1
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Elaiw AM, Almohaimeed EA. Within-host dynamics of HTLV-2 and HIV-1 co-infection with delay. JOURNAL OF BIOLOGICAL DYNAMICS 2025; 19:2506536. [PMID: 40397961 DOI: 10.1080/17513758.2025.2506536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2024] [Accepted: 05/09/2025] [Indexed: 05/23/2025]
Abstract
This paper formulates a mathematical model for the co-infection of HTLV-2 and HIV-1 with latent reservoirs, four types of distributed-time delays and HIV-1-specific B cells. We establish that the solutions remain bounded and nonnegative, identify the system's steady states, and derive sufficient conditions ensuring both their existence and global asymptotic stability. The system's global stability is confirmed using Lyapunov's method. We provide numerical simulations to support the stability results. Sensitivity analysis of basic reproduction numbers of HTLV-2 mono-infection (R 1 ) and HIV-1 mono-infection (R 2 ) is conducted. We examine how time delays influence the interaction between HIV-1 and HTLV-2. Including delay terms in the model reflects the influence of antiviral treatments, which help decrease R 1 and R 2 , thus limiting the spread of infection. This highlights the potential for designing therapies that prolong delay period. Incorporating such delays improves model precision and supports more effective evaluation of treatment strategies.
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Affiliation(s)
- A M Elaiw
- Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - E A Almohaimeed
- Department of Mathematics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
- Department of Mathematics, College of Science, Qassim University, Buraydah, Saudi Arabia
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2
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Sutradhar R, Dalal DC. The roles of continuous and discontinuous proliferations on hepatitis B virus infection. Math Biosci 2025; 385:109448. [PMID: 40274258 DOI: 10.1016/j.mbs.2025.109448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2024] [Revised: 03/02/2025] [Accepted: 04/11/2025] [Indexed: 04/26/2025]
Abstract
The proliferation of both uninfected and infected hepatocytes, as well as the recycling effects of rcDNA-containing capsids are two key mechanisms playing significant roles in the persistence and clearance of hepatitis B virus (HBV) infection. In this study, the temporal dynamics of this viral infection is investigated through two intercellular mathematical models considering proliferation of both types of hepatocytes (uninfected and infected) and recycling effects of capsids. Both models are formulated on the basis of a key finding in the existing literature: mitosis of an infected hepatocytes yields in two uninfected progenies. In the first model (defined by P-model), we examine the continuous proliferation (which occur continuously), while the second one (defined by M-model) deals with the discontinuous proliferation (happen when the concentration of liver cells decreases to less than 70% of its initial concentration). The proposed models are calibrated with the experimental data obtained from an adult chimpanzee. Results of this study suggest that when both hepatocytes proliferate with equal rate, proliferation helps the individual in a rapid recovery from the acute infection whereas in case of chronic infection, the severity of the infection increases. On the other hand, if the infected hepatocytes proliferate at a different rate that of uninfected hepatocytes, the proliferation of uninfected hepatocytes contributes to increase the infection, but the proliferation of infected hepatocytes acts to reduce the infection from the long-term perspective. The global sensitivity analysis also shows the same results. Furthermore, it is also observed that the differences between the outcomes of continuous and discontinuous proliferations are significant and noteworthy.
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Affiliation(s)
- Rupchand Sutradhar
- Department of Mathematics, Indian Institute of Technology Guwahati, Assam, 781039, India.
| | - D C Dalal
- Department of Mathematics, Indian Institute of Technology Guwahati, Assam, 781039, India.
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3
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Chen C, Zhou Y, Ye Z. Stability and optimal control of a cytokine-enhanced general HIV infection model with antibody immune response and CTLs immune response. Comput Methods Biomech Biomed Engin 2024; 27:2199-2230. [PMID: 37933845 DOI: 10.1080/10255842.2023.2275248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 10/14/2023] [Accepted: 10/17/2023] [Indexed: 11/08/2023]
Abstract
In this article, a cytokine-enhanced viral infection model with cytotoxic T lymphocytes (CTLs) immune response and antibody immune response is proposed and analyzed. The model contains six compartments: uninfected CD4+T cells, infected CD4+T cells, inflammatory cytokines, viruses, CTLs and antibodies. Different from the previous works, this model not only considers virus-to-cell transmission and cell-to-cell transmission, but also includes a new infection mode, namely cytokine-enhanced viral infection. The incidence rates of the healthy CD4+T cells with viruses, infected cells and inflammatory cytokines are given by general functions. Moreover, the production/proliferation and removal/death rates of all compartments are represented by general functions. Firstly, we prove that all the solutions of the model are nonnegative and uniformly bounded. Then, five key parameters with strong biological significance, namely the virus basic reproduction number R0, CTLs immune response reproduction number R1, antibody immune response reproductive number R2, CTLs immune competitive reproductive number R3 and antibody immune competitive reproductive number R4 are derived. Then, by using Lyapunov's method and LaSalle's invariance principle, we have shown the global stability of each equilibrium. In addition, the numerical simulation results also show that the theoretical results are correct. Finally, we formulate an optimal control problem and solve it using Pontryagins Maximum Principle and an efficient iterative numerical methods. The results of our numerical simulation show that it is very important to control the infection between viruses and cells and between cells and inflammatory cytokines for controlling HIV.
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Affiliation(s)
- Chong Chen
- School of Mathematics and Statistics, Central South University, Changsha, China
| | - Yinggao Zhou
- School of Mathematics and Statistics, Central South University, Changsha, China
| | - Zhijian Ye
- School of Mathematics and Statistics, Central South University, Changsha, China
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4
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Sadki M, Harroudi S, Allali K. Local and global stability of an HCV viral dynamics model with two routes of infection and adaptive immunity. Comput Methods Biomech Biomed Engin 2024; 27:1510-1537. [PMID: 37599632 DOI: 10.1080/10255842.2023.2245941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 07/08/2023] [Accepted: 07/28/2023] [Indexed: 08/22/2023]
Abstract
The aim of this article is to formulate and study a mathematical model describing hepatitis C virus (HCV) infection dynamics. The model includes two essential modes of infection transmission, namely, virus-to-cell and cell-to-cell. The effect of therapy and adaptive immunity are incorporated in the suggested model. The adaptive immunity is represented by its two categories, namely, the humoral and cellular immune responses. Our article begins by establishing some mathematical results through proving the model's well-posedness in terms of existence, positivity and boundedness of solutions. We present all the steady states of the problem that depend on specific reproduction numbers. It moves then to the theoretical investigation of the local and global stability analysis of the free disease equilibrium and the four disease equilibria. The local and global stability analysis of the HCV mathematical model are established via the Routh-Hurwitz criteria and Lyapunov-LaSalle invariance principle, respectively. Finally, our article presents some numerical simulations to validate the analytical study of the global stability. Numerical simulations have shown the effect of the drug therapies on the system's dynamical behavior.
