai virus clearance after treatment with dexamethasone and cyclophosphamide. Virus-specific antibodies appear to have therapeutic potential. PMID:27589232

Sustainable HIV Treatment in Africa through Viral Load-Informed Differentiated Care

PubMed Central

Phillips, Andrew; Shroufi, Amir; Vojnov, Lara; Cohn, Jennifer; Roberts, Teri; Ellman, Tom; Bonner, Kimberly; Rousseau, Christine; Garnett, Geoff; Cambiano, Valentina; Nakagawa, Fumiyo; Ford, Deborah; Bansi-Matharu, Loveleen; Miners, Alec; Lundgren, Jens; Eaton, Jeff; Parkes-Ratanshi, Rosalind; Katz, Zachary; Maman, David; Ford, Nathan; Vitoria, Marco; Doherty, Meg; Dowdy, David; Nichols, Brooke; Murtagh, Maurine; Wareham, Meghan; Palamountain, Kara; Musanhu, Christine Chiedza; Stevens, Wendy; Katzenstein, David; Ciaranello, Andrea; Barnabas, Ruanne; Braithwaite, Scott; Bendavid, Eran; Nathoo, Kusum J; van de Vijver, David; Wilson, David; Holmes, Charles; Bershteyn, Anna; Walker, Simon; Raizes, Elliot; Jani, Ilesh; Nelson, Lisa; Peeling, Rosanna; Terris-Prestholt, Fern; Murungu, Joseph; Mutasa-Apollo, Tsitsi; Hallett, Timothy; Revill, Paul

2016-01-01

There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy (ART) in sub-Saharan Africa. Patients typically attend clinics every 1–3 months for clinical assessment, with clinic costs being comparable with costs of drugs themselves, CD4 counts are measured every 6 months, yet patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes a transition to more cost-effective ART deliver is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (“viral load”) provides a direct measure of current treatment effect. Viral load informed differentiated care is a means of tailoring care whereby those with suppressed viral load have less frequent clinical visits and attention is paid to those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach in many countries to measure viral load is by collecting dried blood spot (DBS) samples for testing in regional laboratories, although there have been concerns over the sensitivity/specificity of DBS to define treatment failure and the delay in receiving results. We use modelling to synthesize available evidence and evaluate the cost-effectiveness of viral load-informed differentiated care, account for limitations of DBS. We find that viral load-informed differentiated care using DBS is expected to be cost-effective and is recommended as the strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of future availability of point-of-care (POC) viral load tests. PMID:26633768

Ethnicity predicts viral rebound after travel to the tropics in HIV-infected travelers to the tropics in the Swiss HIV Cohort Study.

PubMed

Gebreselassie, H M; Kraus, D; Fux, C A; Haubitz, S; Scherrer, A; Hatz, C; Veit, O; Stoeckle, M; Fehr, J; de Lucia, S; Cavassini, M; Bernasconi, E; Schmid, P; Furrer, H; Staehelin, C

2017-09-01

The number of HIV-infected individuals from developed countries travelling to tropical and subtropical areas has increased as a result of the clinical and survival benefits of combination antiretroviral therapy. The aim of our study was to describe the traveler population in the SHCS and to determine the frequency of viral rebound in virologically suppressed individuals after a travel episode to the tropics compared to non-travelers. Swiss HIV Cohort Study participants with at least one follow-up visit between 1 January 1989 and 28 February 2015 were eligible for inclusion in the study. The primary outcome was the occurrence of viral rebound (viral load > 200 HIV-1 RNA copies/mL) after a travel episode compared with a nontravel episode in previously suppressed individuals (≤ 200 copies/mL). All virologically suppressed patients contributed multiple travel or nontravel episodes to the analysis. Logistic regression was performed including factors associated with viral rebound. We included 16 635 patients in the study, of whom 6084 (36.5%) had ever travelled to the tropics. Travel frequency increased over time, with travellers showing better HIV parameters than nontravellers [less advanced Centers for Disease Control and Prevention (CDC) stage and higher CD4 count nadir]. Viral rebound was seen in 477 (3.9%) of 12 265 travel episodes and in 5121 (4.5%) of 114 884 nontravel episodes [unadjusted odds ratio (OR) 0.87; 95% confidence interval (CI) 0.78-0.97]. Among these 477 post-travel viral rebounds, 115 had a resistance test performed and 51 (44%) of these showed new resistance mutations. Compared with European and North American patients, the odds for viral rebound were significantly lower in Southeast Asian (OR 0.67; 95% CI 0.51-0.88) and higher in sub-Saharan African (SSA) patients (OR 1.41; 95% CI 1.22-1.62). Travel further increased the odds of viral rebound in SSA patients (OR 2.00; 95% CI 1.53-2.61). Region of origin is the main risk factor for viral rebound

Latency reversal and viral clearance to cure HIV-1.

PubMed

Margolis, David M; Garcia, J Victor; Hazuda, Daria J; Haynes, Barton F

2016-07-22

Research toward a cure for human immunodeficiency virus type 1 (HIV-1) infection has joined prevention and treatment efforts in the global public health agenda. A major approach to HIV eradication envisions antiretroviral suppression, paired with targeted therapies to enforce the expression of viral antigen from quiescent HIV-1 genomes, and immunotherapies to clear latent infection. These strategies are targeted to lead to viral eradication--a cure for AIDS. Paired testing of latency reversal and clearance strategies has begun, but additional obstacles to HIV eradication may emerge. Nevertheless, there is reason for optimism that advances in long-acting antiretroviral therapy and HIV prevention strategies will contribute to efforts in HIV cure research and that the implementation of these efforts will synergize to markedly blunt the effect of the HIV pandemic on society. Copyright © 2016, American Association for the Advancement of Science.

CD4+CD73+ T cells are associated with lower T-cell activation and C reactive protein levels and are depleted in HIV-1 infection regardless of viral suppression

PubMed Central

Schuler, Patrick J.; Macatangay, Bernard J.C.; Saze, Zenichiro; Jackson, Edwin K.; Riddler, Sharon A.; Buchanan, William G.; Hilldorfer, Benedict B.; Mellors, John W.; Whiteside, Theresa L.; Rinaldo, Charles R.

2013-01-01

Background The role of the adenosine (ADO) suppression pathway, specifically CD39-expressing and CD73-expressing CD4+ T cells in HIV-1 infection is unclear. Methods We evaluated the frequency and numbers of CD4+CD39+ and CD4+CD73+ T cells, activated T cells, and plasma C reactive protein (CRP) levels in 36 HIV-1-positive individuals and 10 normal controls (NC). Low-level plasma viremia was evaluated using single copy assay. Mass spectrometry was used to measure hydrolysis of ATP by ectoenzyme-expressing CD4+ T cells, whereas cyclic adenosine monophosphate (cAMP) levels were measured using enzyme immunoassay. Suppression of T-cell function by exogenous ADO and CD4+CD73+ T cells was tested by flow cytometry. Results CD39 and CD73 are expressed in different CD4+ T-cell subsets. CD4+CD73+ T cells do not express CD25 and FOXP3, and their frequency and numbers were lower in HIV-1-positive individuals regardless of virologic suppression (P = 0.005 and P < 0.001, respectively). CD4+CD73+ numbers inversely correlated with CD4+CD38+DR+ (P = 0.002), CD8+CD38+DR+ T-cell frequency (P = 0.05), and plasma CRP levels (P = 0.01). Both subsets are required for hydrolysis of exogenous ATP to ADO and can increase CD4+ T-cell cAMP levels when incubated with exogenous ATP. Low-level viremia did not correlate with activated T-cell frequency. In vitro, ADO suppressed T-cell activation and cytokine expression. CD4+CD73+ T cells suppressed T-cell proliferation only in the presence of exogenous 5′-AMP. Conclusion The ADO-producing CD4+CD73+ subset of T cells is depleted in HIV-1-positive individuals regardless of viral suppression and may play a key role in controlling HIV-1-associated immune activation. PMID:24005375

A Re-Examination of Global Suppression of RNA Interference by HIV-1

PubMed Central

Sanghvi, Viraj R.; Steel, Laura F.

2011-01-01

The nature of the interaction between replicating HIV-1 and the cellular RNAi pathway has been controversial, but it is clear that it can be complex and multifaceted. It has been proposed that the interaction is bi-directional, whereby cellular silencing pathways can restrict HIV-1 replication, and in turn, HIV-1 can suppress silencing pathways. Overall suppression of RNAi has been suggested to occur via direct binding and inhibition of Dicer by the HIV-1 Tat protein or through sequestration of TRBP, a Dicer co-factor, by the structured TAR element of HIV-1 transcripts. The role of Tat as an inhibitor of Dicer has been questioned and our results support and extend the conclusion that Tat does not inhibit RNAi that is mediated by either exogenous or endogenous miRNAs. Similarly, we find no suppression of silencing pathways in cells with replicating virus, suggesting that viral products such as the TAR RNA elements also do not reduce the efficacy of cellular RNA silencing. However, knockdown of Dicer does allow increased viral replication and this occurs at a post-transcriptional level. These results support the idea that although individual miRNAs can act to restrict HIV-1 replication, the virus does not counter these effects through a global suppression of RNAi synthesis or processing. PMID:21386885

Exosome-mediated miR-146a transfer suppresses type I interferon response and facilitates EV71 infection

PubMed Central

Fu, Yuxuan; Zhang, Li; Zhang, Fang; Tang, Ting; Zhou, Qi; Feng, Chunhong; Jin, Yu

2017-01-01

Exosomes can transfer genetic materials between cells. Their roles in viral infections are beginning to be appreciated. Researches have shown that exosomes released from virus-infected cells contain a variety of viral and host cellular factors that are able to modulate recipient’s cellular response and result in productive infection of the recipient host. Here, we showed that EV71 infection resulted in upregulated exosome secretion and differential packaging of the viral genomic RNA and miR-146a into exosomes. We provided evidence showing that miR-146a was preferentially enriched in exosomes while the viral RNA was not in infected cells. Moreover, the exosomes contained replication-competent EV71 RNA in complex with miR-146a, Ago2, and GW182 and could mediate EV71 transmission independent of virus-specific receptor. The exosomal viral RNA could be transferred to and replicate in a new target cell while the exosomal miR-146a suppressed type I interferon response in the target cell, thus facilitating the viral replication. Additionally, we found that the IFN-stimulated gene factors (ISGs), BST-2/tetherin, were involved in regulating EV71-induced upregulation of exosome secretion. Importantly, in vivo study showed that exosomal viral RNA exhibited differential tissue accumulation as compared to the free virus particles. Together, our findings provide evidence that exosomes secreted by EV71-infected cells selectively packaged high level miR-146a that can be functionally transferred to and facilitate exosomal EV71 RNA to replicate in the recipient cells by suppressing type I interferon response. PMID:28910400

Viral MicroRNAs Repress the Cholesterol Pathway, and 25-Hydroxycholesterol Inhibits Infection.

PubMed

Serquiña, Anna K P; Kambach, Diane M; Sarker, Ontara; Ziegelbauer, Joseph M

2017-07-11

From various screens, we found that Kaposi's sarcoma-associated herpesvirus (KSHV) viral microRNAs (miRNAs) target several enzymes in the mevalonate/cholesterol pathway. 3-Hydroxy-3-methylglutaryl-coenzyme A (CoA) synthase 1 (HMGCS1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR [a rate-limiting step in the mevalonate pathway]), and farnesyl-diphosphate farnesyltransferase 1 (FDFT1 [a committed step in the cholesterol branch]) are repressed by multiple KSHV miRNAs. Transfection of viral miRNA mimics in primary endothelial cells (human umbilical vein endothelial cells [HUVECs]) is sufficient to reduce intracellular cholesterol levels; however, small interfering RNAs (siRNAs) targeting only HMGCS1 did not reduce cholesterol levels. This suggests that multiple targets are needed to perturb this tightly regulated pathway. We also report here that cholesterol levels were decreased in de novo -infected HUVECs after 7 days. This reduction is at least partially due to viral miRNAs, since the mutant form of KSHV lacking 10 of the 12 miRNA genes had increased cholesterol compared to wild-type infections. We hypothesized that KSHV is downregulating cholesterol to suppress the antiviral response by a modified form of cholesterol, 25-hydroxycholesterol (25HC). We found that the cholesterol 25-hydroxylase (CH25H) gene, which is responsible for generating 25HC, had increased expression in de novo -infected HUVECs but was strongly suppressed in long-term latently infected cell lines. We found that 25HC inhibits KSHV infection when added exogenously prior to de novo infection. In conclusion, we found that multiple KSHV viral miRNAs target enzymes in the mevalonate pathway to modulate cholesterol in infected cells during latency. This repression of cholesterol levels could potentially be beneficial to viral infection by decreasing the levels of 25HC. IMPORTANCE A subset of viruses express unique microRNAs (miRNAs), which act like cellular miRNAs to generally repress host gene

Sustainable HIV treatment in Africa through viral-load-informed differentiated care.

PubMed

Phillips, Andrew; Shroufi, Amir; Vojnov, Lara; Cohn, Jennifer; Roberts, Teri; Ellman, Tom; Bonner, Kimberly; Rousseau, Christine; Garnett, Geoff; Cambiano, Valentina; Nakagawa, Fumiyo; Ford, Deborah; Bansi-Matharu, Loveleen; Miners, Alec; Lundgren, Jens D; Eaton, Jeffrey W; Parkes-Ratanshi, Rosalind; Katz, Zachary; Maman, David; Ford, Nathan; Vitoria, Marco; Doherty, Meg; Dowdy, David; Nichols, Brooke; Murtagh, Maurine; Wareham, Meghan; Palamountain, Kara M; Chakanyuka Musanhu, Christine; Stevens, Wendy; Katzenstein, David; Ciaranello, Andrea; Barnabas, Ruanne; Braithwaite, R Scott; Bendavid, Eran; Nathoo, Kusum J; van de Vijver, David; Wilson, David P; Holmes, Charles; Bershteyn, Anna; Walker, Simon; Raizes, Elliot; Jani, Ilesh; Nelson, Lisa J; Peeling, Rosanna; Terris-Prestholt, Fern; Murungu, Joseph; Mutasa-Apollo, Tsitsi; Hallett, Timothy B; Revill, Paul

2015-12-03

There are inefficiencies in current approaches to monitoring patients on antiretroviral therapy in sub-Saharan Africa. Patients typically attend clinics every 1 to 3 months for clinical assessment. The clinic costs are comparable with the costs of the drugs themselves and CD4 counts are measured every 6 months, but patients are rarely switched to second-line therapies. To ensure sustainability of treatment programmes, a transition to more cost-effective delivery of antiretroviral therapy is needed. In contrast to the CD4 count, measurement of the level of HIV RNA in plasma (the viral load) provides a direct measure of the current treatment effect. Viral-load-informed differentiated care is a means of tailoring care so that those with suppressed viral load visit the clinic less frequently and attention is focussed on those with unsuppressed viral load to promote adherence and timely switching to a second-line regimen. The most feasible approach to measuring viral load in many countries is to collect dried blood spot samples for testing in regional laboratories; however, there have been concerns over the sensitivity and specificity of this approach to define treatment failure and the delay in returning results to the clinic. We use modelling to synthesize evidence and evaluate the cost-effectiveness of viral-load-informed differentiated care, accounting for limitations of dried blood sample testing. We find that viral-load-informed differentiated care using dried blood sample testing is cost-effective and is a recommended strategy for patient monitoring, although further empirical evidence as the approach is rolled out would be of value. We also explore the potential benefits of point-of-care viral load tests that may become available in the future.

A comparison of virological suppression and rebound between Indigenous and non-Indigenous persons initiating combination antiretroviral therapy in a multisite cohort of individuals living with HIV in Canada.

PubMed

Benoit, Anita C; Younger, Jaime; Beaver, Kerrigan; Jackson, Randy; Loutfy, Mona; Masching, Renée; Nobis, Tony; Nowgesic, Earl; O'Brien-Teengs, Doe; Whitebird, Wanda; Zoccole, Art; Hull, Mark; Jaworsky, Denise; Rachlis, Anita; Rourke, Sean; Burchell, Ann N; Cooper, Curtis; Hogg, Robert; Klein, Marina B; Machouf, Nima; Montaner, Julio; Tsoukas, Chris; Raboud, Janet

2017-01-01

This study compared time to virological suppression and rebound between Indigenous and non-Indigenous individuals living with HIV in Canada initiating combination antiretroviral therapy (cART). Data were from the Canadian Observational Cohort collaboration; eight studies of treatment-naive persons with HIV initiating cART after 1/1/2000. Fine and Gray models were used to estimate the effect of ethnicity on time to virological suppression (two consecutive viral loads [VLs] <50 copies/ml at least 3 months apart) after adjusting for the competing risk of death and time until virological rebound (two consecutive VLs >200 copies/ml at least 3 months apart) following suppression. Among 7,080 participants were 497 Indigenous persons of whom 413 (83%) were from British Columbia. The cumulative incidence of suppression 1 year after cART initiation was 54% for Indigenous persons, 77% for Caucasian and 80% for African, Caribbean or Black (ACB) persons. The cumulative incidence of rebound 1 year after suppression was 13% for Indigenous persons, 6% for Caucasian and 7% for ACB persons. Indigenous persons were less likely to achieve suppression than Caucasian participants (aHR=0.58, 95% CI 0.50, 0.68), but not more likely to experience rebound (aHR=1.03, 95% CI 0.84, 1.27) after adjusting for age, gender, injection drug use, men having sex with men status, province of residence, baseline VL and CD4 + T-cell count, antiretroviral class and year of cART initiation. Lower suppression rates among Indigenous persons suggest a need for targeted interventions to improve HIV health outcomes during the first year of treatment when suppression is usually achieved.

Viral Infections

MedlinePlus

... to fight it off. For most viral infections, treatments can only help with symptoms while you wait ... for viral infections. There are antiviral medicines to treat some viral infections. Vaccines can help prevent you ...

Nuclear targeting of viral and non-viral DNA.

PubMed

Chowdhury, E H

2009-07-01

The nuclear envelope presents a major barrier to transgene delivery and expression using a non-viral vector. Virus is capable of overcoming the barrier to deliver their genetic materials efficiently into the nucleus by virtue of the specialized protein components with the unique amino acid sequences recognizing cellular nuclear transport machinery. However, considering the safety issues in the clinical gene therapy for treating critical human diseases, non-viral systems are highly promising compared with their viral counterparts. This review summarizes the progress on exploring the nuclear traffic mechanisms for the prominent viral vectors and the technological innovations for the nuclear delivery of non-viral DNA by mimicking those natural processes evolved for the viruses as well as for many cellular proteins.

Molecular pathogenesis of viral hemorrhagic fever.

PubMed

Basler, Christopher F

2017-07-01

The clinical syndrome referred to as viral hemorrhagic fever (VHF) can be caused by several different families of RNA viruses, including select members of the arenaviruses, bunyaviruses, filoviruses, and flaviviruses. VHF is characterized by malaise, fever, vascular permeability, decreased plasma volume, coagulation abnormalities, and varying degrees of hemorrhage. Study of the filovirus Ebola virus has demonstrated a critical role for suppression of innate antiviral defenses in viral pathogenesis. Additionally, antigen-presenting cells are targets of productive infection and immune dysregulation. Among these cell populations, monocytes and macrophages are proposed to produce damaging inflammatory cytokines, while infected dendritic cells fail to undergo proper maturation, potentially impairing adaptive immunity. Uncontrolled virus replication and accompanying inflammatory responses are thought to promote vascular leakage and coagulopathy. However, the specific molecular pathways that underlie these features of VHF remain poorly understood. The arenavirus Lassa virus and the flavivirus yellow fever virus exhibit similar molecular pathogenesis suggesting common underlying mechanisms. Because non-human primate models that closely mimic VHF are available for Ebola, Lassa, and yellow fever viruses, we propose that comparative molecular studies using these models will yield new insights into the molecular underpinnings of VHF and suggest new therapeutic approaches.

Short Communication: Viral Suppression Is Associated with Increased Likelihood of Colorectal Cancer Screening Among Persons Living with HIV/AIDS.

PubMed

Burkholder, Greer A; Tamhane, Ashutosh R; Appell, Lauren E; Willig, James H; Saag, Michael S; Raper, James L; Westfall, Andrew O; Mugavero, Michael J

2015-05-01

With improved survival and aging, more persons living with HIV/AIDS (PLWHA) are at risk for colorectal cancer (CRC). This retrospective longitudinal study evaluated patient characteristics associated with CRC screening in our HIV cohort. Patients were followed beginning at age 50 years during a study period from January 1, 2003 to December 31, 2010 (n=265). During a median follow-up time of 1.7 years, only 30% of patients underwent CRC screening. The majority of screened patients received endoscopic screening (colonoscopy, 86%; sigmoidoscopy, 8%); among these patients, results were available for 68/75, and adenomatous polyps were found in 13%. No cases of CRC were reported. Among unscreened patients, only 23% had an external primary care provider, indicating an HIV provider was the expected source for CRC screening referral in the majority. Patients with time-varying suppressed HIV viral load were more likely to receive screening (HRadjusted=1.74; 95% CI: 1.05-2.87), independent of CD4 count. Our findings suggest HIV providers are more likely to address non-HIV-related healthcare maintenance when HIV is controlled. In addition, a significant number of neoplastic lesions are likely being missed in PLWHA who have not been screened for CRC. Provision of evidence-based preventive care in addition to HIV care is required for the aging population of PLWHA.

Viral assembly of oriented quantum dot nanowires

NASA Astrophysics Data System (ADS)

Mao, Chuanbin; Flynn, Christine E.; Hayhurst, Andrew; Sweeney, Rozamond; Qi, Jifa; Georgiou, George; Iverson, Brent; Belcher, Angela M.

2003-06-01

The highly organized structure of M13 bacteriophage was used as an evolved biological template for the nucleation and orientation of semiconductor nanowires. To create this organized template, peptides were selected by using a pIII phage display library for their ability to nucleate ZnS or CdS nanocrystals. The successful peptides were expressed as pVIII fusion proteins into the crystalline capsid of the virus. The engineered viruses were exposed to semiconductor precursor solutions, and the resultant nanocrystals that were templated along the viruses to form nanowires were extensively characterized by using high-resolution analytical electron microscopy and photoluminescence. ZnS nanocrystals were well crystallized on the viral capsid in a hexagonal wurtzite or a cubic zinc blende structure, depending on the peptide expressed on the viral capsid. Electron diffraction patterns showed single-crystal type behavior from a polynanocrystalline area of the nanowire formed, suggesting that the nanocrystals on the virus were preferentially oriented with their [001] perpendicular to the viral surface. Peptides that specifically directed CdS nanocrystal growth were also engineered into the viral capsid to create wurtzite CdS virus-based nanowires. Lastly, heterostructured nucleation was achieved with a dual-peptide virus engineered to express two distinct peptides within the same viral capsid. This work represents a genetically controlled biological synthesis route to a semiconductor nanoscale heterostructure.

Viral assembly of oriented quantum dot nanowires.

PubMed

Mao, Chuanbin; Flynn, Christine E; Hayhurst, Andrew; Sweeney, Rozamond; Qi, Jifa; Georgiou, George; Iverson, Brent; Belcher, Angela M

2003-06-10

The highly organized structure of M13 bacteriophage was used as an evolved biological template for the nucleation and orientation of semiconductor nanowires. To create this organized template, peptides were selected by using a pIII phage display library for their ability to nucleate ZnS or CdS nanocrystals. The successful peptides were expressed as pVIII fusion proteins into the crystalline capsid of the virus. The engineered viruses were exposed to semiconductor precursor solutions, and the resultant nanocrystals that were templated along the viruses to form nanowires were extensively characterized by using high-resolution analytical electron microscopy and photoluminescence. ZnS nanocrystals were well crystallized on the viral capsid in a hexagonal wurtzite or a cubic zinc blende structure, depending on the peptide expressed on the viral capsid. Electron diffraction patterns showed single-crystal type behavior from a polynanocrystalline area of the nanowire formed, suggesting that the nanocrystals on the virus were preferentially oriented with their [001] perpendicular to the viral surface. Peptides that specifically directed CdS nanocrystal growth were also engineered into the viral capsid to create wurtzite CdS virus-based nanowires. Lastly, heterostructured nucleation was achieved with a dual-peptide virus engineered to express two distinct peptides within the same viral capsid. This work represents a genetically controlled biological synthesis route to a semiconductor nanoscale heterostructure.

T cells for viral infections after allogeneic hematopoietic stem cell transplant

PubMed Central

Heslop, Helen E.

2016-01-01

Despite recent advances in the field of allogeneic hematopoietic stem cell transplantation (HSCT), viral infections are still a major complication during the period of immune suppression that follows the procedure. Adoptive transfer of donor-derived virus-specific cytotoxic T cells (VSTs) is a strategy to rapidly restore virus-specific immunity to prevent or treat viral diseases after HSCT. Early proof of principle studies demonstrated that the administration of donor-derived T cells specific for cytomegalovirus or Epstein-Barr virus (EBV) could effectively restore virus-specific immunity and control viral infections. Subsequent studies using different expansion or direct selection techniques have shown that donor-derived VSTs confer protection in vivo after adoptive transfer in 70% to 90% of recipients. Because a major cause of failure is lack of immunity to the infecting virus in a naïve donor, more recent studies have infused closely matched third-party VSTs and reported response rates of 60% to 70%. Current efforts have focused on broadening the applicability of this approach by: (1) extending the number of viral antigens being targeted, (2) simplifying manufacture, (3) exploring strategies for recipients of virus-naïve donor grafts, and (4) developing and optimizing “off the shelf” approaches. PMID:27207801

T cells for viral infections after allogeneic hematopoietic stem cell transplant.

PubMed

Bollard, Catherine M; Heslop, Helen E

2016-06-30

Despite recent advances in the field of allogeneic hematopoietic stem cell transplantation (HSCT), viral infections are still a major complication during the period of immune suppression that follows the procedure. Adoptive transfer of donor-derived virus-specific cytotoxic T cells (VSTs) is a strategy to rapidly restore virus-specific immunity to prevent or treat viral diseases after HSCT. Early proof of principle studies demonstrated that the administration of donor-derived T cells specific for cytomegalovirus or Epstein-Barr virus (EBV) could effectively restore virus-specific immunity and control viral infections. Subsequent studies using different expansion or direct selection techniques have shown that donor-derived VSTs confer protection in vivo after adoptive transfer in 70% to 90% of recipients. Because a major cause of failure is lack of immunity to the infecting virus in a naïve donor, more recent studies have infused closely matched third-party VSTs and reported response rates of 60% to 70%. Current efforts have focused on broadening the applicability of this approach by: (1) extending the number of viral antigens being targeted, (2) simplifying manufacture, (3) exploring strategies for recipients of virus-naïve donor grafts, and (4) developing and optimizing "off the shelf" approaches. © 2016 by The American Society of Hematology.

Emodin inhibits coxsackievirus B3 replication via multiple signalling cascades leading to suppression of translation.

PubMed

Zhang, Huifang M; Wang, Fengping; Qiu, Ye; Ye, Xin; Hanson, Paul; Shen, Hongxing; Yang, Decheng

2016-02-15

CVB3 (coxsackievirus 3) is a primary causal agent of viral myocarditis. Emodin is a natural compound isolated from certain plant roots. In the present study, we found that emodin inhibited CVB3 replication in vitro and in mice, and now we report an unrecognized mechanism by which emodin inhibits CVB3 replication through suppression of viral protein translation via multiple pathways. On one hand, emodin treatment inhibited Akt/mTOR (mammalian target of rapamycin) signalling and activated 4EBP1 (eukaryotic initiation factor 4R-binding protein 1), leading to suppression of translation initiation of ribosomal protein L32 encoded by a 5'-TOP (terminal oligopyrimidine) mRNA. On the other hand, emodin treatment differentially regulated multiple signal cascades, including Akt/mTORC1/p70(S6K) (p70 S6 kinase), ERK1/2 (extracellular-signal-regulated kinase 1/2)/p90(RSK) (p90 ribosomal S6 kinase) and Ca(2+)/calmodulin, leading to activation of eEF2K (eukaryotic elongation factor 2 kinase) and subsequent inactivation of eEF2 (eukaryotic elongation factor 2), resulting in inhibition of CVB3 VP1 (viral protein 1) synthesis. These data imply that eEF2K is a major factor mediating cross-talk of different arms of signalling cascades in this signal network. This notion was verified by either overexpressing eEF2K or treating the cells with siRNAs or eEF2K inhibitor A484954. We showed further that the emodin-induced decrease in p70(S6K) phosphorylation plays a dominant positive role in activation of eEF2K and in turn in conferring the antiviral effect of emodin. This finding was further solidified by expressing constitutively active and dominant-negative Akt. Collectively, our data reveal that emodin inhibits viral replication through impairing translational machinery and suppression of viral translation elongation. © 2016 Authors; published by Portland Press Limited.

Three distinct suppressors of RNA silencing encoded by a 20-kb viral RNA genome

NASA Astrophysics Data System (ADS)

Lu, Rui; Folimonov, Alexey; Shintaku, Michael; Li, Wan-Xiang; Falk, Bryce W.; Dawson, William O.; Ding, Shou-Wei

2004-11-01

Viral infection in both plant and invertebrate hosts requires a virus-encoded function to block the RNA silencing antiviral defense. Here, we report the identification and characterization of three distinct suppressors of RNA silencing encoded by the 20-kb plus-strand RNA genome of citrus tristeza virus (CTV). When introduced by genetic crosses into plants carrying a silencing transgene, both p20 and p23, but not coat protein (CP), restored expression of the transgene. Although none of the CTV proteins prevented DNA methylation of the transgene, export of the silencing signal (capable of mediating intercellular silencing spread) was detected only from the F1 plants expressing p23 and not from the CP- or p20-expressing F1 plants, demonstrating suppression of intercellular silencing by CP and p20 but not by p23. Thus, intracellular and intercellular silencing are each targeted by a CTV protein, whereas the third, p20, inhibits silencing at both levels. Notably, CP suppresses intercellular silencing without interfering with intracellular silencing. The novel property of CP suggests a mechanism distinct to p20 and all of the other viral suppressors known to interfere with intercellular silencing and that this class of viral suppressors may not be consistently identified by Agrobacterium coinfiltration because it also induces RNA silencing against the infiltrated suppressor transgene. Our analyses reveal a sophisticated viral counter-defense strategy that targets the silencing antiviral pathway at multiple steps and may be essential for protecting CTV with such a large RNA genome from antiviral silencing in the perennial tree host. RNA interference | citrus tristeza virus | virus synergy | antiviral immunity

Primate Lentiviruses Modulate NF-κB Activity by Multiple Mechanisms to Fine-Tune Viral and Cellular Gene Expression

PubMed Central

Heusinger, Elena; Kirchhoff, Frank

2017-01-01

The transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) plays a complex role during the replication of primate lentiviruses. On the one hand, NF-κB is essential for induction of efficient proviral gene expression. On the other hand, this transcription factor contributes to the innate immune response and induces expression of numerous cellular antiviral genes. Recent data suggest that primate lentiviruses cope with this challenge by boosting NF-κB activity early during the replication cycle to initiate Tat-driven viral transcription and suppressing it at later stages to minimize antiviral gene expression. Human and simian immunodeficiency viruses (HIV and SIV, respectively) initially exploit their accessory Nef protein to increase the responsiveness of infected CD4+ T cells to stimulation. Increased NF-κB activity initiates Tat expression and productive replication. These events happen quickly after infection since Nef is rapidly expressed at high levels. Later during infection, Nef proteins of HIV-2 and most SIVs exert a very different effect: by down-modulating the CD3 receptor, an essential factor for T cell receptor (TCR) signaling, they prevent stimulation of CD4+ T cells via antigen-presenting cells and hence suppress further induction of NF-κB and an effective antiviral immune response. Efficient LTR-driven viral transcription is maintained because it is largely independent of NF-κB in the presence of Tat. In contrast, human immunodeficiency virus type 1 (HIV-1) and its simian precursors have lost the CD3 down-modulation function of Nef and use the late viral protein U (Vpu) to inhibit NF-κB activity by suppressing its nuclear translocation. In this review, we discuss how HIV-1 and other primate lentiviruses might balance viral and antiviral gene expression through a tight temporal regulation of NF-κB activity throughout their replication cycle. PMID:28261165

Interactions between HIV-1 Gag and Viral RNA Genome Enhance Virion Assembly.

PubMed

Dilley, Kari A; Nikolaitchik, Olga A; Galli, Andrea; Burdick, Ryan C; Levine, Louis; Li, Kelvin; Rein, Alan; Pathak, Vinay K; Hu, Wei-Shau

2017-08-15

Most HIV-1 virions contain two copies of full-length viral RNA, indicating that genome packaging is efficient and tightly regulated. However, the structural protein Gag is the only component required for the assembly of noninfectious viruslike particles, and the viral RNA is dispensable in this process. The mechanism that allows HIV-1 to achieve such high efficiency of genome packaging when a packageable viral RNA is not required for virus assembly is currently unknown. In this report, we examined the role of HIV-1 RNA in virus assembly and found that packageable HIV-1 RNA enhances particle production when Gag is expressed at levels similar to those in cells containing one provirus. However, such enhancement is diminished when Gag is overexpressed, suggesting that the effects of viral RNA can be replaced by increased Gag concentration in cells. We also showed that the specific interactions between Gag and viral RNA are required for the enhancement of particle production. Taken together, these studies are consistent with our previous hypothesis that specific dimeric viral RNA-Gag interactions are the nucleation event of infectious virion assembly, ensuring that one RNA dimer is packaged into each nascent virion. These studies shed light on the mechanism by which HIV-1 achieves efficient genome packaging during virus assembly. IMPORTANCE Retrovirus assembly is a well-choreographed event, during which many viral and cellular components come together to generate infectious virions. The viral RNA genome carries the genetic information to new host cells, providing instructions to generate new virions, and therefore is essential for virion infectivity. In this report, we show that the specific interaction of the viral RNA genome with the structural protein Gag facilitates virion assembly and particle production. These findings resolve the conundrum that HIV-1 RNA is selectively packaged into virions with high efficiency despite being dispensable for virion assembly

Abuse and Resilience in Relation to HAART Medication Adherence and HIV Viral Load Among Women with HIV in the United States

PubMed Central

Cohen, Mardge; Weber, Kathleen; Cruise, Ruth; Kelso, Gwendolyn

2014-01-01

Abstract Abuse is highly prevalent among HIV+ women, leading to behaviors, including lower adherence to highly active antiretroviral therapy (HAART) that result in poor health outcomes. Resilience (functioning competently despite adversity) may buffer the negative effects of abuse. This study investigated how resilience interacted with abuse history in relation to HAART adherence, HIV viral load (VL), and CD4+ cell count among a convenience sample of 138 HIV+ women from the Ruth M. Rothstein CORE Center/Cook County Health and Hospital Systems site of the Women's Interagency HIV Study (WIHS). Resilience was measured by the 10-item Connor-Davidson Resilience Scale (CD-RISC). HAART adherence (≥95% vs. <95% self reported usage of prescribed medication) and current or prior sexual, physical, or emotional/domestic abuse, were reported during structured interviews. HIV viral load (≥20 vs. <20 copies/mL) and CD4+ count (200 vs. <200 cells/mm) were measured with blood specimens. Multiple logistic regressions, controlling for age, race, income, enrollment wave, substance use, and depressive symptoms, indicated that each unit increase in resilience was significantly associated with an increase in the odds of having ≥95% HAART adherence and a decrease in the odds of having a detectable viral load. Resilience-Abuse interactions showed that only among HIV+ women with sexual abuse or multiple abuses did resilience significantly relate to an increase in the odds of ≥95% HAART adherence. Interventions to improve coping strategies that promote resilience among HIV+ women may be beneficial for achieving higher HAART adherence and viral suppression. PMID:24568654

Suppression of type I interferon production by porcine epidemic diarrhea virus and degradation of CREB-binding protein by nsp1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Qingzhan; Shi, Kaichuang; Yoo, Dongwan, E-mail: dyoo@illinois.edu

Type I interferons (IFN-α/β) are the major components of the innate immune response of hosts, and in turn many viruses have evolved to modulate the host response during infection. We found that the IFN-β production was significantly suppressed during PEDV infection in cells. To identify viral IFN antagonists and to study their suppressive function, viral coding sequences for the entire structural and nonstructural proteins were cloned and expressed. Of 16 PEDV nonstructural proteins (nsps), nsp1, nsp3, nsp7, nsp14, nsp15 and nsp16 were found to inhibit the IFN-β and IRF3 promoter activities. The sole accessory protein ORF3, structure protein envelope (E),more » membrane (M), and nucleocapsid (N) protein were also shown to inhibit such activities. PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP) by degrading CBP. A further study showed that the CBP degradation by nsp1 was proteasome-dependent. Our data demonstrate that PEDV modulates the host innate immune responses by degrading CBP and suppressing ISGs expression. - Highlights: • PEDV modulates the host innate immune system by suppressing the type I interferon production and ISGs expression. • Ten viral proteins were identified as IFN antagonists, and nsp1 was the most potent viral IFN antagonist. • PEDV nsp1 did not interfere the IRF3 phosphorylation and nuclear translocation but interrupted the enhanceosome assembly of IRF3 and CREB-binding protein (CBP). • PEDV nsp1 caused the CBP degradation in the nucleus, which may be the key mechanism for PEDV-mediated IFN downregulation.« less

Specific interaction between hnRNP H and HPV16 L1 proteins: Implications for late gene auto-regulation enabling rapid viral capsid protein production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Zi-Zheng; Sun, Yuan-Yuan; Zhao, Min

2013-01-18

Highlights: ► The RNA-binding hnRNP H regulates late viral gene expression. ► hnRNP H activity was inhibited by a late viral protein. ► Specific interaction between HPV L1 and hnRNP H was demonstrated. ► Co-localization of HPV L1 and hnRNP H inside cells was observed. ► Viral capsid protein production, enabling rapid capsid assembly, was implicated. -- Abstract: Heterogeneous nuclear ribonucleoproteins (hnRNPs), including hnRNP H, are RNA-binding proteins that function as splicing factors and are involved in downstream gene regulation. hnRNP H, which binds to G triplet regions in RNA, has been shown to play an important role in regulatingmore » the staged expression of late proteins in viral systems. Here, we report that the specific association between hnRNP H and a late viral capsid protein, human papillomavirus (HPV) L1 protein, leads to the suppressed function of hnRNP H in the presence of the L1 protein. The direct interaction between the L1 protein and hnRNP H was demonstrated by complex formation in solution and intracellularly using a variety of biochemical and immunochemical methods, including peptide mapping, specific co-immunoprecipitation and confocal fluorescence microscopy. These results support a working hypothesis that a late viral protein HPV16 L1, which is down regulated by hnRNP H early in the viral life cycle may provide an auto-regulatory positive feedback loop that allows the rapid production of HPV capsid proteins through suppression of the function of hnRNP H at the late stage of the viral life cycle. In this positive feedback loop, the late viral gene products that were down regulated earlier themselves disable their suppressors, and this feedback mechanism could facilitate the rapid production of capsid proteins, allowing staged and efficient viral capsid assembly.« less

An Example of Genetically Distinct HIV Type 1 Variants in Cerebrospinal Fluid and Plasma During Suppressive Therapy

PubMed Central

Dahl, Viktor; Gisslen, Magnus; Hagberg, Lars; Peterson, Julia; Shao, Wei; Spudich, Serena; Price, Richard W.; Palmer, Sarah

2014-01-01

We sequenced the genome of human immunodeficiency virus type 1 (HIV-1) recovered from 70 cerebrospinal fluid (CSF) specimens and 29 plasma samples and corresponding samples obtained before treatment initiation from 17 subjects receiving suppressive therapy. More CSF sequences than plasma sequences were hypermutants. We determined CSF sequences and plasma sequences in specimens obtained from 2 subjects after treatment initiation. In one subject, we found genetically distinct CSF and plasma sequences, indicating that they came from HIV-1 from 2 different compartments, one potentially the central nervous system, during suppressive therapy. In addition, there was little evidence of viral evolution in the CSF during therapy, suggesting that continuous virus replication is not the major cause of viral persistence in the central nervous system. PMID:24338353

An example of genetically distinct HIV type 1 variants in cerebrospinal fluid and plasma during suppressive therapy.

