Human T-cell leukemia/lymphoma virus type I(HTLV-I)is a pathogenic retrovirus,and cytotoxic T lymphocytes(CTLs)or specific CD8+cytotoxic T lymphocytes are considered crucial factors in the human immune system against ...Human T-cell leukemia/lymphoma virus type I(HTLV-I)is a pathogenic retrovirus,and cytotoxic T lymphocytes(CTLs)or specific CD8+cytotoxic T lymphocytes are considered crucial factors in the human immune system against viral infections.Therefore,studying the impact of CTL immune response on HTLV-I infection is essential.This paper investigates a class of HTLV-I infection models that consider latent infected CD4^(+)T cells and viral replication delay(the time from initial infection of healthy CD4^(+)T cells to becoming latent CD4^(+)T infected cells).By analyzing the model,the basic reproduction number for immunological inactivation R_(0)and the basic reproduction number for immunological activation R_(1)are defined.Using R_(0)and R_(1)as thresholds,the local stability of the infection-free equilibrium E0,the immunological inactivation equilibrium point E_(1),and the immunological activation equilibrium point E^(*)is established by analyzing the distribution of roots of the corresponding characteristic equations whenτ=0.Additionally,the local stability forτ≠0 and the existence of Hopf bifurcations with delay as a bifurcation parameter are discussed.展开更多
文摘Human T-cell leukemia/lymphoma virus type I(HTLV-I)is a pathogenic retrovirus,and cytotoxic T lymphocytes(CTLs)or specific CD8+cytotoxic T lymphocytes are considered crucial factors in the human immune system against viral infections.Therefore,studying the impact of CTL immune response on HTLV-I infection is essential.This paper investigates a class of HTLV-I infection models that consider latent infected CD4^(+)T cells and viral replication delay(the time from initial infection of healthy CD4^(+)T cells to becoming latent CD4^(+)T infected cells).By analyzing the model,the basic reproduction number for immunological inactivation R_(0)and the basic reproduction number for immunological activation R_(1)are defined.Using R_(0)and R_(1)as thresholds,the local stability of the infection-free equilibrium E0,the immunological inactivation equilibrium point E_(1),and the immunological activation equilibrium point E^(*)is established by analyzing the distribution of roots of the corresponding characteristic equations whenτ=0.Additionally,the local stability forτ≠0 and the existence of Hopf bifurcations with delay as a bifurcation parameter are discussed.