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Affiliation(s)
- Marya Sadki
- Laboratory of Mathematics, Computer Science and Applications, Faculty of Sciences and Technologies, University Hassan II of Casablanca, PO Box 146, Mohammedia, Morocco
| | - Sanaa Harroudi
- Laboratory of Mathematics, Computer Science and Applications, Faculty of Sciences and Technologies, University Hassan II of Casablanca, PO Box 146, Mohammedia, Morocco
- ENCG of Casablanca, University Hassan II, Casablanca, Morocco
| | - Karam Allali
- Laboratory of Mathematics, Computer Science and Applications, Faculty of Sciences and Technologies, University Hassan II of Casablanca, PO Box 146, Mohammedia, Morocco
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5
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Sutradhar R, Dalal DC. Cytoplasmic recycling of rcDNA-containing capsids enhances HBV infection. NONLINEAR DYNAMICS 2024; 112:12641-12666. [DOI: 10.1007/s11071-024-09681-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/26/2024] [Indexed: 05/17/2025]
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6
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Bunimovich L, Ram A, Skums P. Antigenic cooperation in viral populations: Transformation of functions of intra-host viral variants. J Theor Biol 2024; 580:111719. [PMID: 38158118 DOI: 10.1016/j.jtbi.2023.111719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 09/10/2023] [Accepted: 12/20/2023] [Indexed: 01/03/2024]
Abstract
In this paper, we study intra-host viral adaptation by antigenic cooperation - a mechanism of immune escape that serves as an alternative to the standard mechanism of escape by continuous genomic diversification and allows to explain a number of experimental observations associated with the establishment of chronic infections by highly mutable viruses. Within this mechanism, the topology of a cross-immunoreactivity network forces intra-host viral variants to specialize for complementary roles and adapt to the host's immune response as a quasi-social ecosystem. Here we study dynamical changes in immune adaptation caused by evolutionary and epidemiological events. First, we show that the emergence of a viral variant with altered antigenic features may result in a rapid re-arrangement of the viral ecosystem and a change in the roles played by existing viral variants. In particular, it may push the population under immune escape by genomic diversification towards the stable state of adaptation by antigenic cooperation. Next, we study the effect of a viral transmission between two chronically infected hosts, which results in the merging of two intra-host viral populations in the state of stable immune-adapted equilibrium. In this case, we also describe how the newly formed viral population adapts to the host's environment by changing the functions of its members. The results are obtained analytically for minimal cross-immunoreactivity networks and numerically for larger populations.
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Affiliation(s)
- Leonid Bunimovich
- School of Mathematics, Georgia Institute of Technology, Atlanta, 30332, GA, USA.
| | - Athulya Ram
- School of Mathematics, Georgia Institute of Technology, Atlanta, 30332, GA, USA; Interdisciplinary Graduate Program in Quantitative Biosciences, Georgia Institute of Technology, Atlanta, 30332, GA, USA.
| | - Pavel Skums
- Department of Computer Science and Engineering, University of Connecticut, Storrs, 06269, CT, USA.
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7
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Nangue A, Tchuimeni YJ. Stability of a diffusive-delayed HCV infection model with general cell-to-cell incidence function incorporating immune response and cell proliferation. Theory Biosci 2023; 142:235-258. [PMID: 37436586 DOI: 10.1007/s12064-023-00395-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 06/16/2023] [Indexed: 07/13/2023]
Abstract
In this work, we analyse the dynamics of a five-dimensional hepatitis C virus infection mathematical model including the spatial mobility of hepatitis C virus particles, the transmission of hepatitis C virus infection by mitosis process of infected hepatocytes with logistic growth, time delays, antibody response and cytotoxic T lymphocyte (CTL) immune response with general incidence functions for both modes of infection transmission, namely virus-to-cell as well as cell-to-cell. Firstly, we prove rigorously the existence, the uniqueness, the positivity and the boundedness of the solution of the initial value and boundary problem associated with the new constructed model. Secondly, we found that the basic reproductive number is the sum of the basic reproduction number determined by cell-free virus infection, determined by cell-to-cell infection and determined by proliferation of infected cells. It is proved the existence of five spatially homogeneous equilibria known as infection-free, immune-free, antibody response, CTL response and antibody and CTL responses. By using the linearization methods, the local stability of the latter is established under some rigorous conditions. Finally, we proved the existence of periodic solutions by highlighting the occurrence of a Hopf bifurcation for a certain threshold value of one delay.
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Affiliation(s)
- Alexis Nangue
- Department of Mathematics, University of Maroua, Higher Teachers' Training College, P.O. Box 55, Maroua, Cameroon.
| | - Yanick Junior Tchuimeni
- Department of Mathematics and Computer Science, University of Maroua, Faculty of Science, P.O. Box 814, Maroua, Cameroon
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8
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Bounkaicha C, Allali K. Modelling disease spread with spatio-temporal fractional derivative equations and saturated incidence rate. MODELING EARTH SYSTEMS AND ENVIRONMENT 2023; 10:1-13. [PMID: 37361702 PMCID: PMC10082631 DOI: 10.1007/s40808-023-01773-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 03/27/2023] [Indexed: 06/28/2023]
Abstract
The global analysis of a spatio-temporal fractional order SIR infection model with saturated incidence function is suggested and studied in this paper. The dynamics of the infection is described by three partial differential equations including a time-fractional derivative order for each one of them. The equations of our model describe the evolution of the susceptible, the infected and the recovered individuals with taking into account the spatial diffusion for each compartment. We will choose a saturated incidence rate in order to describe the nonlinear force of the infection. First, we will prove the well-posedness of our suggested model in terms of existence and uniqueness of the solution. Also in this context, the boundedness and the positivity of solutions are established. Afterward, we will give the forms of the disease-free equilibrium and the endemic one. It was demonstrated that the global stability of the each equilibrium depends mainly on the basic reproduction number. Finally, numerical simulations are performed to validate the theoretical results and to show the effect of vaccination in reducing the infection severity. It was shown that the fractional derivative order has no effect on the equilibria stability but only on the convergence speed towards the steady states. It was also observed that vaccination is amongst the good strategies in controlling the disease spread.
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Affiliation(s)
- Chouaib Bounkaicha
- Laboratory of Mathematics and Applications, Faculty of Sciences and Technologies, Hassan II University of Casablanca, PO Box 146, 20650 Mohammedia, Morocco
| | - Karam Allali
- Laboratory of Mathematics and Applications, Faculty of Sciences and Technologies, Hassan II University of Casablanca, PO Box 146, 20650 Mohammedia, Morocco
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9
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Sadki M, Danane J, Allali K. Hepatitis C virus fractional-order model: mathematical analysis. MODELING EARTH SYSTEMS AND ENVIRONMENT 2022; 9:1695-1707. [PMID: 36345473 PMCID: PMC9629771 DOI: 10.1007/s40808-022-01582-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/14/2022] [Indexed: 01/11/2023]
Abstract
Mathematical analysis of epidemics is crucial for the prediction of diseases over time and helps to guide decision makers in terms of public health policy. It is in this context that the purpose of this paper is to study a fractional-order differential mathematical model of HCV infection dynamics, incorporating two fundamental modes of transmission of the infection; virus-to-cell and cell-to-cell along with a cure rate of infected cells. The model includes four compartments, namely, the susceptible hepatocytes, the infected ones, the viral load and the humoral immune response, which is activated in the host to attack the virus. Each compartment involves a long memory effect that is modeled by a Caputo fractional derivative. Our paper starts with the investigation of some basic analytical results. First, we introduce some preliminaries about the needed fractional calculus tools. Next, we establish the well-posedness of our mathematical model in terms of proving the existence, positivity and boundedness of solutions. We present the different problem steady states depending on some reproduction numbers. After that, the paper moves to the stage of proving the global stability of the three steady states. To evaluate the theoretical study of the global stability, we apply a numerical method based on the fundamental theorem of fractional calculus as well as a three-step Lagrange polynomial interpolation method. The numerical simulations show that the free-endemic equilibrium is stable if the basic reproduction number is less than unity. In addition, the numerical tests demonstrate the stability of the other endemic equilibria under some optimal conditions. It is observed that the numerical simulations and the founding theoretical results are coherents.