PubMed

Dahl, Viktor; Gisslen, Magnus; Hagberg, Lars; Peterson, Julia; Shao, Wei; Spudich, Serena; Price, Richard W; Palmer, Sarah

2014-05-15

We sequenced the genome of human immunodeficiency virus type 1 (HIV-1) recovered from 70 cerebrospinal fluid (CSF) specimens and 29 plasma samples and corresponding samples obtained before treatment initiation from 17 subjects receiving suppressive therapy. More CSF sequences than plasma sequences were hypermutants. We determined CSF sequences and plasma sequences in specimens obtained from 2 subjects after treatment initiation. In one subject, we found genetically distinct CSF and plasma sequences, indicating that they came from HIV-1 from 2 different compartments, one potentially the central nervous system, during suppressive therapy. In addition, there was little evidence of viral evolution in the CSF during therapy, suggesting that continuous virus replication is not the major cause of viral persistence in the central nervous system.

The Major Apoptotic Pathway Activated and Suppressed by Poliovirus

PubMed Central

Belov, George A.; Romanova, Lyudmila I.; Tolskaya, Elena A.; Kolesnikova, Marina S.; Lazebnik, Yuri A.; Agol, Vadim I.

2003-01-01

Cells respond to poliovirus infection by switching on the apoptotic program, implementation of which is usually suppressed by viral antiapoptotic functions. We show here that poliovirus infection of HeLa cells or derivatives of MCF-7 cells was accompanied by the efflux of cytochrome c from mitochondria. This efflux occurred during both abortive infection (e.g., interrupted by guanidine-HCl and ending with apoptosis) and productive infection (leading to cytopathic effect). The former type of infection, but not the latter, was accompanied by truncation of the proapoptotic protein Bid. The virus-triggered cytochrome c efflux was suppressed by overexpression of Bcl-2. Both abortive and productive infections also resulted in a decreased level of procaspase-9, as revealed by Western blotting. In the former case, this decrease was accompanied by the accumulation of a protein with the electrophoretic mobility of active caspase-9. In contrast, in the productively infected cells, the latter protein was absent but caspase-9-related polypeptides with altered mobility could be detected. Both caspase-9 and caspase-3 were shown to be essential for the development of such hallmarks of virus-induced apoptosis as chromatin condensation, DNA degradation, and nuclear fragmentation. These and some other results suggest the following scenario. Poliovirus infection activates the apoptotic pathway, involving mitochondrial damage, cytochrome c efflux, and consecutive activation of caspase-9 and caspase-3. The apoptotic signal appears to be amplified by a loop which includes secondary processing of Bid. The implementation of the apoptotic program in productively infected cells may be suppressed, however, by the viral antiapoptotic functions, which act at a step(s) downstream of the cytochrome c efflux. The suppression appears to be caused, at least in part, by aberrant processing and degradation of procaspase-9. PMID:12477809

Computerized counseling reduces HIV-1 viral load and sexual transmission risk: findings from a randomized controlled trial.

PubMed

Kurth, Ann E; Spielberg, Freya; Cleland, Charles M; Lambdin, Barrot; Bangsberg, David R; Frick, Pamela A; Severynen, Anneleen O; Clausen, Marc; Norman, Robert G; Lockhart, David; Simoni, Jane M; Holmes, King K

2014-04-15

Evaluate a computerized intervention supporting antiretroviral therapy (ART) adherence and HIV transmission prevention. Longitudinal randomized controlled trial. An academic HIV clinic and a community-based organization in Seattle. In a total of 240 HIV-positive adults on ART, 209 completed 9-month follow-up (87% retention). Randomization to computerized counseling or assessment only, 4 sessions over 9 months. HIV-1 viral suppression, and self-reported ART adherence and transmission risks, compared using generalized estimating equations. Overall, intervention participants had reduced viral load: mean 0.17 log10 decline, versus 0.13 increase in controls, P = 0.053, and significant difference in ART adherence baseline to 9 months (P = 0.046). Their sexual transmission risk behaviors decreased (odds ratio = 0.55, P = 0.020), a reduction not seen among controls (odds ratio = 1.1, P = 0.664), and a significant difference in change (P = 0.040). Intervention effect was driven by those most in need; among those with detectable virus at baseline (>30 copies/mL, n = 89), intervention effect was mean 0.60 log10 viral load decline versus 0.15 increase in controls, P = 0.034. ART adherence at the final follow-up was 13 points higher among intervention participants versus controls, P = 0.038. Computerized counseling is promising for integrated ART adherence and safer sex, especially for individuals with problems in these areas. This is the first intervention to report improved ART adherence, viral suppression, and reduced secondary sexual transmission risk behavior.

Reported Church Attendance at the Time of Entry into HIV Care is Associated with Viral Load Suppression at 12 Months.

PubMed

Van Wagoner, Nicholas; Elopre, Latesha; Westfall, Andrew O; Mugavero, Michael J; Turan, Janet; Hook, Edward W

2016-08-01

The Southeast has high rates of church attendance and HIV infection rates. We evaluated the relationship between church attendance and HIV viremia in a Southeastern US, HIV-infected cohort. Viremia (viral load ≥200 copies/ml) was analyzed 12 months after initiation of care. Univariate and multivariable logistic regression models were fit for variables potentially related to viremia. Of 382 patients, 74 % were virally suppressed at 12 months. Protective variables included church attendance (AOR 0.5; 95 % CI 0.2, 0.9), being on antiretroviral therapy (AOR 0.01; 95 % CI 0.004, 0.04), CD4(+) T lymphocyte count 200-350 cells/mm(3) at care entry (AOR 0.3; 95 % 0.1, 0.9), and education (AOR 0.5; 95 % CI 0.2, 0.9). Variables predicting viremia included black race (AOR 3.2; 95 % CI 1.4, 7.4) and selective disclosure of HIV status (AOR 2.7; 95 % CI 1.2, 5.6). Church attendance may provide needed support for patients entering HIV care for the first time. El Sur Este de los Estados Unidos tiene tasas altas de visitas a iglesias y de infección por VIH. Evaluamos la relación entre visitas a iglesias y viremia por VIH en una cohorte de pacientes infectados con VIH en el Sur Este de los EEUU. La viremia (carga viral ≥ 200 copias/ml) fue analizada a los 12 meses de iniciar el cuidado médico. Los modelos de regresión logística univariado y multivariado fueron ajustados para variables potencialmente relacionadas a viremia. De 382 pacientes, 75 % tuvieron supresión virológica a los 12 meses. Variables que ofrecieron protección fueron visitas a iglesias (AOR 0.5; IC95 % 0.2-0.9), recibir terapia antiretroviral (AOR 0.01; IC95 % 0.004,0.04), recuento de linfocitos T CD4 + 200-350 al iniciar cuidado médico (AOR 0.3; IC95 % 0.1,09), y educación (AOR 0.5; IC95 % 0.2,0.9). Las variables que predijeron viremia incluyeron raza negra (AOR 3.2; IC95 % 1.4,7.4) y la comunicación selectiva del diagnóstico de VIH a otras personas (AOR 2.7; 95 % IC 1

Debunking the Myth of Exercise-Induced Immune Suppression: Redefining the Impact of Exercise on Immunological Health Across the Lifespan.

PubMed

Campbell, John P; Turner, James E

2018-01-01

Epidemiological evidence indicates that regular physical activity and/or frequent structured exercise reduces the incidence of many chronic diseases in older age, including communicable diseases such as viral and bacterial infections, as well as non-communicable diseases such as cancer and chronic inflammatory disorders. Despite the apparent health benefits achieved by leading an active lifestyle, which imply that regular physical activity and frequent exercise enhance immune competency and regulation, the effect of a single bout of exercise on immune function remains a controversial topic. Indeed, to this day, it is perceived by many that a vigorous bout of exercise can temporarily suppress immune function. In the first part of this review, we deconstruct the key pillars which lay the foundation to this theory-referred to as the "open window" hypothesis-and highlight that: (i) limited reliable evidence exists to support the claim that vigorous exercise heightens risk of opportunistic infections; (ii) purported changes to mucosal immunity, namely salivary IgA levels, after exercise do not signpost a period of immune suppression; and (iii) the dramatic reductions to lymphocyte numbers and function 1-2 h after exercise reflects a transient and time-dependent redistribution of immune cells to peripheral tissues, resulting in a heightened state of immune surveillance and immune regulation, as opposed to immune suppression. In the second part of this review, we provide evidence that frequent exercise enhances-rather than suppresses-immune competency, and highlight key findings from human vaccination studies which show heightened responses to bacterial and viral antigens following bouts of exercise. Finally, in the third part of this review, we highlight that regular physical activity and frequent exercise might limit or delay aging of the immune system, providing further evidence that exercise is beneficial for immunological health. In summary, the over-arching aim of

Effect of HIV Antibody VRC01 on Viral Rebound after Treatment Interruption

PubMed Central

Bar, K.J.; Sneller, M.C.; Harrison, L.J.; Justement, J.S.; Overton, E.T.; Petrone, M.E.; Salantes, D.B.; Seamon, C.A.; Scheinfeld, B.; Kwan, R.W.; Learn, G.H.; Proschan, M.A.; Kreider, E.F.; Blazkova, J.; Bardsley, M.; Refsland, E.W.; Messer, M.; Clarridge, K.E.; Tustin, N.B.; Madden, P.J.; Oden, K.S.; O’Dell, S.J.; Jarocki, B.; Shiakolas, A.R.; Tressler, R.L.; Doria-Rose, N.A.; Bailer, R.T.; Ledgerwood, J.E.; Capparelli, E.V.; Lynch, R.M.; Graham, B.S.; Moir, S.; Koup, R.A.; Mascola, J.R.; Hoxie, J.A.; Fauci, A.S.; Tebas, P.; Chun, T.-W.

2017-01-01

BACKGROUND The discovery of potent and broadly neutralizing antibodies (bNAbs) against human immunodeficiency virus (HIV) has made passive immunization a potential strategy for the prevention and treatment of HIV infection. We sought to determine whether passive administration of VRC01, a bNAb targeting the HIV CD4-binding site, can safely prevent or delay plasma viral rebound after the discontinuation of antiretroviral therapy (ART). METHODS We conducted two open-label trials (AIDS Clinical Trials Group [ACTG] A5340 and National Institutes of Health [NIH] 15-I-0140) of the safety, side-effect profile, pharmacokinetic properties, and antiviral activity of VRC01 in persons with HIV infection who were undergoing interruption of ART. RESULTS A total of 24 participants were enrolled, and one serious alcohol-related adverse event occurred. Viral rebound occurred despite plasma VRC01 concentrations greater than 50 μg per milliliter. The median time to rebound was 4 weeks in the A5340 trial and 5.6 weeks in the NIH trial. Study participants were more likely than historical controls to have viral suppression at week 4 (38% vs. 13%, P = 0.04 by a two-sided Fisher’s exact test in the A5340 trial; and 80% vs. 13%, P<0.001 by a two-sided Fisher’s exact test in the NIH trial) but the difference was not significant at week 8. Analyses of virus populations before ART as well as before and after ART interruption showed that VRC01 exerted pressure on rebounding virus, resulting in restriction of recrudescent viruses and selection for preexisting and emerging antibody neutralization–resistant virus. CONCLUSIONS VRC01 slightly delayed plasma viral rebound in the trial participants, as compared with historical controls, but it did not maintain viral suppression by week 8. In the small number of participants enrolled in these trials, no safety concerns were identified with passive immunization with a single bNAb (VRC01). (Funded by the National Institute of Allergy and

Non-Disclosure of HIV Status and Associations with Psychological Factors, ART Non-Adherence, and Viral Load Non-Suppression Among People Living with HIV in the UK.

PubMed

Daskalopoulou, Marina; Lampe, Fiona C; Sherr, Lorraine; Phillips, Andrew N; Johnson, Margaret A; Gilson, Richard; Perry, Nicky; Wilkins, Ed; Lascar, Monica; Collins, Simon; Hart, Graham; Speakman, Andrew; Rodger, Alison J

2017-01-01

Disclosure of HIV status to family, friends, and a stable partner may be linked to improved health outcomes for people living with HIV. This study assessed whether non-disclosure is associated with psychological symptoms, non-adherence to antiretroviral therapy (ART), and viral load (VL) non-suppression. A total of 3258 HIV-diagnosed individuals in the UK completed the confidential ASTRA study questionnaire (2011-2012). Participants reported whether they told anyone they had HIV; to which confidant(s) (friends, family, work colleagues, stable partner) and to what extent (none, some, most/all). The prevalence and factors associated with non-disclosure were assessed. Associations between non-disclosure and the following factors were established using modified Poisson regression with adjustment for socio-demographic factors (gender, age group, ethnicity), HIV-related factors (time since HIV diagnosis, ART status), and clinic: low social support (score ≤ 12 on modified Duke-UNC FSSQ); depression and anxiety symptoms (≥10 on PHQ-9 and GAD-7 respectively); self-reported ART non-adherence in past 2 weeks/3 months; VL non-suppression (clinic-recorded VL > 50 copies/mL among those who started ART ≥ 6 months ago). Among 3233 participants with disclosure data, the prevalence of non-disclosure to anyone was 16.6 % (n/N = 61/367) among heterosexual men, 15.7 % (98/626) among women, and 5.0 % (113/2240) among MSM. MSM were more likely to disclose to some/all friends compared to family (85.8 vs. 59.9 %) while heterosexuals were less likely to disclose to friends than family (44.1 vs. 61.1 % for men, 57.5 vs. 67.1 % for women). Among 1,631 participants with a stable partner, non-disclosure to a stable partner was 4.9 % for MSM, 10.9 % for heterosexual men, and 13.0 % for women. In adjusted analyses, older age (≥60 years), non-white ethnicity, more recent HIV diagnosis, and not having a stable partner were significantly associated with overall non

Evaluating the care cascade after antiretroviral therapy initiation in Latin America

PubMed Central

Wolff, Marcelo J; Cortes, Claudia P; Mejìa, Fernando A; Padgett, Denis; Belaunzarán-Zamudio, Pablo; Grinsztejn, Beatriz; Giganti, Mark J; McGowan, Catherine C; Rebeiro, Peter F

2018-01-01

Accelerating antiretroviral therapy (ART) administration, improving retention, and achieving viral suppression in low- and middle-income countries must be prioritized. We evaluated trends and disparities in these milestones in a large Latin American cohort. Adults starting ART (ARTstart) from 2003 to 2014 at Caribbean, Central, and South America network for HIV epidemiology sites were assessed for care cascade outcomes: CD4 cell count >200 cells/mm3 at ARTstart; retention (≥1 visit at one year after ARTstart); viral suppression (≥1 HIV-1 RNA <200 copies/ml at one year after ARTstart). Modified Poisson regression provided adjusted prevalence ratios by age, gender, and HIV transmission risk, accounting for site and year of ARTstart. Proportions achieving ARTstart and suppression improved over time (p < 0.05). Older age was associated with better retention and viral suppression, but not ARTstart at CD4 cell count >200 cells/mm3. Females and men who have sex with men (MSM) were more likely to have CD4 cell count >200 cells/mm3 at ARTstart. Injection drug users (IDUs) were less likely to be retained while MSM were more likely to achieve viral suppression (all p <0.05). Despite improvements in these outcomes over the course of a decade in this cohort, significant disparities existed, disadvantaging younger patients, men, and IDUs. These gaps indicate continued progress in providing early diagnosis and ARTstart remain critical. PMID:28618980

Defining the chemokine basis for leukocyte recruitment during viral encephalitis.

PubMed

Michlmayr, Daniela; McKimmie, Clive S; Pingen, Marieke; Haxton, Ben; Mansfield, Karen; Johnson, Nicholas; Fooks, Anthony R; Graham, Gerard J

2014-09-01

The encephalitic response to viral infection requires local chemokine production and the ensuing recruitment of immune and inflammatory leukocytes. Accordingly, chemokine receptors present themselves as plausible therapeutic targets for drugs aimed at limiting encephalitic responses. However, it remains unclear which chemokines are central to this process and whether leukocyte recruitment is important for limiting viral proliferation and survival in the brain or whether it is predominantly a driver of coincident inflammatory pathogenesis. Here we examine chemokine expression and leukocyte recruitment in the context of avirulent and virulent Semliki Forest virus (SFV) as well as West Nile virus infection and demonstrate rapid and robust expression of a variety of inflammatory CC and CXC chemokines in all models. On this basis, we define a chemokine axis involved in leukocyte recruitment to the encephalitic brain during SFV infection. CXCR3 is the most active; CCR2 is also active but less so, and CCR5 plays only a modest role in leukocyte recruitment. Importantly, inhibition of each of these receptors individually and the resulting suppression of leukocyte recruitment to the infected brain have no effect on viral titer or survival following infection with a virulent SFV strain. In contrast, simultaneous blockade of CXCR3 and CCR2 results in significantly reduced mortality in response to virulent SFV infection. In summary, therefore, our data provide an unprecedented level of insight into chemokine orchestration of leukocyte recruitment in viral encephalitis. Our data also highlight CXCR3 and CCR2 as possible therapeutic targets for limiting inflammatory damage in response to viral infection of the brain. Brain inflammation (encephalitis) in response to viral infection can lead to severe illness and even death. This therefore represents an important clinical problem and one that requires the development of new therapeutic approaches. Central to the pathogenesis of

The impact of representative payee services on medication adherence among unstably housed people living with HIV/AIDS.

PubMed

Hawk, Mary; McLaughlin, Jamie; Farmartino, Christina; King, Miranda; Davis, Dana

2016-01-01

Rates of viral suppression among people living with HIV/AIDS remain low, especially within marginalized populations such as people who are unstably housed. Representative payee is a service in which the US Social Security Administration appoints an individual or an organization to provide financial management for vulnerable individuals who are unable to manage their finances including housing payments. Little or no published research examines the association between financial management services such as representative payee and HIV clinical adherence. We conducted a pilot study with 18 unstably housed participants living with HIV/AIDS to examine the impact of representative payee services on viral suppression. Of the 11 participants who were not virally suppressed at baseline, 9 (81.8%) of them had achieved viral suppression at six-month follow-up (p = .004). Our findings suggest that providing unstably housed people living with HIV/AIDS with representative payee services may help them to improve their housing stability and clinical adherence. Additional research is needed to fully explore correlations between representative payee services and viral suppression.

Viral meningitis.

PubMed

Chadwick, David R

2005-01-01

Viruses probably account for most cases of acute meningitis. Viral meningitis is often assumed to be a largely benign disease. For the commonest pathogens causing meningitis, enteroviruses, this is usually the case; however, for many of the other pathogens causing viral meningitis, and for common pathogens in the immunocompromised or infants, viral meningitis is frequently associated with substantial neurological complications and a significant mortality. Diagnostic methods for rapid and accurate identification of pathogens have improved over recent years, permitting more precise and earlier diagnoses. There have been fewer developments in therapies for viral meningitis, and there remain no effective therapies for most pathogens, emphasising the importance of prevention and early diagnosis. This review focuses on the presentation, diagnosis and management of viral meningitis and also covers the prevention of meningitis for pathogens where effective vaccines are available.

Induction and suppression of antiviral RNA interference by influenza A virus in mammalian cells.

PubMed

Li, Yang; Basavappa, Megha; Lu, Jinfeng; Dong, Shuwei; Cronkite, D Alexander; Prior, John T; Reinecker, Hans-Christian; Hertzog, Paul; Han, Yanhong; Li, Wan-Xiang; Cheloufi, Sihem; Karginov, Fedor V; Ding, Shou-Wei; Jeffrey, Kate L

2016-12-05

Influenza A virus (IAV) causes annual epidemics and occasional pandemics, and is one of the best-characterized human RNA viral pathogens 1 . However, a physiologically relevant role for the RNA interference (RNAi) suppressor activity of the IAV non-structural protein 1 (NS1), reported over a decade ago 2 , remains unknown 3 . Plant and insect viruses have evolved diverse virulence proteins to suppress RNAi as their hosts produce virus-derived small interfering RNAs (siRNAs) that direct specific antiviral defence 4-7 by an RNAi mechanism dependent on the slicing activity of Argonaute proteins (AGOs) 8,9 . Recent studies have documented induction and suppression of antiviral RNAi in mouse embryonic stem cells and suckling mice 10,11 . However, it is still under debate whether infection by IAV or any other RNA virus that infects humans induces and/or suppresses antiviral RNAi in mature mammalian somatic cells 12-21 . Here, we demonstrate that mature human somatic cells produce abundant virus-derived siRNAs co-immunoprecipitated with AGOs in response to IAV infection. We show that the biogenesis of viral siRNAs from IAV double-stranded RNA (dsRNA) precursors in infected cells is mediated by wild-type human Dicer and potently suppressed by both NS1 of IAV as well as virion protein 35 (VP35) of Ebola and Marburg filoviruses. We further demonstrate that the slicing catalytic activity of AGO2 inhibits IAV and other RNA viruses in mature mammalian cells, in an interferon-independent fashion. Altogether, our work shows that IAV infection induces and suppresses antiviral RNAi in differentiated mammalian somatic cells.

Platelet activation suppresses HIV-1 infection of T cells

PubMed Central

2013-01-01

Background Platelets, anucleate cell fragments abundant in human blood, can capture HIV-1 and platelet counts have been associated with viral load and disease progression. However, the impact of platelets on HIV-1 infection of T cells is unclear. Results We found that platelets suppress HIV-1 spread in co-cultured T cells in a concentration-dependent manner. Platelets containing granules inhibited HIV-1 spread in T cells more efficiently than degranulated platelets, indicating that the granule content might exert antiviral activity. Indeed, supernatants from activated and thus degranulated platelets suppressed HIV-1 infection. Infection was inhibited at the stage of host cell entry and inhibition was independent of the viral strain or coreceptor tropism. In contrast, blockade of HIV-2 and SIV entry was less efficient. The chemokine CXCL4, a major component of platelet granules, blocked HIV-1 entry and neutralization of CXCL4 in platelet supernatants largely abrogated their anti-HIV-1 activity. Conclusions Release of CXCL4 by activated platelets inhibits HIV-1 infection of adjacent T cells at the stage of virus entry. The inhibitory activity of platelet-derived CXCL4 suggests a role of platelets in the defense against infection by HIV-1 and potentially other pathogens. PMID:23634812

Platelet activation suppresses HIV-1 infection of T cells.

PubMed

Solomon Tsegaye, Theodros; Gnirß, Kerstin; Rahe-Meyer, Niels; Kiene, Miriam; Krämer-Kühl, Annika; Behrens, Georg; Münch, Jan; Pöhlmann, Stefan

2013-05-01

Platelets, anucleate cell fragments abundant in human blood, can capture HIV-1 and platelet counts have been associated with viral load and disease progression. However, the impact of platelets on HIV-1 infection of T cells is unclear. We found that platelets suppress HIV-1 spread in co-cultured T cells in a concentration-dependent manner. Platelets containing granules inhibited HIV-1 spread in T cells more efficiently than degranulated platelets, indicating that the granule content might exert antiviral activity. Indeed, supernatants from activated and thus degranulated platelets suppressed HIV-1 infection. Infection was inhibited at the stage of host cell entry and inhibition was independent of the viral strain or coreceptor tropism. In contrast, blockade of HIV-2 and SIV entry was less efficient. The chemokine CXCL4, a major component of platelet granules, blocked HIV-1 entry and neutralization of CXCL4 in platelet supernatants largely abrogated their anti-HIV-1 activity. Release of CXCL4 by activated platelets inhibits HIV-1 infection of adjacent T cells at the stage of virus entry. The inhibitory activity of platelet-derived CXCL4 suggests a role of platelets in the defense against infection by HIV-1 and potentially other pathogens.

Viral eradication reduces both liver stiffness and steatosis in patients with chronic hepatitis C virus infection who received direct-acting anti-viral therapy.

PubMed

Tada, T; Kumada, T; Toyoda, H; Sone, Y; Takeshima, K; Ogawa, S; Goto, T; Wakahata, A; Nakashima, M; Nakamuta, M; Tanaka, J

2018-04-01

Whether direct-acting anti-viral therapy can reduce liver fibrosis and steatosis in patients with chronic hepatitis C virus (HCV) infection is unclear. To evaluate changes in liver stiffness and steatosis in patients with HCV who received direct-acting anti-viral therapy and achieved sustained virological response (SVR). A total of 198 patients infected with HCV genotype 1 or 2 who achieved SVR after direct-acting anti-viral therapy were analysed. Liver stiffness as evaluated by magnetic resonance elastography, steatosis as evaluated by magnetic resonance imaging-determined proton density fat fraction (PDFF), insulin resistance, and laboratory data were assessed before treatment (baseline) and at 24 weeks after the end of treatment (SVR24). Alanine aminotransferase and homeostatic model assessment-insulin resistance levels decreased significantly from baseline to SVR24. Conversely, platelet count, which is inversely associated with liver fibrosis, increased significantly from baseline to SVR24. In patients with high triglyceride levels (≥150 mg/dL), triglyceride levels significantly decreased from baseline to SVR24 (P = 0.004). The median (interquartile range) liver stiffness values at baseline and SVR24 were 3.10 (2.70-4.18) kPa and 2.80 (2.40-3.77) kPa respectively (P < 0.001). The PDFF values at baseline and SVR 24 were 2.4 (1.7-3.4)% and 1.9 (1.3-2.8)% respectively (P < 0.001). In addition, 68% (19/28) of patients with fatty liver at baseline (PDFF ≥5.2%; n = 28) no longer had fatty liver (PDFF <5.2%) at SVR24. Viral eradication reduces both liver stiffness and steatosis in patients with chronic HCV who received direct-acting anti-viral therapy (UMIN000017020). © 2018 John Wiley & Sons Ltd.

A Tale of Two RNAs during Viral Infection: How Viruses Antagonize mRNAs and Small Non-Coding RNAs in The Host Cell

PubMed Central

Herbert, Kristina M.; Nag, Anita

2016-01-01

Viral infection initiates an array of changes in host gene expression. Many viruses dampen host protein expression and attempt to evade the host anti-viral defense machinery. Host gene expression is suppressed at several stages of host messenger RNA (mRNA) formation including selective degradation of translationally competent messenger RNAs. Besides mRNAs, host cells also express a variety of noncoding RNAs, including small RNAs, that may also be subject to inhibition upon viral infection. In this review we focused on different ways viruses antagonize coding and noncoding RNAs in the host cell to its advantage. PMID:27271653

Plasmacytoid dendritic cell and functional HIV Gag p55-specific T cells before treatment interruption can inform set-point plasma HIV viral load after treatment interruption in chronically suppressed HIV-1(+) patients.

PubMed

Papasavvas, Emmanouil; Foulkes, Andrea; Yin, Xiangfan; Joseph, Jocelin; Ross, Brian; Azzoni, Livio; Kostman, Jay R; Mounzer, Karam; Shull, Jane; Montaner, Luis J

2015-07-01

The identification of immune correlates of HIV control is important for the design of immunotherapies that could support cure or antiretroviral therapy (ART) intensification-related strategies. ART interruptions may facilitate this task through exposure of an ART partially reconstituted immune system to endogenous virus. We investigated the relationship between set-point plasma HIV viral load (VL) during an ART interruption and innate/adaptive parameters before or after interruption. Dendritic cell (DC), natural killer (NK) cell and HIV Gag p55-specific T-cell functional responses were measured in paired cryopreserved peripheral blood mononuclear cells obtained at the beginning (on ART) and at set-point of an open-ended interruption from 31 ART-suppressed chronically HIV-1(+) patients. Spearman correlation and linear regression modeling were used. Frequencies of plasmacytoid DC (pDC), and HIV Gag p55-specific CD3(+)  CD4(-)  perforin(+)  IFN-γ(+) cells at the beginning of interruption associated negatively with set-point plasma VL. Inclusion of both variables with interaction into a model resulted in the best fit (adjusted R(2)  = 0·6874). Frequencies of pDC or HIV Gag p55-specific CD3(+)  CD4(-)  CSFE(lo)  CD107a(+) cells at set-point associated negatively with set-point plasma VL. The dual contribution of pDC and anti-HIV T-cell responses to viral control, supported by our models, suggests that these variables may serve as immune correlates of viral control and could be integrated in cure or ART-intensification strategies. © 2015 John Wiley & Sons Ltd.

MRKAd5 HIV-1 Gag/Pol/Nef Vaccine-Induced T-Cell Responses Inadequately Predict Distance of Breakthrough HIV-1 Sequences to the Vaccine or Viral Load

PubMed Central

Janes, Holly; Frahm, Nicole; DeCamp, Allan; Rolland, Morgane; Gabriel, Erin; Wolfson, Julian; Hertz, Tomer; Kallas, Esper; Goepfert, Paul; Friedrich, David P.; Corey, Lawrence; Mullins, James I.; McElrath, M. Juliana; Gilbert, Peter

2012-01-01

Background The sieve analysis for the Step trial found evidence that breakthrough HIV-1 sequences for MRKAd5/HIV-1 Gag/Pol/Nef vaccine recipients were more divergent from the vaccine insert than placebo sequences in regions with predicted epitopes. We linked the viral sequence data with immune response and acute viral load data to explore mechanisms for and consequences of the observed sieve effect. Methods Ninety-one male participants (37 placebo and 54 vaccine recipients) were included; viral sequences were obtained at the time of HIV-1 diagnosis. T-cell responses were measured 4 weeks post-second vaccination and at the first or second week post-diagnosis. Acute viral load was obtained at RNA-positive and antibody-negative visits. Findings Vaccine recipients had a greater magnitude of post-infection CD8+ T cell response than placebo recipients (median 1.68% vs 1.18%; p = 0·04) and greater breadth of post-infection response (median 4.5 vs 2; p = 0·06). Viral sequences for vaccine recipients were marginally more divergent from the insert than placebo sequences in regions of Nef targeted by pre-infection immune responses (p = 0·04; Pol p = 0·13; Gag p = 0·89). Magnitude and breadth of pre-infection responses did not correlate with distance of the viral sequence to the insert (p>0·50). Acute log viral load trended lower in vaccine versus placebo recipients (estimated mean 4·7 vs 5·1) but the difference was not significant (p = 0·27). Neither was acute viral load associated with distance of the viral sequence to the insert (p>0·30). Interpretation Despite evidence of anamnestic responses, the sieve effect was not well explained by available measures of T-cell immunogenicity. Sequence divergence from the vaccine was not significantly associated with acute viral load. While point estimates suggested weak vaccine suppression of viral load, the result was not significant and more viral load data would be needed to detect suppression. PMID

Food insecurity may lead to incomplete HIV viral suppression and less immune reconstitution among HIV/hepatitis C virus-coinfected people.

PubMed

Aibibula, W; Cox, J; Hamelin, A-M; Moodie, Eem; Naimi, A I; McLinden, T; Klein, M B; Brassard, P

2018-02-01

The aim of this study was to determine the impact of food insecurity (FI) on HIV viral load and CD4 count among people coinfected with HIV and hepatitis C virus (HCV). This study was conducted using data from the Food Security & HIV-HCV Sub-Study of the Canadian Co-Infection Cohort study. FI was measured using the adult scale of Health Canada's Household Food Security Survey Module and was classified into three categories: food security, moderate food insecurity and severe food insecurity. The association between FI, HIV viral load, and CD4 count was assessed using a stabilized inverse probability weighted marginal structural model. A total of 725 HIV/HCV-coinfected people with 1973 person-visits over 3 years of follow-up contributed to this study. At baseline, 23% of participants experienced moderate food insecurity and 34% experienced severe food insecurity. The proportion of people with undetectable HIV viral load was 75% and the median CD4 count was 460 [interquartile range (IQR): 300-665] cells/μL. People experiencing severe food insecurity had 1.47 times [95% confidence interval (CI): 1.14, 1.88] the risk of having detectable HIV viral load and a 0.91-fold (95% CI: 0.84, 0.98) increase in CD4 count compared with people who were food secure. These findings provide evidence of the negative impact of food insecurity on HIV viral load and CD4 count among HIV/HCV-coinfected people. © 2017 British HIV Association.

Discordant CSF/plasma HIV-1 RNA in individuals on virologically suppressive antiretroviral therapy in Western India.

PubMed

Dravid, Ameet N; Natrajan, Kartik; Kulkarni, Milind M; Saraf, Chinmay K; Mahajan, Uma S; Kore, Sachin D; Rathod, Niranjan M; Mahajan, Umakant S; Wadia, Rustom S

2018-02-01

Aim of this study was to estimate the prevalence of cerebrospinal fluid (CSF)/Plasma HIV-1 RNA discordance in virologically suppressed individuals presenting with incident neurologic symptoms.In this retrospective cohort study conducted between March 1, 2009, and March 1, 2017, HIV-1 infected adults exposed to atleast 12 months of antiretroviral therapy (ART) and having plasma viral load (VL) <1000 copies/mL (virologically suppressed) were included. Among these, individuals presenting with neurologic symptoms during follow-up were assessed for CSF/Plasma HIV-1 RNA discordance by measuring HIV-1 RNA in collected plasma and CSF samples. CSF/plasma HIV-1 RNA discordance was defined as either detectable CSF HIV-1 RNA (VL > 20 copies/mL) with an undetectable plasma RNA (complete viral suppression, VL ≤20 copies/mL) or CSF HIV-1 RNA ≥ 0.5 log10 higher than plasma RNA when plasma VL was between 20 and 1000 copies/mL (low-level viremia, LLV).Out of 1584 virologically suppressed patients, 71 (4.4%) presented with incident neurologic symptoms. Twenty out of 71 (28.2%) patients were diagnosed with CSF/Plasma HIV-1 discordance. Median plasma and CSF VL in patients with discordance was 120 [interquartile range (IQR): <20 to 332.5] and 4250 (IQR: 2550.0- 9615.0) copies/mL, respectively. All 9 individuals in which CSF HIV-1 genotypic resistance testing was done showed mutations that would compromise efficacy of prescribed ART regimen. Prevalence of CSF/plasma HIV-1 RNA discordance was higher among neurologically symptomatic patients with plasma LLV as compared with those with complete viral suppression (70% vs 11.8%, P < .001). The risk of discordance was also greater in patients who received protease inhibitor (PI) containing ART (P < .001) and those on ART regimens with central nervous system (CNS) penetration effectiveness (CPE) value <6 (P = .006).CSF/plasma HIV-1 RNA discordance indicates replication of HIV-1 that has adapted to the CNS or has

Fat grafting as a vehicle for the delivery of recombinant adenoassociated viral vectors to achieve gene modification of muscle flaps.

PubMed

Carruthers, Katherine H; During, Matthew J; Muravlev, Alexander; Wang, Chuansong; Kocak, Ergun

2013-06-01

The combination of gene therapy and plastic surgery may have the potential to improve the specificity that is needed to achieve clinically applicable treatment regimens. Our goal was to develop a method for gene modification that would yield sustainable production of gene products but would be less time consuming than existing protocols. An adenoassociated virus was used to deliver gene products to pectoralis muscle flaps. Gene modification was accomplished via either direct injection or novel fat grafting techniques. The production of gene product was observable by both in vivo imaging and immunohistochemical staining. Gene products were not detected in tissues that were not in contact with the fat grafts that were incubated with the viral vector, indicating that the transduction stayed local to the flap. Using novel recombinant adenoassociated virus vectors, we have developed a method for gene delivery that is highly efficient and applicable to muscle flaps.

Community-driven demand creation for the use of routine viral load testing: a model to scale up routine viral load testing.

