While previous studies had linked end-stage dementia due to HIV to the presence of infected and activated immune cells, the nature of neurological changes in earlier stages of the disease, the so-called "chronic phase," were unknown-until now.
Using simian immunodeficiency virus-infected models in the chronic phase, the research team found both virus and infiltrating lymphocytes (CD8+ T cells) in the brain. Molecular analysis revealed that the expression of several immune response genes was increased, including CCL5, which has multiple effects on neurons as well as immune cells. CCL5 was significantly upregulated throughout the course of infection, and was present in the infiltrating lymphocytes.
In addition to Fox, authors of the April 26, 2006 Journal of Neuroscience (Volume 26, Number 17) paper, titled "Host Response and Dysfunction in the CNS During Chronic SIV Infection," are: Eleanor Roberts, Salvador Huitron-Resendiz, Michael Taffe, Cecilia Marcondes, Claudia Flynn, Caroline Lanigan, Jennifer Hammond, Steven Head, and Steven Henriksen.