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Affiliation(s)
- Marya Sadki
- Laboratory of Mathematics, Computer Science and Applications, FST Mohammedia, Hassan II University of Casablanca, PO Box 146, Mohammedia, Morocco
| | - Jaouad Danane
- Laboratory of Systems Modelization and Analysis for Decision Support, National School of Applied Sciences, Hassan First University of Settat, Berrechid, 26100 Morocco
| | - Karam Allali
- Laboratory of Mathematics, Computer Science and Applications, FST Mohammedia, Hassan II University of Casablanca, PO Box 146, Mohammedia, Morocco
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10
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Qurashi MA, Rashid S, Jarad F. A computational study of a stochastic fractal-fractional hepatitis B virus infection incorporating delayed immune reactions via the exponential decay. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:12950-12980. [PMID: 36654030 DOI: 10.3934/mbe.2022605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Recently, researchers have become interested in modelling, monitoring, and treatment of hepatitis B virus infection. Understanding the various connections between pathogens, immune systems, and general liver function is crucial. In this study, we propose a higher-order stochastically modified delay differential model for the evolution of hepatitis B virus transmission involving defensive cells. Taking into account environmental stimuli and ambiguities, we presented numerical solutions of the fractal-fractional hepatitis B virus model based on the exponential decay kernel that reviewed the hepatitis B virus immune system involving cytotoxic T lymphocyte immunological mechanisms. Furthermore, qualitative aspects of the system are analyzed such as the existence-uniqueness of the non-negative solution, where the infection endures stochastically as a result of the solution evolving within the predetermined system's equilibrium state. In certain settings, infection-free can be determined, where the illness settles down tremendously with unit probability. To predict the viability of the fractal-fractional derivative outcomes, a novel numerical approach is used, resulting in several remarkable modelling results, including a change in fractional-order δ with constant fractal-dimension ϖ, δ with changing ϖ, and δ with changing both δ and ϖ. White noise concentration has a significant impact on how bacterial infections are treated.
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Affiliation(s)
- Maysaa Al Qurashi
- Department of Mathematics, King Saud University, P. O. Box 22452, Riyadh 11495, Saudi Arabia
- Department of Mathematics, Saudi Electronic University, Riyadh, Saudi Arabia
| | - Saima Rashid
- Department of Mathematics, Government College University, Faisalabad 38000, Pakistan
| | - Fahd Jarad
- Department of Physics, Government College University, Faisalabad 38000, Pakistan
- Department of Mathmatics, Cankaya University, Ankara, Turkey
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
- Department of Mathematics, King Abdulaziz University, Jeddah, Saudi Arabia
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11
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Rashid S, Ashraf R, Asif QUA, Jarad F. Novel stochastic dynamics of a fractal-fractional immune effector response to viral infection via latently infectious tissues. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:11563-11594. [PMID: 36124604 DOI: 10.3934/mbe.2022539] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In this paper, the global complexities of a stochastic virus transmission framework featuring adaptive response and Holling type II estimation are examined via the non-local fractal-fractional derivative operator in the Atangana-Baleanu perspective. Furthermore, we determine the existence-uniqueness of positivity of the appropriate solutions. Ergodicity and stationary distribution of non-negative solutions are carried out. Besides that, the infection progresses in the sense of randomization as a consequence of the response fluctuating within the predictive case's equilibria. Additionally, the extinction criteria have been established. To understand the reliability of the findings, simulation studies utilizing the fractal-fractional dynamics of the synthesized trajectory under the Atangana-Baleanu-Caputo derivative incorporating fractional-order α and fractal-dimension ℘ have also been addressed. The strength of white noise is significant in the treatment of viral pathogens. The persistence of a stationary distribution can be maintained by white noise of sufficient concentration, whereas the eradication of the infection is aided by white noise of high concentration.
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Affiliation(s)
- Saima Rashid
- Department of Mathematics, Government College University, Faisalabad 38000, Pakistan
| | - Rehana Ashraf
- Department of Mathematics, Lahore College for Women University, Lahore, Pakistan
| | - Qurat-Ul-Ain Asif
- Department of Physics, Government College University, Faisalabad 38000, Pakistan
| | - Fahd Jarad
- Department of Mathmatics, Cankaya University, Ankara, Turkey
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
- Department of Mathematics, King Abdulaziz University, Jeddah, Saudi Arabia
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12
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Ghaznavi H, Shirvaliloo M, Sargazi S, Mohammadghasemipour Z, Shams Z, Hesari Z, Shahraki O, Nazarlou Z, Sheervalilou R, Shirvalilou S. SARS-CoV-2 and Influenza Viruses: Strategies to Cope with Co-infection and Bioinformatics Perspective. Cell Biol Int 2022; 46:1009-1020. [PMID: 35322909 PMCID: PMC9083817 DOI: 10.1002/cbin.11800] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 03/18/2022] [Accepted: 03/20/2022] [Indexed: 12/15/2022]
Abstract
Almost a century after the devastating pandemic of the Spanish flu, humankind is facing the relatively comparable global outbreak of COVID‐19. COVID‐19 is an infectious disease caused by SARS‐CoV‐2 with an unprecedented transmission pattern. In the face of the recent repercussions of COVID‐19, many have argued that the clinical experience with influenza through the last century may have tremendous implications in the containment of this newly emerged viral disease. During the last 2 years, from the emergence of COVID‐19, tremendous advances have been made in diagnosing and treating coinfections. Several approved vaccines are available now for the primary prevention of COVID‐19 and specific treatments exist to alleviate symptoms. The present review article aims to discuss the pathophysiology, diagnosis, and treatment of SARS‐CoV‐2 and influenza A virus coinfection while delivering a bioinformatics‐based insight into this subject matter.
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Affiliation(s)
- Habib Ghaznavi
- Pharmacology Research Center, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Milad Shirvaliloo
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Saman Sargazi
- Cellular and Molecular Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Zahra Mohammadghasemipour
- Department of Infectious Disease, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Zinat Shams
- Department of Biological Science, Kharazmi University, Tehran, Iran
| | - Zahra Hesari
- Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Omolbanin Shahraki
- Pharmacology Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.,Cellular and Molecular Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Ziba Nazarlou
- Material Engineering Department, College of Science Koç University, Istanbul, 34450, Turkey
| | - Roghayeh Sheervalilou
- Pharmacology Research Center, Zahedan University of Medical Sciences, Zahedan, Iran.,Cellular and Molecular Research Center, Research Institute of Cellular and Molecular Sciences in Infectious Diseases, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Sakine Shirvalilou
- Finetech in Medicine Research Center, Iran University of Medical Sciences, Tehran, Iran
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Lestari D, Megawati NY, Susyanto N, Adi-Kusumo F. Qualitative behaviour of a stochastic hepatitis C epidemic model in cellular level. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2022; 19:1515-1535. [PMID: 35135215 DOI: 10.3934/mbe.2022070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this paper, a mathematical model describing the dynamical of the spread of hepatitis C virus (HCV) at a cellular level with a stochastic noise in the transmission rate is developed from the deterministic model. The unique time-global solution for any positive initial value is served. The Ito's Formula, the suitable Lyapunov function, and other stochastic analysis techniques are used to analyze the model dynamics. The numerical simulations are carried out to describe the analytical results. These results highlight the impact of the noise intensity accelerating the extinction of the disease.
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Affiliation(s)
- Dwi Lestari
- Department of Mathematics, Universitas Gadjah Mada, Yogyakarta, Indonesia
- Department of Mathematics Education, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia
| | | | - Nanang Susyanto
- Department of Mathematics, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Fajar Adi-Kusumo
- Department of Mathematics, Universitas Gadjah Mada, Yogyakarta, Indonesia
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14
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Hu X, Li J, Feng X. Threshold dynamics of a HCV model with virus to cell transmission in both liver with CTL immune response and the extrahepatic tissue. JOURNAL OF BIOLOGICAL DYNAMICS 2021; 15:19-34. [PMID: 33357087 DOI: 10.1080/17513758.2020.1859632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 11/16/2020] [Indexed: 06/12/2023]
Abstract
In this paper, a deterministic model characterizing the within-host infection of Hepatitis C virus (HCV) in intrahepatic and extrahepatic tissues is presented. In addition, the model also includes the effect of the cytotoxic T lymphocyte (CTL) immunity described by a linear activation rate by infected cells. Firstly, the non-negativity and boundedness of solutions of the model are established. Secondly, the basic reproduction number R01 and immune reproduction number R02 are calculated, respectively. Three equilibria, namely, infection-free, CTL immune response-free and infected equilibrium with CTL immune response are discussed in terms of these two thresholds. Thirdly, the stability of these three equilibria is investigated theoretically as well as numerically. The results show that when R01<1 , the virus will be cleared out eventually and the CTL immune response will also disappear; when R02<1<R01 , the virus persists within the host, but the CTL immune response disappears eventually; when R02>1 , both of the virus and the CTL immune response persist within the host. Finally, a brief discussion will be given.