PubMed

Killingo, Bactrin M; Taro, Trisa B; Mosime, Wame N

2017-11-01

HIV treatment outcomes are dependent on the use of viral load measurement. Despite global and national guidelines recommending the use of routine viral load testing, these policies alone have not translated into widespread implementation or sufficiently increased access for people living with HIV (PLHIV). Civil society and communities of PLHIV recognize the need to close this gap and to enable the scale up of routine viral load testing. The International Treatment Preparedness Coalition (ITPC) developed an approach to community-led demand creation for the use of routine viral load testing. Using this Community Demand Creation Model, implementers follow a step-wise process to capacitate and empower communities to address their most pressing needs. This includes utlizing a specific toolkit that includes conducting a baseline assessment, developing a treatment education toolkit, organizing mobilization workshops for knowledge building, provision of small grants to support advocacy work and conducting benchmark evaluations. The Community Demand Creation Model to increase demand for routine viral load testing services by PLHIV has been delivered in diverse contexts including in the sub-Saharan African, Asian, Latin American and the Caribbean regions. Between December 2015 and December 2016, ITPC trained more than 240 PLHIV activists, and disbursed US$90,000 to network partners in support of their national advocacy work. The latter efforts informed a regional, community-driven campaign calling for domestic investment in the expeditious implementation of national viral load testing guidelines. HIV treatment education and community mobilization are critical components of demand creation for access to optimal HIV treatment, especially for the use of routine viral load testing. ITPC's Community Demand Creation Model offers a novel approach to achieving this goal. © 2017 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of

TCRγδ+CD4−CD8− T Cells Suppress the CD8+ T-Cell Response to Hepatitis B Virus Peptides, and Are Associated with Viral Control in Chronic Hepatitis B

PubMed Central

Lai, Qintao; Ma, Shiwu; Ge, Jun; Huang, Zuxiong; Huang, Xuan; Jiang, Xiaotao; Li, Yongyin; Zhang, Mingxia; Zhang, Xiaoyong; Sun, Jian; Abbott, William G. H.; Hou, Jinlin

2014-01-01

The immune mechanisms underlying failure to achieve hepatitis B e antigen (HBeAg) seroconversion associated with viral control in chronic hepatitis B (CHB) remain unclear. Here we investigated the role of CD4−CD8− T (double-negative T; DNT) cells including TCRαβ+ DNT (αβ DNT) and TCRγδ+ DNT (γδ DNT) cells. Frequencies of circulating DNT cell subsets were measured by flow cytometry in a retrospective cohort of 51 telbivudine-treated HBeAg-positive CHB patients, 25 immune tolerant carriers (IT), 33 inactive carriers (IC), and 37 healthy controls (HC). We found that γδ DNT cell frequencies did not significantly change during treatment, being lower at baseline (P = 0.019) in patients with HBeAg seroconversion after 52 weeks of antiviral therapy (n = 20) than in those without (n = 31), and higher in the total CHB and IT than IC and HC groups (P<0.001). αβ DNT cell frequencies were similar for all groups. In vitro, γδ DNT cells suppressed HBV core peptide-stimulated interferon-γ and tumor necrosis factor-α production in TCRαβ+CD8+ T cells, which may require cell–cell contact, and could be partially reversed by anti-NKG2A. These findings suggest that γδ DNT cells limit CD8+ T cell response to HBV, and may impede HBeAg seroconversion in CHB. PMID:24551107

hnRNP A2/B1 interacts with influenza A viral protein NS1 and inhibits virus replication potentially through suppressing NS1 RNA/protein levels and NS1 mRNA nuclear export

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yimeng; Zhou, Jianhong; Du, Yuchun, E-mail: ydu@uark.edu

The NS1 protein of influenza viruses is a major virulence factor and exerts its function through interacting with viral/cellular RNAs and proteins. In this study, we identified heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) as an interacting partner of NS1 proteins by a proteomic method. Knockdown of hnRNP A2/B1 by small interfering RNA (siRNA) resulted in higher levels of NS vRNA, NS1 mRNA, and NS1 protein in the virus-infected cells. In addition, we demonstrated that hnRNP A2/B1 proteins are associated with NS1 and NS2 mRNAs and that knockdown of hnRNP A2/B1 promotes transport of NS1 mRNA from the nucleus to themore » cytoplasm in the infected cells. Lastly, we showed that knockdown of hnRNP A2/B1 leads to enhanced virus replication. Our results suggest that hnRNP A2/B1 plays an inhibitory role in the replication of influenza A virus in host cells potentially through suppressing NS1 RNA/protein levels and NS1 mRNA nucleocytoplasmic translocation. - Highlights: • Cellular protein hnRNP A2/B1 interacts with influenza viral protein NS1. • hnRNP A2/B1 suppresses the levels of NS1 protein, vRNA and mRNA in infected cells. • hnRNP A2/B1 protein is associated with NS1 and NS2 mRNAs. • hnRNP A2/B1 inhibits the nuclear export of NS1 mRNAs. • hnRNP A2/B1 inhibits influenza virus replication.« less

Pharyngitis - viral

MedlinePlus

... throat is due to a viral infection. The antibiotics will not help. Using them to treat viral infections helps bacteria become resistant to antibiotics. With some sore throats (such as those caused ...

Rheum emodin inhibits enterovirus 71 viral replication and affects the host cell cycle environment

PubMed Central

Zhong, Ting; Zhang, Li-ying; Wang, Zeng-yan; Wang, Yue; Song, Feng-mei; Zhang, Ya-hong; Yu, Jing-hua

2017-01-01

Human enterovirus 71 (EV71) is the primary causative agent of recent large-scale outbreaks of hand, foot, and mouth disease (HFMD) in Asia. Currently, there are no drugs available for the prevention and treatment of HFMD. In this study, we compared the anti-EV71 activities of three natural compounds, rheum emodin, artemisinin and astragaloside extracted from Chinese herbs Chinese rhubarb, Artemisia carvifolia and Astragalus, respectively, which have been traditionally used for the treatment and prevention of epidemic diseases. Human lung fibroblast cell line MRC5 was mock-infected or infected with EV71, and treated with drugs. The cytotoxicity of the drugs was detected with MTT assay. The cytopathic effects such as cell death and condensed nuclei were morphologically observed. The VP1-coding sequence required for EV71 genome replication was assayed with qRT-PCR. Viral protein expression was analyzed with Western blotting. Viral TCID50 was determined to evaluate EV71 virulence. Flow cytometry analysis of propidium iodide staining was performed to analyze the cell cycle distribution of MRC5 cells. Rheum emodin (29.6 μmol/L) effectively protected MRC5 cells from EV71-induced cytopathic effects, which resulted from the inhibiting viral replication: rheum emodin treatment decreased viral genomic levels by 5.34-fold, viral protein expression by less than 30-fold and EV71 virulence by 0.33107-fold. The fact that inhibition of rheum emodin on viral virulence was much stronger than its effects on genomic levels and viral protein expression suggested that rheum emodin inhibited viral maturation. Furthermore, rheum emodin treatment markedly diminished cell cycle arrest at S phase in MRC5 cells, which was induced by EV71 infection and favored the viral replication. In contrast, neither astragaloside (50 μmol/L) nor artemisinin (50 μmol/L) showed similar anti-EV71 activities. Among the three natural compounds tested, rheum emodin effectively suppressed EV71 viral replication

Rheum emodin inhibits enterovirus 71 viral replication and affects the host cell cycle environment.

PubMed

Zhong, Ting; Zhang, Li-Ying; Wang, Zeng-Yan; Wang, Yue; Song, Feng-Mei; Zhang, Ya-Hong; Yu, Jing-Hua

2017-03-01

Human enterovirus 71 (EV71) is the primary causative agent of recent large-scale outbreaks of hand, foot, and mouth disease (HFMD) in Asia. Currently, there are no drugs available for the prevention and treatment of HFMD. In this study, we compared the anti-EV71 activities of three natural compounds, rheum emodin, artemisinin and astragaloside extracted from Chinese herbs Chinese rhubarb, Artemisia carvifolia and Astragalus, respectively, which have been traditionally used for the treatment and prevention of epidemic diseases. Human lung fibroblast cell line MRC5 was mock-infected or infected with EV71, and treated with drugs. The cytotoxicity of the drugs was detected with MTT assay. The cytopathic effects such as cell death and condensed nuclei were morphologically observed. The VP1-coding sequence required for EV71 genome replication was assayed with qRT-PCR. Viral protein expression was analyzed with Western blotting. Viral TCID50 was determined to evaluate EV71 virulence. Flow cytometry analysis of propidium iodide staining was performed to analyze the cell cycle distribution of MRC5 cells. Rheum emodin (29.6 μmol/L) effectively protected MRC5 cells from EV71-induced cytopathic effects, which resulted from the inhibiting viral replication: rheum emodin treatment decreased viral genomic levels by 5.34-fold, viral protein expression by less than 30-fold and EV71 virulence by 0.33107-fold. The fact that inhibition of rheum emodin on viral virulence was much stronger than its effects on genomic levels and viral protein expression suggested that rheum emodin inhibited viral maturation. Furthermore, rheum emodin treatment markedly diminished cell cycle arrest at S phase in MRC5 cells, which was induced by EV71 infection and favored the viral replication. In contrast, neither astragaloside (50 μmol/L) nor artemisinin (50 μmol/L) showed similar anti-EV71 activities. Among the three natural compounds tested, rheum emodin effectively suppressed EV71 viral replication

Very low level viraemia and risk of virological failure in treated HIV-1-infected patients.

PubMed

Teira, R; Vidal, F; Muñoz-Sánchez, P; Geijo, P; Viciana, P; Ribera, E; Domingo, P; Castaño, M; Martínez, E; Roca, B; Puig, T; Estrada, V; Deig, E; Galindo, M J; de la Fuente, B; Lozano, F; Montero, M; Muñoz-Sanz, A; Sanchez, T; Terrón, A; Romero-Palacios, A; Lacalle, J R; Garrido, M; Suárez-Lozano, I

2017-03-01

The aim of the study was to investigate whether very low level viraemia (VLLV) (20-50 HIV-1 RNA copies/mL) was associated with increased risk of virological failure (VF) as compared with persistent full suppression (< 20 copies/mL). From the VACH Cohort database, we selected those patients who started antiretroviral therapy (ART) after January 1997 and who achieved effective viral suppression [two consecutive viral loads (VLs) < 50 copies/mL] followed by full suppression (at least one VL <20 copies/mL). We carried out survival analyses to investigate whether the occurrence of VLLV rather than maintaining full suppression at < 20 copies/mL was associated with virological failure (two consecutive VLs > 200 copies/mL or one VL > 200 copies/mL followed by a change of ART regimen, administrative censoring or loss to follow-up), adjusted for nadir CD4 cell count, sex, age, ethnicity, transmission group, type of ART and time on effective suppression at < 50 copies/mL. Of 21 480 patients who started ART, 13 674 (63.7%) achieved effective suppression at < 50 copies/mL, of whom 4289 (31.4%) further achieved full suppression at < 20 copies/mL after May 2009. A total of 2623 patients (61.1%) remained fully suppressed thereafter, while 1666 had one or more episodes of VL detection > 20 copies/mL (excluding virological failure). A total of 824 patients had VLLV after suppression at < 20 copies/mL. VLLV was not associated with virological failure as compared with persistent full suppression [hazard ratio (HR) 0.67; 95% confidence interval (CI) 0.44-1.00], independently of the number of blips recorded (from one to 18). In our population of HIV-infected patients on ART who achieved viral suppression at < 20 copies/mL, the risk of virological failure was no different for patients who remained fully suppressed compared with those who experienced subsequent episodes of VLLV. © 2016 British HIV Association.

Vaccination of cattle against bovine viral diarrhea virus.

PubMed

Newcomer, Benjamin W; Chamorro, Manuel F; Walz, Paul H

2017-07-01

Bovine viral diarrhea virus (BVDV) is responsible for significant losses to the cattle industry. Currently, modified-live viral (MLV) and inactivated viral vaccines are available against BVDV, often in combination with other viral and bacterial antigens. Inactivated and MLV vaccines provide cattle producers and veterinarians safe and efficacious options for herd immunization to limit disease associated with BVDV infection. Vaccination of young cattle against BVDV is motivated by prevention of clinical disease and limiting viral spread to susceptible animals. For reproductive-age cattle, vaccination to prevent viremia and birth of persistently infected offspring is considered more important, while also more difficult to achieve than prevention of clinical disease. Recent advances have been made in the understanding of BVDV vaccine efficacy. In terms of preventing clinical disease, current BVDV vaccines have been demonstrated to have a rapid onset of immunity and MLV vaccines can be effectively utilized in calves possessing maternal immunity. For reproductive protection, more recent studies using multivalent MLV vaccines have demonstrated consistent fetal protection rates in the range of 85-100% in experimental studies. Proper timing and administration of BVDV vaccines can be utilized to maximize vaccine efficacy to provide an important contribution to reducing risks associated with BVDV infection. With improvements in vaccine formulations and increased understanding of the protective immune response following vaccination, control of BVDV through vaccination can be enhanced. Copyright © 2017. Published by Elsevier B.V.

Disparities in community viral load among HIV-infected persons in New York City.

PubMed

Laraque, Fabienne; Mavronicolas, Heather A; Robertson, McKaylee M; Gortakowski, Heidi W; Terzian, Arpi S

2013-08-24

HIV infection is a major problem in New York City (NYC), with more than 100,000 living HIV-infected persons. Novel public health approaches are needed to control the epidemic. The NYC Department of Health and Mental Hygiene (DOHMH) analysed community viral load (CVL) for a baseline to monitor the population-level impact of HIV control interventions. A cross-sectional study using routinely collected surveillance data. All HIV-infected persons reported to the NYC HIV Registry who were at least 13 years of age, with at least one viral load test result in 2008, and alive at the end of 31 December 2008 were included. CVL was defined as the mean of individual viral load means reported between January and December 2008. Detectable viral load was defined as an individual mean of more than 400 copies/ml. Differences in CVL and proportion undetectable were computed by socio-demographic characteristics and summary measures were mapped. New York City CVL was 21,318 copies/ml overall (N=62,550) and 44,749 copies/ml (N=28,366) among persons with detectable mean viral loads. CVL varied by demographic and clinical characteristics, with statistically significant differences (P<0.001) in all groups except race/ethnicity (P=0.16). Men, persons aged 20-49 years, MSM, persons with AIDS, those with a CD4 cell count of 200 cells/μl or less and persons diagnosed after 2006 had higher mean viral load. Overall, 54.7% of HIV-infected persons had a suppressed mean viral load, with individual and neighbourhood variations (P<0.0001). This analysis showed strong disparities in reported CVL by individual characteristics and neighbourhoods. CVL patterns can be utilized to target interventions and track their impact.

[Investigation of RNA viral genome amplification by multiple displacement amplification technique].

PubMed

Pang, Zheng; Li, Jian-Dong; Li, Chuan; Liang, Mi-Fang; Li, De-Xin

2013-06-01

In order to facilitate the detection of newly emerging or rare viral infectious diseases, a negative-strand RNA virus-severe fever with thrombocytopenia syndrome bunyavirus, and a positive-strand RNA virus-dengue virus, were used to investigate RNA viral genome unspecific amplification by multiple displacement amplification technique from clinical samples. Series of 10-fold diluted purified viral RNA were utilized as analog samples with different pathogen loads, after a series of reactions were sequentially processed, single-strand cDNA, double-strand cDNA, double-strand cDNA treated with ligation without or with supplemental RNA were generated, then a Phi29 DNA polymerase depended isothermal amplification was employed, and finally the target gene copies were detected by real time PCR assays to evaluate the amplification efficiencies of various methods. The results showed that multiple displacement amplification effects of single-strand or double-strand cDNA templates were limited, while the fold increases of double-strand cDNA templates treated with ligation could be up to 6 X 10(3), even 2 X 10(5) when supplemental RNA existed, and better results were obtained when viral RNA loads were lower. A RNA viral genome amplification system using multiple displacement amplification technique was established in this study and effective amplification of RNA viral genome with low load was achieved, which could provide a tool to synthesize adequate viral genome for multiplex pathogens detection.

Comparing viral metagenomics methods using a highly multiplexed human viral pathogens reagent

PubMed Central

Li, Linlin; Deng, Xutao; Mee, Edward T.; Collot-Teixeira, Sophie; Anderson, Rob; Schepelmann, Silke; Minor, Philip D.; Delwart, Eric

2014-01-01

Unbiased metagenomic sequencing holds significant potential as a diagnostic tool for the simultaneous detection of any previously genetically described viral nucleic acids in clinical samples. Viral genome sequences can also inform on likely phenotypes including drug susceptibility or neutralization serotypes. In this study, different variables of the laboratory methods often used to generate viral metagenomics libraries on the efficiency of viral detection and virus genome coverage were compared. A biological reagent consisting of 25 different human RNA and DNA viral pathogens was used to estimate the effect of filtration and nuclease digestion, DNA/RNA extraction methods, pre-amplification and the use of different library preparation kits on the detection of viral nucleic acids. Filtration and nuclease treatment led to slight decreases in the percentage of viral sequence reads and number of viruses detected. For nucleic acid extractions silica spin columns improved viral sequence recovery relative to magnetic beads and Trizol extraction. Pre-amplification using random RT-PCR while generating more viral sequence reads resulted in detection of fewer viruses, more overlapping sequences, and lower genome coverage. The ScriptSeq library preparation method retrieved more viruses and a greater fraction of their genomes than the TruSeq and Nextera methods. Viral metagenomics sequencing was able to simultaneously detect up to 22 different viruses in the biological reagent analyzed including all those detected by qPCR. Further optimization will be required for the detection of viruses in biologically more complex samples such as tissues, blood, or feces. PMID:25497414

Selective serotonin reuptake inhibitor suppression of HIV infectivity and replication.

PubMed

Benton, Tami; Lynch, Kevin; Dubé, Benoit; Gettes, David R; Tustin, Nancy B; Ping Lai, Jian; Metzger, David S; Blume, Joshua; Douglas, Steven D; Evans, Dwight L

2010-11-01

To test the hypothesis that the selective serotonin reuptake inhibitor (SSRI) citalopram would down-regulate human immunodeficiency virus (HIV) infectivity and that the greatest effects would be seen in people with depression. Depression is a risk factor for morbidity and mortality in HIV/acquired immune deficiency syndrome. Serotonin (5-HT) neurotransmission has been implicated in the pathobiology of depression, and pharmacologic therapies for depression target this system. The 5-HT transporter and 5-HT receptors are widely distributed throughout the central nervous and immune systems. Depression has been associated with suppression of natural killer cells and CD8(+) lymphocytes, key regulators of HIV infection. Ex vivo models for acute and chronic HIV infection were used to study the effects of citalopram on HIV viral infection and replication in 48 depressed and nondepressed women. For both the acute and chronic infection models, HIV reverse transcriptase activity was measured in the citalopram treatment condition and the control condition. The SSRI significantly down-regulated the reverse transcriptase response in both the acute and chronic infection models. Specifically, citalopram significantly decreased the acute HIV infectivity of macrophages. Citalopram also significantly decreased HIV viral replication in the latently infected T-cell line and in the latently infected macrophage cell line. There was no difference in down-regulation by depression status. These studies suggest that an SSRI enhances natural killer/CD8 noncytolytic HIV suppression in HIV/acquired immune deficiency syndrome and decreases HIV viral infectivity of macrophages, ex vivo, suggesting the need for in vivo studies to determine a potential role for agents targeting serotonin in the host defense against HIV.

Role of the HTLV-1 viral factors in the induction of apoptosis.

PubMed

Karimi, Mohammad; Mohammadi, Hamed; Hemmatzadeh, Maryam; Mohammadi, Asadollah; Rafatpanah, Houshang; Baradaran, Behzad

2017-01-01

Adult T-cell leukemia (ATL) and HTLV-1-associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) are the two main diseases that are caused by the HTLV-1 virus. One of the features of HTLV-1 infection is its resistance against programmed cell death, which maintains the survival of cells to oncogenic transformation and underlies the viruses' therapeutic resistance. Two main genes by which the virus develops cancer are Tax and HBZ; playing an essential role in angiogenesis in regulating viral transcription and modulating multiple host factors as well as apoptosis pathways. Here we have reviewed by prior research how the apoptosis pathways are suppressed by the Tax and HBZ and new drugs which have been designed to deal with this suppression. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A Dual Role for Corneal Dendritic Cells in Herpes Simplex Keratitis: Local Suppression of Corneal Damage and Promotion of Systemic Viral Dissemination

PubMed Central

Hu, Kai; Harris, Deshea L.; Yamaguchi, Takefumi; von Andrian, Ulrich H.; Hamrah, Pedram

2015-01-01

The cornea is the shield to the foreign world and thus, a primary site for peripheral infections. However, transparency and vision are incompatible with inflammation and scarring that may result from infections. Thus, the cornea is required to perform a delicate balance between fighting infections and preserving vision. To date, little is known about the specific role of antigen-presenting cells in viral keratitis. In this study, utilizing an established murine model of primary acute herpes simplex virus (HSV)-1 keratitis, we demonstrate that primary HSV keratitis results in increased conventional dendritic cells (cDCs) and macrophages within 24 hours after infection. Local depletion of cDCs in CD11c-DTR mice by subconjuntival diphtheria toxin injections, led to increased viral proliferation, and influx of inflammatory cells, resulting in increased scarring and clinical keratitis. In addition, while HSV infection resulted in significant corneal nerve destruction, local depletion of cDCs resulted in a much more severe loss of corneal nerves. Further, local cDC depletion resulted in decreased corneal nerve infection, and subsequently decreased and delayed systemic viral transmission in the trigeminal ganglion and draining lymph node, resulting in decreased mortality of mice. In contrast, sham depletion or depletion of macrophages through local injection of clodronate liposomes had neither a significant impact on the cornea, nor an effect on systemic viral transmission. In conclusion, we demonstrate that corneal cDCs may play a primary role in local corneal defense during viral keratitis and preserve vision, at the cost of inducing systemic viral dissemination, leading to increased mortality. PMID:26332302

New insights into the nucleolar localization of a plant RNA virus-encoded protein that acts in both RNA packaging and RNA silencing suppression: involvement of importins alpha and relevance for viral infection.

PubMed

Pérez-Cañamás, Miryam; Hernández, Carmen

2018-05-21

Despite replication of plus strand RNA viruses takes place in the cytoplasm of host cells, different proteins encoded by these infectious agents have been shown to localize in the nucleus, with high accumulation at the nucleolus. In most cases, the molecular determinants and/or biological significance of such subcellular localization remain elusive. Recently, we reported that protein p37 encoded by Pelargonium line pattern virus (family Tombusviridae) acts in both RNA packaging and RNA silencing suppression. Connsistently with these functions, p37 was detected in the cytoplasm of plant cells though it was also present in the nucleus and, particularly, in the nucleolus. Here, we have aimed to gain further insights into factors influencing p37 nucleolar localization and into its potential relevance for viral infection. Besides mapping the protein region containing the nucleolar localization signal, we have found that p37 interacts with distinct members of the importin alpha family -main cellular transporters for nucleo-cytoplasmic traffic of proteins-, and that these interactions are crucial for nucleolar targeting of p37. Impairment of p37 nucleolar localization through down-regulation of importin alpha expression resulted in a reduction of viral accumulation, suggesting that sorting of the protein to the major subnuclear compartment is advantageous for the infection process.

Integrated and Total HIV-1 DNA Predict Ex Vivo Viral Outgrowth

PubMed Central

Kiselinova, Maja; De Spiegelaere, Ward; Buzon, Maria Jose; Malatinkova, Eva; Lichterfeld, Mathias; Vandekerckhove, Linos

2016-01-01

The persistence of a reservoir of latently infected CD4 T cells remains one of the major obstacles to cure HIV. Numerous strategies are being explored to eliminate this reservoir. To translate these efforts into clinical trials, there is a strong need for validated biomarkers that can monitor the reservoir over time in vivo. A comprehensive study was designed to evaluate and compare potential HIV-1 reservoir biomarkers. A cohort of 25 patients, treated with suppressive antiretroviral therapy was sampled at three time points, with median of 2.5 years (IQR: 2.4–2.6) between time point 1 and 2; and median of 31 days (IQR: 28–36) between time point 2 and 3. Patients were median of 6 years (IQR: 3–12) on ART, and plasma viral load (<50 copies/ml) was suppressed for median of 4 years (IQR: 2–8). Total HIV-1 DNA, unspliced (us) and multiply spliced HIV-1 RNA, and 2LTR circles were quantified by digital PCR in peripheral blood, at 3 time points. At the second time point, a viral outgrowth assay (VOA) was performed, and integrated HIV-1 DNA and relative mRNA expression levels of HIV-1 restriction factors were quantified. No significant change was found for long- and short-term dynamics of all HIV-1 markers tested in peripheral blood. Integrated HIV-1 DNA was associated with total HIV-1 DNA (p<0.001, R² = 0.85), us HIV-1 RNA (p = 0.029, R² = 0.40), and VOA (p = 0.041, R2 = 0.44). Replication-competent virus was detected in 80% of patients by the VOA and it correlated with total HIV-1 DNA (p = 0.039, R² = 0.54). The mean quantification difference between Alu-PCR and VOA was 2.88 log10, and 2.23 log10 between total HIV-1 DNA and VOA. The levels of usHIV-1 RNA were inversely correlated with mRNA levels of several HIV-1 restriction factors (TRIM5α, SAMHD1, MX2, SLFN11, pSIP1). Our study reveals important correlations between the viral outgrowth and total and integrated HIV-1 DNA measures, suggesting that the total pool of HIV-1 DNA may predict the size of the

Herpesvirus tegument and immediate early proteins are pioneers in the battle between viral infection and nuclear domain 10-related host defense.

PubMed

Zhang, Kuan; van Drunen Littel-van den Hurk, Sylvia

2017-06-15

The sophisticated anti-viral functions of nuclear domain 10 (ND10) are revealed by identifying the role of each component and the countermeasures applied by viruses. Several ND10 proteins suppress herpesviruses at initial and early phases of infection. Herpesviruses need to antagonize these anti-viral proteins to start a productive infection. In this review the recently identified similarities and differences among the strategies adopted by the three subfamilies of herpesviruses are discussed, highlighting that one of the significant purposes of incorporating tegument proteins into the viral particles might be to counteract ND10 proteins immediately after the viral genome enters the host nucleus. Once the infection progresses, a sufficient amount of immediate early proteins is expressed to disperse and hydrolyze ND10 proteins, accelerating the development of infection. Copyright © 2017 Elsevier B.V. All rights reserved.

BRAF inhibitors suppress apoptosis through off-target inhibition of JNK signaling

PubMed Central

Vin, Harina; Ojeda, Sandra S; Ching, Grace; Leung, Marco L; Chitsazzadeh, Vida; Dwyer, David W; Adelmann, Charles H; Restrepo, Monica; Richards, Kristen N; Stewart, Larissa R; Du, Lili; Ferguson, Scarlett B; Chakravarti, Deepavali; Ehrenreiter, Karin; Baccarini, Manuela; Ruggieri, Rosamaria; Curry, Jonathan L; Kim, Kevin B; Ciurea, Ana M; Duvic, Madeleine; Prieto, Victor G; Ullrich, Stephen E; Dalby, Kevin N; Flores, Elsa R; Tsai, Kenneth Y

2013-01-01

Vemurafenib and dabrafenib selectively inhibit the v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) kinase, resulting in high response rates and increased survival in melanoma. Approximately 22% of individuals treated with vemurafenib develop cutaneous squamous cell carcinoma (cSCC) during therapy. The prevailing explanation for this is drug-induced paradoxical ERK activation, resulting in hyperproliferation. Here we show an unexpected and novel effect of vemurafenib/PLX4720 in suppressing apoptosis through the inhibition of multiple off-target kinases upstream of c-Jun N-terminal kinase (JNK), principally ZAK. JNK signaling is suppressed in multiple contexts, including in cSCC of vemurafenib-treated patients, as well as in mice. Expression of a mutant ZAK that cannot be inhibited reverses the suppression of JNK activation and apoptosis. Our results implicate suppression of JNK-dependent apoptosis as a significant, independent mechanism that cooperates with paradoxical ERK activation to induce cSCC, suggesting broad implications for understanding toxicities associated with BRAF inhibitors and for their use in combination therapies. DOI: http://dx.doi.org/10.7554/eLife.00969.001 PMID:24192036

Baicalin benefits the anti-HBV therapy via inhibiting HBV viral RNAs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Hai, E-mail: HHai3552@sina.cn

Background: Although current antiviral treatments (nucleoside analogs, NAs) for chronic hepatitis B virus (HBV) infection are effective in suppressing HBV-DNA replication, their clinical outcomes can be compromised by the increasing drug resistance and the inefficiency in promoting HBsAg/HBeAg seroconversion. Objectives: In this study, we will explore possible effects and mechanism of a natural product baicalin (BA) with the anti-HBV efficacy of entecavir (ETV), a first-line anti-HBV drug, in HBV-DNA, HBsAg/HBeAg seroconversion and drug-resistance. Methods: The co-effects of BA and ETV were conducted in wild-type/NA-resistance mutant HBV cell lines and DHBV-infected duckling models. HBV-DNA/RNAs, HBsAg/HBeAg, host factors (hepatocyte nuclear factors) weremore » explored for possible anti-HBV mechanism. Results and discussion: BA could significantly enhance and reduced HBsAg and HBeAg in hepG2.2.15, a wild-type HBV cell line. Co-treatment of BA and ETV had a more dramatic effect in NA-resistant HBV{sup rtM204V/rtLl80M} transfected hepG2 cells. Our study further revealed that BA mainly inhibited the production of HBV RNAs (3.5, 2.4, 2.1 kb), the templates for viral proteins and HBV-DNA synthesis. BA blocked HBV RNAs transcription possibly by down-regulating transcription and expression of HBV replication dependent hepatocyte nuclear factors (HNF1α and HNF4α). Thus, BA may benefit the anti-HBV therapy via inhibiting HBV viral RNAs. - Highlights: • Baicalin benefits the anti-HBV therapy. • Baicalin enhances ETV antiviral efficacy and overcomes NA-resistant HBV mutation. • The anti-HBV effect of baicalin is achieved by inhibiting HBV RNAs. • Baicalin down-regulates HBV replication-dependent host factors HNF 1α and HNF 4α.« less

JAK-inhibitor tofacitinib suppresses interferon alfa production by plasmacytoid dendritic cells and inhibits arthrogenic and antiviral effects of interferon alfa.

PubMed

Boor, Patrick P C; de Ruiter, Petra E; Asmawidjaja, Patrick S; Lubberts, Erik; van der Laan, Luc J W; Kwekkeboom, Jaap

2017-10-01

Tofacitinib is an oral Janus kinase inhibitor that is effective for the treatment of rheumatoid arthritis and shows encouraging therapeutic effects in several other autoimmune diseases. A prominent adverse effect of tofacitinib therapy is the increased risk of viral infections. Despite its advanced stage of clinical development, the modes of action that mediate the beneficial and adverse effects of tofacitinib in autoimmune diseases remain unclear. Interferon alfa (IFNα) produced by plasmacytoid dendritic cells (PDCs) is critically involved in the pathogenesis of many systemic autoimmune diseases and in immunity to viral infections. Using in vitro culture models with human cells, we studied the effects of tofacitinib on PDC survival and IFNα production, and on arthrogenic and antiviral effects of IFNα. Tofacitinib inhibited the expression of antiapoptotic BCL-A1 and BCL-XL in human PDC and induced PDC apoptosis. TLR7 stimulation upregulated the levels of antiapoptotic Bcl-2 family members and prevented the induction of PDC apoptosis by tofacitinib. However, tofacitinib robustly inhibited the production of IFNα by toll like receptor-stimulated PDC. In addition, tofacitinib profoundly suppressed IFNα-induced upregulation of TLR3 on synovial fibroblasts, thereby inhibiting their cytokine and protease production in response to TLR3 ligation. Finally, tofacitinib counteracted the suppressive effects of IFNα on viral replication. Tofacitinib inhibits PDC survival and IFNα production and suppresses arthrogenic and antiviral effects of IFNα signaling. Inhibition of the IFNα pathway at 2 levels may contribute to the beneficial effects of tofacitinib in autoimmune diseases and explain the increased viral infection rates observed during tofacitinib treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

System and method for suppressing sublimation using opacified aerogel

NASA Technical Reports Server (NTRS)

Sakamoto, Jeff S. (Inventor); Snyder, G. Jeffrey (Inventor); Calliat, Thierry (Inventor); Fleurial, Jean-Pierre (Inventor); Jones, Steven M. (Inventor); Palk, Jong-Ah (Inventor)

2008-01-01

The present invention relates to a castable, aerogel-based, ultra-low thermal conductivity opacified insulation to suppress sublimation. More specifically, the present invention relates to an aerogel opacified with various opacifying or reflecting constituents to suppress sublimation and provide thermal insulation in thermoelectric modules. The opacifying constituent can be graded within the aerogel for increased sublimation suppression, and the density of the aerogel can similarly be graded to achieve optimal thermal insulation and sublimation suppression.

Assessing the HIV Care Continuum in Latin America: progress in clinical retention, cART use and viral suppression

PubMed Central

Rebeiro, Peter F; Cesar, Carina; Shepherd, Bryan E; De Boni, Raquel B; Cortés, Claudia P; Rodriguez, Fernanda; Belaunzarán-Zamudio, Pablo; Pape, Jean W; Padgett, Denis; Hoces, Daniel; McGowan, Catherine C; Cahn, Pedro

2016-01-01

Introduction We assessed trends in HIV Care Continuum outcomes associated with delayed disease progression and reduced transmission within a large Latin American cohort over a decade: clinical retention, combination antiretroviral therapy (cART) use and viral suppression (VS). Methods Adults from Caribbean, Central and South America network for HIV epidemiology clinical cohorts in seven countries contributed data between 2003 and 2012. Retention was defined as two or more HIV care visits annually, >90 days apart. cART was defined as prescription of three or more antiretroviral agents annually. VS was defined as HIV-1 RNA <200 copies/mL at last measurement annually. cART and VS denominators were subjects with at least one visit annually. Multivariable modified Poisson regression was used to assess temporal trends and examine associations between age, sex, HIV transmission mode, cohort, calendar year and time in care. Results Among 18,799 individuals in retention analyses, 14,380 in cART analyses and 13,330 in VS analyses, differences existed between those meeting indicator definitions versus those not by most characteristics. Retention, cART and VS significantly improved from 2003 to 2012 (63 to 77%, 74 to 91% and 53 to 82%, respectively; p<0.05, each). Female sex (risk ratio (RR)=0.97 vs. males) and injection drug use as HIV transmission mode (RR=0.83 vs. male sexual contact with males (MSM)) were significantly associated with lower retention, but unrelated with cART or VS. MSM (RR=0.96) significantly decreased the probability of cART compared with heterosexual transmission. Conclusions HIV Care Continuum outcomes improved over time in Latin America, though disparities for vulnerable groups remain. Efforts must be made to increase retention, cART and VS, while engaging in additional research to sustain progress in these settings. PMID:27065108

Canine viral infections.

PubMed

Willis, A M

2000-09-01

The ophthalmic effects of viral infection are varied. With the added possibility for pathologic effects of attenuated vaccine viruses, the diagnosis of viral diseases can be a challenge. In many cases, ocular manifestations can provide added support to a presumptive diagnosis of viral disease, thereby underscoring the benefit of thorough ophthalmic examination of any animal with nonspecific signs of illness.

Viral Epitranscriptomics

PubMed Central

Kennedy, Edward M.; Courtney, David G.; Tsai, Kevin

2017-01-01

ABSTRACT Although it has been known for over 40 years that eukaryotic mRNAs bear internal base modifications, it is only in the last 5 years that the importance of these modifications has begun to come into focus. The most common mRNA modification, the addition of a methyl group to the N6 position of adenosine (m6A), has been shown to affect splicing, translation, and stability, and m6A is also essential for embryonic development in organisms ranging from plants to mice. While all viral transcripts examined so far have been found to be extensively m6A modified, the role, if any, of m6A in regulating viral gene expression and replication was previously unknown. However, recent data generated using HIV-1 as a model system strongly suggest that sites of m6A addition not only are evolutionarily conserved but also enhance virus replication. It is therefore likely that the field of viral epitranscriptomics, which can be defined as the study of functionally relevant posttranscriptional modifications of viral RNA transcripts that do not change the nucleotide sequence of that RNA, is poised for a major expansion in scientific interest and may well fundamentally change our understanding of how viral replication is regulated. PMID:28250115

The association between cigarette smoking, virologic suppression, and CD4+ lymphocyte count in HIV-Infected Russian women.

PubMed

Brown, Jennifer L; Winhusen, Theresa; DiClemente, Ralph J; Sales, Jessica M; Rose, Eve S; Safonova, Polina; Levina, Olga; Belyakov, Nikolay; Rassokhin, Vadim V

2017-09-01

Cigarette smoking among people living with HIV/AIDS is associated with significant morbidity and mortality, but findings regarding the association between cigarette smoking and HIV viral load and CD4+ lymphocyte counts have been inconsistent. This study characterized the prevalence of cigarette smoking among HIV-infected Russian women and examined the association between smoking frequency and quantity and HIV viral load and CD4+ lymphocyte counts. HIV-infected Russian women (N = 250; M age = 30.0) in St. Petersburg, Russia, completed an audio computer-assisted self-interview survey assessing cigarette use, antiretroviral medication adherence, and provided blood samples assayed for HIV viral load and CD4+ lymphocyte counts. The majority (60.4%) reported cigarette smoking in the past month; 49.0% of recent smokers were classified as moderate or heavy smokers, defined as smoking ≥10 cigarettes daily. Viral load status did not differ between infrequent smokers and regular smokers. However, moderate/heavy smokers (relative to light smokers) were more likely to have a detectable viral load (AOR = 2.3, 95% CI: 1.1, 5.1). There were no significant differences in CD4+ lymphocyte counts by smoking frequency or quantity of cigarettes smoked. Results highlight the need for additional research to examine the association between cigarette smoking and virologic suppression and markers of HIV disease progression. Adverse health consequences of cigarette smoking coupled with a potential link between heavy smoking and poor virologic suppression highlight the need for assessment of cigarette use and provision of evidence-based smoking-cessation interventions within HIV medical care.

Viral-Associated GN: Hepatitis C and HIV.

PubMed

Kupin, Warren L

2017-08-07

Viruses are capable of inducing a wide spectrum of glomerular disorders that can be categorized on the basis of the duration of active viremia: acute, subacute, or chronic. The variable responses of the adaptive immune system to each time period of viral infection results mechanistically in different histologic forms of glomerular injury. The unique presence of a chronic viremic carrier state with either hepatitis C (HCV) or HIV has led to the opportunity to study in detail various pathogenic mechanisms of viral-induced glomerular injury, including direct viral infection of renal tissue and the development of circulating immune complexes composed of viral antigens that deposit along the glomerular basement membrane. Epidemiologic data show that approximately 25%-30% of all HIV patients are coinfected with HCV and 5%-10% of all HCV patients are coinfected with HIV. This situation can often lead to a challenging differential diagnosis when glomerular disease occurs in this dual-infected population and requires the clinician to be familiar with the clinical presentation, laboratory workup, and pathophysiology behind the development of renal disease for both HCV and HIV. Both of these viruses can be categorized under the new classification of infection-associated GN as opposed to being listed as causes of postinfectious GN as has previously been applied to them. Neither of these viruses lead to renal injury after a latent period of controlled and inactive viremia. The geneses of HCV- and HIV-associated glomerular diseases share a total dependence on the presence of active viral replication to sustain renal injury so the renal disease cannot be listed under "postinfectious" GN. With the new availability of direct-acting antivirals for HCV and more effective combined antiretroviral therapy for HIV, successful remission and even regression of glomerular lesions can be achieved if initiated at an early stage. Copyright © 2017 by the American Society of Nephrology.

