| Autor: |
Barcellini, Wilma, Colombo, Gualtiero, La Maestra, Letteria, Clerici, Giuliana, Garofalo, Letizia, Brini, Anna T., Lipton, James M., Catania, Anna |
| Zdroj: |
Journal of Leukocyte Biology; November 2000, Vol. 68 Issue: 5 p693-699, 7p |
| Abstrakt: |
The purpose of the present research was to determine if α‐melanocyte‐stimulating hormone (α‐MSH) and its C‐terminal tripeptide [α‐MSH (11–13), KPV] alter HIV expression in infected cells. The results indicate that chronically HIV‐1‐infected promonocytic U1 cells produce α‐MSH and that immunoneutralization of the endogenous peptide enhances HIV expression. Because U1 cells express the α‐MSH receptor 1 (MC1R), an autocrine‐inhibitory circuit based on the peptide and its receptor likely occurs in these cells. To determine effects of pharmacological concentrations of α‐MSH peptides on HIV expression, we measured p24 antigen release by TNF‐α‐stimulated U1 cells exposed to a wide range of concentrations of synthetic α‐MSH and KPV. Viral expression was reduced by both peptides. KPV also effectively reduced HIV replication in acutely infected monocyte‐derived macrophages (MDM). The basis of the peptide influence on viral replication is at the transcriptional level; KPV inhibited activation of NF‐κB that is known to enhance viral expression. Endogenous α‐MSH likely contributes to natural defense against HIV. However, greater concentrations of synthetic peptide are much more effective in reducing HIV expression in infected cells. |
| Databáze: |
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