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Affiliation(s)
- Xinli Hu
- School of Science, Xi'an Polytechnic University, Xi'an, People's Republic of China
| | - Jianquan Li
- School of Arts and Sciences, Shaanxi University of Science and Technoloty, Xi'an, People's Republic of China
| | - Xiaomei Feng
- School of Mathematics and Informational Sciences, Shaanxi Normal University, Xi'an, People's Republic of China
- School of Mathematics and Informational Technology, Yuncheng University, Yuncheng, People's Republic of China
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15
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Global Dynamics of a Stochastic Viral Infection Model with Latently Infected Cells. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app112110484] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
In this paper, we study the global dynamics of a stochastic viral infection model with humoral immunity and Holling type II response functions. The existence and uniqueness of non-negative global solutions are derived. Stationary ergodic distribution of positive solutions is investigated. The solution fluctuates around the equilibrium of the deterministic case, resulting in the disease persisting stochastically. The extinction conditions are also determined. To verify the accuracy of the results, numerical simulations were carried out using the Euler–Maruyama scheme. White noise’s intensity plays a key role in treating viral infectious diseases. The small intensity of white noises can maintain the existence of a stationary distribution, while the large intensity of white noises is beneficial to the extinction of the virus.
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16
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Optimal Control of a Cell-to-Cell Fractional-Order Model with Periodic Immune Response for HCV. Symmetry (Basel) 2021. [DOI: 10.3390/sym13112121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In this paper, a Caputo fractional-order HCV Periodic immune response model with saturation incidence, cell-to-cell and drug control was proposed. We derive two different basic reproductive numbers and their relation with infection-free equilibrium and the immune-exhausted equilibrium. Moreover, there exists some symmetry in the relationship between the two equilibria and the basic reproduction numbers. We obtain the global stability of the infection-free equilibrium by using Lyapunov function and the local stability of the immune-exhausted equilibrium. The optimal control problem is also considered and two control strategies are given; one is for ITX5061 monotherapy, the other is for ITX5061 and DAAs combination therapy. Matlab numerical simulation shows that combination therapy has lower objective function value; therefore, it is worth trying to use combination therapy to treat HCV infection.
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Elkaranshawy HA, Ezzat HM, Ibrahim NN. Lyapunov function and global asymptotic stability for a new multiscale viral dynamics model incorporating the immune system response: Implemented upon HCV. PLoS One 2021; 16:e0257975. [PMID: 34637445 PMCID: PMC8509987 DOI: 10.1371/journal.pone.0257975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/14/2021] [Indexed: 12/29/2022] Open
Abstract
In this paper, a new mathematical model is formulated that describes the interaction between uninfected cells, infected cells, viruses, intracellular viral RNA, Cytotoxic T-lymphocytes (CTLs), and antibodies. Hence, the model contains certain biological relations that are thought to be key factors driving this interaction which allow us to obtain precise logical conclusions. Therefore, it improves our perception, that would otherwise not be possible, to comprehend the pathogenesis, to interpret clinical data, to control treatment, and to suggest new relations. This model can be used to study viral dynamics in patients for a wide range of infectious diseases like HIV, HPV, HBV, HCV, and Covid-19. Though, analysis of a new multiscale HCV model incorporating the immune system response is considered in detail, the analysis and results can be applied for all other viruses. The model utilizes a transformed multiscale model in the form of ordinary differential equations (ODE) and incorporates into it the interaction of the immune system. The role of CTLs and the role of antibody responses are investigated. The positivity of the solutions is proven, the basic reproduction number is obtained, and the equilibrium points are specified. The stability at the equilibrium points is analyzed based on the Lyapunov invariance principle. By using appropriate Lyapunov functions, the uninfected equilibrium point is proven to be globally asymptotically stable when the reproduction number is less than one and unstable otherwise. Global stability of the infected equilibrium points is considered, and it has been found that each equilibrium point has a specific domain of stability. Stability regions could be overlapped and a bistable equilibria could be found, which means the coexistence of two stable equilibrium points. Hence, the solution converges to one of them depending on the initial conditions.
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Affiliation(s)
- Hesham A. Elkaranshawy
- Faculty of Engineering, Department of Engineering Mathematics and Physics, Alexandria University, Alexandria, Egypt
- * E-mail:
| | - Hossam M. Ezzat
- Faculty of Engineering, Department of Engineering Mathematics and Physics, Alexandria University, Alexandria, Egypt
| | - Nermeen N. Ibrahim
- High Institute of Public Health, Alexandria University, Alexandria, Egypt
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18
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Biggs KRH, Bailes CL, Scott L, Wichman HA, Schwartz EJ. Ecological Approach to Understanding Superinfection Inhibition in Bacteriophage. Viruses 2021; 13:1389. [PMID: 34372595 PMCID: PMC8310164 DOI: 10.3390/v13071389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/13/2021] [Accepted: 07/14/2021] [Indexed: 01/15/2023] Open
Abstract
In microbial communities, viruses compete with each other for host cells to infect. As a consequence of competition for hosts, viruses evolve inhibitory mechanisms to suppress their competitors. One such mechanism is superinfection exclusion, in which a preexisting viral infection prevents a secondary infection. The bacteriophage ΦX174 exhibits a potential superinfection inhibition mechanism (in which secondary infections are either blocked or resisted) known as the reduction effect. In this auto-inhibitory phenomenon, a plasmid containing a fragment of the ΦX174 genome confers resistance to infection among cells that were once permissive to ΦX174. Taking advantage of this plasmid system, we examine the inhibitory properties of the ΦX174 reduction effect on a range of wild ΦX174-like phages. We then assess how closely the reduction effect in the plasmid system mimics natural superinfection inhibition by carrying out phage-phage competitions in continuous culture, and we evaluate whether the overall competitive advantage can be predicted by phage fitness or by a combination of fitness and reduction effect inhibition. Our results show that viral fitness often correctly predicts the winner. However, a phage's reduction sequence also provides an advantage to the phage in some cases, modulating phage-phage competition and allowing for persistence where competitive exclusion was expected. These findings provide strong evidence for more complex dynamics than were previously thought, in which the reduction effect may inhibit fast-growing viruses, thereby helping to facilitate coexistence.
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Affiliation(s)
- Karin R. H. Biggs
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA; (K.R.H.B.); (C.L.B.)
| | - Clayton L. Bailes
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA; (K.R.H.B.); (C.L.B.)
| | - LuAnn Scott
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (L.S.); (H.A.W.)
| | - Holly A. Wichman
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (L.S.); (H.A.W.)
- Institute for Modeling Collaboration and Innovation, University of Idaho, Moscow, ID 83844, USA
| | - Elissa J. Schwartz
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA; (K.R.H.B.); (C.L.B.)
- Department of Mathematics & Statistics, Washington State University, P.O. Box 643113, Pullman, WA 99164, USA
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Rihan FA, Alsakaji HJ. Analysis of a stochastic HBV infection model with delayed immune response. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:5194-5220. [PMID: 34517484 DOI: 10.3934/mbe.2021264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Considering the environmental factors and uncertainties, we propose, in this paper, a higher-order stochastically perturbed delay differential model for the dynamics of hepatitis B virus (HBV) infection with immune system. Existence and uniqueness of an ergodic stationary distribution of positive solution to the system are investigated, where the solution fluctuates around the endemic equilibrium of the deterministic model and leads to the stochastic persistence of the disease. Under some conditions, infection-free can be obtained in which the disease dies out exponentially with probability one. Some numerical simulations, by using Milstein's scheme, are carried out to show the effectiveness of the obtained results. The intensity of white noise plays an important role in the treatment of infectious diseases.