Inflammasome control of viral infection

PubMed Central

Lupfer, Christopher; Malik, Ankit; Kanneganti, Thirumala-Devi

2015-01-01

The inflammasome is a caspase-1 containing complex that activates the proinflammatory cytokines IL-1β and IL-18 and results in the proinflammatory cell death known as pyroptosis. Numerous recent publications have highlighted the importance of inflammasome activation in the control of virus infection. Inflammasome activation during viral infection is dependent on a variety of upstream receptors including the NOD-Like receptor, RIG-I-Like receptor and AIM2-Like receptor families. Various receptors also function in inflammasome activation in different cellular compartments, including the cytoplasm and the nucleus. The effectiveness of inflammasomes at suppressing virus replication is highlighted by the prevalence and diversity of virus encoded inflammasome inhibitors. Also, the host has a myriad of regulatory mechanisms in place to prevent unwanted inflammasome activation and overt inflammation. Finally, recent reports begin to suggest that inflammasome activation and inflammasome modulation may have important clinical applications. Herein, we highlight recent advances and discuss potential future directions toward understanding the role of inflammasomes during virus infection. PMID:25771504

Evaluation of viral removal by nanofiltration using real-time quantitative polymerase chain reaction.

PubMed

Zhao, Xiaowen; Bailey, Mark R; Emery, Warren R; Lambooy, Peter K; Chen, Dayue

2007-06-01

Nanofiltration is commonly introduced into purification processes of biologics produced in mammalian cells to serve as a designated step for removal of potential exogenous viral contaminants and endogenous retrovirus-like particles. The LRV (log reduction value) achieved by nanofiltration is often determined by cell-based infectivity assay, which is time-consuming and labour-intensive. We have explored the possibility of employing QPCR (quantitative PCR) to evaluate LRV achieved by nanofiltration in scaled-down studies using two model viruses, namely xenotropic murine leukemia virus and murine minute virus. We report here the successful development of a QPCR-based method suitable for quantification of virus removal by nanofiltration. The method includes a nuclease treatment step to remove free viral nucleic acids, while viral genome associated with intact virus particles is shielded from the nuclease. In addition, HIV Armored RNA was included as an internal control to ensure the accuracy and reliability of the method. The QPCRbased method described here provides several advantages such as better sensitivity, faster turnaround time, reduced cost and higher throughput over the traditional cell-based infectivity assays.

Tip60 degradation by adenovirus relieves transcriptional repression of viral transcriptional activator EIA.

PubMed

Gupta, A; Jha, S; Engel, D A; Ornelles, D A; Dutta, A

2013-10-17

Adenoviruses are linear double-stranded DNA viruses that infect human and rodent cell lines, occasionally transform them and cause tumors in animal models. The host cell challenges the virus in multifaceted ways to restrain viral gene expression and DNA replication, and sometimes even eliminates the infected cells by programmed cell death. To combat these challenges, adenoviruses abrogate the cellular DNA damage response pathway. Tip60 is a lysine acetyltransferase that acetylates histones and other proteins to regulate gene expression, DNA damage response, apoptosis and cell cycle regulation. Tip60 is a bona fide tumor suppressor as mice that are haploid for Tip60 are predisposed to tumors. We have discovered that Tip60 is degraded by adenovirus oncoproteins EIB55K and E4orf6 by a proteasome-mediated pathway. Tip60 binds to the immediate early adenovirus promoter and suppresses adenovirus EIA gene expression, which is a master regulator of adenovirus transcription, at least partly through retention of the virally encoded repressor pVII on this promoter. Thus, degradation of Tip60 by the adenoviral early proteins is important for efficient viral early gene transcription and for changes in expression of cellular genes.

Viral Disease Networks?

NASA Astrophysics Data System (ADS)

Gulbahce, Natali; Yan, Han; Vidal, Marc; Barabasi, Albert-Laszlo

2010-03-01

Viral infections induce multiple perturbations that spread along the links of the biological networks of the host cells. Understanding the impact of these cascading perturbations requires an exhaustive knowledge of the cellular machinery as well as a systems biology approach that reveals how individual components of the cellular system function together. Here we describe an integrative method that provides a new approach to studying virus-human interactions and its correlations with diseases. Our method involves the combined utilization of protein - protein interactions, protein -- DNA interactions, metabolomics and gene - disease associations to build a ``viraldiseasome''. By solely using high-throughput data, we map well-known viral associated diseases and predict new candidate viral diseases. We use microarray data of virus-infected tissues and patient medical history data to further test the implications of the viral diseasome. We apply this method to Epstein-Barr virus and Human Papillomavirus and shed light into molecular development of viral diseases and disease pathways.

Primate lentiviruses use at least three alternative strategies to suppress NF-κB-mediated immune activation

PubMed Central

Gawanbacht, Ali; Van Driessche, Benoît; Van Lint, Carine; Peeters, Martine; Kirchhoff, Frank

2017-01-01

Primate lentiviruses have evolved sophisticated strategies to suppress the immune response of their host species. For example, HIV-2 and most simian immunodeficiency viruses (SIVs) use their accessory protein Nef to prevent T cell activation and antiviral gene expression by downmodulating the T cell receptor CD3. This Nef function was lost in HIV-1 and other vpu-encoding viruses suggesting that the acquisition of Vpu-mediated NF-κB inhibition reduced the selection pressure for inhibition of T cell activation by Nef. To obtain further insights into the modulation of NF-κB activity by primate lentiviral accessory factors, we analyzed 32 Vpr proteins from a large panel of divergent primate lentiviruses. We found that those of SIVcol and SIVolc infecting Colobinae monkeys showed the highest efficacy in suppressing NF-κB activation. Vpr-mediated inhibition of NF-κB resulted in decreased IFNβ promoter activity and suppressed type I IFN induction in virally infected primary cells. Interestingly, SIVcol and SIVolc differ from all other primate lentiviruses investigated by the lack of both, a vpu gene and efficient Nef-mediated downmodulation of CD3. Thus, primate lentiviruses have evolved at least three alternative strategies to inhibit NF-κB-dependent immune activation. Functional analyses showed that the inhibitory activity of SIVolc and SIVcol Vprs is independent of DCAF1 and the induction of cell cycle arrest. While both Vprs target the IKK complex or a factor further downstream in the NF-κB signaling cascade, only SIVolc Vpr stabilizes IκBα and inhibits p65 phosphorylation. Notably, only de-novo synthesized but not virion-associated Vpr suppressed the activation of NF-κB, thus enabling NF-κB-dependent initiation of viral gene transcription during early stages of the replication cycle, while minimizing antiviral gene expression at later stages. Our findings highlight the key role of NF-κB in antiviral immunity and demonstrate that primate lentiviruses

Itchy fish and viral dermatopathies: sampling, diagnosis, and management of common viral diseases.

PubMed

Weber, E P Scott

2013-09-01

Viral dermatopathies of fish bear clinical signs similar to those of dermatopathies from other causes. This article offers an overview to approaching dermatologic presentations in fish, with an emphasis on sampling, diagnosis, and management of viral dermatopathies, building on previous publications. It is vital to recognize clinical signs associated with viral dermatopathies because there are currently no treatments available. Avoidance and prevention is the key to controlling viral diseases in fish. Optimizing husbandry practices and providing appropriate quarantine procedures can help prevent viral disease outbreaks in collection and aquaculture stocks. Copyright © 2013 Elsevier Inc. All rights reserved.

Suppressing Nitrite-oxidizing Bacteria Growth to Achieve Nitrogen Removal from Domestic Wastewater via Anammox Using Intermittent Aeration with Low Dissolved Oxygen

PubMed Central

Ma, Bin; Bao, Peng; Wei, Yan; Zhu, Guibing; Yuan, Zhiguo; Peng, Yongzhen

2015-01-01

Achieving nitrogen removal from domestic wastewater using anaerobic ammonium oxidation (anammox) has the potential to make wastewater treatment energy-neutral or even energy-positive. The challenge is to suppress the growth of nitrite-oxidizing bacteria (NOB). This study presents a promising method based on intermittent aeration with low dissolved oxygen to limit NOB growth, thereby providing an advantage to anammox bacteria to form a partnership with the ammonium-oxidizing bacteria (AOB). The results showed that NOB was successfully suppressed using that method, with the relative abundance of NOB maintained between 2.0–2.6%, based on Fluorescent in-situ Hybridization. Nitrogen could be effectively removed from domestic wastewater with anammox at a temperature above 20 °C, with an effluent total nitrogen (TN) concentration of 6.6 ± 2.7 mg/L, while the influent TN and soluble chemical oxygen demand were 62.6 ± 3.1 mg/L and 88.0 ± 8.1 mg/L, respectively. PMID:26354321

Tenofovir disoproxil fumarate in Asian or Pacific Islander chronic hepatitis B patients with high viral load (≥ 9 log10 copies/ml).

PubMed

Fung, Scott; Gordon, Stuart C; Krastev, Zahary; Horban, Andrzej; Petersen, Jörg; Sperl, Jan; Gane, Edward; Jacobson, Ira M; Yee, Leland J; Dinh, Phillip; Martins, Eduardo B; Flaherty, John F; Kitrinos, Kathryn M; Dusheiko, Geoffrey; Trinh, Huy; Flisiak, Robert; Rustgi, Vinod K; Buti, Maria; Marcellin, Patrick

2015-02-01

We evaluated the antiviral response of Asian or Pacific Islander (API) patients with chronic hepatitis B (CHB) who had baseline high viral load (HVL), defined as pre-treatment hepatitis B virus (HBV) DNA ≥9 log10 copies/ml, following up to 288 weeks of tenofovir disoproxil fumarate (TDF) treatment. A total of 205 HBeAg-negative and HBeAg-positive self-described API patients received 48 weeks of TDF 300 mg (HVL n = 18) or adefovir dipivoxil 10 mg (HVL n = 15) in a blinded fashion, followed by open-label TDF for an additional 240 weeks. The proportions of HVL vs. non-HVL patients with HBV DNA <400 copies/ml were compared. Mean declines in HBV DNA were evaluated in API vs. non-API patients. Throughout the first 72 weeks of treatment, a smaller proportion of HVL API patients reached HBV DNA <400 copies/ml than non-HVL API patients. However, after this timepoint similar proportions of HVL and non-HVL API patients achieved HBV DNA <400 copies/ml (100% vs. 97%, respectively), which was maintained through week 288, where 92% of HVL patients and 99% of non-HVL API patients on treatment had HBV DNA <400 copies/ml. During the 288 weeks of treatment, API patients had similar mean HBV DNA declines as non-API patients, regardless of whether patients were HVL or non-HVL. No API HVL patient had persistent viremia at week 288. No resistance was detected among HVL or non-HVL patients. API patients with HVL CHB achieve HBV DNA <400 copies/ml with long-term TDF treatment; however, achieving viral suppression may take longer for HVL patients relative to non-HVL API patients. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Interaction of CtBP with adenovirus E1A suppresses immortalization of primary epithelial cells and enhances virus replication during productive infection.

PubMed

Subramanian, T; Zhao, Ling-Jun; Chinnadurai, G

2013-09-01

Adenovirus E1A induces cell proliferation, oncogenic transformation and promotes viral replication through interaction with p300/CBP, TRRAP/p400 multi-protein complex and the retinoblastoma (pRb) family proteins through distinct domains in the E1A N-terminal region. The C-terminal region of E1A suppresses E1A/Ras co-transformation and interacts with FOXK1/K2, DYRK1A/1B/HAN11 and CtBP1/2 (CtBP) protein complexes. To specifically dissect the role of CtBP interaction with E1A, we engineered a mutation (DL→AS) within the CtBP-binding motif, PLDLS, and investigated the effect of the mutation on immortalization and Ras cooperative transformation of primary cells and viral replication. Our results suggest that CtBP-E1A interaction suppresses immortalization and Ras co-operative transformation of primary rodent epithelial cells without significantly influencing the tumorigenic activities of transformed cells in immunodeficient and immunocompetent animals. During productive infection, CtBP-E1A interaction enhances viral replication in human cells. Between the two CtBP family proteins, CtBP2 appears to restrict viral replication more than CtBP1 in human cells. Copyright © 2013 Elsevier Inc. All rights reserved.

Interaction of CtBP with adenovirus E1A suppresses immortalization of primary epithelial cells and enhances virus replication during productive infection

PubMed Central

Subramanian, T.; Zhao, Ling-jun; Chinnadurai, G.

2013-01-01

Adenovirus E1A induces cell proliferation, oncogenic transformation and promotes viral replication through interaction with p300/CBP, TRRAP/p400 multi-protein complex and the retinoblastoma (pRb) family proteins through distinct domains in the E1A N-terminal region. The C-terminal region of E1A suppresses E1A/Ras co-transformation and interacts with FOXK1/K2, DYRK1A/1B/HAN11 and CtBP1/2 (CtBP) protein complexes. To specifically dissect the role of CtBP interaction with E1A, we engineered a mutation (DL→AS) within the CtBP-binding motif, PLDLS, and investigated the effect of the mutation on immortalization and Ras cooperative transformation of primary cells and viral replication. Our results suggest that CtBP-E1A interaction suppresses immortalization and Ras co-operative transformation of primary rodent epithelial cells without significantly influencing the tumorigenic activities of transformed cells in immunodeficient and immunocompetent animals. During productive infection, CtBP-E1A interaction enhances viral replication in human cells. Between the two CtBP family proteins, CtBP2 appears to restrict viral replication more than CtBP1 in human cells. PMID:23747199

Autophagy is involved in anti-viral activity of pentagalloylglucose (PGG) against Herpes simplex virus type 1 infection in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pei, Ying, E-mail: peiying-19802@163.com; Chen, Zhen-Ping, E-mail: 530670663@qq.com; Ju, Huai-Qiang, E-mail: 344464448@qq.com

2011-02-11

Research highlights: {yields} We showed PGG has anti-viral activity against Herpes simplex virus type 1 (HSV-1) and can induce autophgy. {yields} Autophagy may be a novel and important mechanism mediating PGG anti-viral activities. {yields} Inhibition of mTOR pathway is an important mechanism of induction of autophagy by PGG. -- Abstract: Pentagalloylglucose (PGG) is a natural polyphenolic compound with broad-spectrum anti-viral activity, however, the mechanisms underlying anti-viral activity remain undefined. In this study, we investigated the effects of PGG on anti-viral activity against Herpes simplex virus type 1 (HSV-1) associated with autophagy. We found that the PGG anti-HSV-1 activity was impairedmore » significantly in MEF-atg7{sup -/-} cells (autophagy-defective cells) derived from an atg7{sup -/-} knockout mouse. Transmission electron microscopy revealed that PGG-induced autophagosomes engulfed HSV-1 virions. The mTOR signaling pathway, an essential pathway for the regulation of autophagy, was found to be suppressed following PGG treatment. Data presented in this report demonstrated for the first time that autophagy induced following PGG treatment contributed to its anti-HSV activity in vitro.« less

Growth in Virologically Suppressed HIV-Positive Children on Antiretroviral Therapy: Individual and Population-level References.

PubMed

Keiser, Olivia; Blaser, Nello; Davies, Mary-Ann; Wessa, Patrick; Eley, Brian; Moultrie, Harry; Rabie, Helena; Technau, Karl-Günther; Ndirangu, James; Garone, Daniela; Giddy, Janet; Grimwood, Ashraf; Gsponer, Thomas; Egger, Matthias

2015-10-01

Combination antiretroviral therapy (ART) suppresses viral replication in HIV-infected children. The growth of virologically suppressed children on ART has not been well documented. We aimed to develop dynamic reference curves for weight-for-age Z scores (WAZ) and height-for-age Z scores (HAZ). Children aged <11 years at ART initiation with continuously undetectable viral loads (<400 copies/mL) treated at 7 South African ART programs with routine viral load monitoring were included. We used multilevel models to define trajectories of WAZ and HAZ up to 3 years and developed a web application to monitor trajectories in individual children. A total of 4876 children were followed for 7407 person-years. Analyses were stratified by baseline Z scores and age, which were the most important predictors of growth response. The youngest children showed the most pronounced increase in weight and height initially but catch-up growth stagnated after 1-2 years. Three years after starting ART, WAZ ranged from -2.2 [95% prediction interval (PrI), -5.6 to 0.8] in children with baseline age >5 years and Z score less than -3 to 0.0 (95% PrI, -2.7 to 2.4) in children with baseline age <2 years and WAZ greater than -1. For HAZ, the corresponding range was -2.3 (95% PrI, -4.9 to 0.3) in children with baseline age >5 years and Z score less than -3 to 0.3 (95% PrI, -3.1 to 3.4) in children with baseline age 2-5 years and HAZ greater than -1. We have developed an online tool to calculate reference trajectories in fully suppressed children. The web application could help to define "optimal" growth response and identify children with treatment failure.

Viral papillomatosis in Florida manatees (Trichechus manatus latirostris).

PubMed

Bossart, Gregory D; Ewing, Ruth Y; Lowe, Mark; Sweat, Mark; Decker, Susan J; Walsh, Catherine J; Ghim, Shin-je; Jenson, A Bennett

2002-02-01

The Florida manatee (Trichechus manatus latirostris) is one of the most endangered marine mammals in American coastal waters. Naturally resistant to infectious disease, the manatee immune system appears highly developed to protect it against the harsh marine environment and the effects of human-related injury. In 1997, seven captive Florida manatees developed multiple, cutaneous, pedunculated papillomas over a period of 6 months. Approximately 3 years later, four of the seven manatees developed multiple, cutaneous, sessile papillomas topically and clinically distinct from the initial lesions, some of which are still present. Histologic, ultrastructural, and immunohistochemical features indicated that the two distinct phenotypic lesions were caused by papillomaviruses (PVs). Preliminary immunologic data correlated with daily clinical observations suggested that the manatees were immunologically suppressed and that the papillomas were caused by activation of latent PV infections and reinoculation from active infections. The emergence of PV-induced papillomas in captive manatees, the possibility of activation of latent infection or transmission of active infection to free-ranging manatees, and the underlying cause of immune suppression predisposing manatees to develop viral papillomatosis are serious concerns for the future management of this highly endangered species. Copyright 2002 Elsevier Science.

T Cell Inactivation by Poxviral B22 Family Proteins Increases Viral Virulence

PubMed Central

Alzhanova, Dina; Hammarlund, Erika; Reed, Jason; Meermeier, Erin; Rawlings, Stephanie; Ray, Caroline A.; Edwards, David M.; Bimber, Ben; Legasse, Alfred; Planer, Shannon; Sprague, Jerald; Axthelm, Michael K.; Pickup, David J.; Lewinsohn, David M.; Gold, Marielle C.; Wong, Scott W.; Sacha, Jonah B.; Slifka, Mark K.; Früh, Klaus

2014-01-01

Infections with monkeypox, cowpox and weaponized variola virus remain a threat to the increasingly unvaccinated human population, but little is known about their mechanisms of virulence and immune evasion. We now demonstrate that B22 proteins, encoded by the largest genes of these viruses, render human T cells unresponsive to stimulation of the T cell receptor by MHC-dependent antigen presentation or by MHC-independent stimulation. In contrast, stimuli that bypass TCR-signaling are not inhibited. In a non-human primate model of monkeypox, virus lacking the B22R homologue (MPXVΔ197) caused only mild disease with lower viremia and cutaneous pox lesions compared to wild type MPXV which caused high viremia, morbidity and mortality. Since MPXVΔ197-infected animals displayed accelerated T cell responses and less T cell dysregulation than MPXV US2003, we conclude that B22 family proteins cause viral virulence by suppressing T cell control of viral dissemination. PMID:24832205

T cell inactivation by poxviral B22 family proteins increases viral virulence.

PubMed

Alzhanova, Dina; Hammarlund, Erika; Reed, Jason; Meermeier, Erin; Rawlings, Stephanie; Ray, Caroline A; Edwards, David M; Bimber, Ben; Legasse, Alfred; Planer, Shannon; Sprague, Jerald; Axthelm, Michael K; Pickup, David J; Lewinsohn, David M; Gold, Marielle C; Wong, Scott W; Sacha, Jonah B; Slifka, Mark K; Früh, Klaus

2014-05-01

Infections with monkeypox, cowpox and weaponized variola virus remain a threat to the increasingly unvaccinated human population, but little is known about their mechanisms of virulence and immune evasion. We now demonstrate that B22 proteins, encoded by the largest genes of these viruses, render human T cells unresponsive to stimulation of the T cell receptor by MHC-dependent antigen presentation or by MHC-independent stimulation. In contrast, stimuli that bypass TCR-signaling are not inhibited. In a non-human primate model of monkeypox, virus lacking the B22R homologue (MPXVΔ197) caused only mild disease with lower viremia and cutaneous pox lesions compared to wild type MPXV which caused high viremia, morbidity and mortality. Since MPXVΔ197-infected animals displayed accelerated T cell responses and less T cell dysregulation than MPXV US2003, we conclude that B22 family proteins cause viral virulence by suppressing T cell control of viral dissemination.

Viral posterior uveitis

PubMed Central

Lee, Joanne H.; Agarwal, Aniruddha; Mahendradas, Padmamalini; Lee, Cecilia S.; Gupta, Vishali; Pavesio, Carlos E.; Agrawal, Rupesh

2017-01-01

The causes of posterior uveitis can be divided into infectious, autoimmune, or masquerade syndromes. Viral infections, a significant cause of sight-threatening ocular diseases in the posterior segment, include human herpesviruses, measles, rubella, and arboviruses such as dengue, West Nile, and chikungunya virus. Viral posterior uveitis may occur as an isolated ocular disease in congenital or acquired infections or as part of a systemic viral illness. Many viruses remain latent in the infected host with a risk of reactivation that depends on various factors, including virulence and host immunity, age, and comorbidities. Although some viral illnesses are self-limiting and have a good visual prognosis, others, such as cytomegalovirus retinitis or acute retinal necrosis, may result in serious complications and profound vision loss. Since some of these infections may respond well to antiviral therapy, it is important to work up all cases of posterior uveitis to rule out an infectious etiology. We review the clinical features, diagnostic tools, treatment regimens, and long-term outcomes for each of these viral posterior uveitides. PMID:28012878

“Computerized Counseling Reduces HIV-1 Viral Load and Sexual Transmission Risk: Findings from a Randomized Controlled Trial”

PubMed Central

KURTH, Ann E.; SPIELBERG, Freya; CLELAND, Charles M.; LAMBDIN, Barrot; BANGSBERG, David R.; FRICK, Pamela A.; SEVERYNEN, Anneleen O.; CLAUSEN, Marc; NORMAN, Robert G.; LOCKHART, David; SIMONI, Jane M.; HOLMES, King K.

2014-01-01

Objective Evaluate a computerized intervention supporting antiretroviral therapy (ART) adherence and HIV transmission prevention. Design Longitudinal RCT. Settings An academic HIV clinic and a community-based organization in Seattle. Subjects 240 HIV-positive adults on ART; 209 completed nine-month follow-up (87% retention). Intervention Randomization to computerized counseling or assessment-only, 4 sessions over 9 months. Main Outcome Measures HIV-1 viral suppression, and self-reported ART adherence, and transmission risks, compared using generalized estimating equations. Results Overall, intervention participants had reduced viral load (VL): mean 0.17 log10 decline, versus 0.13 increase in controls, p = 0.053, and significant difference in ART adherence baseline to 9 months (p = 0.046). Their sexual transmission risk behaviors decreased (OR = 0.55, p = 0.020), a reduction not seen among controls (OR = 1.1, p = 0.664), and a significant difference in change (p = 0.040). Intervention effect was driven by those most in need: among those with detectable virus at baseline (>30 copies/milliliter, n=89), intervention effect was mean 0.60 log10 VL decline versus 0.15 increase in controls, p=0.034. ART adherence at the final follow-up was 13 points higher among intervention participants versus controls, p = 0.038. Conclusions Computerized counseling is promising for integrated ART adherence and safer sex, especially for individuals with problems in these areas. This is the first intervention to report improved ART adherence, viral suppression, and reduced secondary sexual transmission risk behavior. PMID:24384803

Viral genome methylation as an epigenetic defense against geminiviruses.

PubMed

Raja, Priya; Sanville, Bradley C; Buchmann, R Cody; Bisaro, David M

2008-09-01

Geminiviruses encapsidate single-stranded DNA genomes that replicate in plant cell nuclei through double-stranded DNA intermediates that associate with cellular histone proteins to form minichromosomes. Like most plant viruses, geminiviruses are targeted by RNA silencing and encode suppressor proteins such as AL2 and L2 to counter this defense. These related proteins can suppress silencing by multiple mechanisms, one of which involves interacting with and inhibiting adenosine kinase (ADK), a cellular enzyme associated with the methyl cycle that generates S-adenosyl-methionine, an essential methyltransferase cofactor. Thus, we hypothesized that the viral genome is targeted by small-RNA-directed methylation. Here, we show that Arabidopsis plants with mutations in genes encoding cytosine or histone H3 lysine 9 (H3K9) methyltransferases, RNA-directed methylation pathway components, or ADK are hypersensitive to geminivirus infection. We also demonstrate that viral DNA and associated histone H3 are methylated in infected plants and that cytosine methylation levels are significantly reduced in viral DNA isolated from methylation-deficient mutants. Finally, we demonstrate that Beet curly top virus L2- mutant DNA present in tissues that have recovered from infection is hypermethylated and that host recovery requires AGO4, a component of the RNA-directed methylation pathway. We propose that plants use chromatin methylation as a defense against DNA viruses, which geminiviruses counter by inhibiting global methylation. In addition, our results establish that geminiviruses can be useful models for genome methylation in plants and suggest that there are redundant pathways leading to cytosine methylation.

Viral Hemorrhagic Fevers

MedlinePlus

... Controls Cancel Submit Search the CDC Viral Hemorrhagic Fevers (VHFs) Note: Javascript is disabled or is not ... visit this page: About CDC.gov . Viral Hemorrhagic Fevers (VHFs) Virus Families Arenaviruses Old World/New World ...

Design and implementation of an external quality assessment program for HIV viral load measurements using dried blood spots.

PubMed

Prach, Lisa M; Puren, Adrian; Lippman, Sheri A; Carmona, Sergio; Stephenson, Sophie; Cutler, Ewalde; Barnhart, Scott; Liegler, Teri

2015-03-01

An external quality assurance program was developed for HIV-1 RNA viral load measurements taken from dried blood spots using a reference panel and field-collected specimens. The program demonstrated that accurate and reproducible quantitation can be obtained from field-collected specimens. Residual proviral DNA may confound interpretation in virologically suppressed subjects. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Respiratory viral diseases: access to RNA interference therapy

PubMed Central

Bitko, Vira; Barik, Sailen

2008-01-01

This review summarizes recent experimental achievements in the area of the development of new RNA interference (RNAi) therapeutics for the treatment of viral respiratory diseases. Delivery of siRNA to their intended target tissue remains the biggest problem for most therapeutic applications of these compounds. Appropriate formulations and chemical modifications for improved stability will boost the probability of utilization of RNAi drugs in the clinical applications. PMID:19081824

Viral hemorrhagic septicemia

USGS Publications Warehouse

Batts, William N.; Winton, James R.

2012-01-01

Viral hemorrhagic septicemia (VHS) is one of the most important viral diseases of finfish worldwide. In the past, VHS was thought to affect mainly rainbow trout Oncorhynchus mykiss reared at freshwater facilities in Western Europe where it was known by various names including Egtved disease and infectious kidney swelling and liver degeneration (Wolf 1988). Today, VHS is known as an important source of mortality for cultured and wild fish in freshwater and marine environments in several regions of the northern hemisphere (Dixon 1999; Gagné et al. 2007; Kim and Faisal 2011; Lumsden et al. 2007; Marty et al. 1998, 2003; Meyers and Winton 1995; Skall et al. 2005b; Smail 1999; Takano et al. 2001). Viral hemorrhagic septicemia is caused by the fish rhabdovirus, viral hemorrhagic septicemia virus (VHSV), a member of the genus Novirhabdovirus of the family Rhabdoviridae

Routine viral load monitoring in HIV-infected infants and children in low- and middle-income countries: challenges and opportunities.

PubMed

Arpadi, Stephen M; Shiau, Stephanie; De Gusmao, Eduarda Pimentel; Violari, Avy

2017-11-01

The objective of this commentary is to review considerations for implementing routine viral load (VL) monitoring programmes for HIV-infected infants and children living in low- and middle-income countries (LMIC). Since 2013, the World Health Organization (WHO) guidelines recommend VL testing as the preferred monitoring approach for all individuals treated with ART in order to assess treatment response, detect treatment failure and determine the need to switch to a second-line regimen in a timely manner. More recently, WHO guidelines from 2016 identify HIV-infected infants and children as a priority group for routine VL monitoring. There are a number of reasons why HIV-infected infants and children should be prioritized for routine VL monitoring. Data from national VL monitoring programmes as well as systematic reviews and meta-analyses from LMIC indicate rates of viral suppression are lower for infants and children compared to adults. The number of antiretroviral drugs and palatable formulations suitable for young children are limited. In addition, emotional and developmental issues particular to children can make daily medication administration difficult and pose a challenge to adherence and achievement of sustained viral suppression. VL monitoring can be instrumental for identifying those in need of additional adherence support, reducing regimen switches and preserving treatment options. The needs of infants and children warrant consideration in all aspects of VL monitoring services. If capacity for paediatric venipuncture is not assured, platforms that accept dried blood spot specimens are necessary in order for infants and children to have equitable access. Healthcare systems also need to prepare to manage the substantial number of infants and children identified with elevated VL, including adherence interventions that are appropriate for children. Establishing robust systems to evaluate processes and outcomes of routine VL monitoring services and to support

Virally mediated gene manipulation in the adult CNS

PubMed Central

Edry, Efrat; Lamprecht, Raphael; Wagner, Shlomo; Rosenblum, Kobi

2011-01-01

Understanding how the CNS functions poses one of the greatest challenges in modern life science and medicine. Studying the brain is especially challenging because of its complexity, the heterogeneity of its cellular composition, and the substantial changes it undergoes throughout its life-span. The complexity of adult brain neural networks results also from the diversity of properties and functions of neuronal cells, governed, inter alia, by temporally and spatially differential expression of proteins in mammalian brain cell populations. Hence, research into the biology of CNS activity and its implications to human and animal behavior must use novel scientific tools. One source of such tools is the field of molecular genetics—recently utilized more and more frequently in neuroscience research. Transgenic approaches in general, and gene targeting in rodents have become fundamental tools for elucidating gene function in the CNS. Although spectacular progress has been achieved over recent decades by using these approaches, it is important to note that they face a number of restrictions. One of the main challenges is presented by the temporal and spatial regulation of introduced genetic manipulations. Viral vectors provide an alternative approach to temporally regulated, localized delivery of genetic modifications into neurons. In this review we describe available technologies for gene transfer into the adult mammalian CNS that use both viral and non-viral tools. We discuss viral vectors frequently used in neuroscience, with emphasis on lentiviral vector (LV) systems. We consider adverse effects of LVs, and the use of LVs for temporally and spatially controllable manipulations. Especially, we highlight the significance of viral vector-mediated genetic manipulations in studying learning and memory processes, and how they may be effectively used to separate out the various phases of learning: acquisition, consolidation, retrieval, and maintenance. PMID:22207836

Comparison of reproductive protection against bovine viral diarrhea virus provided by multivalent viral vaccines containing inactivated fractions of bovine viral diarrhea virus 1 and 2.

PubMed

Walz, Paul H; Riddell, Kay P; Newcomer, Benjamin W; Neill, John D; Falkenberg, Shollie M; Cortese, Victor S; Scruggs, Daniel W; Short, Thomas H

2018-04-23

Bovine viral diarrhea virus (BVDV) is an important viral cause of reproductive disease, immune suppression and clinical disease in cattle. The objective of this study was to compare reproductive protection in cattle against the impacts of bovine viral diarrhea virus (BVDV) provided by three different multivalent vaccines containing inactivated BVDV. BVDV negative beef heifers and cows (n = 122) were randomly assigned to one of four groups. Groups A-C (n = 34/group) received two pre-breeding doses of one of three commercially available multivalent vaccines containing inactivated fractions of BVDV 1 and BVDV 2, and Group D (n = 20) served as negative control and received two doses of saline prior to breeding. Animals were bred, and following pregnancy diagnosis, 110 cattle [Group A (n = 31); Group B (n = 32); Group C (n = 31); Group D (n = 16)] were subjected to a 28-day exposure to cattle persistently infected (PI) with BVDV (1a, 1b and 2a). Of the 110 pregnancies, 6 pregnancies resulted in fetal resorption with no material for testing. From the resultant 104 pregnancies, BVDV transplacental infections were demonstrated in 73 pregnancies. The BVDV fetal infection rate (FI) was calculated at 13/30 (43%) for Group A cows, 27/29 (93%) for Group B cows, 18/30 (60%) for Group C cows, and 15/15 (100%) for Group D cows. Statistical differences were observed between groups with respect to post-vaccination antibody titers, presence and duration of viremia in pregnant cattle, and fetal infection rates in offspring from BVDV-exposed cows. Group A vaccination resulted in significant protection against BVDV infection as compared to all other groups based upon outcome measurements, while Group B vaccination did not differ in protection against BVDV infection from control Group D. Ability of inactivated BVDV vaccines to provide protection against BVDV fetal infection varies significantly among commercially available products; however, in this challenge

Up-regulation of antioxidants in tobacco by low concentrations of H₂O₂ suppresses necrotic disease symptoms.

PubMed

Hafez, Yaser Mohamed; Bacsó, Renáta; Király, Zoltán; Künstler, András; Király, Lóránt

2012-09-01

Pretreatment of tobacco leaves with low concentrations (5 to 10 mM) of H₂O₂ suppressed hypersensitive-type necrosis associated with resistance to Tobacco mosaic virus (TMV) or Pseudomonas syringae pv. phaseolicola. The same pretreatment resulted in suppression of normosensitive necrosis associated with susceptibility to Botrytis cinerea. This type of H₂O₂-mediated, induced disease symptom resistance correlated with enhanced host antioxidant capacity, i.e., elevated enzymatic activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (POX) after viral and bacterial infections. Induction of genes that encode the antioxidants superoxide dismutase (SOD), CAT, and APX was also enhanced early after TMV infection. Artificial application of SOD and CAT suppressed necroses caused by viral, bacterial, or fungal pathogens similarly as H₂O₂ pretreatment, implying that H₂O₂-mediated symptom resistance operates through enhancement of plant antioxidant capacity. Pathogen multiplication was not significantly affected in H₂O₂-pretreated plants. Salicylic acid (SA), a central component of plant defense, does not seem to function in this type of H₂O₂-mediated symptom resistance, indicated by unchanged levels of free and bound SA and a lack of early up-regulation of an SA glucosyltransferase gene in TMV-infected H₂O₂-pretreated tobacco. Taken together, H₂O₂-mediated, induced resistance to necrotic symptoms in tobacco seems to depend on enhanced antioxidant capacity.

Arenavirus budding resulting from viral-protein-associated cell membrane curvature

PubMed Central

Schley, David; Whittaker, Robert J.; Neuman, Benjamin W.

2013-01-01

Viral replication occurs within cells, with release (and onward infection) primarily achieved through two alternative mechanisms: lysis, in which virions emerge as the infected cell dies and bursts open; or budding, in which virions emerge gradually from a still living cell by appropriating a small part of the cell membrane. Virus budding is a poorly understood process that challenges current models of vesicle formation. Here, a plausible mechanism for arenavirus budding is presented, building on recent evidence that viral proteins embed in the inner lipid layer of the cell membrane. Experimental results confirm that viral protein is associated with increased membrane curvature, whereas a mathematical model is used to show that localized increases in curvature alone are sufficient to generate viral buds. The magnitude of the protein-induced curvature is calculated from the size of the amphipathic region hypothetically removed from the inner membrane as a result of translation, with a change in membrane stiffness estimated from observed differences in virion deformation as a result of protein depletion. Numerical results are based on experimental data and estimates for three arenaviruses, but the mechanisms described are more broadly applicable. The hypothesized mechanism is shown to be sufficient to generate spontaneous budding that matches well both qualitatively and quantitatively with experimental observations. PMID:23864502

Oncolytic Viral Therapy and the Immune System: A Double-Edged Sword Against Cancer.

PubMed

Marelli, Giulia; Howells, Anwen; Lemoine, Nicholas R; Wang, Yaohe

2018-01-01

Oncolytic viral therapy is a new promising strategy against cancer. Oncolytic viruses (OVs) can replicate in cancer cells but not in normal cells, leading to lysis of the tumor mass. Beside this primary effect, OVs can also stimulate the immune system. Tumors are an immuno-suppressive environment in which the immune system is silenced in order to avoid the immune response against cancer cells. The delivery of OVs into the tumor wakes up the immune system so that it can facilitate a strong and durable response against the tumor itself. Both innate and adaptive immune responses contribute to this process, producing an immune response against tumor antigens and facilitating immunological memory. However, viruses are recognized by the immune system as pathogens and the consequent anti-viral response could represent a big hurdle for OVs. Finding a balance between anti-tumor and anti-viral immunity is, under this new light, a priority for researchers. In this review, we provide an overview of the various ways in which different components of the immune system can be allied with OVs. We have analyzed the different immune responses in order to highlight the new and promising perspectives leading to increased anti-tumor response and decreased immune reaction to the OVs.

Viral Infection in Adults with Severe Acute Respiratory Infection in Colombia

PubMed Central

Remolina, Yuly Andrea; Ulloa, María Mercedes; Vargas, Hernán; Díaz, Liliana; Gómez, Sandra Liliana; Saavedra, Alfredo; Sánchez, Edgar; Cortés, Jorge Alberto

2015-01-01

Objectives To identify the viral aetiology in adult patients with severe acute respiratory infection (SARI) admitted to sentinel surveillance institutions in Bogotá in 2012. Design A cross-sectional study was conducted in which microarray molecular techniques for viral identification were used on nasopharyngeal samples of adult patients submitted to the surveillance system, and further descriptions of clinical features and relevant clinical outcomes, such as mortality, need for critical care, use of mechanical ventilation and hospital stay, were obtained. Setting Respiratory infections requiring hospital admission in surveillance centres in Bogotá, Colombia. Participants Ninety-one adult patients with acute respiratory infection (55% were female). Measurements Viral identification, intensive care unit admission, hospital stay, and mortality. Results Viral identification was achieved for 63 patients (69.2%). Comorbidity was frequently identified and mainly involved chronic pulmonary disease or pregnancy. Influenza, Bocavirus and Adenovirus were identified in 30.8%, 28.6% and 18.7% of the cases, respectively. Admission to the intensive care unit occurred in 42.9% of the cases, while mechanical ventilation was required for 36.3%. The average hospital stay was 9.9 days, and mortality was 15.4%. Antibiotics were empirically used in 90.1% of patients. Conclusions The prevalence of viral aetiology of SARI in this study was high, with adverse clinical outcomes, intensive care requirements and high mortality. PMID:26576054

Inhibition of human T cell leukemia virus type 2 replication by the suppressive action of class II transactivator and nuclear factor Y.

