Models of interactions between HIV and other pathogens.
We investigate possible interactions between HIV and other pathogens that would arise if HIV replication were enhanced by the activation of T helper cells specific to other pathogens. Using mathematical models of the population dynamics of T helper cells, HIV and other pathogens we address three facets of the interactions between HIV and other pathogens: enhanced HIV replication due to immune stimulation by other pathogens; modified immune control of other pathogens due to immunosuppression by HIV; and the vicious circle formed by positive feedback between these two effects. The models predict that there is a correlation between higher levels of activated TH cells and disease progression and that there is a threshold number of activated TH cells above which the HIV infected immune system is unable to control pre-established pathogens. This threshold marks the boundary between a suppressed but still functioning immune system and the vicious circle of CD4 cell depletion that marks the final stages of AIDS.
McLean
A R
AR
National Institute for Medical Research, The Ridgeway, Mill Hill, London, U.K.
Nowak
M A
MA
D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology; D005246:Feedback / Q000502:physiology; D006678:HIV / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology; D008954:Models, Biological; D013601:T-Lymphocytes / Q000276:immunology*; D014779:Virus Replication / Q000276:immunology; D014780:Viruses / Q000276:immunology