Dynamics of Compartmentalized HIV-1 Populations in the Central Nervous System Patrick R. Harrington Postdoctoral Fellow Laboratory of Ronald Swanstrom Lineberger Comprehensive Cancer Center University of North Carolina at Chapel Hill Chapel Hill, NC, USA
Dynamics of Compartmentalized HIV-1 Populations in the Central Nervous System Kimberly Ritola,1 Kevin Robertson,2 Susan A. Fiscus,1 Colin Hall,2 and Ronald Swanstrom.1 Increased HIV-1 env compartmentalization in the presence of HIV-associated dementia. Journal of Virology. In press (Aug. 2005). Patrick R. Harrington,1 David W. Haas,3 Kimberly Ritola,1 and Ronald Swanstrom.1 Compartmentalized HIV-1 present in cerebrospinal fluid is produced by short-lived cells. Journal of Virology. In press (July 2005). 1Lineberger Comprehensive Cancer Center, Center for AIDS Research, Department of Biochemistry and Biophysics, and 2Department of Neurology, University of North Carolina, Chapel Hill, North Carolina, USA 3Departments of Medicine, Microbiology and Immunology, and Vanderbilt Meharry Center for AIDS Research, Vanderbilt University School of Medicine, Nashville, Tennessee, USA Funding Lineberger Cancer Center, UNC-Chapel Hill NIMH, NINDS, NIH UNC Center for AIDS Research Vanderbilt Meharry Center for AIDS Research
Unique env populations in plasma and CSF Similar env populations Unique env populations in plasma Unique env populations in CSF BP CSF BP CSF BP CSF BP CSF Compartmentalization of HIV-1 Genetic Populations in Blood Plasma and CSF Revealed by V1/V2 (env) HTA *single-stranded probe band unique to compartment
Relative Abundance of Unique env Variants in CSF HAD No HAD Increased Compartmentalization Between Plasma and CSF HIV-1 env Populations is Associated with Neurological Status Patients with compartmentalized env sequences % of Patients
Dynamics of HIV-1 Populations in Blood and CSF of Asymptomatic Subjects During the Initiation of Antiretroviral Therapy
free virus short-lived, productively infected cells (CD4+ T cells) Sources of HIV-1 RNA long-lived infected cells (Macrophages, resting T cells) 0 -0.5 -1 -1.5 -2 -2.5 -3 0 2 4 6 8 10 12 14 16 At Least Two Phases of Viral Decline in the Periphery During Antiretroviral Therapy Change in log plasma HIV RNA Limit of detection Time after initiation of antiretroviral therapy (Perelson, et al., Shaw, et al. 1995) Adapted from HIVpositive.com
CD4+ T cells Macrophages Periphery CSF CNS Macrophages Perivascular Microglia Astrocytes Neurons Antiretroviral Therapy and HIV-1 in cerebrospinal fluid • Studies of Bulk HIV-1 RNA in CSF • Usually a rapid decline in CSF viral load during therapy • Slower declineNeurological disease (Ellis, et. al. 2000; Eggers, et. al. 2003) • Kinetics of CSF viral decay do not correlate with blood • Not known which source is being treated when bulk viral loads decline in CSF • Experimental Design: use HTA to measure the decline of individual HIV-1 genetic variants in blood and CSF Hypothesis CSF HIV-1 variants produced by cells within the CNS will decline more slowly in response to antiretroviral therapy compared with CSF HIV-1 coming from peripheral sources.
CSF/Plasma Sampling Start CSF/Plasma Sampling End Three-drug therapy Start CSF/Plasma Sampling Start CSF/Plasma Sampling End -120 -96 -72 -48 -24 0 24 48 72 96 120 Baseline Time (Hours) 72-120 hours post-initiation of therapy Haas Study-4 treatment-naïve, asymptomatic subjects
BP CSF BP CSF # Relative Variant Load (copies/ml) # # single-stranded probe *unique variant in CSF #enriched variant in CSF HIV-1 Compartmentalization in the CNS
Patient 2 V4/V5 Variants Decline of CSF HIV-1 Variants (h) Relative Variant Load (copies/ml) # Time on therapy (h) CSF HIV-1 variants shared with the periphery Compartmentalized HIV-1 Variants in CSF Decline of HIV-1 Genetic Variants During Antiretroviral Therapy: Compartmentalized HIV-1 Variants in CSF Decline Rapidly
Decline of HIV-1 Variants in CSF During Antiretroviral Therapy Conclusion A short-lived, HIV-productively infected cell population exists in the central nervous system and contributes to the HIV-1 population in cerebrospinal fluid.
Dynamics of Compartmentalized HIV-1 Populations in the Central Nervous System Conclusions The amount of CNS-specific production of HIV-1 in CSF is associated with neurological disease status. In asymptomatic subjects, short-lived cells (perhaps trafficking CD4+ T cells) play an important role in the production and maintenance of locally produced HIV-1 populations in CSF. • Grazie molto per la vostra attenzione! • (Thank you very much for your attention)