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Affiliation(s)
- Fathalla A Rihan
- Department of Mathematical Sciences, College of Science, United Arab Emirates University, Al-Ain 15551, UAE
| | - Hebatallah J Alsakaji
- Department of Mathematical Sciences, College of Science, United Arab Emirates University, Al-Ain 15551, UAE
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20
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Icer Baykal PB, Lara J, Khudyakov Y, Zelikovsky A, Skums P. Quantitative differences between intra-host HCV populations from persons with recently established and persistent infections. Virus Evol 2020; 7:veaa103. [PMID: 33505710 PMCID: PMC7816669 DOI: 10.1093/ve/veaa103] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Detection of incident hepatitis C virus (HCV) infections is crucial for identification of outbreaks and development of public health interventions. However, there is no single diagnostic assay for distinguishing recent and persistent HCV infections. HCV exists in each infected host as a heterogeneous population of genomic variants, whose evolutionary dynamics remain incompletely understood. Genetic analysis of such viral populations can be applied to the detection of incident HCV infections and used to understand intra-host viral evolution. We studied intra-host HCV populations sampled using next-generation sequencing from 98 recently and 256 persistently infected individuals. Genetic structure of the populations was evaluated using 245,878 viral sequences from these individuals and a set of selected features measuring their diversity, topological structure, complexity, strength of selection, epistasis, evolutionary dynamics, and physico-chemical properties. Distributions of the viral population features differ significantly between recent and persistent infections. A general increase in viral genetic diversity from recent to persistent infections is frequently accompanied by decline in genomic complexity and increase in structuredness of the HCV population, likely reflecting a high level of intra-host adaptation at later stages of infection. Using these findings, we developed a machine learning classifier for the infection staging, which yielded a detection accuracy of 95.22 per cent, thus providing a higher accuracy than other genomic-based models. The detection of a strong association between several HCV genetic factors and stages of infection suggests that intra-host HCV population develops in a complex but regular and predictable manner in the course of infection. The proposed models may serve as a foundation of cyber-molecular assays for staging infection, which could potentially complement and/or substitute standard laboratory assays.
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Affiliation(s)
- Pelin B Icer Baykal
- Department of Computer Science, Georgia State University, 25 Park Place, Atlanta, GA 30302, USA
| | - James Lara
- Division of Viral Hepatitis, Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30329, USA
| | - Yury Khudyakov
- Division of Viral Hepatitis, Centers for Disease Control and Prevention, 1600 Clifton Rd., Atlanta, GA 30329, USA
| | - Alex Zelikovsky
- Department of Computer Science, Georgia State University, 25 Park Place, Atlanta, GA 30302, USA
| | - Pavel Skums
- Department of Computer Science, Georgia State University, 25 Park Place, Atlanta, GA 30302, USA
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21
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Lombardo SD, Lombardo S. Some stability results for a model of Hepatitis C including alanine aminotransferase and immune system. INT J BIOMATH 2020. [DOI: 10.1142/s1793524520500801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In clinical practice, many cirrhosis scores based on alanine aminotransferase (ALT) levels exist. Although the most recent direct acting antivirals (DAAs) reduce fibrosis and ALT levels, the Hepatitis C virus (HCV) is not always removed. In this paper, we study a mathematical model of the HCV virus, which takes into account the role of the immune system, to investigate the ALT behavior during therapy. We find five equilibrium points and analyze their stability. A sufficient condition for global asymptotical stability of the infection-free equilibrium is obtained and local asymptotical stability conditions are given for the immune-free infection and cytotoxic T lymphocytes (CTL) response equilibria. The stability of the infection equilibrium with the full immune response is numerically performed.
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Affiliation(s)
- Salvo Danilo Lombardo
- CeMM Research Center for Molecular Medicine of the Austrian, Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, A-1090 Vienna, Austria
| | - Sebastiano Lombardo
- Department of Mathematics and Computer Science, University of Catania (Ret.), 95125, Catania, Italy
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22
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Bunimovich L, Shu L. Local Immunodeficiency: Role of Neutral Viruses. Bull Math Biol 2020; 82:140. [DOI: 10.1007/s11538-020-00813-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/25/2020] [Indexed: 12/12/2022]
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23
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Yang J, Bi S. Stability and Hopf bifurcation of a delayed virus infection model with latently infected cells and Beddington–DeAngelis incidence. INT J BIOMATH 2020. [DOI: 10.1142/s179352452050045x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this paper, the dynamical behaviors for a five-dimensional virus infection model with Latently Infected Cells and Beddington–DeAngelis incidence are investigated. In the model, four delays which denote the latently infected delay, the intracellular delay, virus production period and CTL response delay are considered. We define the basic reproductive number and the CTL immune reproductive number. By using Lyapunov functionals, LaSalle’s invariance principle and linearization method, the threshold conditions on the stability of each equilibrium are established. It is proved that when the basic reproductive number is less than or equal to unity, the infection-free equilibrium is globally asymptotically stable; when the CTL immune reproductive number is less than or equal to unity and the basic reproductive number is greater than unity, the immune-free infection equilibrium is globally asymptotically stable; when the CTL immune reproductive number is greater than unity and immune response delay is equal to zero, the immune infection equilibrium is globally asymptotically stable. The results show that immune response delay may destabilize the steady state of infection and lead to Hopf bifurcation. The existence of the Hopf bifurcation is discussed by using immune response delay as a bifurcation parameter. Numerical simulations are carried out to justify the analytical results.
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Affiliation(s)
- Junxian Yang
- School of Science, Anhui Agricultural University, Hefei 230036, P. R. China
| | - Shoudong Bi
- School of Science, Anhui Agricultural University, Hefei 230036, P. R. China
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24
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Nabi KN, Podder CN. Sensitivity analysis of chronic hepatitis C virus infection with immune response and cell proliferation. INT J BIOMATH 2020. [DOI: 10.1142/s1793524520500175] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A new mathematical model of chronic hepatitis C virus (HCV) infection incorporating humoral and cell-mediated immune responses, distinct cell proliferation rates for both uninfected and infected hepatocytes, and antiviral treatment all at once, is formulated and analyzed meticulously. Analysis of the model elucidates the existence of multiple equilibrium states. Moreover, the model has a locally asymptotically stable disease-free equilibrium (DFE) whenever the basic reproduction number is less than unity. Local sensitivity analysis (LSA) result exhibits that the most influential (negatively sensitive) parameters on the epidemic threshold are the drug efficacy of blocking virus production and the drug efficacy of removing infection. However, LSA does not accurately assess uncertainty and sensitivity in the system and may mislead us since by default this technique holds all other parameters fixed at baseline values. To overcome this pitfall, one of the most robust and efficient global sensitivity analysis (GSA) methods, which is Latin hypercube sampling-partial rank correlation coefficient technique, elucidates that the proliferation rate of infected hepatocytes and the drug efficacy of killing infected hepatocytes are highly sensitive parameters that affect the transmission dynamics of HCV in any population. Our study suggests that cell proliferation of the infected hepatocytes can be very crucial in controlling disease outbreak. Thus, a future HCV drug that boosts cell-mediated immune response is expected to be quite effective in controlling disease outbreak.
