Background. The central nervous system (CNS) is a recognized target for human immunodeficiency virus type 1 (HIV-1). CD8+ T cells may mediate viral clearance from the CNS but also may contribute to immune-mediated neuronal damage. Methods. Using 4- and 6-color flow cytometry, we investigated the role of adhesion molecules (very late antigen [VLA]-4 [α4β1 integrin] and leukocyte function antigen [LFA]-1 [αLβ2 integrin]) and chemokine receptors (CXCR3 and CCR5) in CD8+ T cell migration to cerebrospinal fluid (CSF) during HIV-1 infection. Results. CD8+ T cells trafficking to CSF were uniformly VLA-4high, LFA-1 high. CCR5 expression was significantly enhanced in T cells from CSF, compared with those from blood (P < .001), including HIV-1-specific CD8 + T cells, and most T cells from CSF expressed both CXCR3 and CCR5. Interferon-inducible protein (IP)-10 (CXCL10) levels in CSF were significantly increased in HIV-1-positive individuals, relative to IP-10 levels in control subjects (P = .007), and a positive correlation was found between IP-10 levels and virus load in CSF (r2 = .777; P = .0007). Conclusions. These findings suggest that LFA-1, CCR5 and CXCR3, and IP-10 play an important role in lymphocyte trafficking to CSF during HIV-1 infection. These observations suggest a "push-pull" model, in which lymphocyte extravasation is driven by lymphocyte activation, expression of adhesion molecules, and increased vascular permeability and is coupled with chemokine-mediated trafficking to inflammatory sites in the CNS.
ASJC Scopus subject areas
- Public Health, Environmental and Occupational Health