PubMed

Tosi, Giovanna; Pilotti, Elisabetta; Mortara, Lorenzo; De Lerma Barbaro, Andrea; Casoli, Claudio; Accolla, Roberto S

2006-08-22

The master regulator of MHC-II gene transcription, class II transactivator (CIITA), acts as a potent inhibitor of human T cell leukemia virus type 2 (HTLV-2) replication by blocking the activity of the viral Tax-2 transactivator. Here, we show that this inhibitory effect takes place at the nuclear level and maps to the N-terminal 1-321 region of CIITA, where we identified a minimal domain, from positions 64-144, that is strictly required to suppress Tax-2 function. Furthermore, we show that Tax-2 specifically cooperates with cAMP response element binding protein-binding protein (CBP) and p300, but not with p300/CBP-associated factor, to enhance transcription from the viral promoter. This finding represents a unique difference with respect to Tax-1, which uses all three coactivators to transactivate the human T cell leukemia virus type 1 LTR. Direct sequestering of CBP or p300 is not the primary mechanism by which CIITA causes suppression of Tax-2. Interestingly, we found that the transcription factor nuclear factor Y, which interacts with CIITA to increase transcription of MHC-II genes, exerts a negative regulatory action on the Tax-2-mediated HTLV-2 LTR transactivation. Thus, CIITA may inhibit Tax-2 function, at least in part, through nuclear factor Y. These findings demonstrate the dual defensive role of CIITA against pathogens: it increases the antigen-presenting function for viral determinants and suppresses HTLV-2 replication in infected cells.

Modeling Viral Spread

PubMed Central

Graw, Frederik; Perelson, Alan S.

2016-01-01

The way in which a viral infection spreads within a host is a complex process that is not well understood. Different viruses, such as human immunodeficiency virus type 1 and hepatitis C virus, have evolved different strategies, including direct cell-to-cell transmission and cell-free transmission, to spread within a host. To what extent these two modes of transmission are exploited in vivo is still unknown. Mathematical modeling has been an essential tool to get a better systematic and quantitative understanding of viral processes that are difficult to discern through strictly experimental approaches. In this review, we discuss recent attempts that combine experimental data and mathematical modeling in order to determine and quantify viral transmission modes. We also discuss the current challenges for a systems-level understanding of viral spread, and we highlight the promises and challenges that novel experimental techniques and data will bring to the field. PMID:27618637

Time of HIV Diagnosis and Engagement in Prenatal Care Impact Virologic Outcomes of Pregnant Women with HIV.

PubMed

Momplaisir, Florence M; Brady, Kathleen A; Fekete, Thomas; Thompson, Dana R; Diez Roux, Ana; Yehia, Baligh R

2015-01-01

HIV suppression at parturition is beneficial for maternal, fetal and public health. To eliminate mother-to-child transmission of HIV, an understanding of missed opportunities for antiretroviral therapy (ART) use during pregnancy and HIV suppression at delivery is required. We performed a retrospective analysis of 836 mother-to-child pairs involving 656 HIV-infected women in Philadelphia, 2005-2013. Multivariable regression examined associations between patient (age, race/ethnicity, insurance status, drug use) and clinical factors such as adequacy of prenatal care measured by the Kessner index which classifies prenatal care as inadequate, intermediate, or adequate prenatal care; timing of HIV diagnosis; and the outcomes: receipt of ART during pregnancy and viral suppression at delivery. Overall, 25% of the sample was diagnosed with HIV during pregnancy; 39%, 38%, and 23% were adequately, intermediately, and inadequately engaged in prenatal care. Eight-five percent of mother-to-child pairs received ART during pregnancy but only 52% achieved suppression at delivery. Adjusting for patient factors, pairs diagnosed with HIV during pregnancy were less likely to receive ART (AOR 0.39, 95% CI 0.25-0.61) and achieve viral suppression (AOR 0.70, 95% CI 0.49-1.00) than those diagnosed before pregnancy. Similarly, women with inadequate prenatal care were less likely to receive ART (AOR 0.06, 95% CI 0.03-0.11) and achieve viral suppression (AOR 0.31, 95% CI 0.20-0.47) than those with adequate prenatal care. Targeted interventions to diagnose HIV prior to pregnancy and engage HIV-infected women in prenatal care have the potential to improve HIV related outcomes in the perinatal period.

Viral peptides-MHC interaction: Binding probability and distance from human peptides.

PubMed

Santoni, Daniele

2018-05-23

Identification of peptides binding to MHC class I complex can play a crucial role in retrieving potential targets able to trigger an immune response. Affinity binding of viral peptides can be estimated through effective computational methods that in the most of cases are based on machine learning approach. Achieving a better insight into peptide features that impact on the affinity binding rate is a challenging issue. In the present work we focused on 9-mer peptides of Human immunodeficiency virus type 1 and Human herpes simplex virus 1, studying their binding to MHC class I. Viral 9-mers were partitioned into different classes, where each class is characterized by how far (in terms of mutation steps) the peptides belonging to that class are from human 9-mers. Viral 9-mers were partitioned in different classes, based on the number of mutation steps they are far from human 9-mers. We showed that the overall binding probability significantly differs among classes, and it typically increases as the distance, computed in terms of number of mutation steps from the human set of 9-mers, increases. The binding probability is particularly high when considering viral 9-mers that are far from all human 9-mers more than three mutation steps. A further evidence, providing significance to those special viral peptides and suggesting a potential role they can play, comes from the analysis of their distribution along viral genomes, as it revealed they are not randomly located, but they preferentially occur in specific genes. Copyright © 2018 Elsevier B.V. All rights reserved.

Marine Viral Pathogens.

DTIC Science & Technology

1998-05-13

coccolithophorid Emiliania huxleyi. Experiments are continuing to determine whether the pathogens are viral. We have continued the development of PCR primers... Emiliania huxleyi; further work will be required to determine if the pathogen is viral. We have also continued methodological work to improve our ability

Cytokine Diedel and a viral homologue suppress the IMD pathway in Drosophila.

PubMed

Lamiable, Olivier; Kellenberger, Christine; Kemp, Cordula; Troxler, Laurent; Pelte, Nadège; Boutros, Michael; Marques, Joao Trindade; Daeffler, Laurent; Hoffmann, Jules A; Roussel, Alain; Imler, Jean-Luc

2016-01-19

Viruses are obligatory intracellular parasites that suffer strong evolutionary pressure from the host immune system. Rapidly evolving viral genomes can adapt to this pressure by acquiring genes that counteract host defense mechanisms. For example, many vertebrate DNA viruses have hijacked cellular genes encoding cytokines or cytokine receptors to disrupt host cell communication. Insect viruses express suppressors of RNA interference or apoptosis, highlighting the importance of these cell intrinsic antiviral mechanisms in invertebrates. Here, we report the identification and characterization of a family of proteins encoded by insect DNA viruses that are homologous to a 12-kDa circulating protein encoded by the virus-induced Drosophila gene diedel (die). We show that die mutant flies have shortened lifespan and succumb more rapidly than controls when infected with Sindbis virus. This reduced viability is associated with deregulated activation of the immune deficiency (IMD) pathway of host defense and can be rescued by mutations in the genes encoding the homolog of IKKγ or IMD itself. Our results reveal an endogenous pathway that is exploited by insect viruses to modulate NF-κB signaling and promote fly survival during the antiviral response.

Viral infection, inflammation and schizophrenia

PubMed Central

Kneeland, Rachel E.; Fatemi, S. Hossein

2012-01-01

Schizophrenia is a severe neurodevelopmental disorder with genetic and environmental etiologies. Prenatal viral/bacterial infections and inflammation play major roles in the genesis of schizophrenia. In this review, we describe a viral model of schizophrenia tested in mice whereby the offspring of mice prenatally infected with influenza at E7, E9, E16, and E18 show significant gene, protein, and brain structural abnormalities postnatally. Similarly, we describe data on rodents exposed to bacterial infection or injected with a synthetic viral mimic (PolyI:C) also demonstrating brain structural and behavioral abnormalities. Moreover, human serologic data has been indispensible in supporting the viral theory of schizophrenia. Individuals born seropositive for bacterial and viral agents are at a significantly elevated risk of developing schizophrenia. While the specific mechanisms of prenatal viral/bacterial infections and brain disorder are unclear, recent findings suggest that the maternal inflammatory response may be associated with fetal brain injury. Preventive and therapeutic treatment options are also proposed. This review presents data related to epidemiology, human serology, and experimental animal models which support the viral model of schizophrenia. PMID:22349576

Differential Properties of Cytomegalovirus pUL97 Kinase Isoforms Affect Viral Replication and Maribavir Susceptibility

PubMed Central

Webel, Rike; Hakki, Morgan; Prichard, Mark N.; Rawlinson, William D.; Marschall, Manfred

2014-01-01

ABSTRACT The human cytomegalovirus (HCMV)-encoded kinase pUL97 is required for efficient viral replication. Previous studies described two isoforms of pUL97, the full-length isoform (M1) and a smaller isoform likely resulting from translation initiation at codon 74 (M74). Here, we report the detection of a third pUL97 isoform during viral infection resulting from translation initiation at codon 157 (isoform M157). The consistent expression of isoform M157 as a minor component of pUL97 during infection with clinical and laboratory-adapted HCMV strains was suppressed when codon 157 was mutagenized. Viral mutants expressing specific isoforms were generated to compare their growth and drug susceptibility phenotypes, as well as pUL97 intracellular localization patterns and kinase activities. The exclusive expression of isoform M157 resulted in substantially reduced viral growth and resistance to the pUL97 inhibitor maribavir while retaining susceptibility to ganciclovir. Confocal imaging demonstrated reduced nuclear import of amino-terminal deletion isoforms compared to isoform M1. Isoform M157 showed reduced efficiency of various substrate protein interactions and autophosphorylation, whereas Rb phosphorylation was preserved. These results reveal differential properties of pUL97 isoforms that affect viral replication, with implications for the antiviral efficacy of maribavir. IMPORTANCE The HCMV UL97 kinase performs important functions in viral replication that are targeted by the antiviral drug maribavir. Here, we describe a naturally occurring short isoform of the kinase that when expressed by itself in a recombinant virus results in altered intracellular localization, impaired growth, and high-level resistance to maribavir compared to those of the predominant full-length counterpart. This is another factor to consider in explaining why maribavir appears to have variable antiviral activity in cell culture and in vivo. PMID:24522923

Viral respiratory diseases.

PubMed

Moise, N S

1985-09-01

An overview of the more commonly encountered viral diseases of the dog and cat is presented. The reader is acquainted with the principles of antiviral therapy and the drugs that have been studied for use in animal viral respiratory diseases. An update on vaccination principles and guidelines is provided.

Gene therapy mediated seizure suppression in Genetic Generalised Epilepsy: Neuropeptide Y overexpression in a rat model.

PubMed

Powell, Kim L; Fitzgerald, Xavier; Shallue, Claire; Jovanovska, Valentina; Klugmann, Matthias; Von Jonquieres, Georg; O'Brien, Terence J; Morris, Margaret J

2018-05-01

Neuropeptide Y (NPY) is an important 36 amino acid peptide that is abundantly expressed in the mammalian CNS and is known to be an endogenous modulator of seizure activity, including in rat models of Genetic Generalised Epilepsy (GGE) with absence seizures. Studies have shown that viral-mediated "gene therapy" with overexpression of NPY in the hippocampus can suppress seizures in acquired epilepsy animal models. This study investigated whether NPY gene delivery to the thalamus or somatosensory cortex, using recombinant adeno-associated viral vector (rAAV), could produce sustained seizure suppression in the GAERS model of GGE with absence seizures. Three cohorts of GAERS were injected bilaterally into the thalamus (short term n = 14 and long term n = 8) or the somatosensory cortex (n = 26) with rAAV-NPY or rAAV-empty. EEG recordings were acquired weekly post-treatment and seizure expression was quantified. Anxiety levels were tested using elevated plus maze and open field test. NPY and NPY receptor mRNA and protein expression were evaluated using quantitative PCR, immunohistochemistry and immunofluorescence. Viral overexpression of human NPY in the thalamus and somatosensory cortex in GAERS significantly reduced the time spent in seizure activity and number of seizures, whereas seizure duration was only reduced after thalamic NPY overexpression. Human and rat NPY and rat Y2 receptor mRNA expression was significantly increased in the somatosensory cortex. NPY overexpression in the thalamus was observed in rAAV-NPY treated rats compared to controls in the long term cohort. No effect was observed on anxiety behaviour. We conclude that virally-mediated human NPY overexpression in the thalamus or somatosensory cortex produces sustained anti-epileptic effects in GAERS. NPY gene therapy may represent a novel approach for the treatment of patients with genetic generalised epilepsies. Copyright © 2018 Elsevier Inc. All rights reserved.

Suppression of adenoviral gene expression in the liver: role of innate vs adaptive immunity and their cell lysis mechanisms.

PubMed

Minagawa, Masahiro; Kawamura, Hiroki; Liu, Zhangxu; Govindarajan, Sugantha; Dennert, Gunther

2005-06-01

Injection of adenoviral constructs causes liver infection prompting immunity, which suppress viral gene expression. Innate and adaptive immunity mediate these processes raising the question which pathways are the most prominent. Adenovirus expressing the beta-galactosidase (beta-gal) gene was injected into normal and immunodeficient mice. Elimination of beta-gal-expressing hepatocytes and increases in liver enzymes were assayed. Major histocompatibility complex (MHC) class I densities, perforin channel insertion and apoptosis by Fas and tumor necrosis factor (TNF)-alpha were assayed. At high virus doses, suppression of viral gene expression was as efficient in immunodeficient as in normal mice, while at low doses effects of cytotoxic T lymphocytes (CTL) were demonstrable. Despite CTL priming and elimination of infected hepatocytes no liver injury is detected. Hepatocyte MHC I densities were able to trigger CTL granule exocytosis and perforin lysis in vitro but not in vivo. This is we show is because of decreased sensitivity of hepatocytes from infected mice to perforin and increased sensitivity to Fas and TNF-alpha lysis. Effector cells of the innate immune system are exceedingly effective in suppressing adenoviral gene expression. Perforin-independent pathways, those mediated by TNF-alpha and Fas are very efficient in hepatocytes from virus-infected livers.

Interfering RNA with multi-targets for efficient gene suppression in HCC cells.

PubMed

Li, Tiejun; Zhu, York Yuanyuan; Ji, Yi; Zhou, Songfeng

2018-06-01

RNA interference (RNAi) technology has been widely used in therapeutics development, especially multiple targeted RNAi strategy, which is a better method for multiple gene suppression. In the study, interfering RNAs (iRNAs) were designed for carrying two or three different siRNA sequences in different secondary structure formats (loop or cloverleaf). By using these types of iRNAs, co-inhibition of survivin and B-cell lymphoma-2 (Bcl-2) was investigated in hepatocellular carcinoma (HCC) cells, and we obtained promising gene silencing effects without showing undesirable interferon response. Furthermore, suppression effects on proliferation, invasion, and induced apoptosis in HCC cells were validated. The results suggest that long iRNAs with secondary structure may be a preferred strategy for multigenic disease therapy, especially for cancer and viral gene therapy and their iRNA drug development.

[Decimeter-wave physiotherapy in viral hepatitis].

PubMed

Kents, V V; Mavrodiĭ, V M

1995-01-01

Effectiveness was evaluated of magnetotherapy, inductothermy, UNF electric field and electromagnetic waves of decimetric wave band (460 MHz) on the projection of the liver, adrenals and thyroid gland in controlled trials enrolling a total of 835 patients with viral hepatitis (type A, B, associated forms). A conclusion is reached that optimum effectiveness of decimetric field on the projection of the adrenals and thyroid gland can be achieved through the application of minimum power and everyday alternation of exposures. It has been estimated that as many as 69 percent of the patients derive benefit from the above treatment.

GNOSIS: an OH suppression unit for near-infrared spectrographs

NASA Astrophysics Data System (ADS)

Ellis, S. C.; Bland-Hawthorn, J.; Lawrence, J. S.; Bryant, J.; Haynes, R.; Horton, A.; Lee, S.; Leon-Saval, S.; Löhmannsröben, Hans-Gerd; Mladenoff, J.; O'Byrne, J.; Rambold, W.; Roth, M.; Trinh, C.

2010-07-01

GNOSIS is an OH suppression unit to be used in conjunction with existing spectrographs. The OH suppression is achieved using fibre Bragg gratings (FBGs), and will deliver the darkest near-infrared background of any ground-based instrument. Laboratory and on-sky tests demonstrate that FBGs can suppress OH lines by 30dB whilst maintaing > 90% throughput between the lines, resulting in a 4 mag decrease in the background. In the first implementation GNOSIS will feed IRIS2 on the AAT. It will consist of a seven element lenslet array, covering 1.4" on the sky, and will suppress the 103 brightest OH lines between 1.47 and 1.70 μm. Future upgrades will include J-band suppression and implementation on an 8m telescope.

In vitro anti-reovirus activity of kuraridin isolated from Sophora flavescens against viral replication and hemagglutination.

PubMed

Kwon, Hyung-Jun; Jeong, Jae-Ho; Lee, Seung Woong; Ryu, Young Bae; Jeong, Hyung Jae; Jung, Kyungsook; Lim, Jae Sung; Cho, Kyoung-Oh; Lee, Woo Song; Rho, Mun-Chual; Park, Su-Jin

2015-08-01

In this study, we evaluated the anti-reovirus activity of kuraridin isolated from the roots of Sophora flavescens. In particular, we focused on whether this property is attributable to direct inhibition of reovirus attachment and/or inhibition of viral replication with the aid of time-of-addition (pre-treatment, simultaneous treatment, and post-treatment) experiments. No significant antiviral activity of kuraridin was detected in the pre-treatment assay. In the simultaneous assay, the 50% effective inhibitory concentrations (EC50) of kuraridin were 15.3-176.9 μM against human type 1-3 reoviruses (HRV1-3) and Korean porcine reovirus (PRV). Kuraridin completely blocked binding of viral sigma 1 protein to sialic acids at concentrations lower than 82.5 μM in the hemagglutination inhibition assay. Moreover, kuraridin inhibited HRV1-3 and PRV viral replication with EC50 values of 14.0-62.0 μM. Quantitative real-time PCR analysis disclosed strong suppression of reovirus RNA synthesis at the late stage (18 h) of virus replication by kuraridin. The viral yields of kuraridin-treated cells were significantly reduced at 24 h post-infection, compared with DMSO-treated cells. Our results collectively suggest that kuraridin inhibits virus adsorption and replication by inhibiting hemagglutination, viral RNA and protein synthesis and virus shedding, supporting its utility as a viable candidate antiviral drug against reoviruses. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Twelve-Month Antiretroviral Therapy Suppresses Plasma and Genital Viral Loads but Fails to Alter Genital Levels of Cytokines, in a Cohort of HIV-Infected Rwandan Women

PubMed Central

Ondoa, Pascale; Gautam, Raju; Rusine, John; Lutter, Rene; Jurriaans, Suzanne; Kootstra, Neeltje; Karita, Etienne; van de Wijgert, Janneke

2015-01-01

Background Genital viral load (GVL) is the main determinant of sexual transmission of human immune-deficiency virus (HIV). The effect of antiretroviral therapy (ART) on local cervico-vaginal immunological factors associated with GVL is poorly described. We aimed to identify the risk factors of detectable GVL, and the impact of ART on HIV genital shedding and its correlates in a cohort of HIV-infected women, attending HIV care in Kigali, Rwanda. Materials and Methods All participants were evaluated for GVL, plasma viral load (PVL), CD4 count, various sexually-transmitted infections (STIs) at baseline and at month 12. Genital concentration of 19 cytokines and mRNA expression of APOBEC3G and BST2, two host HIV restriction factors, were evaluated at baseline in all participants. Cytokine levels were re-assessed at month 12 only in participants eligible for ART at baseline. Risk factors of GVL ≥40copies/mL at baseline and month 12 were assessed using logistic regression. Effect of 12-month ART on various local and systemic immunological parameters was examined using a paired t-test and McNemar as appropriate. Results 96 of the 247 women enrolled in the study were eligible for ART. After 12 months of ART, PVL and GVL decreased to undetectable level in respectively 74 and 88% of treated participants. ART did not affect cytokine levels. HIV genital shedding occurred only when PVL was detectable. At baseline, GVL was independently associated with IL-1β after controlling for PVL, age and N. gonorrhea infection (95% CI 1.32-2.15) and at month 12 with MIP-1β (95% CI 0.96-21.32) after controlling for baseline GVL, PVL and month 12 IL-8. Conclusion Suppressive ART does not necessarily reduce genital level of immune activation. Minimizing all conditions favoring genital inflammation, including active detection and treatment of STIs, might reduce the risk of HIV transmission as supplement to the provision of potent ART. PMID:26010956

Improved Cognitive Performance and Reduced Monocyte Activation in Virally Suppressed Chronic HIV Following Dual CCR2 and CCR5 Antagonism.

PubMed

D'Antoni, Michelle L; Paul, Robert H; Mitchell, Brooks I; Kohorn, Lindsay; Fischer, Laurent; Lefebvre, Eric; Seyedkazemi, Star; Nakamoto, Beau K; Walker, Maegen; Kallianpur, Kalpana J; Ogata-Arakaki, Debra; Ndhlovu, Lishomwa C; Shikuma, Cecilia

2018-05-16

To evaluate changes in neuropsychological (NP) performance and in plasma and cell surface markers of peripheral monocyte activation/migration following treatment with cenicriviroc (CVC), a dual C-C chemokine receptor type 2 (CCR2) and type 5 (CCR5) antagonist, in treatment-experienced, HIV-infected individuals. Single-arm, 24-week, open-label clinical trial. HIV-infected individuals on antiretroviral therapy (ART) >1 year with plasma HIV RNA <50 copies/ml and below-normal cognitive performance [defined as age, gender and education-adjusted NP performance (NPZ) <-0.5 in a single cognitive domain or in global performance] were enrolled. Changes over 24 weeks were assessed for global and domain-specific NPZ scores, plasma markers of monocyte/macrophage activation [neopterin, soluble (s)CD14 and sCD163] quantified by ELISA, and CCR2 and CCR5 expression on monocytes and T cells measured by flow cytometry. Seventeen of 20 enrolled participants completed the study. Improvements over 24 weeks were observed in global NPZ [median change (Δ)=0.24; p=0.008], and in cognitive domains of attention (Δ0.23; p=0.011) and working memory (Δ0.44; p=0.017). Plasma levels of sCD163, sCD14, and neopterin decreased significantly (p's<0.01). CCR2 and CCR5 monocyte expression remained unchanged; however, CCR5 levels on CD4 and CD8 T cells and CCR2 expression on CD4 T cells increased (p's<0.01). CVC given over 24 weeks was associated with improved NP test performance and decreased plasma markers of monocyte immune activation in virally-suppressed, HIV-infected participants. These data potentially link changes in monocyte activation to cognitive performance. Further study of CVC for HIV cognitive impairment in a randomized controlled study is warranted.

Comparative Analysis of Measures of Viral Reservoirs in HIV-1 Eradication Studies

PubMed Central

Lysenko, Elena S.; Bosch, Ronald J.; Lai, Jun; Chioma, Stanley; Emad, Fatemeh; Abdel-Mohsen, Mohamed; Hoh, Rebecca; Hecht, Frederick; Hunt, Peter; Somsouk, Ma; Wong, Joseph; Johnston, Rowena; Siliciano, Robert F.; Richman, Douglas D.; O'Doherty, Una; Palmer, Sarah; Deeks, Steven G.; Siliciano, Janet D.

2013-01-01

HIV-1 reservoirs preclude virus eradication in patients receiving highly active antiretroviral therapy (HAART). The best characterized reservoir is a small, difficult-to-quantify pool of resting memory CD4+ T cells carrying latent but replication-competent viral genomes. Because strategies targeting this latent reservoir are now being tested in clinical trials, well-validated high-throughput assays that quantify this reservoir are urgently needed. Here we compare eleven different approaches for quantitating persistent HIV-1 in 30 patients on HAART, using the original viral outgrowth assay for resting CD4+ T cells carrying inducible, replication-competent viral genomes as a standard for comparison. PCR-based assays for cells containing HIV-1 DNA gave infected cell frequencies at least 2 logs higher than the viral outgrowth assay, even in subjects who started HAART during acute/early infection. This difference may reflect defective viral genomes. The ratio of infected cell frequencies determined by viral outgrowth and PCR-based assays varied dramatically between patients. Although strong correlations with the viral outgrowth assay could not be formally excluded for most assays, correlations achieved statistical significance only for integrated HIV-1 DNA in peripheral blood mononuclear cells and HIV-1 RNA/DNA ratio in rectal CD4+ T cells. Residual viremia was below the limit of detection in many subjects and did not correlate with the viral outgrowth assays. The dramatic differences in infected cell frequencies and the lack of a precise correlation between culture and PCR-based assays raise the possibility that the successful clearance of latently infected cells may be masked by a larger and variable pool of cells with defective proviruses. These defective proviruses are detected by PCR but may not be affected by reactivation strategies and may not require eradication to accomplish an effective cure. A molecular understanding of the discrepancy between infected cell

Status of HIV Epidemic Control Among Adolescent Girls and Young Women Aged 15-24 Years - Seven African Countries, 2015-2017.

PubMed

Brown, Kristin; Williams, Daniel B; Kinchen, Steve; Saito, Suzue; Radin, Elizabeth; Patel, Hetal; Low, Andrea; Delgado, Stephen; Mugurungi, Owen; Musuka, Godfrey; Tippett Barr, Beth A; Nwankwo-Igomu, E Amaka; Ruangtragool, Leala; Hakim, Avi J; Kalua, Thokozani; Nyirenda, Rose; Chipungu, Gertrude; Auld, Andrew; Kim, Evelyn; Payne, Danielle; Wadonda-Kabondo, Nellie; West, Christine; Brennan, Elizabeth; Deutsch, Beth; Worku, Anteneh; Jonnalagadda, Sasi; Mulenga, Lloyd B; Dzekedzeke, Kumbutso; Barradas, Danielle T; Cai, Haotian; Gupta, Sundeep; Kamocha, Stanley; Riggs, Margaret A; Sachathep, Karampreet; Kirungi, Wilford; Musinguzi, Joshua; Opio, Alex; Biraro, Sam; Bancroft, Elizabeth; Galbraith, Jennifer; Kiyingi, Herbert; Farahani, Mansoor; Hladik, Wolfgang; Nyangoma, Edith; Ginindza, Choice; Masangane, Zandile; Mhlanga, Fortune; Mnisi, Zandile; Munyaradzi, Pasipamire; Zwane, Amos; Burke, Sean; Kayigamba, Felix B; Nuwagaba-Biribonwoha, Harriet; Sahabo, Ruben; Ao, Trong T; Draghi, Chiara; Ryan, Caroline; Philip, Neena M; Mosha, Fausta; Mulokozi, Aroldia; Ntigiti, Phausta; Ramadhani, Angela A; Somi, Geoffrey R; Makafu, Cecilia; Mugisha, Veronicah; Zelothe, Julius; Lavilla, Kayla; Lowrance, David W; Mdodo, Rennatus; Gummerson, Elizabeth; Stupp, Paul; Thin, Kyaw; Frederix, Koen; Davia, Stefania; Schwitters, Amee M; McCracken, Stephen D; Duong, Yen T; Hoos, David; Parekh, Bharat; Justman, Jessica E; Voetsch, Andrew C

2018-01-12

In 2016, an estimated 1.5 million females aged 15-24 years were living with human immunodeficiency virus (HIV) infection in Eastern and Southern Africa, where the prevalence of HIV infection among adolescent girls and young women (3.4%) is more than double that for males in the same age range (1.6%) (1). Progress was assessed toward the Joint United Nations Programme on HIV/AIDS (UNAIDS) 2020 targets for adolescent girls and young women in sub-Saharan Africa (90% of those with HIV infection aware of their status, 90% of HIV-infected persons aware of their status on antiretroviral treatment [ART], and 90% of those on treatment virally suppressed [HIV viral load <1,000 HIV RNA copies/mL]) (2) using data from recent Population-based HIV Impact Assessment (PHIA) surveys in seven countries. The national prevalence of HIV infection in adolescent girls and young women aged 15-24 years, the percentage who were aware of their status, and among those persons who were aware, the percentage who had achieved viral suppression were calculated. The target for viral suppression among all persons with HIV infection is 73% (the product of 90% x 90% x 90%). Among all seven countries, the prevalence of HIV infection among adolescent girls and young women was 3.6%; among those in this group, 46.3% reported being aware of their HIV-positive status, and 45.0% were virally suppressed. Sustained efforts by national HIV and public health programs to diagnose HIV infection in adolescent girls and young women as early as possible to ensure rapid initiation of ART should help achieve epidemic control among adolescent girls and young women.

Theoretical and experimental analysis of the impacts of removable storage media and antivirus software on viral spread

NASA Astrophysics Data System (ADS)

Gan, Chenquan; Yang, Xiaofan

2015-05-01

In this paper, a new computer virus propagation model, which incorporates the effects of removable storage media and antivirus software, is proposed and analyzed. The global stability of the unique equilibrium of the model is independent of system parameters. Numerical simulations not only verify this result, but also illustrate the influences of removable storage media and antivirus software on viral spread. On this basis, some applicable measures for suppressing virus prevalence are suggested.

Discovering the influential users oriented to viral marketing based on online social networks

NASA Astrophysics Data System (ADS)

Zhu, Zhiguo

2013-08-01

The target of viral marketing on the platform of popular online social networks is to rapidly propagate marketing information at lower cost and increase sales, in which a key problem is how to precisely discover the most influential users in the process of information diffusion. A novel method is proposed in this paper for helping companies to identify such users as seeds to maximize information diffusion in the viral marketing. Firstly, the user trust network oriented to viral marketing and users’ combined interest degree in the network including isolated users are extensively defined. Next, we construct a model considering the time factor to simulate the process of information diffusion in viral marketing and propose a dynamic algorithm description. Finally, experiments are conducted with a real dataset extracted from the famous SNS website Epinions. The experimental results indicate that the proposed algorithm has better scalability and is less time-consuming. Compared with the classical model, the proposed algorithm achieved a better performance than does the classical method on the two aspects of network coverage rate and time-consumption in our four sub-datasets.

Dexamethasone treatment decreases replication of viral hemorrhagic septicemia virus in Epithelioma papulosum cyprini cells.

PubMed

Kim, Min Sun; Lee, Su Jin; Choi, Seung Hyuk; Kang, Yue Jai; Kim, Ki Hong

2017-05-01

The expression of Mx1 in EPC cells after treatment with poly(I:C) or infection with viral hemorrhagic septicemia virus (VHSV) was significantly suppressed by treatment with dexamethasone. However, the titer of VHSV did not increase but instead decreased after dexamethasone treatment. This suggests that dexamethasone not only downregulates type I IFN but also affects certain factors that are necessary for VHSV replication. An important effect of HSP90 on replication of RNA viruses and downregulation of HSP90 by glucocorticoids have been reported. In this study, dexamethasone downregulated HSP90α expression in EPC cells that were stimulated with poly(I:C) or infected with VHSV. Furthermore, cells treated with an HSP90 inhibitor, geldanamycin, showed significantly decreased titers of VHSV, suggesting that HSP90 may be an important host component involved in VHSV replication, and HSP90 inhibition might be one of the causes for the observed reduction in viral titer caused by dexamethasone treatment.

Virologic outcomes in early antiretroviral treatment: HPTN 052

PubMed Central

Eshleman, Susan H.; Wilson, Ethan A.; Zhang, Xinyi C.; Ou, San-San; Piwowar-Manning, Estelle; Eron, Joseph J.; McCauley, Marybeth; Gamble, Theresa; Gallant, Joel E.; Hosseinipour, Mina C.; Kumarasamy, Nagalingeswaran; Hakim, James G.; Kalonga, Ben; Pilotto, Jose H.; Grinsztejn, Beatriz; Godbole, Sheela V.; Chotirosniramit, Nuntisa; Santos, Breno Riegel; Shava, Emily; Mills, Lisa A.; Panchia, Ravindre; Mwelase, Noluthando; Mayer, Kenneth H.; Chen, Ying Q.; Cohen, Myron S.; Fogel, Jessica M.

2017-01-01

INTRODUCTION The HPTN 052 trial demonstrated that early antiretroviral therapy (ART) prevented 93% of HIV transmission events in serodiscordant couples. Some linked infections were observed shortly after ART initiation or after virologic failure. OBJECTIVE To evaluate factors associated with time to viral suppression and virologic failure in participants who initiated ART in HPTN 052. METHODS 1,566 participants who had a viral load (VL) >400 copies/mL at enrollment were included in the analyses. This included 832 in the early ART arm (CD4 350–550 cells/mm3 at ART initiation) and 734 in the delayed ART arm (204 with a CD4 <250 cells/mm3 at ART initiation; 530 with any CD4 at ART initiation). Viral suppression was defined as two consecutive VLs ≤400 copies/mL after ART initiation; virologic failure was defined as two consecutive VLs >1,000 copies/mL >24 weeks after ART initiation. RESULTS Overall, 93% of participants achieved viral suppression by 12 months. The annual incidence of virologic failure was 3.6%. Virologic outcomes were similar in the two study arms. Longer time to viral suppression was associated with younger age, higher VL at ART initiation, and region (Africa vs. Asia). Virologic failure was strongly associated with younger age, lower educational level, and lack of suppression by 3 months; lower VL and higher CD4 at ART initiation were also associated with virologic failure. CONCLUSIONS Several clinical and demographic factors were identified that were associated with longer time to viral suppression and virologic failure. Recognition of these factors may help optimize ART for HIV treatment and prevention. PMID:28385131

Virologic outcomes in early antiretroviral treatment: HPTN 052.

PubMed

Eshleman, Susan H; Wilson, Ethan A; Zhang, Xinyi C; Ou, San-San; Piwowar-Manning, Estelle; Eron, Joseph J; McCauley, Marybeth; Gamble, Theresa; Gallant, Joel E; Hosseinipour, Mina C; Kumarasamy, Nagalingeswaran; Hakim, James G; Kalonga, Ben; Pilotto, Jose H; Grinsztejn, Beatriz; Godbole, Sheela V; Chotirosniramit, Nuntisa; Santos, Breno Riegel; Shava, Emily; Mills, Lisa A; Panchia, Ravindre; Mwelase, Noluthando; Mayer, Kenneth H; Chen, Ying Q; Cohen, Myron S; Fogel, Jessica M

2017-05-01

The HIV Prevention Trials Network (HPTN) 052 trial demonstrated that early antiretroviral therapy (ART) prevented 93% of HIV transmission events in serodiscordant couples. Some linked infections were observed shortly after ART initiation or after virologic failure. To evaluate factors associated with time to viral suppression and virologic failure in participants who initiated ART in HPTN 052. 1566 participants who had a viral load (VL) > 400 copies/mL at enrollment were included in the analyses. This included 832 in the early ART arm (CD4 350-550 cells/mm 3 at ART initiation) and 734 in the delayed ART arm (204 with a CD4 < 250 cells/mm 3 at ART initiation; 530 with any CD4 at ART initiation). Viral suppression was defined as two consecutive VLs ≤ 400 copies/mL after ART initiation; virologic failure was defined as two consecutive VLs > 1000 copies/mL > 24 weeks after ART initiation. Overall, 93% of participants achieved viral suppression by 12 months. The annual incidence of virologic failure was 3.6%. Virologic outcomes were similar in the two study arms. Longer time to viral suppression was associated with younger age, higher VL at ART initiation, and region (Africa vs. Asia). Virologic failure was strongly associated with younger age, lower educational level, and lack of suppression by three months; lower VL and higher CD4 at ART initiation were also associated with virologic failure. Several clinical and demographic factors were identified that were associated with longer time to viral suppression and virologic failure. Recognition of these factors may help optimize ART for HIV treatment and prevention.

A natural component from Euphorbia humifusa Willd displays novel, broad-spectrum anti-influenza activity by blocking nuclear export of viral ribonucleoprotein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, So Young; Park, Ji Hoon; Kim, Young Ho

The need to develop anti-influenza drugs with novel antiviral mechanisms is urgent because of the rapid rate of antigenic mutation and the emergence of drug-resistant viruses. We identified a novel anti-influenza molecule by screening 861 plant-derived natural components using a high-throughput image-based assay that measures inhibition of the influenza virus infection. 1,3,4,6-tetra-O-galloyl-β-D-glucopyranoside (TGBG) from Euphorbia humifusa Willd showed broad-spectrum anti-influenza activity against two seasonal influenza A strains, A/California/07/2009 (H1N1) and A/Perth/16/2009 (H3N2), and seasonal influenza B strain B/Florida/04/2006. We investigated the mode of action of TGBG using neuraminidase activity inhibition and time-of-addition assays, which evaluate the viral release and entrymore » steps, respectively. We found that TGBG exhibits a novel antiviral mechanism that differs from the FDA-approved anti-influenza drugs oseltamivir which inhibits viral release, and amantadine which inhibits viral entry. Immunofluorescence assay demonstrated that TGBG significantly inhibits nuclear export of influenza nucleoproteins (NP) during the early stages of infection causing NP to accumulate in the nucleus. In addition, influenza-induced activation of the Akt signaling pathway was suppressed by TGBG in a dose-dependent manner. These data suggest that a putative mode of action of TGBG involves inhibition of viral ribonucleoprotein (vRNP) export from the nucleus to the cytoplasm consequently disrupting the assembly of progeny virions. In summary, TGBG has potential as novel anti-influenza therapeutic with a novel mechanism of action. - Highlights: • The plant-derived natural product TGBG has broad-spectrum antiviral activity against seasonal influenza A and B viruses. • TGBG has a novel anti-viral mechanism of action that from differs from the currently available anti-influenza drugs. • TGBG hinders nuclear export of the influenza virus ribonucleoprotein (v

Cannabinoids and Viral Infections

PubMed Central

Reiss, Carol Shoshkes

2010-01-01

Exogenous cannabinoids or receptor antagonists may influence many cellular and systemic host responses. The anti-inflammatory activity of cannabinoids may compromise host inflammatory responses to acute viral infections, but may be beneficial in persistent infections. In neurons, where innate antiviral/pro-resolution responses include the activation of NOS-1, inhibition of Ca2+ activity by cannabinoids, increased viral replication and disease. This review examines the effect(s) of cannabinoids and their antagonists in viral infections. PMID:20634917

P‐TEFb goes viral

PubMed Central

Zaborowska, Justyna; Isa, Nur F.

