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HIV viral dynamics

Brennan S Dirk, Logan R Van Nynatten, Jimmy D Dikeakos
Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell-cell transmission and cell-free viral transmission...
October 19, 2016: Viruses
Cameron Browne
This paper concerns modeling the coupled within-host population dynamics of virus and CTL (Cytotoxic T Lymphocyte) immune response. There is substantial evidence that the CTL immune response plays a crucial role in controlling HIV in infected patients. Recent experimental studies have demonstrated that certain CTL variants can recognize HIV infected cells early in the infected cell lifecycle before viral production, while other CTLs only detect viral proteins (epitopes) presented on the surface of infected cells after viral production...
October 1, 2016: Mathematical Biosciences and Engineering: MBE
Filip Bielejec, Guy Baele, Allen G Rodrigo, Marc A Suchard, Philippe Lemey
Various factors determine the rate at which mutations are generated and fixed in viral genomes. Viral evolutionary rates may vary over the course of a single persistent infection and can reflect changes in replication rates and selective dynamics. Dedicated statistical inference approaches are required to understand how the complex interplay of these processes shapes the genetic diversity and divergence in viral populations. Although evolutionary models accommodating a high degree of complexity can now be formalized, adequately informing these models by potentially sparse data, and assessing the association of the resulting estimates with external predictors, remains a major challenge...
July 2016: Virus Evolution
Rafael Conceição de Souza, Gabriela de Medeiros Muniz, Andrei Santos Siqueira, Adonis de Melo Lima, Alessandra Pereira da Silva, Evonnildo Costa Gonçalves, João Lídio da Silva Gonçalves Vianez Júnior
Human immunodeficiency virus (HIV) infections continue to exert an enormous impact on global human health. This led experts to emphasize the importance of new measures for preventing HIV infections, including the development of vaccines and novel drugs. In this context, a promising approach involves the use of lectins that can bind the surface envelope glycoprotein gp120 of HIV with high affinity, preventing viral entry. The cyanobacterial lectin microvirin (MVN) has been proposed as a candidate for development as a topical microbicide because of its ability to bind to high mannose-type glycans, potently inhibiting HIV-1 entry...
November 2016: Journal of Molecular Modeling
Jihad Slim, Christopher F Saling
Advancements in antiretroviral therapy have drastically increased the life expectancy for those infected with HIV. Today, a new subgroup of older patients with long-term controlled HIV exists, and its populace is continuously mounting. Therefore, it is essential to understand the enduring effects of chronic suppressed HIV infection in order to further improve HIV management in these patients. This paper will examine the role of HIV in chronic inflammation and immune dysfunction, the dynamic interaction that exists between comorbidity and HIV, and the potential consequences of long-term antiretroviral therapy in an effort to provide the best management options for the virally suppressed HIV patient...
2016: BioMed Research International
Mahar Fatima, Bharat Prajapati, Kanza Saleem, Rina Kumari, Chitra Mohindar Singh Singal, Pankaj Seth
Astroglia are indispensable component of the tripartite synapse ensheathing innumerous soma and synapses. Its proximity to neurons aids the regulation of neuronal functions, health and survival through dynamic neuroglia crosstalk. Susceptibility of astrocyte to HIV-1 infection and subsequent latency culminates in compromised neuronal health. The viral protein HIV-1 transactivator of transcription (Tat) is neurotoxic. HIV-1 Tat is detected in brain of AIDS patients even in cases where viral load is non-detectable due to successful HAART therapy...
October 20, 2016: Glia
Ting Yuan, Weitong Yao, Kenzo Tokunaga, Rongge Yang, Binlian Sun
BACKGROUND: Several members of the TRIM family have been implicated in antiviral defense. Our previous report showed that human TRIM11 potently inhibited HIV-1 transduction by reducing the viral reverse transcripts. These results prompted us to examine the effect of TRIM11 on HIV-1 uncoating, which is closely related to viral reverse transcription. RESULTS: Using a combination of in vitro binding and in situ proximity ligation assay, we showed that TRIM11 could interact with HIV-1 capsid...
October 13, 2016: Retrovirology
Xia Wang, Sanyi Tang, Xinyu Song, Libin Rong
HIV can infect cells via virus-to-cell infection or cell-to-cell viral transmission. These two infection modes may occur in a synergistic way and facilitate viral spread within an infected individual. In this paper, we developed an HIV latent infection model including both modes of transmission and time delays between viral entry and integration or viral production. We analysed the model by defining the basic reproductive number, showing the existence, positivity and boundedness of the solution, and proving the local and global stability of the infection-free and infected steady states...
