Long-term HIV-1 infection of neural progenitor populations.
BACKGROUND
HIV can reside in the brain for many years. While astrocytes are known to tolerate long-term HIV infection, the potential of other neural cell types to harbour HIV is unclear.


OBJECTIVE
To investigate whether HIV can persist in neural progenitor cell populations.


METHODS
A multipotent human neural stem cell line (HNSC.100) was used to compare HIV infection in neural progenitor and astrocyte cell populations.


METHODS
Expression of cellular genes/proteins was analysed by real-time reverse transcriptase PCR, Western blot, immunocytochemistry and flow cytometry. Morphological properties of cells were measured by quantitative fluorescent image analysis. Virus release by cells exposed to HIV-1IIIB was monitored by enzyme-linked immunosorbent assay for Gag. Proviral copy numbers were determined by real-time PCR and early HIV transcripts by reverse transcriptase PCR. Rev activity was determined with a fluorescent-based reporter assay.


RESULTS
Progenitor populations differed from astrocyte populations by showing much lower glial fibrillary acidic protein (GFAP) production, higher cell-surface expression of the CXCR4 chemokine receptor, higher Rev activity and distinct cell morphologies. HIV-exposed progenitor cultures released moderate amounts of virus for over 2 months and continued to display cell-associated HIV markers (proviral DNA, early HIV transcripts) during the entire observation period (115 days). Differentiation of HIV-infected progenitor cells to astrocytes was associated with transient activation of virus production. Long-term HIV infection of progenitor populations led to upregulation of GFAP and changes in cell morphology.


CONCLUSIONS
These studies suggest that neural progenitor populations can contribute to the reservoir for HIV in the brain and undergo changes as a consequence of HIV persistence.
Rothenaigner
Ina
I
GSF--National Research Center for Environment and Health, Institute of Molecular Virology, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.
Kramer
Susanne
S
Ziegler
Manja
M
Wolff
Horst
H
Kleinschmidt
Andrea
A
Brack-Werner
Ruth
R
D053687:Adult Stem Cells / Q000821:virology*; D001253:Astrocytes / Q000821:virology; D015415:Biomarkers / Q000032:analysis; D001923:Brain Chemistry; D002460:Cell Line; D002908:Chronic Disease; D005434:Flow Cytometry; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D016655:HIV Core Protein p24 / Q000032:analysis; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000502:physiology*; D006801:Humans; D009474:Neurons / Q000821:virology*; D011533:Proviruses; D020133:Reverse Transcriptase Polymerase Chain Reaction; D018709:Statistics, Nonparametric; D013997:Time Factors; D054321:rev Gene Products, Human Immunodeficiency Virus / Q000032:analysis
D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D016655:HIV Core Protein p24; D054321:rev Gene Products, Human Immunodeficiency Virus