Selective up-regulation of functional CXCR4 expression in erythroid cells by HIV-1 Tat protein

D. Gibellini, M. C. Re, F. Vitone, N. Rizzo, C. Maldini, M. La Placa, G. Zauli

Research output: Contribution to journalArticlepeer-review


CXCR4 is the high affinity receptor for the SDF-1 α chemokine and represents the main coreceptor for HIV-1 T-tropic strains. The surface expression of CXCR4 was analysed in CD34+ haematopoietic progenitors, induced to differentiate along the erythroid or granulocytic lineages, in liquid cultures supplemented or not with HIV-1 Tat protein. At concentrations as low as 1-10 ng/ml, synthetic Tat protein significantly increased the surface expression of CXCR4 in erythroid but not in granulocytic cells. The Tat-mediated up-regulation of surface CXCR4 was accompanied by a concomitant increase of CXCR4 mRNA and total CXCR4 protein content in cells developing along the erythroid lineage after 6-10 days of culture. Moreover, addition of SDF-1 α (200 ng/ml) induced a significant higher rate of apoptosis in Tat-treated erythroid cells in comparison with control cells. These results demonstrated for the first time a direct positive role in haematopoietic gene regulation of Tat protein, and suggest the possible involvement of Tat in HIV-1-induced anaemia.

Original languageEnglish
Pages (from-to)428-435
Number of pages8
JournalClinical and Experimental Immunology
Issue number3
Publication statusPublished - Mar 1 2003


  • CD34
  • CXCR4
  • Erythroid cells
  • HIV-1
  • Tat

ASJC Scopus subject areas

  • Immunology


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