October 12, 2016: Journal of Biological Dynamics
Saghi Sepehri, Lotfollah Saghaie, Afshin Fassihi
The fusion of viral and host cell membranes is mediated using gp41 subunit of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein. As the HIV-1 enters the host cells, the two helical regions (HR1 and HR2) in the ectodomain of gp41 form a six-helix bundle, which carries the target and viral cell membranes to close proximity. Steps of this process serve as attractive targets for developing HIV-1 fusion inhibitors. Identification of some novel HIV fusion inhibitors with the goal of blocking the formation of the six-helix bundle was accomplished by computer-aided drug design techniques...
October 12, 2016: Molecular Informatics
Andréia P Andrade, Suzy D B Pacheco, Fabricio Q Silva, Luiz M L Pinheiro, Jairo A A Castro, Carlos E M Amaral, Renata B Hermes, Benedikt Fischer, João R R Pinho, José Alexandre R Lemos, Aldemir B Oliveira-Filho
South America is considered to have a low prevalence of hepatitis B virus (HBV) infection, although areas with a relatively high prevalence have been identified in northern Brazil. Few epidemiological studies of populations at risk of HBV infection are available for this region. Given this, in the present study, we investigated the prevalence of HBV and the factors associated with infection among illicit drug users (DUs) in the Marajó Archipelago, northern Brazil. In this cross-sectional study, we collected samples and epidemiological information from DUs in 11 municipalities of the Marajó Archipelago...
October 7, 2016: Archives of Virology
K F Gurski, K A Hoffman
In 1992, Watts and May introduced a simple dynamical systems model of the spread of HIV based on disease transmission per partnership including the length of partnership duration. This model allowed for the treatment of concurrent partnerships, although it was hampered by the assumption of an important latent phase which generated a non-autonomous system. Subsequent models including concurrency have been based on networks, Monte Carlo, and stochastic simulations which lose a qualitative understanding of the effects of concurrency...
October 3, 2016: Mathematical Biosciences
Katrina A Lythgoe, François Blanquart, Lorenzo Pellis, Christophe Fraser
The viral population of HIV-1, like many pathogens that cause systemic infection, is structured and differentiated within the body. The dynamics of cellular immune trafficking through the blood and within compartments of the body has also received wide attention. Despite these advances, mathematical models, which are widely used to interpret and predict viral and immune dynamics in infection, typically treat the infected host as a well-mixed homogeneous environment. Here, we present mathematical, analytical, and computational results that demonstrate that consideration of the spatial structure of the viral population within the host radically alters predictions of previous models...
October 2016: PLoS Biology
Gelayol Nazari Golpayegani, Amir Homayoun Jafari, Nader Jafarnia Dabanloo
BACKGROUND: According to the World Health Organization, by the end of last year, about 37 million people throughout the world were diagnosed with AIDS and millions of people die each year from this disease. OBJECTIVE: To develop an appropriate model which depicts the mechanism of the dynamics involved in the interactions between HIV and immune system in peripheral bloodstream of HIV infected individuals by considering the phenomena of virus mutation and taking into account the role of latently infected cells in speared of infection and considering the effects of antiretroviral drugs and occurrence of drug resistance in our model in order to assess the results obtained from applying different therapeutic methods...
September 23, 2016: Technology and Health Care: Official Journal of the European Society for Engineering and Medicine
Guoying Ni, Yuejian Wang, Scott Cummins, Shelley Walton, Kate Mounsey, Xiaosong Liu, Ming Q Wei, Tianfang Wang
Interleukin 10 (IL-10) is a cytokine that is able to downregulate inflammation. Its overexpression is directly associated with the difficulty in the clearance of chronic viral infections, such as chronic hepatitis B, hepatitis C and HIV infection, and infection-related cancer. IL-10 signaling blockade has been proposed as a promising way of clearing chronic viral infection and preventing tumor growth in animal models. Recently, we have reported that peptides with a helical repeating pattern of hydrophobic and hydrophilic residues are able to inhibit IL-10 significantly both in vitro and in vivo (1) ...