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Affiliation(s)
- Khondoker Nazmoon Nabi
- Department of Mathematics, Bangladesh University of Engineering and Technology (BUET), Dhaka 1000, Bangladesh
| | - Chandra N. Podder
- Department of Mathematics, University of Dhaka, Dhaka 1000, Bangladesh
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25
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Pan S, Chakrabarty SP. Hopf Bifurcation and Stability Switches Induced by Humoral Immune Delay in Hepatitis C. INDIAN JOURNAL OF PURE AND APPLIED MATHEMATICS 2020; 51:1673-1695. [PMCID: PMC7782052 DOI: 10.1007/s13226-020-0489-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Accepted: 11/08/2019] [Indexed: 07/13/2023]
Abstract
The role of humoral immune delay on the dynamics of HCV infection incorporating both the modes of infection transmission, namely, viral and cellular transmissions with a non-cytolytic cure of infected hepatocytes is studied. The local and global asymptotic stability of the boundary equilibria, namely, infection-free and immune-free equilibrium are analyzed theoretically as well as numerically under the conditions on the basic reproduction number and the humoral immune reproduction number. The existence of Hopf bifurcation and consequent occurrence of bifurcating periodic orbits around the humoral immune activated equilibrium are illustrated. The findings show that Hopf bifurcation and stability switches occur under certain conditions as the bifurcation parameter crosses the critical values. Furthermore, the dynamical effect of the development rate of B cells is investigated numerically. The results obtained show that the system becomes unstable from stable and regains stability from instability depending on the development rate of B cells for a fixed delay value. Further, the results suggest that a high antigenic stimulation in humoral immunity is beneficial for uninfected hepatocytes with a significant reduction in virions density.
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Affiliation(s)
- Sonjoy Pan
- Department of Mathematics, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039 India
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26
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Elaiw AM, AlShamrani NH. Impact of adaptive immune response and cellular infection on delayed virus dynamics with multi-stages of infected cells. INT J BIOMATH 2019. [DOI: 10.1142/s1793524520500035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this investigation, we propose and analyze a virus dynamics model with multi-stages of infected cells. The model incorporates the effect of both humoral and cell-mediated immune responses. We consider two modes of transmissions, virus-to-cell and cell-to-cell. Multiple intracellular discrete-time delays have been integrated into the model. The incidence rate of infection as well as the generation and removal rates of all compartments are described by general nonlinear functions. We derive five threshold parameters which determine the existence of the equilibria of the model under consideration. A set of conditions on the general functions has been established which is sufficient to investigate the global stability of the five equilibria of the model. The global asymptotic stability of all equilibria is proven by utilizing Lyapunov function and LaSalle’s invariance principle. The theoretical results are illustrated by numerical simulations of the model with specific forms of the general functions.
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Affiliation(s)
- A. M. Elaiw
- Department of Mathematics, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589, Saudi Arabia
| | - N. H. AlShamrani
- Department of Mathematics, Faculty of Science, King Abdulaziz University, P. O. Box 80203, Jeddah 21589, Saudi Arabia
- Department of Mathematics, Faculty of Science, University of Jeddah, P. O. Box 80327, Jeddah 21589, Saudi Arabia
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27
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Reisch C, Langemann D. Chemotactic effects in reaction-diffusion equations for inflammation. J Biol Phys 2019; 45:253-273. [PMID: 31309352 DOI: 10.1007/s10867-019-09527-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/16/2019] [Indexed: 10/26/2022] Open
Abstract
Predator-prey systems are used to model time-dependent virus and lymphocyte population during a liver infection and to discuss the influence of chemotactic behavior on the chronification tendency of such infections. Therefore, a model family of reaction-diffusion equations is presented, and the long-term behavior of the solutions is estimated by a critical value containing the reaction strength, the diffusion rate, and the extension of the liver domain. Fourier techniques are applied to evaluate the influence of chemotactic behavior of the immune response to the long-term behavior of locally linearized models. It turns out that the chemotaxis is a subordinated influence with respect to the chronification of liver infections.
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Affiliation(s)
- Cordula Reisch
- TU Braunschweig, Institute of Computational Mathematics, AG PDE, Universitätsplatz 2, 38106, Braunschweig, Germany.
| | - Dirk Langemann
- TU Braunschweig, Institute of Computational Mathematics, AG PDE, Universitätsplatz 2, 38106, Braunschweig, Germany
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28
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Bunimovich L, Shu L. Local immunodeficiency: Minimal networks and stability. Math Biosci 2019; 310:31-49. [PMID: 30772457 DOI: 10.1016/j.mbs.2019.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 02/06/2019] [Accepted: 02/11/2019] [Indexed: 11/15/2022]
Abstract
Some basic aspects of the recently discovered phenomenon of local immunodeficiency (Skums et al. [1]) generated by antigenic cooperation in cross-immunoreactivity (CR) networks are investigated. We prove that local immunodeficiency (LI) that is stable under perturbations already occurs in very small networks and under general conditions on their parameters. Therefore our results are applicable not only to Hepatitis C where CR networks are known to be large (Skums et al. [1]), but also to other diseases with CR. A major necessary feature of such networks is the non-homogeneity of their topology. It is also shown that one can construct larger CR networks with stable LI by using small networks with stable LI as their building blocks. Our results imply that stable LI occurs in networks with quite general topology. In particular, the scale-free property of a CR network, assumed in Skums et al. [1], is not required.
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Affiliation(s)
- Leonid Bunimovich
- School of Mathematics, Georgia Institute of Technology, Atlanta, GA 30332-0160, USA.
| | - Longmei Shu
- School of Mathematics, Georgia Institute of Technology, Atlanta, GA 30332-0160, USA.
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29
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Pitchaimani M, Brasanna Devi M. Effects of randomness on viral infection model with application. IFAC JOURNAL OF SYSTEMS AND CONTROL 2018; 6:53-69. [PMCID: PMC7148646 DOI: 10.1016/j.ifacsc.2018.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 07/24/2018] [Accepted: 09/04/2018] [Indexed: 05/31/2023]
Abstract
Virus population disease dynamics in various species of ecosystem keep the research interests alive for many centuries. In this research article, an attempt has been made to understand the qualitative behavior of a virus infection model with Lytic and Non-Lytic Immune Responses by perturbing with randomness (white noise) via Lyapunov technique. The conditions for the extinction and permanence of the viral infection in the interacting populations has been found, analyzed and supported with numerical simulations. An application to HIV infection model has also been presented for drawing a comparative study of the model under various modeling methods. The research findings of this paper reveal that a study that includes random fluctuations of the environment prove to be the ideal way to bring out the qualitative analysis of a mathematical model that will depict the real world scenario.
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Miao H, Teng Z, Abdurahman X. Stability and Hopf bifurcation for a five-dimensional virus infection model with Beddington-DeAngelis incidence and three delays. JOURNAL OF BIOLOGICAL DYNAMICS 2018; 12:146-170. [PMID: 29198164 DOI: 10.1080/17513758.2017.1408861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 11/17/2017] [Indexed: 06/07/2023]
Abstract
In this paper, the dynamical behaviours for a five-dimensional virus infection model with three delays which describes the interactions of antibody, cytotoxic T-lymphocyte (CTL) immune responses and Beddington-DeAngelis incidence are investigated. The reproduction numbers for virus infection, antibody immune response, CTL immune response, CTL immune competition and antibody immune competition, respectively, are calculated. By using the Lyapunov functionals and linearization method, the threshold conditions on the local and global stability of the equilibria for infection-free, immune-free, antibody response, CTL response and interior, respectively, are established. The existence of Hopf bifurcation with immune delay as a bifurcation parameter is investigated by using the bifurcation theory. Numerical simulations are presented to justify the analytical results.
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Affiliation(s)
- Hui Miao
- a School of Applied Mathematics , Shanxi University of Finance and Economics , Taiyuan , People's Republic of China
| | - Zhidong Teng
- b College of Mathematics and System Sciences , Xinjiang University , Urumqi , People's Republic of China
| | - Xamxinur Abdurahman
- b College of Mathematics and System Sciences , Xinjiang University , Urumqi , People's Republic of China
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31
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Jiang C, Wang K, Song L. Global dynamics of a delay virus model with recruitment and saturation effects of immune responses. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2018; 14:1233-1246. [PMID: 29161858 DOI: 10.3934/mbe.2017063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this paper, we formulate a virus dynamics model with the recruitment of immune responses, saturation effects and an intracellular time delay. With the help of uniform persistence theory and Lyapunov method, we show that the global stability of the model is totally determined by the basic reproductive number R0. Furthermore, we analyze the effects of the recruitment of immune responses on virus infection by numerical simulation. The results show ignoring the recruitment of immune responses will result in overestimation of the basic reproductive number and the severity of viral infection.