2015-01-01

Positive transcription elongation factor b (P‐TEFb), which comprises cyclin‐dependent kinase 9 (CDK9) kinase and cyclin T subunits, is an essential kinase complex in human cells. Phosphorylation of the negative elongation factors by P‐TEFb is required for productive elongation of transcription of protein‐coding genes by RNA polymerase II (pol II). In addition, P‐TEFb‐mediated phosphorylation of the carboxyl‐terminal domain (CTD) of the largest subunit of pol II mediates the recruitment of transcription and RNA processing factors during the transcription cycle. CDK9 also phosphorylates p53, a tumor suppressor that plays a central role in cellular responses to a range of stress factors. Many viral factors affect transcription by recruiting or modulating the activity of CDK9. In this review, we will focus on how the function of CDK9 is regulated by viral gene products. The central role of CDK9 in viral life cycles suggests that drugs targeting the interaction between viral products and P‐TEFb could be effective anti‐viral agents. PMID:27398404

Metabolism Goes Viral

PubMed Central

Miyake-Stoner, Shigeki J.; O’Shea, Clodagh C.

2014-01-01

Viral and cellular oncogenes converge in targeting critical protein interaction networks to reprogram the cellular DNA and protein replication machinery for pathological replication. In this issue, Thai et al. (2014) show that adenovirus E4ORF1 activates MYC glycolytic targets to induce a Warburg-like effect that converts glucose into nucleotides for viral replication. PMID:24703688

Function of ubiquitin (Ub) specific protease 15 (USP15) in HIV-1 replication and viral protein degradation.

PubMed

Pyeon, Dohun; Timani, Khalid Amine; Gulraiz, Fahad; He, Johnny J; Park, In-Woo

2016-09-02

HIV-1 Nef is necessary and may be sufficient for HIV-1-associated AIDS pathogenicity, in that knockout of Nef alone can protect HIV-infected patients from AIDS. We therefore investigated the feasibility of physical knockout of Nef, using the host ubiquitin proteasome system in HIV-1-infected cells. Our co-immunoprecipitation analysis demonstrated that Nef interacted with ubiquitin specific protease 15 (USP15), and that USP15, which is known to stabilize cellular proteins, degraded Nef. Nef could also cause decay of USP15, although Nef-mediated degradation of USP15 was weaker than USP15-mediated Nef degradation. Direct interaction between Nef and USP15 was essential for the observed reciprocal decay of the proteins. Further, USP15 degraded not only Nef but also HIV-1 structural protein, Gag, thereby substantially inhibiting HIV-1 replication. However, Gag did not degrade USP15, indicating that the Nef and USP15 complex, in distinction to other viral proteins, play an integral role in coordinating viral protein degradation and hence HIV-1 replication. Moreover, Nef and USP15 globally suppressed ubiquitylation of cellular proteins, indicating that these proteins are major determinants for the stability of cellular as well as viral proteins. Taken together, these data indicate that Nef and USP15 are vital in regulating degradation of viral and cellular proteins and thus HIV-1 replication, and specific degradation of viral, not cellular proteins, by USP15 points to USP15 as a candidate therapeutic agent to combat AIDS by eliminating viral proteins from the infected cells via USP15-mediated proteosomal degradation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Viral drug sensitivity testing using quantitative PCR: effect of tyrosine kinase inhibitors on polyomavirus BK replication.

PubMed

Randhawa, Parmjeet S; Farasati, Noush A; Huang, Yuchen; Mapara, Markus Y; Shapiro, Ron

2010-12-01

Our objective was to determine whether quantitative polymerase chain reaction (PCR) can be used to measure the effect of tyrosine kinase (TK) inhibition on polyomavirus BK (BKV) replication. The BKV was grown in a cell culture system. The rate of viral replication in the presence or absence of the drug being tested was assessed by amplifying the viral genome using primers directed against the viral capsid 1 protein. Dasatinib, erlotinib, gefitinib, imatinib, sunitinib, and sorafenib all showed antiviral activity at micromolar concentrations. The 50% effective concentration for erlotinib and sorafenib was within blood concentrations readily achieved in human subjects. Quantitative PCR is a convenient method for viral drug sensitivity testing for slow-growing viruses that do not readily produce cytopathic effect. TK inhibitors deserve further consideration as a potential therapeutic option for BKV-associated nephropathy and hemorrhagic cystitis.

Toll-Like Receptor 7 Agonist GS-9620 Induces HIV Expression and HIV-Specific Immunity in Cells from HIV-Infected Individuals on Suppressive Antiretroviral Therapy.

PubMed

Tsai, Angela; Irrinki, Alivelu; Kaur, Jasmine; Cihlar, Tomas; Kukolj, George; Sloan, Derek D; Murry, Jeffrey P

2017-04-15

Antiretroviral therapy can suppress HIV replication to undetectable levels but does not eliminate latent HIV, thus necessitating lifelong therapy. Recent efforts to target this persistent reservoir have focused on inducing the expression of latent HIV so that infected cells may be recognized and eliminated by the immune system. Toll-like receptor (TLR) activation stimulates antiviral immunity and has been shown to induce HIV from latently infected cells. Activation of TLR7 leads to the production of several stimulatory cytokines, including type I interferons (IFNs). In this study, we show that the selective TLR7 agonist GS-9620 induced HIV in peripheral blood mononuclear cells (PBMCs) from HIV-infected individuals on suppressive antiretroviral therapy. GS-9620 increased extracellular HIV RNA 1.5- to 2-fold through a mechanism that required type I IFN signaling. GS-9620 also activated HIV-specific T cells and enhanced antibody-mediated clearance of HIV-infected cells. Activation by GS-9620 in combination with HIV peptide stimulation increased CD8 T cell degranulation, production of intracellular cytokines, and cytolytic activity. T cell activation was again dependent on type I IFNs produced by plasmacytoid dendritic cells. GS-9620 induced phagocytic cell maturation and improved effector-mediated killing of HIV-infected CD4 T cells by the HIV envelope-specific broadly neutralizing antibody PGT121. Collectively, these data show that GS-9620 can activate HIV production and improve the effector functions that target latently infected cells. GS-9620 may effectively complement orthogonal therapies designed to stimulate antiviral immunity, such as therapeutic vaccines or broadly neutralizing antibodies. Clinical studies are under way to determine if GS-9620 can target HIV reservoirs. IMPORTANCE Though antiretroviral therapies effectively suppress viral replication, they do not eliminate integrated proviral DNA. This stable intermediate of viral infection is persistently

Toll-Like Receptor 7 Agonist GS-9620 Induces HIV Expression and HIV-Specific Immunity in Cells from HIV-Infected Individuals on Suppressive Antiretroviral Therapy

PubMed Central

Tsai, Angela; Irrinki, Alivelu; Kaur, Jasmine; Cihlar, Tomas; Kukolj, George

2017-01-01

ABSTRACT Antiretroviral therapy can suppress HIV replication to undetectable levels but does not eliminate latent HIV, thus necessitating lifelong therapy. Recent efforts to target this persistent reservoir have focused on inducing the expression of latent HIV so that infected cells may be recognized and eliminated by the immune system. Toll-like receptor (TLR) activation stimulates antiviral immunity and has been shown to induce HIV from latently infected cells. Activation of TLR7 leads to the production of several stimulatory cytokines, including type I interferons (IFNs). In this study, we show that the selective TLR7 agonist GS-9620 induced HIV in peripheral blood mononuclear cells (PBMCs) from HIV-infected individuals on suppressive antiretroviral therapy. GS-9620 increased extracellular HIV RNA 1.5- to 2-fold through a mechanism that required type I IFN signaling. GS-9620 also activated HIV-specific T cells and enhanced antibody-mediated clearance of HIV-infected cells. Activation by GS-9620 in combination with HIV peptide stimulation increased CD8 T cell degranulation, production of intracellular cytokines, and cytolytic activity. T cell activation was again dependent on type I IFNs produced by plasmacytoid dendritic cells. GS-9620 induced phagocytic cell maturation and improved effector-mediated killing of HIV-infected CD4 T cells by the HIV envelope-specific broadly neutralizing antibody PGT121. Collectively, these data show that GS-9620 can activate HIV production and improve the effector functions that target latently infected cells. GS-9620 may effectively complement orthogonal therapies designed to stimulate antiviral immunity, such as therapeutic vaccines or broadly neutralizing antibodies. Clinical studies are under way to determine if GS-9620 can target HIV reservoirs. IMPORTANCE Though antiretroviral therapies effectively suppress viral replication, they do not eliminate integrated proviral DNA. This stable intermediate of viral infection is

Computational clustering for viral reference proteomes

PubMed Central

Chen, Chuming; Huang, Hongzhan; Mazumder, Raja; Natale, Darren A.; McGarvey, Peter B.; Zhang, Jian; Polson, Shawn W.; Wang, Yuqi; Wu, Cathy H.

2016-01-01

Motivation: The enormous number of redundant sequenced genomes has hindered efforts to analyze and functionally annotate proteins. As the taxonomy of viruses is not uniformly defined, viral proteomes pose special challenges in this regard. Grouping viruses based on the similarity of their proteins at proteome scale can normalize against potential taxonomic nomenclature anomalies. Results: We present Viral Reference Proteomes (Viral RPs), which are computed from complete virus proteomes within UniProtKB. Viral RPs based on 95, 75, 55, 35 and 15% co-membership in proteome similarity based clusters are provided. Comparison of our computational Viral RPs with UniProt’s curator-selected Reference Proteomes indicates that the two sets are consistent and complementary. Furthermore, each Viral RP represents a cluster of virus proteomes that was consistent with virus or host taxonomy. We provide BLASTP search and FTP download of Viral RP protein sequences, and a browser to facilitate the visualization of Viral RPs. Availability and implementation: http://proteininformationresource.org/rps/viruses/ Contact: chenc@udel.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:27153712

High viral abundance as a consequence of low viral decay in the Baltic Sea redoxcline

PubMed Central

Scharnreitner, Lisa; Jürgens, Klaus; Labrenz, Matthias; Herndl, Gerhard J.; Winter, Christian

2017-01-01

Throughout the Baltic Sea redoxcline, virus production and the frequency of lytically-infected prokaryotic cells were estimated from parallel incubations of undiluted seawater and seawater that contained prokaryotes with substantially reduced numbers of viruses (virus dilution approach), effectively preventing viral reinfection during the incubation period. Undiluted seawater incubations resulted in much higher estimates of virus production (6–35×104 mL-1 h-1) and the frequency of infected cells (5–84%) than the virus dilution approach (virus production: 1–3×104 mL-1 h-1; frequency of infected cells: 1–11%). Viral production and the frequency of infected cells from both approaches, however, cannot be directly compared, as data obtained from undiluted incubations were biased by viral reinfection and other uncontrollable processes during the incubation period. High in situ viral abundance (1–2×107 mL-1) together with low virus production rates based on the virus dilution approach resulted in some of the longest viral turnover times (24–84 d) ever reported for the epipelagial. Throughout a wide range of environmental conditions, viral turnover time and burst size were negatively correlated. Given that viral decay estimated in ultra-filtered water was below the detection limit and the burst size was low (1–17), we conclude that prokaryotic viruses in the Baltic Sea redoxcline are investing most of their resources into stress defense (strong capsids) rather than proliferation (high burst size). In summary, the Baltic Sea redoxcline constitutes an environment where low virus production is found in combination with low viral decay, resulting in high viral abundance. PMID:28594863

Intrapatient viral diversity and treatment outcome in patients with genotype 3a hepatitis C virus infection on sofosbuvir-containing regimens.

PubMed

Bhardwaj, N; Ragonnet-Cronin, M; Murrell, B; Chodavarapu, K; Martin, R; Chang, S; Miller, M D; Feld, J J; Sulkowski, M; Mangia, A; Wertheim, J O; Osinusi, A; McNally, J; Brainard, D; Mo, H; Svarovskaia, E S

2018-04-01

Treatment with the direct-acting antiviral agent (DAA) sofosbuvir (SOF), an NS5B inhibitor, and velpatasvir (VEL), an NS5A inhibitor, demonstrates viral cure rates of ≥95% in hepatitis C virus (HCV) genotypes (GT) 1-6. Here, we investigated intrapatient HCV diversity in NS5A and NS5B using Shannon entropy to examine the relationship between viral diversity and treatment outcome. At baseline, HCV diversity was lowest in patients infected with HCV GT3 as compared to the other GTs, and viral diversity was greater in NS5A than NS5B (P < .0001). Treatment outcome with SOF/VEL or the comparator regimen of SOF with ribavirin (RBV) was not correlated with baseline diversity. However, among persons treated with SOF/VEL, a decrease in diversity from baseline was observed at relapse in the majority virologic failures, consistent with a viral bottleneck event at relapse. In contrast, an increase in diversity was observed in 27% of SOF+RBV virologic failures. We investigated whether the increase in diversity was due to an increase in the transition rate, one mode of potential RBV-mediated mutagenesis; however, we found no evidence of this mechanism. Overall, we did not observe that viral diversity at baseline influenced treatment outcome, but the diversity changes observed at relapse can improve our understanding of RBV viral suppression in vivo. © 2017 John Wiley & Sons Ltd.

Analysis of host genetic diversity and viral entry as sources of between-host variation in viral load

USGS Publications Warehouse

Wargo, Andrew R.; Kell, Alison M.; Scott, Robert J.; Thorgaard, Gary H.; Kurath, Gael

2012-01-01

Little is known about the factors that drive the high levels of between-host variation in pathogen burden that are frequently observed in viral infections. Here, two factors thought to impact viral load variability, host genetic diversity and stochastic processes linked with viral entry into the host, were examined. This work was conducted with the aquatic vertebrate virus, Infectious hematopoietic necrosis virus (IHNV), in its natural host, rainbow trout. It was found that in controlled in vivo infections of IHNV, a suggestive trend of reduced between-fish viral load variation was observed in a clonal population of isogenic trout compared to a genetically diverse population of out-bred trout. However, this trend was not statistically significant for any of the four viral genotypes examined, and high levels of fish-to-fish variation persisted even in the isogenic trout population. A decrease in fish-to-fish viral load variation was also observed in virus injection challenges that bypassed the host entry step, compared to fish exposed to the virus through the natural water-borne immersion route of infection. This trend was significant for three of the four virus genotypes examined and suggests host entry may play a role in viral load variability. However, high levels of viral load variation also remained in the injection challenges. Together, these results indicate that although host genetic diversity and viral entry may play some role in between-fish viral load variation, they are not major factors. Other biological and non-biological parameters that may influence viral load variation are discussed.

Laboratory procedures to generate viral metagenomes.

PubMed

Thurber, Rebecca V; Haynes, Matthew; Breitbart, Mya; Wegley, Linda; Rohwer, Forest

2009-01-01

This collection of laboratory protocols describes the steps to collect viruses from various samples with the specific aim of generating viral metagenome sequence libraries (viromes). Viral metagenomics, the study of uncultured viral nucleic acid sequences from different biomes, relies on several concentration, purification, extraction, sequencing and heuristic bioinformatic methods. No single technique can provide an all-inclusive approach, and therefore the protocols presented here will be discussed in terms of hypothetical projects. However, care must be taken to individualize each step depending on the source and type of viral-particles. This protocol is a description of the processes we have successfully used to: (i) concentrate viral particles from various types of samples, (ii) eliminate contaminating cells and free nucleic acids and (iii) extract, amplify and purify viral nucleic acids. Overall, a sample can be processed to isolate viral nucleic acids suitable for high-throughput sequencing in approximately 1 week.

Hepatitis A through E (Viral Hepatitis)

MedlinePlus

... Treatment Eating, Diet, & Nutrition Clinical Trials Wilson Disease Hepatitis (Viral) View or Print All Sections What is Viral Hepatitis? Viral hepatitis is an infection that causes liver inflammation ...

Toll-Like Receptor–2/6 and Toll-Like Receptor–9 Agonists Suppress Viral Replication but Not Airway Hyperreactivity in Guinea Pigs

PubMed Central

Evans, Scott E.; Dickey, Burton F.; Fryer, Allison D.; Jacoby, David B.

2013-01-01

Respiratory virus infections cause airway hyperreactivity (AHR). Preventative strategies for virus-induced AHR remain limited. Toll-like receptors (TLRs) have been suggested as a therapeutic target because of their central role in triggering antiviral immune responses. Previous studies showed that concurrent treatment with TLR2/6 and TLR9 agonists reduced lethality and the microbial burden in murine models of bacterial and viral pneumonia. This study investigated the effects of TLR2/6 and TLR9 agonist pretreatment on parainfluenza virus pneumonia and virus-induced AHR in guinea pigs in vivo. Synthetic TLR2/6 lipopeptide agonist Pam2CSK4 and Class C oligodeoxynucleotide TLR9 agonist ODN2395, administered in combination 24 hours before virus infection, significantly reduced viral replication in the lung. Despite a fivefold reduction in viral titers, concurrent TLR2/6 and TLR9 agonist pretreatment did not prevent virus-induced AHR or virus-induced inhibitory M2 muscarinic receptor dysfunction. Interestingly, the TLR agonists independently caused non–M2-dependent AHR. These data confirm the therapeutic antiviral potential of TLR agonists, while suggesting that virus inhibition may be insufficient to prevent virus-induced airway pathophysiology. Furthermore, TLR agonists independently cause AHR, albeit through a distinctly different mechanism from that of parainfluenza virus. PMID:23449736

[The viral hepatitis and its economic significance and prevention].

PubMed

Petruchuk, O E; Shchenin, V O; Bedrin, A V; Leshcheva, G A

2008-01-01

The reference of only part of diseases having contagious nature to the infectious pathology is closely related to the tradition of considering the infections as highly contagious diseases inclined to epidemic propagation. The data is presented related to the morbidity of viral hepatitis among the population of the City of Krasnodar. The corresponding economic losses and the achievements of medical preventive activities considering the social economic and other characteristics of the specific socium are considered.

Short-term pIFN-α2a treatment does not significantly reduce the viral reservoir of SIV-infected, ART-treated rhesus macaques.

PubMed

Palesch, David; Bosinger, Steven E; Mavigner, Maud; Billingsley, James M; Mattingly, Cameron; Carnathan, Diane; Paiardini, Mirko; Chahroudi, Ann; Vanderford, Thomas; Silvestri, Guido

2018-05-02

The major obstacle to HIV-1 eradication is a reservoir of latently infected cells that persists despite long-term antiretroviral therapy (ART) and causes rapid viral rebound if treatment is interrupted. Type I interferons are immunomodulatory cytokines that induce antiviral factors and have been evaluated for the treatment of HIV-infected individuals, resulting in moderate reduction of viremia and inconclusive data about their effect on reservoir size. Here, we assessed the potential of pegylated IFN-α2a (pIFN-α2a) to reduce the viral reservoir in SIV-infected, ART-treated rhesus macaques (RMs). We found that pIFN-α2a treatment of animals in which virus replication is effectively suppressed with ART is safe and well-tolerated as no major clinical side effects were observed. By monitoring the cellular immune response during this intervention, we established that pIFN-α2a administration is not associated with either CD4 + T cell depletion or increased immune activation. Importantly, we found that Interferon Stimulated Genes (ISGs) were significantly up-regulated in IFN-treated RMs when compared to control animals, confirming that pIFN-α2a is bioactive in vivo. To evaluate the effect of pIFN-α2a administration on the viral reservoir in CD4 + T cells, we performed cell-associated proviral SIV DNA measurements in multiple tissues and assessed levels of replication-competent virus by a quantitative viral outgrowth assay (QVOA). These analyses failed to reveal any significant difference in reservoir size between IFN-treated and control animals. In summary, our data suggest that short-term type I interferon treatment in combination with suppressive ART is not sufficient to induce a significant reduction of the viral reservoir in SIV-infected RMs. IMPORTANCE The potential of type I interferons to reduce the viral reservoir has been recently studied in clinical trials in HIV-infected humans. However, given the lack of mechanistic data and the potential for safety

Discordance of Self-report and Laboratory Measures of HIV Viral Load Among Young Men Who Have Sex with Men and Transgender Women in Chicago: Implications for Epidemiology, Care, and Prevention.

PubMed

Mustanski, Brian; Ryan, Daniel T; Remble, Thomas A; D'Aquila, Richard T; Newcomb, Michael E; Morgan, Ethan

2018-04-10

Suppressing HIV viral load through daily antiretroviral therapy (ART) substantially reduces the risk of HIV transmission, however, the potential population impact of treatment as prevention (TasP) is mitigated due to challenges with sustained care engagement and ART adherence. For an undetectable viral load (VL) to inform decision making about transmission risk, individuals must be able to accurately classify their VL as detectable or undetectable. Participants were 205 HIV-infected young men who have sex with men (YMSM) and transgender women (TGW) from a large cohort study in the Chicago area. Analyses examined correspondence among self-reported undetectable VL, study-specific VL, and most recent medical record VL. Among HIV-positive YMSM/TGW, 54% had an undetectable VL (< 200 copies/mL) via study-specific laboratory testing. Concordance between self-report and medical record VL values was 80% and between self-report and study-specific laboratory testing was 73%; 34% of participants with a detectable study-specific VL self-reported an undetectable VL at last medical visit, and another 28% reported not knowing their VL status. Periods of lapsed viral suppression between medical visits may represent a particular risk for the TasP strategy among YMSM/TGW. Strategies for frequent viral load monitoring, that are not burdensome to patients, may be necessary to optimize TasP.

A single CD4 test with 250 cells/mm3 threshold predicts viral suppression in HIV-infected adults failing first-line therapy by clinical criteria.

PubMed

Gilks, Charles F; Walker, A Sarah; Munderi, Paula; Kityo, Cissy; Reid, Andrew; Katabira, Elly; Goodall, Ruth L; Grosskurth, Heiner; Mugyenyi, Peter; Hakim, James; Gibb, Diana M

2013-01-01

In low-income countries, viral load (VL) monitoring of antiretroviral therapy (ART) is rarely available in the public sector for HIV-infected adults or children. Using clinical failure alone to identify first-line ART failure and trigger regimen switch may result in unnecessary use of costly second-line therapy. Our objective was to identify CD4 threshold values to confirm clinically-determined ART failure when VL is unavailable. 3316 HIV-infected Ugandan/Zimbabwean adults were randomised to first-line ART with Clinically-Driven (CDM, CD4s measured but blinded) or routine Laboratory and Clinical Monitoring (LCM, 12-weekly CD4s) in the DART trial. CD4 at switch and ART failure criteria (new/recurrent WHO 4, single/multiple WHO 3 event; LCM: CD4<100 cells/mm(3)) were reviewed in 361 LCM, 314 CDM participants who switched over median 5 years follow-up. Retrospective VLs were available in 368 (55%) participants. Overall, 265/361 (73%) LCM participants failed with CD4<100 cells/mm(3); only 7 (2%) switched with CD4≥250 cells/mm(3), four switches triggered by WHO events. Without CD4 monitoring, 207/314 (66%) CDM participants failed with WHO 4 events, and 77(25%)/30(10%) with single/multiple WHO 3 events. Failure/switching with single WHO 3 events was more likely with CD4≥250 cells/mm(3) (28/77; 36%) (p = 0.0002). CD4 monitoring reduced switching with viral suppression: 23/187 (12%) LCM versus 49/181 (27%) CDM had VL<400 copies/ml at failure/switch (p<0.0001). Amongst CDM participants with CD4<250 cells/mm(3) only 11/133 (8%) had VL<400 copies/ml, compared with 38/48 (79%) with CD4≥250 cells/mm(3) (p<0.0001). Multiple, but not single, WHO 3 events predicted first-line ART failure. A CD4 threshold 'tiebreaker' of ≥250 cells/mm(3) for clinically-monitored patients failing first-line could identify ∼80% with VL<400 copies/ml, who are unlikely to benefit from second-line. Targeting CD4s to single WHO stage 3 'clinical failures' would particularly avoid premature

A Single CD4 Test with 250 Cells/Mm3 Threshold Predicts Viral Suppression in HIV-Infected Adults Failing First-Line Therapy by Clinical Criteria

PubMed Central

Munderi, Paula; Kityo, Cissy; Reid, Andrew; Katabira, Elly; Goodall, Ruth L.; Grosskurth, Heiner; Mugyenyi, Peter; Hakim, James; Gibb, Diana M.

2013-01-01

Background In low-income countries, viral load (VL) monitoring of antiretroviral therapy (ART) is rarely available in the public sector for HIV-infected adults or children. Using clinical failure alone to identify first-line ART failure and trigger regimen switch may result in unnecessary use of costly second-line therapy. Our objective was to identify CD4 threshold values to confirm clinically-determined ART failure when VL is unavailable. Methods 3316 HIV-infected Ugandan/Zimbabwean adults were randomised to first-line ART with Clinically-Driven (CDM, CD4s measured but blinded) or routine Laboratory and Clinical Monitoring (LCM, 12-weekly CD4s) in the DART trial. CD4 at switch and ART failure criteria (new/recurrent WHO 4, single/multiple WHO 3 event; LCM: CD4<100 cells/mm3) were reviewed in 361 LCM, 314 CDM participants who switched over median 5 years follow-up. Retrospective VLs were available in 368 (55%) participants. Results Overall, 265/361 (73%) LCM participants failed with CD4<100 cells/mm3; only 7 (2%) switched with CD4≥250 cells/mm3, four switches triggered by WHO events. Without CD4 monitoring, 207/314 (66%) CDM participants failed with WHO 4 events, and 77(25%)/30(10%) with single/multiple WHO 3 events. Failure/switching with single WHO 3 events was more likely with CD4≥250 cells/mm3 (28/77; 36%) (p = 0.0002). CD4 monitoring reduced switching with viral suppression: 23/187 (12%) LCM versus 49/181 (27%) CDM had VL<400 copies/ml at failure/switch (p<0.0001). Amongst CDM participants with CD4<250 cells/mm3 only 11/133 (8%) had VL<400copies/ml, compared with 38/48 (79%) with CD4≥250 cells/mm3 (p<0.0001). Conclusion Multiple, but not single, WHO 3 events predicted first-line ART failure. A CD4 threshold ‘tiebreaker’ of ≥250 cells/mm3 for clinically-monitored patients failing first-line could identify ∼80% with VL<400 copies/ml, who are unlikely to benefit from second-line. Targeting CD4s to single WHO stage 3 ‘clinical failures�

Suppression of the asymmetric modes for experimentally achieving gigawatt-level radiation from a Ku-band Cerenkov type oscillator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Hua; Shu, Ting, E-mail: mrtingshu@qq.com; Ju, Jinchuan

2014-08-15

We present the analysis and suppression of asymmetric modes in a Ku-band Cerenkov-type oscillator numerically and experimentally. The asymmetric modes generated in the initial experiments were identified to be HE{sub 11}, HE{sub 21}, and HE{sub 31} modes, respectively, by analyzing of the dispersion relationships, the simulation results and the experiment phenomenon. The factors, such as the cathode emission uniformity, the diode voltage, guiding magnetic field, and the concentricity play key roles in the excitation and suppression of these asymmetric modes. In the improved experiments, the asymmetric modes were suppressed effectively. In the improved experiments the asymmetric modes are suppressed effectively,more » and the designed TM{sub 01} mode microwave is generated at a frequency of 13.76 GHz with a power of 1.1 GW, which is in good agreement with numerically predications.« less

A Comparison of Urge Intensity and the Probability of Tic Completion During Tic Freely and Tic Suppression Conditions.

PubMed

Specht, Matt W; Nicotra, Cassandra M; Kelly, Laura M; Woods, Douglas W; Ricketts, Emily J; Perry-Parrish, Carisa; Reynolds, Elizabeth; Hankinson, Jessica; Grados, Marco A; Ostrander, Rick S; Walkup, John T

2014-03-01

Tic-suppression-based treatments (TSBTs) represent a safe and effective treatment option for Chronic Tic Disorders (CTDs). Prior research has demonstrated that treatment naive youths with CTDs have the capacity to safely and effectively suppress tics for prolonged periods. It remains unclear how tic suppression is achieved. The current study principally examines how effective suppression is achieved and preliminary correlates of the ability to suppress tics. Twelve youths, ages 10 to 17 years, with moderate-to-marked CTDs participated in an alternating sequence of tic freely and reinforced tic suppression conditions during which urge intensity and tic frequency were frequently assessed. Probability of tics occurring was half as likely following high-intensity urges during tic suppression (31%) in contrast to low-intensity urges during tic freely conditions (60%). Age was not associated with ability to suppress. Intelligence indices were associated with or trended toward greater ability to suppress tics. Attention difficulties were not associated with ability to suppress but were associated with tic severity. In contrast to our "selective suppression" hypothesis, we found participants equally capable of suppressing their tics regardless of urge intensity during reinforced tic suppression. Tic suppression was achieved with an "across-the-board" effort to resist urges. Preliminary data suggest that ability to suppress may be associated with general cognitive variables rather than age, tic severity, urge severity, and attention. Treatment naive youths appear to possess a capacity for robust tic suppression. TSBTs may bolster these capacities and/or enable their broader implementation, resulting in symptom improvement. © The Author(s) 2014.

Viral genetic variation accounts for a third of variability in HIV-1 set-point viral load in Europe

PubMed Central

Wymant, Chris; Cornelissen, Marion; Gall, Astrid; Bakker, Margreet; Bezemer, Daniela; Hall, Matthew; Hillebregt, Mariska; Ong, Swee Hoe; Albert, Jan; Bannert, Norbert; Fellay, Jacques; Fransen, Katrien; Gourlay, Annabelle J.; Grabowski, M. Kate; Gunsenheimer-Bartmeyer, Barbara; Günthard, Huldrych F.; Kivelä, Pia; Kouyos, Roger; Laeyendecker, Oliver; Liitsola, Kirsi; Meyer, Laurence; Porter, Kholoud; Ristola, Matti; van Sighem, Ard; Vanham, Guido; Berkhout, Ben; Kellam, Paul; Reiss, Peter; Fraser, Christophe

2017-01-01

HIV-1 set-point viral load—the approximately stable value of viraemia in the first years of chronic infection—is a strong predictor of clinical outcome and is highly variable across infected individuals. To better understand HIV-1 pathogenesis and the evolution of the viral population, we must quantify the heritability of set-point viral load, which is the fraction of variation in this phenotype attributable to viral genetic variation. However, current estimates of heritability vary widely, from 6% to 59%. Here we used a dataset of 2,028 seroconverters infected between 1985 and 2013 from 5 European countries (Belgium, Switzerland, France, the Netherlands and the United Kingdom) and estimated the heritability of set-point viral load at 31% (CI 15%–43%). Specifically, heritability was measured using models of character evolution describing how viral load evolves on the phylogeny of whole-genome viral sequences. In contrast to previous studies, (i) we measured viral loads using standardized assays on a sample collected in a strict time window of 6 to 24 months after infection, from which the viral genome was also sequenced; (ii) we compared 2 models of character evolution, the classical “Brownian motion” model and another model (“Ornstein–Uhlenbeck”) that includes stabilising selection on viral load; (iii) we controlled for covariates, including age and sex, which may inflate estimates of heritability; and (iv) we developed a goodness of fit test based on the correlation of viral loads in cherries of the phylogenetic tree, showing that both models of character evolution fit the data well. An overall heritability of 31% (CI 15%–43%) is consistent with other studies based on regression of viral load in donor–recipient pairs. Thus, about a third of variation in HIV-1 virulence is attributable to viral genetic variation. PMID:28604782

Viral genetic variation accounts for a third of variability in HIV-1 set-point viral load in Europe.

PubMed

Blanquart, François; Wymant, Chris; Cornelissen, Marion; Gall, Astrid; Bakker, Margreet; Bezemer, Daniela; Hall, Matthew; Hillebregt, Mariska; Ong, Swee Hoe; Albert, Jan; Bannert, Norbert; Fellay, Jacques; Fransen, Katrien; Gourlay, Annabelle J; Grabowski, M Kate; Gunsenheimer-Bartmeyer, Barbara; Günthard, Huldrych F; Kivelä, Pia; Kouyos, Roger; Laeyendecker, Oliver; Liitsola, Kirsi; Meyer, Laurence; Porter, Kholoud; Ristola, Matti; van Sighem, Ard; Vanham, Guido; Berkhout, Ben; Kellam, Paul; Reiss, Peter; Fraser, Christophe

2017-06-01

HIV-1 set-point viral load-the approximately stable value of viraemia in the first years of chronic infection-is a strong predictor of clinical outcome and is highly variable across infected individuals. To better understand HIV-1 pathogenesis and the evolution of the viral population, we must quantify the heritability of set-point viral load, which is the fraction of variation in this phenotype attributable to viral genetic variation. However, current estimates of heritability vary widely, from 6% to 59%. Here we used a dataset of 2,028 seroconverters infected between 1985 and 2013 from 5 European countries (Belgium, Switzerland, France, the Netherlands and the United Kingdom) and estimated the heritability of set-point viral load at 31% (CI 15%-43%). Specifically, heritability was measured using models of character evolution describing how viral load evolves on the phylogeny of whole-genome viral sequences. In contrast to previous studies, (i) we measured viral loads using standardized assays on a sample collected in a strict time window of 6 to 24 months after infection, from which the viral genome was also sequenced; (ii) we compared 2 models of character evolution, the classical "Brownian motion" model and another model ("Ornstein-Uhlenbeck") that includes stabilising selection on viral load; (iii) we controlled for covariates, including age and sex, which may inflate estimates of heritability; and (iv) we developed a goodness of fit test based on the correlation of viral loads in cherries of the phylogenetic tree, showing that both models of character evolution fit the data well. An overall heritability of 31% (CI 15%-43%) is consistent with other studies based on regression of viral load in donor-recipient pairs. Thus, about a third of variation in HIV-1 virulence is attributable to viral genetic variation.

Metabolism goes viral.

PubMed

Miyake-Stoner, Shigeki J; O'Shea, Clodagh C

2014-04-01

Viral and cellular oncogenes converge in targeting critical protein interaction networks to reprogram the cellular DNA and protein replication machinery for pathological replication. In this issue, Thai et al. (2014) show that adenovirus E4ORF1 activates MYC glycolytic targets to induce a Warburg-like effect that converts glucose into nucleotides for viral replication. Copyright © 2014 Elsevier Inc. All rights reserved.

Mechanisms of viral mutation.

PubMed

Sanjuán, Rafael; Domingo-Calap, Pilar

2016-12-01

The remarkable capacity of some viruses to adapt to new hosts and environments is highly dependent on their ability to generate de novo diversity in a short period of time. Rates of spontaneous mutation vary amply among viruses. RNA viruses mutate faster than DNA viruses, single-stranded viruses mutate faster than double-strand virus, and genome size appears to correlate negatively with mutation rate. Viral mutation rates are modulated at different levels, including polymerase fidelity, sequence context, template secondary structure, cellular microenvironment, replication mechanisms, proofreading, and access to post-replicative repair. Additionally, massive numbers of mutations can be introduced by some virus-encoded diversity-generating elements, as well as by host-encoded cytidine/adenine deaminases. Our current knowledge of viral mutation rates indicates that viral genetic diversity is determined by multiple virus- and host-dependent processes, and that viral mutation rates can evolve in response to specific selective pressures.

NASA Instep/mdmsc Jitter Suppression Experiment (JITTER)

NASA Technical Reports Server (NTRS)

White, Edward V.

1992-01-01

The objectives are the following: (1) to develop and demonstrate in-space performance of both passive and active damping systems for suppression of micro-amplitude vibration on an actual application structure and operate despite uncertain dynamics and uncertain disturbance characteristics; and (2) to correlate ground and in-space performance - the performance metric is vibration attenuation. The goals are to achieve vibration suppression equivalent to 5 percent passive damping in selected models and 15 percent active damping in selected modes. Various aspects of this experiment are presented in viewgraph form.

NRSF causes cAMP-sensitive suppression of sodium current in cultured hippocampal neurons

NASA Technical Reports Server (NTRS)

Nadeau, H.; Lester, H. A.

2002-01-01

The neuron restrictive silencer factor (NRSF/REST) has been shown to bind to the promoters of many neuron-specific genes and is able to suppress transcription of Na(+) channels in PC12 cells, although its functional effect in terminally differentiated neurons is unknown. We constructed lentiviral vectors to express NRSF as a bicistronic message with green fluorescent protein (GFP) and followed infected hippocampal neurons in culture over a period of 1-2 wk. NRSF-expressing neurons showed a time-dependent suppression of Na(+) channel function as measured by whole cell electrophysiology. Suppression was reversed or prevented by the addition of membrane-permeable cAMP analogues and enhanced by cAMP antagonists but not affected by increasing protein expression with a viral enhancer. Secondary effects, including altered sensitivity to glutamate and GABA and reduced outward K(+) currents, were duplicated by culturing GFP-infected control neurons in TTX. The striking similarity of the phenotypes makes NRSF potentially useful as a genetic "silencer" and also suggests avenues of further exploration that may elucidate the transcription factor's in vivo role in neuronal plasticity.

Intranasal delivery of Duox2 DNA using cationic polymer can prevent acute influenza A viral infection in vivo lung.

PubMed

Kim, Bong Jik; Cho, Sung Woo; Jeon, Yung Jin; An, Sujin; Jo, Ara; Lim, Jae Hyun; Kim, Dong-Young; Won, Tae-Bin; Han, Doo Hee; Rhee, Chae-Seo; Kim, Hyun Jik

2018-01-01

We studied the contribution of Duox2 in mucosal host defense against influenza A virus (IAV) infection in in vivo lung. We found that Duox2 was required for the induction of type I and III interferon (IFN)s and transient Duox2 overexpression using cationic polymer polyethyleneimine (PEI) leads to suppression of IAV infection in in vivo lung. Twenty mice (C57BL/6J) were anesthetized and challenged by intranasal administration of 213 pfu/30 μl of IAV (WS/33/H1N1), and IAV-infected mice were euthanized at 1, 3, 5, 7, 10, 14 days post infection (dpi). Duox2 small hairpin RNA (shRNA) and pCMV-Duox2 formulated with PEI were inoculated to mice to assess the regulatory mechanism between Duox2 and IFN secretion. Following intranasal IAV inoculation, viral infection was significantly aggravated from 3 dpi in in vivo lung and viral titer was highest at 7 dpi. Consistent with this, Duox2 messenger RNA (mRNA) and protein expressions were significantly induced from 3 dpi in the lung tissue of IAV-infected mice. Viral titer was much higher in IAV-infected mice that were inoculated with Duox2 shRNA accompanied with lower survival rate and extensive lung pathologies. Interestingly, severe lung pathologies in IAV-infected mice were not observed and viral titer was significantly reduced in mice with pulmonary administration of pCMV-Duox2 formulated with PEI before IAV inoculation. Both mRNA and secreted protein levels of IFN-β and IFN-λ 2/3 were highly elevated in IAV-infected mice with pCMV-Duox2 formulated with PEI. Duox2 is necessary for the regulation of IFN secretion in in vivo lung, and pulmonary administration of Duox2 DNA using cationic polymer triggers the induction of type I and III IFNs resulting in more complete suppression of IAV infection.