September 29, 2016: Human Vaccines & Immunotherapeutics
Birthe Trautz, Virginia Pierini, Rebecka Wombacher, Bettina Stolp, Amanda J Chase, Massimo Pizzato, Oliver T Fackler
: SERINC 3 and 5 are recently identified host cell inhibitors of HIV-1 particle infectivity that are counteracted by the viral pathogenesis factor Nef. Here we confirm that HIV-1 Nef, but not HIV-1 Vpu, antagonizes the particle infectivity restriction of SERINC5. SERINC5 antagonism occurred in parallel to other Nef activities including cell surface receptor downregulation, trans-Golgi-network targeting of Lck and inhibition of host cell actin dynamics. Interaction motifs with host cell endocytic machinery, Nef-associated kinase complex as well as CD4 cytoplasmic tail/HIV-1 protease were identified as essential Nef determinants for SERINC5 antagonism...
September 28, 2016: Journal of Virology
Naveen K Vaidya, Ruy M Ribeiro, Alan S Perelson, Anil Kumar
Complications of HIV-1 infection in individuals who utilize drugs of abuse is a significant problem, because these drugs have been associated with higher virus replication and accelerated disease progression as well as severe neuropathogenesis. To gain further insight it is important to quantify the effects of drugs of abuse on HIV-1 infection dynamics. Here, we develop a mathematical model that incorporates experimentally observed effects of morphine on inducing HIV-1 co-receptor expression. For comparison we also considered viral dynamic models with cytolytic or noncytolytic effector cell responses...
September 2016: PLoS Computational Biology
Zhou Qihui, Zhu Biao
Latent reservoir (LR) of HIV is the cells (such as CD4(+)T cell) where HIV is able to hide. These cellular reservoirs are located throughout the body, including the spleen, lymph nodes, gastrointestinal lymphoid tissues, and become the major obstacle to cure HIV infection. To truly cure patients, a new strategy "shock and kill" was put forward by scientists, which is to shock HIV-infected cells out of hidden reservoirs in the body and then kill them. Quantitatively evaluating the size of long-lived LR is essential to this strategy...
May 25, 2016: Zhejiang da Xue Xue Bao. Yi Xue Ban, Journal of Zhejiang University. Medical Sciences
Chaitra Gopalappa, Paul G Farnham, Yao-Hsuan Chen, Stephanie L Sansom
BACKGROUND: HIV transmission is the result of complex dynamics in the risk behaviors, partnership choices, disease stage and position along the HIV care continuum-individual characteristics that themselves can change over time. Capturing these dynamics and simulating transmissions to understand the chief sources of transmission remain important for prevention. METHODS: The Progression and Transmission of HIV/AIDS (PATH 2.0) is an agent-based model of a sample of 10,000 people living with HIV (PLWH), who represent all men who have sex with men (MSM) and heterosexuals living with HIV in the U...
September 19, 2016: Medical Decision Making: An International Journal of the Society for Medical Decision Making
Jayna Raghwani, Rebecca Rose, Isabelle Sheridan, Philippe Lemey, Marc A Suchard, Teresa Santantonio, Patrizia Farci, Paul Klenerman, Oliver G Pybus
The treatment of HCV infection has seen significant progress, particularly since the approval of new direct-acting antiviral drugs. However these clinical achievements have been made despite an incomplete understanding of HCV replication and within-host evolution, especially compared with HIV-1. Here, we undertake a comprehensive analysis of HCV within-host evolution during chronic infection by investigating over 4000 viral sequences sampled longitudinally from 15 HCV-infected patients. We compare our HCV results to those from a well-studied HIV-1 cohort, revealing key differences in the evolutionary behaviour of these two chronic-infecting pathogens...
September 2016: PLoS Pathogens
Heather A Prentice, Hailin Lu, Matthew A Price, Anatoli Kamali, Etienne Karita, Shabir Lakhi, Eduard J Sanders, Omu Anzala, Susan Allen, Paul A Goepfert, Eric Hunter, Jill Gilmour, Jianming Tang
: In individuals with HIV-1 infection, depletion of CD4(+) T-cells is often accompanied by a malfunction of CD8(+) T-cells that are persistently activated and/or exhausted. While the dynamics and correlates of CD4 counts have been well-documented, the same does not apply to CD8 counts. Here, we examined CD8 counts in a cohort of 497 Africans with primary HIV-1 infection and monthly to quarterly follow-up visits for up to three years in the absence of antiretroviral therapy. Statistical models revealed that i) CD8 counts were relatively steady in the 3-36 months period of infection and similar between men and women; ii) neither geography nor heterogeneity in HIV-1 set-point viral load could account for the roughly 10-fold range of CD8 counts in the cohort (P >0...
September 14, 2016: Journal of Virology
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