Stability and Hopf bifurcation analysis of immune response delayed HIV type 1 infection model with two target cells

2014 ◽  
Vol 38 (17) ◽  
pp. 3653-3669 ◽  
Author(s):  
P. Balasubramaniam ◽  
M. Prakash ◽  
P. Tamilalagan
2018 ◽  
Vol 28 (09) ◽  
pp. 1850109 ◽  
Author(s):  
Xiangming Zhang ◽  
Zhihua Liu

We make a mathematical analysis of an age structured HIV infection model with both virus-to-cell and cell-to-cell transmissions to understand the dynamical behavior of HIV infection in vivo. In the model, we consider the proliferation of uninfected CD[Formula: see text] T cells by a logistic function and the infected CD[Formula: see text] T cells are assumed to have an infection-age structure. Our main results concern the Hopf bifurcation of the model by using the theory of integrated semigroup and the Hopf bifurcation theory for semilinear equations with nondense domain. Bifurcation analysis indicates that there exist some parameter values such that this HIV infection model has a nontrivial periodic solution which bifurcates from the positive equilibrium. The numerical simulations are also carried out.


2019 ◽  
Vol 29 (12) ◽  
pp. 1950161 ◽  
Author(s):  
Jinhu Xu ◽  
Yan Geng ◽  
Suxia Zhang

We have developed a class of viral infection model with cell-to-cell transmission and humoral immune response. The model addresses both immune and intracellular delays. We also constructed Lyapunov functionals to establish the global dynamical properties of the equilibria. Theoretical results indicate that considering only two intracellular delays did not affect the dynamical behavior of the model, but incorporating an immune delay greatly affects the dynamics, i.e. an immune delay may destabilize the immunity-activated equilibrium and lead to Hopf bifurcation, oscillations and stability switches. Our results imply that an immune delay dominates the intracellular delays in the model. We also investigated the direction of the Hopf bifurcation and the stability of the periodic solutions by applying normal form and center manifold theory, and investigated the existence of global Hopf bifurcation by regarding the immune delay as a bifurcation parameter. Numerical simulations are carried out to support the analytical conclusions.


1992 ◽  
Vol 165 (6) ◽  
pp. 1012-1019 ◽  
Author(s):  
Mario Clerici ◽  
Janis V. Giorgi ◽  
Chen-Cheng Chou ◽  
Vaheideh K. Gudeman ◽  
Jerome A. Zack ◽  
...  

2002 ◽  
Vol 46 (12) ◽  
pp. 3917-3925 ◽  
Author(s):  
Andrei N. Vzorov ◽  
Dabney W. Dixon ◽  
Jenna S. Trommel ◽  
Luigi G. Marzilli ◽  
Richard W. Compans

ABSTRACT We have evaluated the anti-human immunodeficiency virus (HIV) activity of a series of natural and synthetic porphyrins to identify compounds that could potentially be used as microbicides to provide a defense against infection by sexually transmitted virus. For assays we used an epithelial HeLa-CD4 cell line with an integrated long terminal repeat-β-galactosidase gene. For structure-activity analysis, we divided the porphyrins tested into three classes: (i) natural porphyrins, (ii) metallo-tetraphenylporphyrin tetrasulfonate (metallo-TPPS4) derivatives, and (iii) sulfonated tetra-arylporphyrin derivatives. None of the natural porphyrins studied reduced infection by more than 80% at a concentration of 5 μg/ml in these assays. Some metal chelates of TPPS4 were more active, and a number of sulfonated tetra-aryl derivatives showed significantly higher activity. Some of the most active compounds were the sulfonated tetranaphthyl porphyrin (TNapPS), sulfonated tetra-anthracenyl porphyrin (TAnthPS), and sulfonated 2,6-difluoro-meso-tetraphenylporphine [TPP(2,6-F2)S] and its copper chelate [TPP(2,6-F2)S,Cu], which reduced infection by 99, 96, 94, and 96%, respectively. Our observations indicate that at least some of these compounds are virucidal, i.e., that they render the virus noninfectious. The active compounds were found to inhibit binding of the HIV type 1 gp120 to CD4 and also to completely inhibit the ability of Env proteins expressed from recombinant vectors to induce cell fusion with receptor-bearing target cells. These results support the conclusion that modified porphyrins exhibit substantial activity against HIV and that their target is the HIV Env protein.


2014 ◽  
Vol 07 (05) ◽  
pp. 1450055 ◽  
Author(s):  
A. M. Elaiw ◽  
R. M. Abukwaik ◽  
E. O. Alzahrani

In this paper, we study the global properties of a human immunodeficiency virus (HIV) infection model with cytotoxic T lymphocytes (CTL) immune response. The model is a six-dimensional that describes the interaction of the HIV with two classes of target cells, CD4+ T cells and macrophages. The infection rate is given by saturation functional response. Two types of distributed time delays are incorporated into the model to describe the time needed for infection of target cell and virus replication. Using the method of Lyapunov functional, we have established that the global stability of the model is determined by two threshold numbers, the basic infection reproduction number R0 and the immune response activation number [Formula: see text]. We have proven that if R0 ≤ 1, then the uninfected steady state is globally asymptotically stable (GAS), if [Formula: see text], then the infected steady state without CTL immune response is GAS, and if [Formula: see text], then the infected steady state with CTL immune response is GAS.


2016 ◽  
Vol 21 (2) ◽  
pp. 143-158
Author(s):  
Jia Liu ◽  
Qunying Zhang ◽  
Canrong Tian

This paper is concerned with the dynamics of a viral infection model with diffusion under the assumption that the immune response is retarded. A time delay is incorporated into the model described the delayed immune response after viral infection. Based upon a stability analysis, we demonstrate that the appearance, or the absence, of spatial patterns is determined by the delay under some conditions. Moreover, the spatial patterns occurs as a consequence of Hopf bifurcation. By applying the normal form and the center manifold theory, the direction as well as the stability of the Hopf bifurcation is explored. In addition, a series of numerical simulations are performed to illustrate our theoretical results.


2007 ◽  
Vol 23 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Johan Söderlund ◽  
Taha Hirbod ◽  
Anna Smed-Sörensen ◽  
Ulrika Johansson ◽  
Joshua Kimani ◽  
...  

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