Anti-viral role of toll like receptor 4 in hepatitis B virus infection: An in vitro study.

PubMed

Das, Dipanwita; Sarkar, Neelakshi; Sengupta, Isha; Pal, Ananya; Saha, Debraj; Bandopadhyay, Manikankana; Das, Chandrima; Narayan, Jimmy; Singh, Shivram Prasad; Chakravarty, Runu

2016-12-21

Toll like receptors plays a significant anti-viral role in different infections. The aim of this study was to look into the role of toll like receptor 4 (TLR4) in hepatitis B virus (HBV) infection. Real time PCR was used to analyze the transcription of TLR4 signaling molecules, cell cycle regulators and HBV DNA viral load after triggering the HepG2.2.15 cells with TLR4 specific ligand. Nuclear factor (NF)-κB translocation on TLR4 activation was analyzed using microscopic techniques. Protein and cell cycle analysis was done using Western Blot and FACS respectively. The present study shows that TLR4 activation represses HBV infection. As a result of HBV suppression, there are several changes in host factors which include partial release in G1/S cell cycle arrest and changes in host epigenetic marks. Finally, it was observed that anti-viral action of TLR4 takes place through the NF-κB pathway. The study shows that TLR4 activation in HBV infection brings about changes in hepatocyte microenvironment and can be used for developing a promising therapeutic target in future.

Novel Nonreplicating Vaccinia Virus Vector Enhances Expression of Heterologous Genes and Suppresses Synthesis of Endogenous Viral Proteins.

PubMed

Wyatt, Linda S; Xiao, Wei; Americo, Jeffrey L; Earl, Patricia L; Moss, Bernard

2017-06-06

Viruses are used as expression vectors for protein synthesis, immunology research, vaccines, and therapeutics. Advantages of poxvirus vectors include the accommodation of large amounts of heterologous DNA, the presence of a cytoplasmic site of transcription, and high expression levels. On the other hand, competition of approximately 200 viral genes with the target gene for expression and immune recognition may be disadvantageous. We describe a vaccinia virus (VACV) vector that uses an early promoter to express the bacteriophage T7 RNA polymerase; has the A23R intermediate transcription factor gene deleted, thereby restricting virus replication to complementing cells; and has a heterologous gene regulated by a T7 promoter. In noncomplementing cells, viral early gene expression and DNA replication occurred normally but synthesis of intermediate and late proteins was prevented. Nevertheless, the progeny viral DNA provided templates for abundant expression of heterologous genes regulated by a T7 promoter. Selective expression of the Escherichia coli lac repressor gene from an intermediate promoter reduced transcription of the heterologous gene specifically in complementing cells, where large amounts might adversely impact VACV replication. Expression of heterologous proteins mediated by the A23R deletion vector equaled that of a replicating VACV, was higher than that of a nonreplicating modified vaccinia virus Ankara (MVA) vector used for candidate vaccines in vitro and in vivo , and was similarly immunogenic in mice. Unlike the MVA vector, the A23R deletion vector still expresses numerous early genes that can restrict immunogenicity as demonstrated here by the failure of the prototype vector to induce interferon alpha. By deleting immunomodulatory genes, we anticipate further improvements in the system. IMPORTANCE Vaccines provide an efficient and effective way of preventing infectious diseases. Nevertheless, new and better vaccines are needed. Vaccinia virus, which

Utilization of host SR protein kinases and RNA-splicing machinery during viral replication

PubMed Central

Fukuhara, Takeshi; Hosoya, Takamitsu; Shimizu, Saki; Sumi, Kengo; Oshiro, Takako; Yoshinaka, Yoshiyuki; Suzuki, Masaaki; Yamamoto, Naoki; Herzenberg, Leonore A.; Herzenberg, Leonard A.; Hagiwara, Masatoshi

2006-01-01

Although the viral genome is often quite small, it encodes a broad series of proteins. The virus takes advantage of the host-RNA-processing machinery to provide the alternative splicing capability necessary for the expression of this proteomic diversity. Serine–arginine-rich (SR) proteins and the kinases that activate them are central to this alternative splicing machinery. In studies reported here, we use the HIV genome as a model. We show that HIV expression decreases overall SR protein/activity. However, we also show that HIV expression is significantly increased (20-fold) when one of the SR proteins, SRp75 is phosphorylated by SR protein kinase (SRPK)2. Thus, inhibitors of SRPK2 and perhaps of functionally related kinases, such as SRPK1, could be useful antiviral agents. Here, we develop this hypothesis and show that HIV expression down-regulates SR proteins in Flp-In293 cells, resulting in only low-level HIV expression in these cells. However, increasing SRPK2 function up-regulates HIV expression. In addition, we introduce SR protein phosphorylation inhibitor 340 (SRPIN340), which preferentially inhibits SRPK1 and SRPK2 and down-regulates SRp75. Although an isonicotinamide compound, SPRIN340 (or its derivatives) remain to be optimized for better specificity and lower cytotoxicity, we show here that SRPIN340 suppresses propagation of Sindbis virus in plaque assay and variably suppresses HIV production. Thus, we show that SRPK, a well known kinase in the cellular RNA-processing machinery, is used by at least some viruses for propagation and hence suggest that SRPIN340 or its derivatives may be useful for curbing viral diseases. PMID:16840555

VIRAL INFECTIONS DURING PREGNANCY

PubMed Central

Silasi, Michelle; Cardenas, Ingrid; Racicot, Karen; Kwon, Ja-Young; Aldo, Paula; Mor, Gil

2015-01-01

Viral infections during pregnancy have long been considered benign conditions with a few notable exceptions, such as herpes virus. The recent Ebola outbreak and other viral epidemics and pandemics show how pregnant women suffer worse outcomes (such as preterm labor and adverse fetal outcomes) than the general population and non-pregnant women. New knowledge about the ways the maternal-fetal interface and placenta interact with the maternal immune system may explain these findings. Once thought to be “immunosuppressed”, the pregnant woman actually undergoes an immunological transformation, where the immune system is necessary to promote and support the pregnancy and growing fetus. When this protection is breached, as in a viral infection, this security is weakened and infection with other microorganisms can then propagate and lead to outcomes, such as preterm labor. In this manuscript, we review the major viral infections relevant to pregnancy, and offer potential mechanisms for the associated adverse pregnancy outcomes. PMID:25582523

Underreporting of viral encephalitis and viral meningitis, Ireland, 2005-2008.

PubMed

Kelly, Tara A; O'Lorcain, Piaras; Moran, Joanne; Garvey, Patricia; McKeown, Paul; Connell, Jeff; Cotter, Suzanne

2013-01-01

Viral encephalitis (VE) and viral meningitis (VM) have been notifiable infectious diseases under surveillance in the Republic of Ireland since 1981. Laboratories have reported confirmed cases by detection of viral nucleic acid in cerebrospinal fluid since 2004. To determine the prevalence of these diseases in Ireland during 2005-2008, we analyzed 3 data sources: Hospital In-patient Enquiry data (from hospitalized following patients discharge) accessed through Health Intelligence Ireland, laboratory confirmations from the National Virus Reference Laboratory, and events from the Computerised Infectious Disease Reporting surveillance system. We found that the national surveillance system underestimates the incidence of these diseases in Ireland with a 10-fold higher VE hospitalization rate and 3-fold higher VM hospitalization rate than the reporting rate. Herpesviruses were responsible for most specified VE and enteroviruses for most specified VM from all 3 sources. Recommendations from this study have been implemented to improve the surveillance of these diseases in Ireland.

Flavivirus RNAi suppression: decoding non-coding RNA.

PubMed

Pijlman, Gorben P

2014-08-01

Flaviviruses are important human pathogens that are transmitted by invertebrate vectors, mostly mosquitoes and ticks. During replication in their vector, flaviviruses are subject to a potent innate immune response known as antiviral RNA interference (RNAi). This defense mechanism is associated with the production of small interfering (si)RNA that lead to degradation of viral RNA. To what extent flaviviruses would benefit from counteracting antiviral RNAi is subject of debate. Here, the experimental evidence to suggest the existence of flavivirus RNAi suppressors is discussed. I will highlight the putative role of non-coding, subgenomic flavivirus RNA in suppression of RNAi in insect and mammalian cells. Novel insights from ongoing research will reveal how arthropod-borne viruses modulate innate immunity including antiviral RNAi. Copyright © 2014 Elsevier B.V. All rights reserved.

Viral Hepatitis in South Korea

PubMed Central

Alastal, Yaseen; Khan, Zubair; Darr, Umar

2017-01-01

In South Korea (S. Korea), viral hepatitis is a major public health burden. Advances in healthcare policy, evidence-based medicine, and therapeutic strategies in S. Korea have brought a rapid change in the sociodemographic and clinical characteristics of viral hepatitis. This review discusses the innovative approaches that S. Korea has taken to curb the epidemic of viral hepatitis. In addition, the efficacy of various preventive and therapeutic modalities is discussed. This review aims to provide a brief overview to guide future research direction and healthcare policy changes. How to cite this article: Pak SC, Alastal Y, Khan Z, Darr U. Viral Hepatitis in South Korea. Euroasian J Hepato-Gastroenterol 2017;7(2):163-165. PMID:29201801

Antiviral RNA silencing suppression activity of Tomato spotted wilt virus NSs protein.

PubMed

Ocampo Ocampo, T; Gabriel Peralta, S M; Bacheller, N; Uiterwaal, S; Knapp, A; Hennen, A; Ochoa-Martinez, D L; Garcia-Ruiz, H

2016-06-17

In addition to regulating gene expression, RNA silencing is an essential antiviral defense system in plants. Triggered by double-stranded RNA, silencing results in degradation or translational repression of target transcripts. Viruses are inducers and targets of RNA silencing. To condition susceptibility, most plant viruses encode silencing suppressors that interfere with this process, such as the Tomato spotted wilt virus (TSWV) NSs protein. The mechanism by which NSs suppresses RNA silencing and its role in viral infection and movement remain to be determined. We cloned NSs from the Hawaii isolate of TSWV and using two independent assays show for the first time that this protein restored pathogenicity and supported the formation of local infection foci by suppressor-deficient Turnip mosaic virus and Turnip crinkle virus. Demonstrating the suppression of RNA silencing directed against heterologous viruses establishes the foundation to determine the means used by NSs to block this antiviral process.

Current Good Manufacturing Practice Production of an Oncolytic Recombinant Vesicular Stomatitis Viral Vector for Cancer Treatment

PubMed Central

Meseck, M.; Derecho, I.; Lopez, P.; Knoblauch, C.; McMahon, R.; Anderson, J.; Dunphy, N.; Quezada, V.; Khan, R.; Huang, P.; Dang, W.; Luo, M.; Hsu, D.; Woo, S.L.C.; Couture, L.

2011-01-01

Abstract Vesicular stomatitis virus (VSV) is an oncolytic virus currently being investigated as a promising tool to treat cancer because of its ability to selectively replicate in cancer cells. To enhance the oncolytic property of the nonpathologic laboratory strain of VSV, we generated a recombinant vector [rVSV(MΔ51)-M3] expressing murine gammaherpesvirus M3, a secreted viral chemokine-binding protein that binds to a broad range of mammalian chemokines with high affinity. As previously reported, when rVSV(MΔ51)-M3 was used in an orthotopic model of hepatocellular carcinoma (HCC) in rats, it suppressed inflammatory cell migration to the virus-infected tumor site, which allowed for enhanced intratumoral virus replication leading to increased tumor necrosis and substantially prolonged survival. These encouraging results led to the development of this vector for clinical translation in patients with HCC. However, a scalable current Good Manufacturing Practice (cGMP)-compliant manufacturing process has not been described for this vector. To produce the quantities of high-titer virus required for clinical trials, a process that is amenable to GMP manufacturing and scale-up was developed. We describe here a large-scale (50-liter) vector production process capable of achieving crude titers on the order of 109 plaque-forming units (PFU)/ml under cGMP. This process was used to generate a master virus seed stock and a clinical lot of the clinical trial agent under cGMP with an infectious viral titer of approximately 2 × 1010 PFU/ml (total yield, 1 × 1013 PFU). The lot has passed all U.S. Food and Drug Administration-mandated release testing and will be used in a phase 1 clinical translational trial in patients with advanced HCC. PMID:21083425

Current good manufacturing practice production of an oncolytic recombinant vesicular stomatitis viral vector for cancer treatment.

PubMed

Ausubel, L J; Meseck, M; Derecho, I; Lopez, P; Knoblauch, C; McMahon, R; Anderson, J; Dunphy, N; Quezada, V; Khan, R; Huang, P; Dang, W; Luo, M; Hsu, D; Woo, S L C; Couture, L

2011-04-01

Vesicular stomatitis virus (VSV) is an oncolytic virus currently being investigated as a promising tool to treat cancer because of its ability to selectively replicate in cancer cells. To enhance the oncolytic property of the nonpathologic laboratory strain of VSV, we generated a recombinant vector [rVSV(MΔ51)-M3] expressing murine gammaherpesvirus M3, a secreted viral chemokine-binding protein that binds to a broad range of mammalian chemokines with high affinity. As previously reported, when rVSV(MΔ51)-M3 was used in an orthotopic model of hepatocellular carcinoma (HCC) in rats, it suppressed inflammatory cell migration to the virus-infected tumor site, which allowed for enhanced intratumoral virus replication leading to increased tumor necrosis and substantially prolonged survival. These encouraging results led to the development of this vector for clinical translation in patients with HCC. However, a scalable current Good Manufacturing Practice (cGMP)-compliant manufacturing process has not been described for this vector. To produce the quantities of high-titer virus required for clinical trials, a process that is amenable to GMP manufacturing and scale-up was developed. We describe here a large-scale (50-liter) vector production process capable of achieving crude titers on the order of 10(9) plaque-forming units (PFU)/ml under cGMP. This process was used to generate a master virus seed stock and a clinical lot of the clinical trial agent under cGMP with an infectious viral titer of approximately 2 × 10(10) PFU/ml (total yield, 1 × 10(13) PFU). The lot has passed all U.S. Food and Drug Administration-mandated release testing and will be used in a phase 1 clinical translational trial in patients with advanced HCC.

Time from HIV infection to virological suppression: dramatic fall from 2007 to 2016.

PubMed

Medland, Nicholas A; Nicholson, Suellen; Chow, Eric P F; Read, Timothy R H; Bradshaw, Catriona S; Denham, Ian; Fairley, Christopher K

2017-11-13

Time from HIV infection to virological suppression: dramatic fall from 2007 to 2016. We examined the time from HIV infection to virological suppression in MSM who were first diagnosed at Melbourne Sexual Health Centre between 2007 and 2016. Retrospective cohort. Date of infection was imputed from the testing history or serological evidence of recent infection (negative or indeterminate western blot) or baseline CD4 cell count. Date of virological suppression was determined using clinical viral load data. We analysed predictors of diagnosis with serological evidence of recent infection (logistic regression) and time from diagnosis to suppression and from infection to suppression (Cox regression) using demographic, clinical, and behavioral covariates. Between 2007 and 2016, the median time from HIV infection to diagnosis fell from 6.8 to 4.3 months (P = 0.001), from diagnosis to suppression fell from 22.7 to 3.2 months (P < 0.0001), and from infection to suppression fell from 49.0 to 9.6 months (P < 0.0001). Serological evidence of recent infection increased from 15.6 to 34.3% (P < 0.0001) of diagnoses. In the multivariate analyses, age, being recently arrived from a non-English speaking country, history of IDU, other sexually transmitted infections, and sexual risk were not associated with any of these measures. The duration of infectiousness in MSM diagnosed with HIV infection at Melbourne Sexual Health Centre in Victoria has fallen dramatically between 2007 and 2016 and the proportion diagnosed with serological evidence of recent infection has increased. This effect is observed across all population subgroups and marks a positive milestone for the treatment as prevention paradigm.

Multifunctional roles of leader protein of foot-and-mouth disease viruses in suppressing host antiviral responses.

PubMed

Liu, Yingqi; Zhu, Zixiang; Zhang, Miaotao; Zheng, Haixue

2015-10-28

Foot-and-mouth disease virus (FMDV) leader protein (L(pro)) is a papain-like proteinase, which plays an important role in FMDV pathogenesis. L(pro) exists as two forms, Lab and Lb, due to translation being initiated from two different start codons separated by 84 nucleotides. L(pro) self-cleaves from the nascent viral polyprotein precursor as the first mature viral protein. In addition to its role as a viral proteinase, L(pro) also has the ability to antagonize host antiviral effects. To promote FMDV replication, L(pro) can suppress host antiviral responses by three different mechanisms: (1) cleavage of eukaryotic translation initiation factor 4 γ (eIF4G) to shut off host protein synthesis; (2) inhibition of host innate immune responses through restriction of interferon-α/β production; and (3) L(pro) can also act as a deubiquitinase and catalyze deubiquitination of innate immune signaling molecules. In the light of recent functional and biochemical findings regarding L(pro), this review introduces the basic properties of L(pro) and the mechanisms by which it antagonizes host antiviral responses.

Aseptic meningitis and viral myelitis.

PubMed

Irani, David N

2008-08-01

Meningitis and myelitis represent common and very infrequent viral infections of the central nervous system, respectively. The number of cases of viral meningitis that occurs annually exceeds the total number of meningitis cases caused by all other etiologies combined. Focal central nervous system infections, such as occur in the spinal cord with viral myelitis, are much less common and may be confused with noninfectious disorders that cause acute flaccid paralysis. This article reviews some of the important clinical features, epidemiology, diagnostic approaches, and management strategies for patients with aseptic meningitis and viral myelitis. Particular focus is placed on the diseases caused by enteroviruses, which as a group account for most aseptic meningitis cases and many focal infections of the spinal cord.

Production of non viral DNA vectors.

PubMed

Schleef, Martin; Blaesen, Markus; Schmeer, Marco; Baier, Ruth; Marie, Corinne; Dickson, George; Scherman, Daniel

2010-12-01

After some decades of research, development and first clinical approaches to use DNA vectors in gene therapy, cell therapy and DNA vaccination, the requirements for the pharmaceutical manufacturing of gene vectors has improved significantly step by step. Even the expression level and specificity of non viral DNA vectors were significantly modified and followed the success of viral vectors. The strict separation of "viral" and "non viral" gene transfer are historic borders between scientist and we will show that both fields together are able to allow the next step towards successful prevention and therapy. Here we summarize the features of producing and modifying these non-viral gene vectors to ensure the required quality to modify cells and to treat human and animals.

Viral replication rate regulates clinical outcome and CD8 T cell responses during highly pathogenic H5N1 influenza virus infection in mice.

PubMed

Hatta, Yasuko; Hershberger, Karen; Shinya, Kyoko; Proll, Sean C; Dubielzig, Richard R; Hatta, Masato; Katze, Michael G; Kawaoka, Yoshihiro; Suresh, M

2010-10-07

Since the first recorded infection of humans with H5N1 viruses of avian origin in 1997, sporadic human infections continue to occur with a staggering mortality rate of >60%. Although sustained human-to-human transmission has not occurred yet, there is a growing concern that these H5N1 viruses might acquire this trait and raise the specter of a pandemic. Despite progress in deciphering viral determinants of pathogenicity, we still lack crucial information on virus/immune system interactions pertaining to severe disease and high mortality associated with human H5N1 influenza virus infections. Using two human isolates of H5N1 viruses that differ in their pathogenicity in mice, we have defined mechanistic links among the rate of viral replication, mortality, CD8 T cell responses, and immunopathology. The extreme pathogenicity of H5N1 viruses was directly linked to the ability of the virus to replicate rapidly, and swiftly attain high steady-state titers in the lungs within 48 hours after infection. The remarkably high replication rate of the highly pathogenic H5N1 virus did not prevent the induction of IFN-β or activation of CD8 T cells, but the CD8 T cell response was ineffective in controlling viral replication in the lungs and CD8 T cell deficiency did not affect viral titers or mortality. Additionally, BIM deficiency ameliorated lung pathology and inhibited T cell apoptosis without affecting survival of mice. Therefore, rapidly replicating, highly lethal H5N1 viruses could simply outpace and overwhelm the adaptive immune responses, and kill the host by direct cytopathic effects. However, therapeutic suppression of early viral replication and the associated enhancement of CD8 T cell responses improved the survival of mice following a lethal H5N1 infection. These findings suggest that suppression of early H5N1 virus replication is key to the programming of an effective host response, which has implications in treatment of this infection in humans.

Viral RNA-Unprimed Rig-I Restrains Stat3 Activation in the Modulation of Regulatory T Cell/Th17 Cell Balance.

PubMed

Yang, Hui; Guo, He-Zhou; Li, Xian-Yang; Lin, Jian; Zhang, Wu; Zhao, Jun-Mei; Zhang, Hong-Xin; Chen, Sai-Juan; Chen, Zhu; Zhu, Jiang

2017-07-01

Innate immunity activation by viral RNA-primed retinoid acid inducible gene-I (Rig-I) in CD4 + T cells antagonizes TGFβ signaling to suppress the differentiation of regulatory T cells (Tregs). However, how viral RNA-unliganded Rig-I (apo-Rig-I) modulates Treg generation remains unclear. In this article, we show that, in the absence of viral infection, Treg differentiation of Rig-I -/- CD4 + T cells was compromised, in the presence of increased generation of Th17 cells and overactivation of Stat3, a critical regulator tilting the Treg/Th17 cell balance. Mechanistically, apo-Rig-I physically associates with Stat3, thereby inhibiting Jak1's association with Stat3 while facilitating Shp2's association to inhibit p-Stat3 levels. Interestingly, inhibition of Stat3 ameliorates the Treg/Th17 imbalance and the colitis observed in Rig-I -/- mice. Collectively, these results uncover an independent functional contribution of the apo-Rig-I/Stat3 interaction in the maintenance of Treg/Th17 cell balance. Copyright © 2017 by The American Association of Immunologists, Inc.

Using artificial microRNA sponges to achieve microRNA loss-of-function in cancer cells.

PubMed

Tay, Felix Chang; Lim, Jia Kai; Zhu, Haibao; Hin, Lau Cia; Wang, Shu

2015-01-01

Widely observed dysregulation of microRNAs (miRNAs) in human cancer has led to substantial speculation regarding possible functions of these short, non-coding RNAs in cancer development and manipulation of miRNA expression to treat cancer. To achieve miRNA loss-of-function, miRNA sponge technology has been developed to use plasmid or viral vectors for intracellular expression of tandemly arrayed, bulged miRNA binding sites complementary to a miRNA target to saturate its ability to regulate natural mRNAs. A strong viral promoter can be used in miRNA sponge vectors to generate high-level expression of the competitive inhibitor transcripts for either transient or long-term inhibition of miRNA function. Taking the advantage of sharing a common seed sequence by members of a miRNA family, this technology is especially useful in knocking down the expression of a family of miRNAs, providing a powerful means for simultaneous inhibition of multiple miRNAs of interest with a single inhibitor. Knockdown of overexpressed oncogenic miRNAs with the technology can be a rational therapeutic strategy for cancer, whereas inhibition of tumor-suppressive miRNAs by the sponges will be useful in deciphering functions of miRNAs in oncogenesis. Herein, we discuss the design of miRNA sponge expression vectors and the use of the vectors to gain better understanding of miRNA's roles in cancer biology and as an alternative tool for anticancer gene therapy. Copyright © 2014 Elsevier B.V. All rights reserved.

Integrase inhibitors in late pregnancy and rapid HIV viral load reduction.

PubMed

Rahangdale, Lisa; Cates, Jordan; Potter, JoNell; Badell, Martina L; Seidman, Dominika; Miller, Emilly S; Coleman, Jenell S; Lazenby, Gweneth B; Levison, Judy; Short, William R; Yawetz, Sigal; Ciaranello, Andrea; Livingston, Elizabeth; Duthely, Lunthita; Rimawi, Bassam H; Anderson, Jean R; Stringer, Elizabeth M

2016-03-01

Minimizing time to HIV viral suppression is critical in pregnancy. Integrase strand transfer inhibitors (INSTIs), like raltegravir, are known to rapidly suppress plasma HIV RNA in nonpregnant adults. There are limited data in pregnant women. We describe time to clinically relevant reduction in HIV RNA in pregnant women using INSTI-containing and non-INSTI-containing antiretroviral therapy (ART) options. We conducted a retrospective cohort study of pregnant HIV-infected women in the United States from 2009 through 2015. We included women who initiated ART, intensified their regimen, or switched to a new regimen due to detectable viremia (HIV RNA >40 copies/mL) at ≥20 weeks gestation. Among women with a baseline HIV RNA permitting 1-log reduction, we estimated time to 1-log RNA reduction using the Kaplan-Meier estimator comparing women starting/adding an INSTI in their regimen vs other ART. To compare groups with similar follow-up time, we also conducted a subgroup analysis limited to women with ≤14 days between baseline and follow-up RNA data. This study describes 101 HIV-infected pregnant women from 11 US clinics. In all, 75% (76/101) of women were not taking ART at baseline; 24 were taking non-INSTI containing ART, and 1 received zidovudine monotherapy. In all, 39% (39/101) of women started an INSTI-containing regimen or added an INSTI to their ART regimen. Among 90 women with a baseline HIV RNA permitting 1-log reduction, the median time to 1-log RNA reduction was 8 days (interquartile range [IQR], 7-14) in the INSTI group vs 35 days (IQR, 20-53) in the non-INSTI ART group (P < .01). In a subgroup of 39 women with first and last RNA measurements ≤14 days apart, median time to 1-log reduction was 7 days (IQR, 6-10) in the INSTI group vs 11 days (IQR, 10-14) in the non-INSTI group (P < .01). ART that includes INSTIs appears to induce more rapid viral suppression than other ART regimens in pregnancy. Inclusion of an INSTI may play a role in optimal reduction

Viral infections in transplant recipients.

PubMed

Razonable, R R; Eid, A J

2009-12-01

Solid organ and hematopoietic stem cell transplant recipients are uniquely predisposed to develop clinical illness, often with increased severity, due to a variety of common and opportunistic viruses. Patients may acquire viral infections from the donor (donor-derived infections), from reactivation of endogenous latent virus, or from the community. Herpes viruses, most notably cytomegalovirus and Epstein Barr virus, are the most common among opportunistic viral pathogens that cause infection after solid organ and hematopoietic stem cell transplantation. The polyoma BK virus causes opportunistic clinical syndromes predominantly in kidney and allogeneic hematopoietic stem cell transplant recipients. The agents of viral hepatitis B and C present unique challenges particularly among liver transplant recipients. Respiratory viral illnesses due to influenza, respiratory syncytial virus, and parainfluenza virus may affect all types of transplant recipients, although severe clinical disease is observed more commonly among lung and allogeneic hematopoietic stem cell transplant recipients. Less common viral infections affecting transplant recipients include those caused by adenoviruses, parvovirus B19, and West Nile virus. Treatment for viruses with proven effective antiviral drug therapies should be complemented by reduction in the degree of immunosuppression. For others with no proven antiviral drugs for therapy, reduction in the degree of immunosuppression remains as the sole effective strategy for management. Prevention of viral infections is therefore of utmost importance, and this may be accomplished through vaccination, antiviral strategies, and aggressive infection control measures.

[Viral hepatitis in travellers].

PubMed

Abreu, Cândida

2007-01-01

Considering the geographical asymmetric distribution of viral hepatitis A, B and E, having a much higher prevalence in the less developed world, travellers from developed countries are exposed to a considerable and often underestimated risk of hepatitis infection. In fact a significant percentage of viral hepatitis occurring in developed countries is travel related. This results from globalization and increased mobility from tourism, international work, humanitarian and religious missions or other travel related activities. Several studies published in Europe and North America shown that more than 50% of reported cases of hepatitis A are travel related. On the other hand frequent outbreaks of hepatitis A and E in specific geographic areas raise the risk of infection in these restricted zones and that should be clearly identified. Selected aspects related with the distribution of hepatitis A, B and E are reviewed, particularly the situation in Portugal according to the published studies, as well as relevant clinical manifestations and differential diagnosis of viral hepatitis. Basic prevention rules considering enteric transmitted hepatitis (hepatitis A and hepatitis E) and parenteral transmitted (hepatitis B) are reviewed as well as hepatitis A and B immunoprophylaxis. Common clinical situations and daily practice "pre travel" advice issues are discussed according to WHO/CDC recommendations and the Portuguese National Vaccination Program. Implications from near future availability of a hepatitis E vaccine, a currently in phase 2 trial, are highlighted. Potential indications for travellers to endemic countries like India, Nepal and some regions of China, where up to 30% of sporadic cases of acute viral hepatitis are caused by hepatitis E virus, are considered. Continued epidemiological surveillance for viral hepatitis is essential to recognize and control possible outbreaks, but also to identify new viral hepatitis agents that may emerge as important global health

Finding quasi-modules of human and viral miRNAs: a case study of human cytomegalovirus (HCMV)

PubMed Central

2012-01-01

Background MicroRNAs (miRNAs) are important regulators of gene expression encoded by a variety of organisms, including viruses. Although the function of most of the viral miRNAs is currently unknown, there is evidence that both viral and host miRNAs contribute to the interactions between viruses and their hosts. miRNAs constitute a complex combinatorial network, where one miRNA may target many genes and one gene may be targeted by multiple miRNAs. In particular, viral and host miRNAs may also have mutual target genes. Based on published evidence linking viral and host miRNAs there are three modes of mutual regulation: competing, cooperating, and compensating modes. Results In this paper we explore the compensating mode of mutual regulation upon Human Cytomegalovirus (HCMV) infection, when host miRNAs are down regulated and viral miRNAs compensate by mimicking their function. To achieve this, we develop a new algorithm which finds groups, called quasi-modules, of viral and host miRNAs and their mutual target genes, and use a new host miRNA expression data for HCMV-infected and uninfected cells. For two of the reported quasi-modules, supporting evidence from biological and medical literature is provided. Conclusions The modules found by our method may advance the understanding of the role of miRNAs in host-viral interactions, and the genes in these modules may serve as candidates for further experimental validation. PMID:23206407

Viral Perturbations of Host Networks Reflect Disease Etiology

PubMed Central

Dricot, Amélie; Padi, Megha; Byrdsong, Danielle; Franchi, Rachel; Lee, Deok-Sun; Rozenblatt-Rosen, Orit; Mar, Jessica C.; Calderwood, Michael A.; Baldwin, Amy; Zhao, Bo; Santhanam, Balaji; Braun, Pascal; Simonis, Nicolas; Huh, Kyung-Won; Hellner, Karin; Grace, Miranda; Chen, Alyce; Rubio, Renee; Marto, Jarrod A.; Christakis, Nicholas A.; Kieff, Elliott; Roth, Frederick P.; Roecklein-Canfield, Jennifer; DeCaprio, James A.; Cusick, Michael E.; Quackenbush, John; Hill, David E.; Münger, Karl; Vidal, Marc; Barabási, Albert-László

2012-01-01

Many human diseases, arising from mutations of disease susceptibility genes (genetic diseases), are also associated with viral infections (virally implicated diseases), either in a directly causal manner or by indirect associations. Here we examine whether viral perturbations of host interactome may underlie such virally implicated disease relationships. Using as models two different human viruses, Epstein-Barr virus (EBV) and human papillomavirus (HPV), we find that host targets of viral proteins reside in network proximity to products of disease susceptibility genes. Expression changes in virally implicated disease tissues and comorbidity patterns cluster significantly in the network vicinity of viral targets. The topological proximity found between cellular targets of viral proteins and disease genes was exploited to uncover a novel pathway linking HPV to Fanconi anemia. PMID:22761553

Viral Space Situational Awareness

NASA Astrophysics Data System (ADS)

Gleckler, A.; Butterfield, M. C.

2012-09-01

Viral SSA takes advantage of the amateur astronomy community to provide an extremely low-cost and geographically-diverse network of optical SSA sites. In the spirit of programs such as DARPA's Grand Challenge and the National Weather Service's program of providing amateur meteorologists with weather stations linked to a central professional meteorological facility, we form a cooperative bond with a willing community of technically-minded individuals. We term this program "viral" because we will qualify an initial set of astronomers for SSA operation and then use word of mouth in the astronomy community, as well as an outreach program, to pull in new observers. The use of modern remote controlled telescopes allows the incorporation of certified amateur, university, and commercial telescope systems. The availability of the local Viral SSA member for troubleshooting eliminates most significant costs of operating a large network. In this talk, we discuss the key concepts of Viral SSA and the route to a network of 100+ sites in a three year or less timeframe.

Experiments in DIII-D Toward Achieving Rapid Shutdown with Runaway Electron Suppression

NASA Astrophysics Data System (ADS)

Hollmann, E. M.

2009-11-01

For safe discharge shutdown in future large tokamaks in the event of an unavoidable disruption, it is important to develop rapid (˜ several ms)shutdown methods to avoid large runaway electron currents, which pose a serious threat to plasma facing components. Prevention of runaway current formation has been proposed by either increasing electron-electron collisionality with massive particle injection, or magnetically by using externally applied non-axisymmetric fields to increase radial diffusive losses of a runaway seed population. Experiments studying both approaches have been pursued in the DIII-D tokamak. For collisional suppression, three different rapid shutdown methods are being investigated: massive gas injection, massive shattered cryogenic pellet injection, and polystyrene shell pellet injection. First-of-kind demonstrations of fast shutdowns were produced by 3000 Torr-l (0.8-g) shattered D2 pellets and large, 10-mm diameter, 0.3-g polystyrene shell pellets filled with boron powder. The application of external magnetic perturbations shows promising preliminary results in suppressing seed runaway electrons, although lack of repeatability in the runaway seed term made these results challenging to interpret. Experiments have been performed to help understand how runaways form and are transported during rapid shutdown. These experiments confirm that the commonly used 0D loop voltage + Dreicer evaporation picture of runaway seed formation is not applicable here, with relativistic E > 0.5,MeV electrons forming before any external loop voltage appears. Present applications of 0D, 1D, and 2D models to the rapid shutdown and runaway confinement experiments, as well as preliminary extrapolations to ITER, will be discussed.

Modeling Viral Capsid Assembly

PubMed Central

2014-01-01

I present a review of the theoretical and computational methodologies that have been used to model the assembly of viral capsids. I discuss the capabilities and limitations of approaches ranging from equilibrium continuum theories to molecular dynamics simulations, and I give an overview of some of the important conclusions about virus assembly that have resulted from these modeling efforts. Topics include the assembly of empty viral shells, assembly around single-stranded nucleic acids to form viral particles, and assembly around synthetic polymers or charged nanoparticles for nanotechnology or biomedical applications. I present some examples in which modeling efforts have promoted experimental breakthroughs, as well as directions in which the connection between modeling and experiment can be strengthened. PMID:25663722

Ethical Considerations in Research Participation Virality.

PubMed

Ellis-Barton, Carol

2016-07-01

This article seeks to commence and encourage discussion around the upcoming ethical challenges of virality in network structures. When the call for participation in a research project on lupus in Ireland went from an advertisement in a newsletter to a meme (unit of transmissible information) on a closed Facebook page, the ethical considerations of virality were raised. The article analyzes the Association of Internet Researchers guidelines, Facebook policies, and the context of privacy in relation to virality. Virality creates the leverage for methodological pluralism. The nature of the inquiry can determine the method rather than the other way around. Viral ethical considerations are evolving due to the cyber world becoming the primary meme of communication, with flexibility in the researcher's protocol providing opportunities for efficient, cost-effective, and diverse recruitment. © The Author(s) 2016.

Retinoid X receptor α attenuates host antiviral response by suppressing type I interferon

PubMed Central

Ma, Feng; Liu, Su-Yang; Razani, Bahram; Arora, Neda; Li, Bing; Kagechika, Hiroyuki; Tontonoz, Peter; Núñez, Vanessa; Ricote, Mercedes; Cheng, Genhong

2015-01-01

The retinoid X receptor α (RXRα), a key nuclear receptor in metabolic processes, is down-regulated during host antiviral response. However, the roles of RXRα in host antiviral response are unknown. Here we show that RXRα overexpression or ligand activation increases host susceptibility to viral infections in vitro and in vivo, while Rxra −/− or antagonist treatment reduces infection by the same viruses. Consistent with these functional studies, ligand activation of RXR inhibits the expression of antiviral genes including type I interferon (IFN) and Rxra −/− macrophages produce more IFNβ than WT macrophages in response to polyI:C stimulation. Further results indicate that ligand activation of RXR suppresses the nuclear translocation of β-catenin, a co-activator of IFNβ enhanceosome. Thus, our studies have uncovered a novel RXR-dependent innate immune regulatory pathway, suggesting that the downregulation of RXR expression or RXR antagonist treatment benefits host antiviral response, whereas RXR agonist treatment may increase the risk of viral infections. PMID:25417649

Kaposi's Sarcoma-Associated Herpesvirus mRNA Accumulation in Nuclear Foci Is Influenced by Viral DNA Replication and Viral Noncoding Polyadenylated Nuclear RNA.

PubMed

Vallery, Tenaya K; Withers, Johanna B; Andoh, Joana A; Steitz, Joan A

2018-07-01

Kaposi's sarcoma-associated herpesvirus (KSHV), like other herpesviruses, replicates within the nuclei of its human cell host and hijacks host machinery for expression of its genes. The activities that culminate in viral DNA synthesis and assembly of viral proteins into capsids physically concentrate in nuclear areas termed viral replication compartments. We sought to better understand the spatiotemporal regulation of viral RNAs during the KSHV lytic phase by examining and quantifying the subcellular localization of select viral transcripts. We found that viral mRNAs, as expected, localized to the cytoplasm throughout the lytic phase. However, dependent on active viral DNA replication, viral transcripts also accumulated in the nucleus, often in foci in and around replication compartments, independent of the host shutoff effect. Our data point to involvement of the viral long noncoding polyadenylated nuclear (PAN) RNA in the localization of an early, intronless viral mRNA encoding ORF59-58 to nuclear foci that are associated with replication compartments. IMPORTANCE Late in the lytic phase, mRNAs from Kaposi's sarcoma-associated herpesvirus accumulate in the host cell nucleus near viral replication compartments, centers of viral DNA synthesis and virion production. This work contributes spatiotemporal data on herpesviral mRNAs within the lytic host cell and suggests a mechanism for viral RNA accumulation. Our findings indicate that the mechanism is independent of the host shutoff effect and splicing but dependent on active viral DNA synthesis and in part on the viral noncoding RNA, PAN RNA. PAN RNA is essential for the viral life cycle, and its contribution to the nuclear accumulation of viral messages may facilitate propagation of the virus. Copyright © 2018 American Society for Microbiology.

