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Comparative Study
. 1998 Mar 17;95(6):3117-21.
doi: 10.1073/pnas.95.6.3117.

Induction of monocyte chemoattractant protein-1 in HIV-1 Tat-stimulated astrocytes and elevation in AIDS dementia

K Conant  1 , A Garzino-Demo, A Nath, J C McArthur, W Halliday, C Power, R C Gallo, E O Major
Affiliations
Comparative Study

Induction of monocyte chemoattractant protein-1 in HIV-1 Tat-stimulated astrocytes and elevation in AIDS dementia

K Conant et al. Proc Natl Acad Sci U S A. .

Abstract

Activated monocytes release a number of substances, including inflammatory cytokines and eicosanoids, that are highly toxic to cells of the central nervous system. Because monocytic infiltration of the central nervous system closely correlates with HIV-1-associated dementia, it has been suggested that monocyte-derived toxins mediate nervous system damage. In the present study, we show that the HIV-1 transactivator protein Tat significantly increases astrocytic expression and release of monocyte chemoattractant protein-1 (MCP-1). Astrocytic release of beta-chemokines, which are relatively less selective for monocytes, including RANTES, macrophage inflammatory protein-1alpha, and macrophage inflammatory protein-1beta, was not observed. We also show that MCP-1 is expressed in the brains of patients with HIV-1-associated dementia and that, of the beta-chemokines tested, only MCP-1 could be detected in the cerebrospinal fluid of patients with this condition. Together, these data provide a potential link between the presence of HIV-1 in the brain and the monocytic infiltration that may substantially contribute to dementia.

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Figures

Figure 1
Figure 1
(A) Total RNA was extracted from T lymphoblastoid HUT 78 cells (ATCC) and from variously treated human astrocytes. Ten micrograms per lane were then run on a 1% agarose–6% formaldehyde gel. After transfer of RNA to nitrocellulose, the blot was probed with the full-length cDNA for MCP-1 and, subsequently, RANTES. RNA from untreated astrocytes was run in lanes 2 and 4. Both 4 hr stimulation with 5 ng/ml of interleukin-1β (lane 3) and 2 or 4 hr stimulation with 100 nM of Tat (lanes 5 and 6) were associated with an increase in astrocytic MCP-1 expression. Astrocytic expression of RANTES was not detected. (B) Similar experiment except that RNA from HUT 78 cells (lane 1) was compared with RNA from astrocytes that were unstimulated (lane 2) or stimulated for 2 hr with 100 nM of Tat (lane 3), 25 μM of TPCK followed by 100nM of Tat (lane 4), or 25 μM of TPCK (lane 5). In A and B, the G6-PD probe was used as a control (24).
Figure 2
Figure 2
MCP-1 ELISA analysis of supernatants from variously treated human astrocytes. (A) Astrocytes were grown to near confluency in 35-cm plates. Each well contained 106 cells in 1 ml of medium. The medium was then changed and astrocytes were stimulated with exogenous Tat in doses ranging from 0.01 to 1.0 μM. Twenty hours later, samples were taken for analysis by immunoassay (R&D Systems). As compared with untreated astrocytes (−) that, when grown in tissue culture, express MCP-1 in the absence of stimulation, Tat-stimulated astrocytes showed a significant increase in MCP-1 release. Data are shown as mean + SE for three replicates. (B) Similar experiment except that astrocytes were stimulated with 100 nM of Tat or with an equivalent amount of Tat that had first been either digested with trypsin (Tat-tr) or immunoabsorbed (Tat-im).
Figure 3
Figure 3
Western blot analysis of MCP-1 in astrocyte supernatants. In lanes 2–7, 50 μg of protein from variously treated astrocyte supernatants were run on a 15% Tris⋅glycine denaturing gel. Three nanograms of non-glycosylated recombinant MCP-1 (R&D Systems) was run in lane 1 as a control. After protein transfer to nitrocellulose, the blot was probed with a polyclonal antibody that recognizes human MCP-1 (R&D Systems). After washing, an appropriate secondary antibody was applied [horseradish peroxidase conjugated anti-goat (Santa Cruz Biotechnology)] and electrochemiluminescence (Amersham) was used to visualize the bands. The two bands, which are specifically increased in association with Tat, are indicated by arrows. The lower arrow represents a band that runs with an apparent molecular mass of 9 kDa, whereas the upper band, of slightly higher molecular mass, is likely to represent MCP-1 that has been altered by the addition of O-linked carbohydrates. Both forms of MCP-1 are active in vitro (15).
Figure 4
Figure 4
MCP-1 levels in CSF. MCP-1 levels were analyzed by ELISA (R&D Systems) in CSF samples from HIVD patients (HIVD, n = 10), HIV(N) patients [HIV(N), n = 10], patients with MS (MS, n = 10) and patients with NIN conditions (NIN, n = 10). All data are represented as mean + SE and analyzed by non-parametric analysis using the Mann–Whitney test. The comparisons of HIVD to HIV(N), MS, and NIN were significant at P < 0.002, P < 0.001, and P < 0.001, respectively. The comparisons of HIV(N) to MS and NIN were significant at P < 0.01. There were no significant differences between the MS and the NIN groups.
Figure 5
Figure 5
Detection of MCP-1 RNA in brain tissue by in situ hybridization. Tissue sections were hybridized with an MCP-1 antisense probe. (a and b) Cells within the cerebral white matter of a HIVD patient show a strong signal for the presence of MCP-1 RNA. (c) Signal-positive cells are also seen in perivascular regions. A representative area from a normal patient shows absence of signal (d), as does a sample from an HIVD patient that was hybridized with an MCP-1 sense probe (e). (Scale bars represent 25 μm.)
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References

    1. Price R W, Brew B, Sidtis J, Rosenblum M, Scheck A C, Cleary P. Science. 1988;239:586–592. - PubMed
    1. Glass J D, Fedor H S, Wesselingh S L, McArthur J C. Ann Neurol. 1995;38:755–762. - PubMed
    1. Gartner S, Markovits P, Markovitz D, Kaplan M, Gallo R, Popovic M. Science. 1986;233:215–219. - PubMed
    1. Wiley C, Schrier R, Nelson J, Lampert P, Oldstone M. Proc Natl Acad Sci USA. 1986;83:7089–7093. - PMC - PubMed
    1. Koenig S, Gendelman H E, Orenstein J M, DalCanto M C, Pezeshkpour G H, Yungbluth M, Janotta F, Aksamit A, Martin M A, Fauci A S. Science. 1986;233:1089–1093. - PubMed

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