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Affiliation(s)
- Cuicui Jiang
- Department of Mathematics, School of Biomedical Engineering, Third Military Medical University, Chongqing 400038, China
| | - Kaifa Wang
- Department of Mathematics, School of Biomedical Engineering, Third Military Medical University, Chongqing 400038, China
| | - Lijuan Song
- Department of Mathematics, School of Biomedical Engineering, Third Military Medical University, Chongqing 400038, China
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32
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Modeling the Adaptive Immunity and Both Modes of Transmission in HIV Infection. COMPUTATION 2018. [DOI: 10.3390/computation6020037] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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33
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Elaiw AM, AlShamrani NH. Stability of latent pathogen infection model with adaptive immunity and delays. J Integr Neurosci 2018; 17:547-576. [PMID: 29710733 DOI: 10.3233/jin-180087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this paper we propose and analyze a pathogen dynamics model with antibody and Cytotoxic T Lymphocyte (CTL) immune responses. We incorporate latently infected cells and three distributed time delays into the model. We show that the solutions of the proposed model are nonnegative and ultimately bounded. We derive four threshold parameters which fully determine the existence and stability of the five steady states of the model. Using Lyapunov functionals, we established the global stability of the steady states of the model. The theoretical results are confirmed by numerical simulations.
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Affiliation(s)
- A M Elaiw
- Department of Mathematics, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia. E-mails: ,
| | - N H AlShamrani
- Department of Mathematics, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia. E-mails: ,
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34
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Miao H, Teng Z, Abdurahman X, Li Z. Global stability of a diffusive and delayed virus infection model with general incidence function and adaptive immune response. COMPUTATIONAL AND APPLIED MATHEMATICS 2018. [PMCID: PMC7149116 DOI: 10.1007/s40314-017-0543-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
In this paper, the dynamical behaviors for a five-dimensional virus infection model with diffusion and two delays which describes the interactions of antibody, cytotoxic T-lymphocyte (CTL) immune responses and a general incidence function are investigated. The reproduction numbers for virus infection, antibody immune response, CTL immune response, CTL immune competition and antibody immune competition, respectively, are calculated. By using the Lyapunov functionals and linearization methods, the threshold conditions on the global stability of the equilibria for infection-free, immune-free, antibody response, CTL response and antibody and CTL responses, respectively, are established if the space is assumed as homogeneous. When the space is inhomogeneous, the effects of diffusion, intracellular delay and production delay are obtained by the numerical simulations.
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Affiliation(s)
- Hui Miao
- School of Applied Mathematics, Shanxi University of Finance and Economics, Taiyuan, 030006 People’s Republic of China
| | - Zhidong Teng
- College of Mathematics and System Sciences, Xinjiang University, Urumqi, 830046 People’s Republic of China
| | - Xamxinur Abdurahman
- College of Mathematics and System Sciences, Xinjiang University, Urumqi, 830046 People’s Republic of China
| | - Zhiming Li
- College of Mathematics and System Sciences, Xinjiang University, Urumqi, 830046 People’s Republic of China
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35
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Elaiw AM, Ghaleb SA, Hobiny A. Effect of Time Delay and Antibodies on HCV Dynamics with Cure Rate and Two Routes of Infection. ACTA ACUST UNITED AC 2018. [DOI: 10.4236/jamp.2018.65096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Wang J, Teng Z, Miao H. Global dynamics for discrete-time analog of viral infection model with nonlinear incidence and CTL immune response. ADVANCES IN DIFFERENCE EQUATIONS 2016; 2016:143. [PMID: 32226448 PMCID: PMC7099752 DOI: 10.1186/s13662-016-0862-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/10/2016] [Indexed: 06/10/2023]
Abstract
In this paper, a discrete-time analog of a viral infection model with nonlinear incidence and CTL immune response is established by using the Micken non-standard finite difference scheme. The two basic reproduction numbers R 0 and R 1 are defined. The basic properties on the positivity and boundedness of solutions and the existence of the virus-free, the no-immune, and the infected equilibria are established. By using the Lyapunov functions and linearization methods, the global stability of the equilibria for the model is established. That is, when R 0 ≤ 1 then the virus-free equilibrium is globally asymptotically stable, and under the additional assumption ( A 4 ) when R 0 > 1 and R 1 ≤ 1 then the no-immune equilibrium is globally asymptotically stable and when R 0 > 1 and R 1 > 1 then the infected equilibrium is globally asymptotically stable. Furthermore, the numerical simulations show that even if assumption ( A 4 ) does not hold, the no-immune equilibrium and the infected equilibrium also may be globally asymptotically stable.
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Affiliation(s)
- Jianpeng Wang
- College of Mathematics and Systems Science, Xinjiang University, Urumqi, 830046 People’s Republic of China
| | - Zhidong Teng
- College of Mathematics and Systems Science, Xinjiang University, Urumqi, 830046 People’s Republic of China
| | - Hui Miao
- College of Mathematics and Systems Science, Xinjiang University, Urumqi, 830046 People’s Republic of China
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37
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Korpusik A, Kolev M. Single injection of CD8+ T lymphocytes derived from hematopoietic stem cells - Mathematical and numerical insights. Biosystems 2016; 144:46-54. [PMID: 27095371 DOI: 10.1016/j.biosystems.2016.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 04/01/2016] [Accepted: 04/14/2016] [Indexed: 12/22/2022]
Abstract
Recently, hematopoietic stem cell (HSC) based therapy is being discussed as a possible treatment for HIV infection. The main advantage of this approach is that it limits the immune impairing effect of infection by introducing an independent influx of antigen-specific cytotoxic T lymphocytes (CTL). In this paper, we present a mathematical approach to predict the dynamics of HSC based therapy. We use a modification of a basic mathematical model for virus induced impairment of help to study how virus - immune system dynamics can be influenced by a single injection of CD8+ T lymphocytes derived from hematopoietic stem cells. Our mathematical and numerical results indicate that a single, large enough dose of genetically derived CTL may lead to restoration of the cellular immune response and result in long-term control of infection.
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Affiliation(s)
- Adam Korpusik
- Faculty of Technical Sciences, University of Warmia and Mazury, ul. Oczapowskiego 11, 10-719 Olsztyn, Poland.
| | - Mikhail Kolev
- Faculty of Mathematics and Computer Science, University of Warmia and Mazury, ul. Słoneczna 54, 10-710 Olsztyn, Poland.
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38
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Optimal control of a delayed hepatitis B viral infection model with cytotoxic T-lymphocyte and antibody responses. ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s40435-016-0231-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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39
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Antigenic cooperation among intrahost HCV variants organized into a complex network of cross-immunoreactivity. Proc Natl Acad Sci U S A 2015; 112:6653-8. [PMID: 25941392 DOI: 10.1073/pnas.1422942112] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Hepatitis C virus (HCV) has the propensity to cause chronic infection. Continuous immune escape has been proposed as a mechanism of intrahost viral evolution contributing to HCV persistence. Although the pronounced genetic diversity of intrahost HCV populations supports this hypothesis, recent observations of long-term persistence of individual HCV variants, negative selection increase, and complex dynamics of viral subpopulations during infection as well as broad cross-immunoreactivity (CR) among variants are inconsistent with the immune-escape hypothesis. Here, we present a mathematical model of intrahost viral population dynamics under the condition of a complex CR network (CRN) of viral variants and examine the contribution of CR to establishing persistent HCV infection. The model suggests a mechanism of viral adaptation by antigenic cooperation (AC), with immune responses against one variant protecting other variants. AC reduces the capacity of the host's immune system to neutralize certain viral variants. CRN structure determines specific roles for each viral variant in host adaptation, with variants eliciting broad-CR antibodies facilitating persistence of other variants immunoreacting with these antibodies. The proposed mechanism is supported by empirical observations of intrahost HCV evolution. Interference with AC is a potential strategy for interruption and prevention of chronic HCV infection.