Viral reprogramming of the Daxx histone H3.3 chaperone during early Epstein-Barr virus infection.

PubMed

Tsai, Kevin; Chan, Lilian; Gibeault, Rebecca; Conn, Kristen; Dheekollu, Jayaraju; Domsic, John; Marmorstein, Ronen; Schang, Luis M; Lieberman, Paul M

2014-12-01

Host chromatin assembly can function as a barrier to viral infection. Epstein-Barr virus (EBV) establishes latent infection as chromatin-assembled episomes in which all but a few viral genes are transcriptionally silent. The factors that control chromatin assembly and guide transcription regulation during the establishment of latency are not well understood. Here, we demonstrate that the EBV tegument protein BNRF1 binds the histone H3.3 chaperone Daxx to modulate histone mobility and chromatin assembly on the EBV genome during the early stages of primary infection. We demonstrate that BNRF1 substitutes for the repressive cochaperone ATRX to form a ternary complex of BNRF1-Daxx-H3.3-H4, using coimmunoprecipitation and size-exclusion chromatography with highly purified components. FRAP (fluorescence recovery after photobleaching) assays were used to demonstrate that BNRF1 promotes global mobilization of cellular histone H3.3. Mutation of putative nucleotide binding motifs on BNRF1 attenuates the displacement of ATRX from Daxx. We also show by immunofluorescence combined with fluorescence in situ hybridization that BNRF1 is important for the dissociation of ATRX and Daxx from nuclear bodies during de novo infection of primary B lymphocytes. Virion-delivered BNRF1 suppresses Daxx-ATRX-mediated H3.3 loading on viral chromatin as measured by chromatin immunoprecipitation assays and enhances viral gene expression during early infection. We propose that EBV tegument protein BNRF1 replaces ATRX to reprogram Daxx-mediated H3.3 loading, in turn generating chromatin suitable for latent gene expression. Epstein-Barr Virus (EBV) is a human herpesvirus that efficiently establishes latent infection in primary B lymphocytes. Cellular chromatin assembly plays an important role in regulating the establishment of EBV latency. We show that the EBV tegument protein BNRF1 functions to regulate chromatin assembly on the viral genome during early infection. BNRF1 alters the host cellular

[Neuropsychiatric sequelae of viral meningitis in adults].

PubMed

Damsgaard, Jesper; Hjerrild, Simon; Renvillard, Signe Groth; Leutscher, Peter Derek Christian

2011-10-10

Viral meningitis is considered to be a benign illness with only mild symptoms. In contrast to viral encephalitis and bacterial meningitis, the prognosis is usually good. However, retrospective studies have demonstrated that patients suffering from viral meningitis may experience cognitive impairment following the acute course of infection. Larger controlled studies are needed to elucidate the potential neuropsychiatric adverse outcome of viral meningitis.

Exploring viral infection using single-cell sequencing.

PubMed

Rato, Sylvie; Golumbeanu, Monica; Telenti, Amalio; Ciuffi, Angela

2017-07-15

Single-cell sequencing (SCS) has emerged as a valuable tool to study cellular heterogeneity in diverse fields, including virology. By studying the viral and cellular genome and/or transcriptome, the dynamics of viral infection can be investigated at single cell level. Most studies have explored the impact of cell-to-cell variation on the viral life cycle from the point of view of the virus, by analyzing viral sequences, and from the point of view of the cell, mainly by analyzing the cellular host transcriptome. In this review, we will focus on recent studies that use single-cell sequencing to explore viral diversity and cell variability in response to viral replication. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Membrane dynamics associated with viral infection.

PubMed

de Armas-Rillo, Laura; Valera, María-Soledad; Marrero-Hernández, Sara; Valenzuela-Fernández, Agustín

2016-05-01

Viral replication and spreading are fundamental events in the viral life cycle, accounting for the assembly and egression of nascent virions, events that are directly associated with viral pathogenesis in target hosts. These processes occur in cellular compartments that are modified by specialized viral proteins, causing a rearrangement of different cell membranes in infected cells and affecting the ER, mitochondria, Golgi apparatus, vesicles and endosomes, as well as processes such as autophagic membrane flux. In fact, the activation or inhibition of membrane trafficking and other related activities are fundamental to ensure the adequate replication and spreading of certain viruses. In this review, data will be presented that support the key role of membrane dynamics in the viral cycle, especially in terms of the assembly, egression and infection processes. By defining how viruses orchestrate these events it will be possible to understand how they successfully complete their route of infection, establishing viral pathogenesis and provoking disease. © 2015 The Authors Reviews in Medical Virology Published by John Wiley & Sons, Ltd.

PA28γ is a novel corepressor of HTLV-1 replication and controls viral latency

PubMed Central

Ko, Nga Ling; Taylor, John M.; Bellon, Marcia; Bai, Xue Tao; Shevtsov, Sergey P.; Dundr, Miroslav

2013-01-01

The establishment of a latent reservoir by human tumor viruses is a vital step in initiating cellular transformation and represents a major shortcoming to current therapeutic strategies and the ability to eradicate virus-infected cells. Human T-cell leukemia virus type 1 (HTLV-1) establishes a lifelong infection and is linked to adult T-cell leukemia lymphoma (ATLL). Here, we demonstrate that HTLV-1 p30 recruits the cellular proteasome activator PA28γ onto the viral tax/rex mRNA to prevent its nuclear export and suppress virus replication. Interaction of p30 with a PA28γ retaining fully functional proteasome activity is required for p30's ability to repress HTLV-1. Consistently, HTLV-1 molecular clones replicate better and produce more virus particles in PA28γ-deficient cells. These results define a unique and novel role for the cellular factor PA28γ in the control of nuclear RNA trafficking and HTLV-1–induced latency. Importantly, knockdown of PA28γ expression in ATLL cells latently infected with HTLV-1 reactivates expression of viral tax/rex RNA and the Tax protein. Because Tax is the most immunogenic viral antigen and triggers strong CTL responses, our results suggest that PA28γ-targeted therapy may reactivate virus expression from latently infected cells and allow their eradication from the host. PMID:23104922

TESTOSTERONE LEVELS ACHIEVED BY MEDICALLY TREATED TRANSGENDER WOMEN IN A UNITED STATES ENDOCRINOLOGY CLINIC COHORT.

PubMed

Liang, Jennifer J; Jolly, Divya; Chan, Kelly J; Safer, Joshua D

2018-02-01

Most transgender women depend on medical treatment alone to lower testosterone levels in order to align physical appearance with gender identity. The medical regimen in the United States typically includes spironolactone and estrogens. The purpose of this cross-sectional study was to assess the testosterone suppression achieved among transgender women treated with spironolactone and estrogens. Testosterone and estradiol levels were extracted from the electronic medical records of 98 anonymized transgender women treated with oral spironolactone and oral estrogen therapy at the Endocrinology Clinic at Boston Medical Center. Patients starting therapy required about 9 months to reach a steady-state testosterone, with significant heterogeneity of levels achieved among patients. Patients with normal body mass index (BMI) had higher testosterone levels, whereas patients with obese BMI had lower testosterone levels throughout treatment. Stratification of patients by age or spironolactone dosage revealed no significant difference in testosterone levels achieved. At steady state, patients in the highest suppressing quartile were able to achieve testosterone levels of 27 ng/dL, with a standard deviation of 21 ng/dL. Measured serum estradiol levels did not change over time and did not correlate with dosage of estradiol administered. Among a cohort of transgender women treated with spironolactone and estrogen, the highest suppressing quartile could reliably achieve testosterone levels in the female range at virtually all times. The second highest suppressing quartile could not achieve female levels but remained below the male range virtually all of the time. One quartile was unable to achieve any significant suppression. BMC = Boston Medical Center BMI = body mass index CPY = cyproterone acetate LC-MS/MS = liquid chromatography-tandem mass spectrometry Q = quartile.

The effect of churn on "community viral load" in a well-defined regional population.

PubMed

Krentz, Hartmut B; Gill, M John

2013-10-01

The concept of community viral load (CVL) was introduced to quantify the pool of transmissible HIV within a community and to monitor the potential impact of highly active antiretroviral therapy (HAART) on reducing new infections. The implications of churn (patient movement in/out of care in a community) on CVL have not been studied. The annual CVL was determined in the entire geographic HIV population receiving care in southern Alberta from 2001 to 2010; the CVL for specific subpopulations was analyzed for 2009. CVL was determined for patients under continuous care, newly diagnosed, new to the region, moved away, returned, and lost to follow-up (LTFU). Viral loads (VLs) <50 or <200 copies per milliliter were deemed undetectable and suppressed, respectively. The mean VL per patient and total VL were used to determine CVL. From 2001 to 2010, the HAART uptake for all patients increased from 62% to 81%, undetectability from 32% to 66%, and suppression from 49% to 72%. The annual total CVL however did not vary significantly after 2003. Incidence rates for new locally diagnosed infections increased from 4.4 to 5.8/100,000 per year. In 2009, newly diagnosed HIV patients (6.6%) contributed 37.5% to the CVL, whereas patients transferring in/out of the region or lost to follow-up contributed 33% to the CVL. Patients in continuous care (79% of all patients) contributed 29.5% to the total CVL. Increasing HAART coverage did not reduce the CVL or reduce new HIV diagnoses in our population. The effect of churn significantly limited CVL use as a measure for evaluating the impact of HAART in reducing HIV transmissions in our population.

Kaposi's Sarcoma-Associated Herpesvirus Viral Interferon Regulatory Factor 4 (vIRF4) Perturbs the G1-S Cell Cycle Progression via Deregulation of the cyclin D1 Gene.

PubMed

Lee, Hye-Ra; Mitra, Jaba; Lee, Stacy; Gao, Shou-Jiang; Oh, Tae-Kwang; Kim, Myung Hee; Ha, Taekjip; Jung, Jae U

2016-01-15

Kaposi's sarcoma-associated herpesvirus (KSHV) infection modulates the host cell cycle to create an environment optimal for its viral-DNA replication during the lytic life cycle. We report here that KSHV vIRF4 targets the β-catenin/CBP cofactor and blocks its occupancy on the cyclin D1 promoter, suppressing the G1-S cell cycle progression and enhancing KSHV replication. This shows that KSHV vIRF4 suppresses host G1-S transition, possibly providing an intracellular milieu favorable for its replication. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Underreporting of Viral Encephalitis and Viral Meningitis, Ireland, 2005–2008

PubMed Central

O’Lorcain, Piaras; Moran, Joanne; Garvey, Patricia; McKeown, Paul; Connell, Jeff; Cotter, Suzanne

2013-01-01

Viral encephalitis (VE) and viral meningitis (VM) have been notifiable infectious diseases under surveillance in the Republic of Ireland since 1981. Laboratories have reported confirmed cases by detection of viral nucleic acid in cerebrospinal fluid since 2004. To determine the prevalence of these diseases in Ireland during 2005–2008, we analyzed 3 data sources: Hospital In-patient Enquiry data (from hospitalized following patients discharge) accessed through Health Intelligence Ireland, laboratory confirmations from the National Virus Reference Laboratory, and events from the Computerised Infectious Disease Reporting surveillance system. We found that the national surveillance system underestimates the incidence of these diseases in Ireland with a 10-fold higher VE hospitalization rate and 3-fold higher VM hospitalization rate than the reporting rate. Herpesviruses were responsible for most specified VE and enteroviruses for most specified VM from all 3 sources. Recommendations from this study have been implemented to improve the surveillance of these diseases in Ireland. PMID:23965781

Aseptic Meningitis and Viral Myelitis

PubMed Central

Irani, David N.

2008-01-01

SYNOPSIS Meningitis and myelitis represent common and very infrequent viral infections of the central nervous system (CNS), respectively. Indeed, the number of cases of viral meningitis that occurs annually exceeds the total number of meningitis cases caused by all other etiologies combined. Focal CNS infections, on the other hand, such as occur in the spinal cord with viral myelitis, are much less common and may be confused with non-infectious disorders that cause acute flaccid paralysis (AFP). This chapter will review some of the important clinical features, epidemiology, diagnostic approaches, and management strategies for patients with aseptic meningitis and viral myelitis. Particular focus will be placed on the diseases caused by enteroviruses (EVs), which as a group account for the vast majority of all aseptic meningitis cases as well as many focal infections of the spinal cord. PMID:18657719

Viral Oncolytic Therapeutics for Neoplastic Meningitis

DTIC Science & Technology

2012-07-01

will in due course approach DOD for approval of the animal protocol. 15. SUBJECT TERMS Viral oncolysis, neoplastic meningitis , cell lines, HSV-1...proposed study is to develop novel, safe and efficient therapy for neoplastic meningitis – that of HSV-1 oncolysis. The viral genome is genetically...1 AD_________________ Award Number: W81XWH-11-1-0388 TITLE: Viral Oncolytic Therapeutics for Neoplastic

Viral Protein Inhibits RISC Activity by Argonaute Binding through Conserved WG/GW Motifs

PubMed Central

García-Chapa, Meritxell; López-Moya, Juan José; Burgyán, József

2010-01-01

RNA silencing is an evolutionarily conserved sequence-specific gene-inactivation system that also functions as an antiviral mechanism in higher plants and insects. To overcome antiviral RNA silencing, viruses express silencing-suppressor proteins. These viral proteins can target one or more key points in the silencing machinery. Here we show that in Sweet potato mild mottle virus (SPMMV, type member of the Ipomovirus genus, family Potyviridae), the role of silencing suppressor is played by the P1 protein (the largest serine protease among all known potyvirids) despite the presence in its genome of an HC-Pro protein, which, in potyviruses, acts as the suppressor. Using in vivo studies we have demonstrated that SPMMV P1 inhibits si/miRNA-programmed RISC activity. Inhibition of RISC activity occurs by binding P1 to mature high molecular weight RISC, as we have shown by immunoprecipitation. Our results revealed that P1 targets Argonaute1 (AGO1), the catalytic unit of RISC, and that suppressor/binding activities are localized at the N-terminal half of P1. In this region three WG/GW motifs were found resembling the AGO-binding linear peptide motif conserved in metazoans and plants. Site-directed mutagenesis proved that these three motifs are absolutely required for both binding and suppression of AGO1 function. In contrast to other viral silencing suppressors analyzed so far P1 inhibits both existing and de novo formed AGO1 containing RISC complexes. Thus P1 represents a novel RNA silencing suppressor mechanism. The discovery of the molecular bases of P1 mediated silencing suppression may help to get better insight into the function and assembly of the poorly explored multiprotein containing RISC. PMID:20657820

HIV-1 non-R5 tropism correlates with a larger size of the cellular viral reservoir and a detectable residual viremia in patients under suppressive ART.

PubMed

Lombardi, Francesca; Belmonti, Simone; Rapone, Lucrezia; Borghetti, Alberto; Ciccullo, Arturo; Gagliardini, Roberta; Baldin, Gianmaria; Montagnani, Francesca; Moschese, Davide; Emiliozzi, Arianna; Rossetti, Barbara; De Luca, Andrea; Di Giambenedetto, Simona

2018-06-01

The influence of HIV-1 co-receptor usage on the course of therapy in subjects fully responding to ART has been poorly investigated. To explore the relationship between co-receptor tropism and cellular reservoir size, residual viremia and subsequent virological outcome in ART-treated patients with HIV-1 RNA stable <50 copies/mL. Viral co-receptor usage was predicted by viral env DNA sequencing with geno2pheno interpretation (FPR20%) and classified as R5 and non-R5. Total blood-associated HIV-1 DNA levels (log 10 copies/10 6 leukocytes) were measured by qRT-PCR (5'LTR). Residual plasma viremia was categorized as detectable (1-49 cps/mL) or undetectable (<1 copy/mL). Virological rebounds (any HIV-1 RNA >50 copies/mL) were evaluated over 96 weeks. The study included 116 subjects. Patients with R5 virus (n = 59) and non-R5 virus (n = 57) were homogeneous for the main characteristics except for the lower nadir CD4 cell count in the non-R5 group. Patients with non-R5 variants showed higher levels of HIV-1 DNA as compared to patients with R5 virus: mean 2.47 (95% CI 2.37-2.56) vs 2.17 (2.08-2.26) (p < 0.001). Moreover, a higher proportion of patients in the non-R5 group displayed detectable residual viremia with respect to the R5-group (54.4% vs 32.2%, p = .016). Detectable residual viremia was found to be significantly associated with viral rebounds. The presence of non-R5 viral DNA variants is related to a higher probability of residual viremia and to a larger size of the cellular viral reservoir in this setting. These data highlight a potential role of viral tropism in the monitoring of HIV-1 infection in virologically controlled subject. Copyright © 2018 Elsevier B.V. All rights reserved.

A Luciferase Reporter Gene Assay to Measure Ebola Virus Viral Protein 35-Associated Inhibition of Double-Stranded RNA-Stimulated, Retinoic Acid-Inducible Gene 1-Mediated Induction of Interferon β.

PubMed

Cannas, Valeria; Daino, Gian Luca; Corona, Angela; Esposito, Francesca; Tramontano, Enzo

2015-10-01

During Ebola virus (EBOV) infection, the type I interferon α/β (IFN-α/β) innate immune response is suppressed by EBOV viral protein 35 (VP35), a validated drug target. Identification of EBOV VP35 inhibitors requires a cellular system able to assess the VP35-based inhibitory functions of viral double-stranded RNA (dsRNA) IFN-β induction. We established a miniaturized luciferase gene reporter assay in A549 cells that measures IFN-β induction by viral dsRNA and is dose-dependently inhibited by VP35 expression. When compared to influenza A virus NS1 protein, EBOV VP35 showed improved inhibition of viral dsRNA-based IFN-β induction. This assay can be used to screen for EBOV VP35 inhibitors. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Perspectives for immunotherapy: which applications might achieve an HIV functional cure?

PubMed

Vieillard, Vincent; Gharakhanian, Shahin; Lucar, Olivier; Katlama, Christine; Launay, Odile; Autran, Brigitte; Ho Tsong Fang, Raphael; Crouzet, Joël; Murphy, Robert L; Debré, Patrice

2016-06-21

The major advances achieved in devising successful combined antiretroviral therapy (cART) have enabled the sustained control of HIV replication. However, this is associated with costly lifelong treatment, partial immune restoration, chronic inflammation and persistent viral reservoirs. In this context, new therapeutic strategies deserve investigation as adjuncts to cART so as to potentiate immune responses that are capable of completely containing HIV pathogenicity, particularly if cART is discontinued. This may seem a dauntingly high hurdle given the results to date. This review outlines the key research efforts that have recently resurrected immunotherapeutic options, and some of the approaches tested to date. These areas include promising cytokines or vaccine strategies, using different viral or non-viral vectors based on polyvalent "mosaic" antigens and highly conserved HIV envelope peptides, broadly neutralizing antibodies or new properties of antibodies to improve the control of immune system homeostasis. These novel immunotherapeutic strategies appear promising per se, or in combination with TLR-agonists in order to bypass the complexity of the interplay between immune activation, massive CD4+ T-cell loss and viral persistence.

Viral Hepatitis: A through E and Beyond

MedlinePlus

... National Digestive Diseases Information Clearinghouse What is viral hepatitis? Viral hepatitis is inflammation of the liver caused by ... and serious. Drugs are available to treat chronic hepatitis. 4 Viral Hepatitis: A through E and Beyond What else ...

Molecular mechanism of RNA silencing suppression mediated by p19 protein of tombusviruses

PubMed Central

Lakatos, Lóránt; Szittya, György; Silhavy, Dániel; Burgyán, József

2004-01-01

RNA silencing is an evolutionarily conserved surveillance system that occurs in a broad range of eukaryotic organisms. In plants, RNA silencing acts as an antiviral system; thus, successful virus infection requires suppression of gene silencing. A number of viral suppressors have been identified so far; however, the molecular bases of silencing suppression are still poorly understood. Here we show that p19 of Cymbidium ringspot virus (CymRSV) inhibits RNA silencing via its small RNA-binding activity in vivo. Small RNAs bound by p19 in planta are bona fide double-stranded siRNAs and they are silencing competent in the in vitro RNA-silencing system. p19 also suppresses RNA silencing in the heterologous Drosophila in vitro system by preventing siRNA incorporation into RISC. During CymRSV infection, p19 markedly diminishes the amount of free siRNA in cells by forming p19–siRNA complexes, thus making siRNAs inaccessible for effector complexes of RNA-silencing machinery. Furthermore, the obtained results also suggest that the p19-mediated sequestration of siRNAs in virus-infected cells blocks the spread of the mobile, systemic signal of RNA silencing. PMID:14976549

Viral Hepatitis: Information for Gay and Bisexual Men

MedlinePlus

VIRAL HEPATITIS Information for Gay and Bisexual Men What is viral hepatitis? Viral hepatitis is an infection of the liver caused by one of several ... each virus is spread in different ways. Are gay and bisexual men at risk for viral hepatitis? ...

Comparative Viral Metagenomics of Environmental Samples from Korea

PubMed Central

Kim, Min-Soo; Whon, Tae Woong

2013-01-01

The introduction of metagenomics into the field of virology has facilitated the exploration of viral communities in various natural habitats. Understanding the viral ecology of a variety of sample types throughout the biosphere is important per se, but it also has potential applications in clinical and diagnostic virology. However, the procedures used by viral metagenomics may produce technical errors, such as amplification bias, while public viral databases are very limited, which may hamper the determination of the viral diversity in samples. This review considers the current state of viral metagenomics, based on examples from Korean viral metagenomic studies-i.e., rice paddy soil, fermented foods, human gut, seawater, and the near-surface atmosphere. Viral metagenomics has become widespread due to various methodological developments, and much attention has been focused on studies that consider the intrinsic role of viruses that interact with their hosts. PMID:24124407

APOBEC3H haplotypes and HIV-1 pro-viral vif DNA sequence diversity in early untreated human immunodeficiency virus-1 infection.

PubMed

Gourraud, P A; Karaouni, A; Woo, J M; Schmidt, T; Oksenberg, J R; Hecht, F M; Liegler, T J; Barbour, J D

2011-03-01

We examined single nucleotide polymorphisms (SNP) in the APOBEC3 locus on chromosome 22, paired with population sequences of pro-viral human immunodeficiency virus-1 (HIV-1) vif from peripheral blood mononuclear cells, from 96 recently HIV-1-infected treatment-naive adults. We found evidence for the existence of an APOBEC3H linkage disequilibrium (LD) block associated with variation in GA → AA, or APOBEC3F/H signature, sequence changes in pro-viral HIV-1 vif sequence (top 10 significant SNPs with a significant p = 4.8 × 10(-3)). We identified a common five position risk haplotype distal to APOBEC3H (A3Hrh). These markers were in high LD (D' = 1; r(2) = 0.98) to a previously described A3H "RED" haplotype containing a variant (E121) with enhanced susceptibility to HIV-1 Vif. This association was confirmed by a haplotype analysis. Homozygote carriers of the A3Hrh had lower GA->AA (A3F/H) sequence editing upon pro-viral HIV-1 vif sequence (p = 0.01), and lower HIV-1 RNA levels over time during early, untreated HIV-1 infection, (p = 0.015 mixed effects model). This effect may be due to enhanced susceptibility of A3H forms to HIV-1 Vif mediated viral suppression of sequence editing activity, slowing viral diversification and escape from immune responses. Copyright © 2011 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Mechanisms of Hepatitis C Viral Resistance to Direct Acting Antivirals.

PubMed

Ahmed, Asma; Felmlee, Daniel J

2015-12-18

There has been a remarkable transformation in the treatment of chronic hepatitis C in recent years with the development of direct acting antiviral agents targeting virus encoded proteins important for viral replication including NS3/4A, NS5A and NS5B. These agents have shown high sustained viral response (SVR) rates of more than 90% in phase 2 and phase 3 clinical trials; however, this is slightly lower in real-life cohorts. Hepatitis C virus resistant variants are seen in most patients who do not achieve SVR due to selection and outgrowth of resistant hepatitis C virus variants within a given host. These resistance associated mutations depend on the class of direct-acting antiviral drugs used and also vary between hepatitis C virus genotypes and subtypes. The understanding of these mutations has a clear clinical implication in terms of choice and combination of drugs used. In this review, we describe mechanism of action of currently available drugs and summarize clinically relevant resistance data.

Viral Oncolytic Therapeutics for Neoplastic Meningitis

DTIC Science & Technology

2013-07-01

SUBTITLE 5a. CONTRACT NUMBER Viral Oncolytic Therapeutics for Neoplastic Meningitis 5b. GRANT NUMBER W81XWH-11-1-0388 5c. PROGRAM ELEMENT NUMBER... viral and cellular kinetics with bioluminescence and PET are being written up for publication. 15. SUBJECT TERMS Neoplastic meningitis , mouse...model of meningeal metastases, breast cancer, bioluminescence, MRI, viral oncolysis, HSV- 1. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

CD4+ T-cell engagement by both wild-type and variant HCV peptides modulates the conversion of viral clearing helper T cells to Tregs

PubMed Central

Cusick, Matthew F; Libbey, Jane E; Cox Gill, Joan; Fujinami, Robert S; Eckels, David D

2013-01-01

Aim To determine whether modulation of T-cell responses by naturally occurring viral variants caused an increase in numbers of Tregs in HCV-infected patients. Patients, materials & methods Human peripheral blood mononuclear cells, having proliferative responses to a wild-type HCV-specific CD4+ T-cell epitope, were used to quantify, via proliferative assays, flow cytometry and class II tetramers, the effects of naturally occurring viral variants arising in the immunodominant epitope. Results In combination, the wild-type and variant peptides led to enhanced suppression of an anti-HCV T-cell response. The variant had a lower avidity for the wild-type-specific CD4+ T cell. Variant-stimulated CD4+ T cells had increased Foxp3, compared with wild-type-stimulated cells. Conclusion A stable viral variant from a chronic HCV subject was able to induce Tregs in multiple individuals that responded to the wild-type HCV-specific CD4+ T-cell epitope. PMID:24421862

Suppression of RIP3-dependent Necroptosis by Human Cytomegalovirus

PubMed Central

Omoto, Shinya; Guo, Hongyan; Talekar, Ganesh R.; Roback, Linda; Kaiser, William J.; Mocarski, Edward S.

2015-01-01

Necroptosis is an alternate programmed cell death pathway that is unleashed by caspase-8 compromise and mediated by receptor-interacting protein kinase 3 (RIP3). Murine cytomegalovirus (CMV) and herpes simplex virus (HSV) encode caspase-8 inhibitors that prevent apoptosis together with competitors of RIP homotypic interaction motif (RHIM)-dependent signal transduction to interrupt the necroptosis. Here, we show that pro-necrotic murine CMV M45 mutant virus drives virus-induced necroptosis during nonproductive infection of RIP3-expressing human fibroblasts, whereas WT virus does not. Thus, M45-encoded RHIM competitor, viral inhibitor of RIP activation, sustains viability of human cells like it is known to function in infected mouse cells. Importantly, human CMV is shown to block necroptosis induced by either TNF or M45 mutant murine CMV in RIP3-expressing human cells. Human CMV blocks TNF-induced necroptosis after RIP3 activation and phosphorylation of the mixed lineage kinase domain-like (MLKL) pseudokinase. An early, IE1-regulated viral gene product acts on a necroptosis step that follows MLKL phosphorylation prior to membrane leakage. This suppression strategy is distinct from RHIM signaling competition by murine CMV or HSV and interrupts an execution process that has not yet been fully elaborated. PMID:25778401

Statistical Mechanics of Viral Entry

NASA Astrophysics Data System (ADS)

Zhang, Yaojun; Dudko, Olga K.

2015-01-01

Viruses that have lipid-membrane envelopes infect cells by fusing with the cell membrane to release viral genes. Membrane fusion is known to be hindered by high kinetic barriers associated with drastic structural rearrangements—yet viral infection, which occurs by fusion, proceeds on remarkably short time scales. Here, we present a quantitative framework that captures the principles behind the invasion strategy shared by all enveloped viruses. The key to this strategy—ligand-triggered conformational changes in the viral proteins that pull the membranes together—is treated as a set of concurrent, bias field-induced activated rate processes. The framework results in analytical solutions for experimentally measurable characteristics of virus-cell fusion and enables us to express the efficiency of the viral strategy in quantitative terms. The predictive value of the theory is validated through simulations and illustrated through recent experimental data on influenza virus infection.

High-Risk Human Papillomaviral Oncogenes E6 and E7 Target Key Cellular Pathways to Achieve Oncogenesis.

PubMed

Yeo-Teh, Nicole S L; Ito, Yoshiaki; Jha, Sudhakar

2018-06-08

Infection with high-risk human papillomavirus (HPV) has been linked to several human cancers, the most prominent of which is cervical cancer. The integration of the viral genome into the host genome is one of the manners in which the viral oncogenes E6 and E7 achieve persistent expression. The most well-studied cellular targets of the viral oncogenes E6 and E7 are p53 and pRb, respectively. However, recent research has demonstrated the ability of these two viral factors to target many more cellular factors, including proteins which regulate epigenetic marks and splicing changes in the cell. These have the ability to exert a global change, which eventually culminates to uncontrolled proliferation and carcinogenesis.

Focal posterior pole viral retinitis.

PubMed

Hazirolan, Dicle; Sungur, Gulten; Demir, Necati; Kasim, Remzi; Duman, Sunay

2010-01-01

To describe the clinical features of an atypical form of viral retinitis in immunocompetent patients. This was a retrospective noncomparative case series. The charts of 8 patients diagnosed with and treated for focal posterior viral retinitis were reviewed. Clinical and demographic features were evaluated. All the patients had extensive laboratory tests, fundus fluorescein angiography, optical coherence tomography of macula, and polymerase chain reaction of vitreous. All the patients were referred to our Uveitis Service from other hospitals, as their uveitis symptoms deteriorated in spite of treatment. The mean age of 4 male and 4 female patients was 32.1 years (range, 22-42 years). The mean follow-up period was 10 months (range, 6-18 months). All of the patients had unilateral disease. Polymerase chain reaction analysis of vitreous specimen was positive for herpes simplex virus-1 in 5 patients and varicella zoster virus in 3 patients. Retinitis resolved after systemic acyclovir treatment in all patients. Viral etiology must be borne in mind in the differential diagnosis of atypical retinitis. It can be a milder form of viral retinitis like focal viral retinitis, as mentioned in this study. The prognosis of this disease is better than the other forms of necrotizing retinopathies involving a larger area of retina.

Computational mechanics of viral capsids.

PubMed

Gibbons, Melissa M; Perotti, Luigi E; Klug, William S

2015-01-01

Viral capsids undergo significant mechanical deformations during their assembly, maturation, and infective life-span. In order to characterize the mechanics of viral capsids, their response to applied external forces is analyzed in several experimental studies using, for instance, Atomic Force Microscope (AFM) indentation experiments. In recent years, a broader approach to study the mechanics of viral capsids has leveraged the theoretical tools proper of continuum mechanics. Even though the theory of continuum elasticity is most commonly used to study deformable bodies at larger macroscopic length scales, it has been shown that this very rich theoretical field can still offer useful insights into the mechanics of viral structures at the nanometer scale. Here we show the construction of viral capsid continuum mechanics models starting from different forms of experimental data. We will discuss the kinematics assumptions, the issue of the reference configuration, the material constitutive laws, and the numerical discretization necessary to construct a complete Finite Element capsid mechanical model. Some examples in the second part of the chapter will show the predictive capabilities of the constructed models and underline useful practical aspects related to efficiency and accuracy. We conclude each example by collecting several key findings discovered by simulating AFM indentation experiments using the constructed numerical models.

Kinetics of viral shedding provide insights into the epidemiology of viral hemorrhagic septicemia in Pacific herring

USGS Publications Warehouse

Hershberger, Paul K.; Gregg, Jacob L.; Winton, James R.; Grady, Courtney; Collins, Rachael

2010-01-01

Losses from infectious diseases are an important component of natural mortality among marine fish species, but factors controlling the ecology of these diseases and their potential responses to anthropogenic changes are poorly understood. We used viral hemorrhagic septicemia virus (VHSV) and a laboratory stock of Pacific herring Clupea pallasii to investigate the kinetics of viral shedding and its effect on disease transmission and host mortality. Outbreaks of acute disease, accompanied by mortality and viral shedding, were initiated after waterborne exposure of herring to concentrations of VHSV as low as 101 plaque-forming units (pfu) ml–1. Shed virus in flow-through tanks was first detected 4 to 5 d post-exposure, peaked after 6 to 10 d, and was no longer detected after 16 d. Shedding rates, calculated from density, flow and waterborne virus titer reached 1.8 to 5.0 × 108 pfu fish–1 d–1. Onset of viral shedding was dose-dependent and preceded initial mortality by 2 d. At 21 d, cumulative mortality in treatment groups ranged from 81 to 100% and was dependent not on challenge dose, but on the kinetics and level of viral shedding by infected fish in the tank. Possible consequences of the viral shedding and disease kinetics are discussed in the context of epizootic initiation and perpetuation among populations of wild Pacific herring.

Kinetics of viral shedding provide insights into the epidemiology of viral hemorrhagic septicemia in Pacific herring

USGS Publications Warehouse

Hershberger, P.; Gregg, J.; Grady, C.; Collins, R.; Winton, J.

2010-01-01

Losses from infectious diseases are an important component of natural mortality among marine fish species, but factors controlling the ecology of these diseases and their potential responses to anthropogenic changes are poorly understood. We used viral hemorrhagic septicemia virus (VHSV) and a laboratory stock of Pacific herring Clupea pallasii to investigate the kinetics of viral shedding and its effect on disease transmission and host mortality. Outbreaks of acute disease, accompanied by mortality and viral shedding, were initiated after waterborne exposure of herring to concentrations of VHSV as low as 10 1 plaque-forming units (pfu) ml-1. Shed virus in flow-through tanks was first detected 4 to 5 d post-exposure, peaked after 6 to 10 d, and was no longer detected after 16 d. Shedding rates, calculated from density, flow and waterborne virus titer reached 1.8 to 5.0 ?? ?10 8 pfu fish-1 d-1. Onset of viral shedding was dose-dependent and preceded initial mortality by 2 d. At 21 d, cumulative mortality in treatment groups ranged from 81 to 100% and was dependent not on challenge dose, but on the kinetics and level of viral shedding by infected fish in the tank. Possible consequences of the viral shedding and disease kinetics are discussed in the context of epizootic initiation and perpetuation among populations of wild Pacific herring. ?? Inter-Research 2010.

Viral load strategy: impact on risk behaviour and serocommunication of men who have sex with men in specialized care.

PubMed

Kuhn, E; Potthoff, A; Dirks, H; Borgmann, R; Esser, S; Scherbaum, N; Brockmeyer, N H; Skaletz-Rorowski, A

2016-09-01

Incidence and prevalence of HIV are continuously high in German men, who have sex with men (MSM). Different transmission risk minimizing strategies have been observed. The viral load strategy rates patients unlikely to be sexually infectious if their viral load under effective therapy is stably suppressed during 6 months and no other sexually transmitted infections are present. We aim to objectify the current popularity of the viral load strategy, the adherence to basic conditions and its impact on risk behaviour and serocommunication. Until now, no data on a German sample of HIV-positive MSM in regular specialized outpatient care are available. Cross-sectional study with group comparisons between user group and non-user-group of the viral load strategy. Self-report questionnaires were conducted with 269 sexually active German HIV+MSM under effective treatment in specialized outpatient care. Structured interviews gathered additional information about approach to and realization of definite action levels concerning sexual risk behaviour and transmission risk minimizing strategies. Twenty-seven of 269 participants (10%) affirmed knowledge of having an undetectable viral load and stated this to be criteria for unprotected sexual behaviour. This subgroup reported more unprotected insertive (P = 0.018) and receptive anal intercourse (P = 0.042), more anonymous sex partners (P = 0.008) and less consistent safer sex. Analysing serocommunication, less addressing HIV/AIDS in general (P = 0.043) and less disclosing to sex partners (P = 0.023) was found, especially in anonymous settings. Differentiating serocommunication characteristics, a focus on seroguessing was depicted. The user group of the viral load strategy is small. But a less frequent, more reactive and assumptive serocommunication leads to an imprecise information exchange paired with higher frequency of risky behaviour, especially in anonymous settings, where frank serocommunication is often avoided. The targeted

IFITM3-containing exosome as a novel mediator for anti-viral response in dengue virus infection.

PubMed

Zhu, Xun; He, Zhenjian; Yuan, Jie; Wen, Weitao; Huang, Xuan; Hu, Yiwen; Lin, Cuiji; Pan, Jing; Li, Ran; Deng, Haijing; Liao, Shaowei; Zhou, Rui; Wu, Jueheng; Li, Jun; Li, Mengfeng

2015-01-01

Interferon-inducible transmembrane proteins 1, 2 and 3 (IFITM1, IFITM2 and IFITM3) have recently been identified as potent antiviral effectors that function to suppress the entry of a broad range of enveloped viruses and modulate cellular tropism independent of viral receptor expression. However, the antiviral effect and mechanisms of IFITMs in response to viral infections remain incompletely understood and characterized. In this work, we focused our investigation on the function of the extracellular IFITM3 protein. In cell models of DENV-2 infection, we found that IFITM3 contributed to both the baseline and interferon-induced inhibition of DENV entry. Most importantly, our study for the first time demonstrated the presence of IFITM-containing exosome in the extracellular environment, and identified an ability of cellular exosome to intercellularly deliver IFITM3 and thus transmit its antiviral effect from infected to non-infected cells. Thus, our findings provide new insights in the basic mechanisms underlying the actions of IFITM3, which might lead to future development of exosome-mediated anti-viral strategies using IFITM3 as a therapeutic agent. Conceivably, variations in the basal and inducible levels of IFITMs, as well as in intracellular and extracellular levels of IFITMs, might predict the severity of dengue virus infections among individuals or across species. © 2014 John Wiley & Sons Ltd.

The type I interferon response during viral infections: a "SWOT" analysis.

PubMed