HIV infection is multi-faceted and a multi-step process. The virus-induced pathogenic
mechanisms are manifold and mediated through a range of positive and negative feedback
regulations of immune and physiological processes engaged in virus-host interactions. The
fundamental questions towards understanding the pathogenesis of HIV infection are now
shifting to ‘dynamic’ categories: (i) why is the HIV-immune response equilibrium finally
disrupted? (ii) can one modify the dynamic equilibrium for host benefit? (iii) can one
predict the outcome of a system perturbation via antiviral drugs or drugs modulating the
host immune response dynamics? Answering these questions requires a major
interdisciplinary effort, and in particular, the development of novel mathematical
approaches for a coherent quantitative description and prediction of intra-patient HIV
evolution, the immunological responses to HIV infection, and the systems level homeostatic
regulation of specific effector and regulatory lymphocyte populations in correlation with
disease status. Here we summarized fundamental biological features of HIV infection and
current mathematical modelling attempts to understand HIV pathogenesis.