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40
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Dynamical analysis on a chronic hepatitis C virus infection model with immune response. J Theor Biol 2014; 365:337-46. [PMID: 25451526 DOI: 10.1016/j.jtbi.2014.10.039] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 08/23/2014] [Accepted: 10/29/2014] [Indexed: 01/11/2023]
Abstract
A mathematical model for HCV infection is established, in which the effect of dendritic cells (DC) and cytotoxic T lymphocytes (CTL) on HCV infection is considered. The basic reproduction numbers of chronic HCV infection and immune control are found. The obtained results show that the infection dies out finally as the basic reproduction number of HCV infection is less than unity, and the infection becomes chronic as it is greater than unity. In the presence of chronic infection, the existence of immune control equilibrium is discussed completely, which illustrates that the backward bifurcation may occur under certain conditions, and that the two quantities, the sizes of the activated DC and the removed CTL during their average life-terms, play a critical role in controlling chronic HCV infection and immune response. The occurrence of backward bifurcation implies that there may be bistability for the model, i.e., the outcome of infection depends on the initial situation. By choosing the activated rate of non-activated DC or the cross-representation rate of activated DC as bifurcation number, Hopf bifurcation for certain condition shows the existence of periodic solution of the model. Again, numerical simulations suggest the dynamical complexity of the model including the instability of immune control equilibrium and the existence of stable periodic solution.
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41
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Li Q, Lu F, Deng G, Wang K. Modeling the effects of covalently closed circular DNA and dendritic cells in chronic HBV infection. J Theor Biol 2014; 357:1-9. [DOI: 10.1016/j.jtbi.2014.04.037] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 04/13/2014] [Accepted: 04/29/2014] [Indexed: 12/12/2022]
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42
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Jiang C, Wang W. Complete classification of global dynamics of a virus model with
immune responses. ACTA ACUST UNITED AC 2014. [DOI: 10.3934/dcdsb.2014.19.1087] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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43
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Schwartz EJ, Pawelek KA, Harrington K, Cangelosi R, Madrid S. Immune Control of Equine Infectious Anemia Virus Infection by Cell-Mediated and Humoral Responses. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/am.2013.48a023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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44
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Wang X, Wang W. An HIV infection model based on a vectored immunoprophylaxis experiment. J Theor Biol 2012; 313:127-35. [DOI: 10.1016/j.jtbi.2012.08.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 08/18/2012] [Accepted: 08/20/2012] [Indexed: 10/28/2022]
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45
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Dunia R, Bonnecaze R. Mathematical modeling of viral infection dynamics in spherical organs. J Math Biol 2012; 67:1425-55. [DOI: 10.1007/s00285-012-0593-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 09/06/2012] [Indexed: 01/22/2023]
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46
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Sheikhan M, Ghoreishi SA. Application of covariance matrix adaptation–evolution strategy to optimal control of hepatitis B infection. Neural Comput Appl 2012. [DOI: 10.1007/s00521-012-1013-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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47
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Huang G, Takeuchi Y, Korobeinikov A. HIV evolution and progression of the infection to AIDS. J Theor Biol 2012; 307:149-59. [PMID: 22634206 DOI: 10.1016/j.jtbi.2012.05.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 05/11/2012] [Accepted: 05/14/2012] [Indexed: 12/12/2022]
Abstract
In this paper, we propose and discuss a possible mechanism, which, via continuous mutations and evolution, eventually enables HIV to break from immune control. In order to investigate this mechanism, we employ a simple mathematical model, which describes the relationship between evolving HIV and the specific CTL response and explicitly takes into consideration the role of CD4(+)T cells (helper T cells) in the activation of the CTL response. Based on the assumption that HIV evolves towards higher replication rates, we quantitatively analyze the dynamical properties of this model. The model exhibits the existence of two thresholds, defined as the immune activation threshold and the immunodeficiency threshold, which are critical for the activation and persistence of the specific cell-mediated immune response: the specific CTL response can be established and is able to effectively control an infection when the virus replication rate is between these two thresholds. If the replication rate is below the immune activation threshold, then the specific immune response cannot be reliably established due to the shortage of antigen-presenting cells. Besides, the specific immune response cannot be established when the virus replication rate is above the immunodeficiency threshold due to low levels of CD4(+)T cells. The latter case implies the collapse of the immune system and beginning of AIDS. The interval between these two thresholds roughly corresponds to the asymptomatic stage of HIV infection. The model shows that the duration of the asymptomatic stage and progression of the disease are very sensitive to variations in the model parameters. In particularly, the rate of production of the naive lymphocytes appears to be crucial.
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Affiliation(s)
- Gang Huang
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, PR China
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48
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Chakrabarty SP, Murray JM. Modelling hepatitis C virus infection and the development of hepatocellular carcinoma. J Theor Biol 2012; 305:24-9. [PMID: 22575547 DOI: 10.1016/j.jtbi.2012.03.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 03/23/2012] [Accepted: 03/23/2012] [Indexed: 02/08/2023]
Abstract
While mathematical models exist describing the dynamics of hepatitis C virus (HCV), most of them focus on the short term dynamics after the commencement of antiviral therapy. This work is the first attempt at mathematically modelling the full course of HCV infection and the impact that these viral and immune processes have on the progression to hepatocellular carcinoma (HCC). This model is based on the premise that these long term conditions are ultimately random and likely driven by the cell-mediated immune response. The risk of cancer arising is modelled through a stochastic model that incorporates the dynamics of HCV over the course of infection. Our model simulations produce approximately 9% prevalence of HCC in individuals after 40 years, consistent with the literature estimates. We find that higher viral infectivity leads to a greater likelihood of developing HCC (p<0.0001), but it does not determine the speed with which it arises. This infectivity drives the level of immune response, the amount of hepatocyte proliferation, and the risk of a mutational event. In our simulations the probability of developing HCC increases approximately linearly with duration of infection at the rate of 2.4 incident cases per thousand HCV-infected person years. This indicates that the sooner viral replication can be suppressed through antiviral therapy, the greater the chance of forestalling HCC.
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Affiliation(s)
- Siddhartha P Chakrabarty
- Department of Mathematics, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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49
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Yan Y, Wang W. Global stability of a five-dimensional model with immune responses
and delay. ACTA ACUST UNITED AC 2012. [DOI: 10.3934/dcdsb.2012.17.401] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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50
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Noninvasive monitoring of hepatic damage from hepatitis C virus infection. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2011; 2011:325470. [PMID: 21331263 PMCID: PMC3038561 DOI: 10.1155/2011/325470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Accepted: 12/16/2010] [Indexed: 11/21/2022]
Abstract
The mathematical model for the dynamics of the hepatitis C proposed in Avendaño et al. (2002), with four populations (healthy and unhealthy hepatocytes, the viral load of the hepatitis C virus, and T killer cells), is revised. Showing that the reduced model obtained by considering only the first three of these populations, known as basic model, has two possible equilibrium states: the uninfected one where viruses are not present in the individual, and the endemic one where viruses and infected cells are present. A threshold parameter (the basic reproductive virus number) is introduced, and in terms of it, the global stability of both two possible equilibrium states is established. Other central result consists in showing, by model numerical simulations, the feasibility of monitoring liver damage caused by HCV, avoiding unnecessary biopsies and the undesirable related inconveniences/imponderables to the patient; another result gives a mathematical modelling basis to recently developed techniques for the disease assessment based essentially on viral load measurements.
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