GM-CSF and M-CSF modulate beta-chemokine and HIV-1 expression in microglia.
Significant numbers of patients with acquired immunodeficiency syndrome (AIDS) develop CNS infection primarily in macrophages and microglial cells. Therefore, the regulation of human immunodeficiency virus type 1 (HIV-1) infection and activation of the brain mononuclear phagocytes subsequent to infection are important areas of investigation. In the current report, we studied the role of granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage-CSF (M-CSF) in the expression of antiviral beta-chemokines and HIV-1 p24 in cultures of primary human fetal microglia. We found that stimulation with GM-CSF or M-CSF induced macrophage inflammatory proteins (MIP-1alpha and MIP-1beta) and augmented RANTES expression, after HIV-1 infection of microglia. This was not due to the effect of GM-CSF on viral expression because GM-CSF was neither necessary nor stimulatory for viral infection, nor did GM-CSF enhance the expression of env-pseudotyped reporter viruses. Blocking GM-CSF-induced microglial proliferation by nocodazole had no effect on beta-chemokine or p24 expression. The functional significance of the GM-CSF-induced beta-chemokines was suggested by the finding that, in the presence of GM-CSF, exogenous beta-chemokines lost their anti-HIV-1 effects. We further show that although HIV-1-infected microglia produced M-CSF, they failed to produce GM-CSF. In vivo, GM-CSF expression was localized to activated astrocytes and some inflammatory cells in HIV-1 encephalitis, suggesting paracrine activation of microglia through GM-CSF. Our results demonstrate a complex interplay between CSFs, chemokines, and virus in microglial cells and may have bearing on the interpretation of data derived in vivo and in vitro.
Department of Pathology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Qiusheng
Q
Si
Melissa
M
Cosenza
Meng-Liang
ML
Zhao
Harris
H
Goldstein
Sunhee C
SC
Lee
D015526:AIDS Dementia Complex / Q000276:immunology* / Q000378:metabolism / Q000821:virology; D000276:Adjuvants, Immunologic / Q000494:pharmacology; D001921:Brain / Q000276:immunology* / Q000473:pathology / Q000821:virology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology; D002478:Cells, Cultured; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5 / Q000276:immunology / Q000378:metabolism; D019742:Chemokines, CC / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005333:Fetus; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000276:immunology* / Q000494:pharmacology; D016655:HIV Core Protein p24 / Q000276:immunology / Q000378:metabolism; D015497:HIV-1 / Q000187:drug effects / Q000276:immunology* / Q000378:metabolism; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008262:Macrophage Activation / Q000187:drug effects / Q000276:immunology; D016173:Macrophage Colony-Stimulating Factor / Q000276:immunology* / Q000494:pharmacology; D019402:Macrophage Inflammatory Proteins / Q000276:immunology / Q000378:metabolism; D017628:Microglia / Q000187:drug effects / Q000276:immunology* / Q000821:virology; D011247:Pregnancy; D011993:Recombinant Fusion Proteins / Q000187:drug effects / Q000276:immunology; D014779:Virus Replication / Q000187:drug effects / Q000276:immunology
D000276:Adjuvants, Immunologic; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D018946:Chemokine CCL5; D019742:Chemokines, CC; D016655:HIV Core Protein p24; D019402:Macrophage Inflammatory Proteins; D011993:Recombinant Fusion Proteins; D016173:Macrophage Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor