Human interferon-inducible protein 10: Expression and purification of recombinant protein demonstrate inhibition of early human hematopoietic progenitors

Andreas H. Sarris, Hal E. Broxmeyer, Urs Wirthmueller, Nikos Karasavvas, Scott Cooper, Li Lu, James Krueger

Research output: Contribution to journalArticle

81 Scopus citations


Human interferon-inducible protein 10 (IP-10), a member of the family of the small secreted proteins called intercrine cytokines or chemokines, is secreted by interferon γ-stimulated T cells, monocytes, endothelial cells, and keratinocytes. We have begun to explore the biological properties of IP-10 by cloning and overexpression in baculovirus and in bacterial protein expression systems. A 9.9-kD protein was secreted by infected insect cells, which on sodium dodecyl sulfate-polyacrilamide gel electrophoresis comigrated with keratinocyte IP-10 and with f(22-98), a bacterial recombinant fragment lacking the signal sequence but containing all other residues of IP-10. All three reacted with antibodies recognizing residues 10-98 (αIP-10) and 77-98 of IP-10 (α22), demonstrating that it is secreted by keratinocytes and insect cells after removal of the signal sequence but without proteolysis of the COOH-terminal end. Purified rIP-10 suppresses in vitro colony formation by early human bone marrow progenitor cells which need r-steel factor (rSLF) and rGM-CSF or rSLF and r-erythropoeitin (rEPO). The inhibition is dose dependent, is complete at concentrations ≥50 ng/ml, is prevented by preincubation of rIP-10 with αIP-10, but not by α22, and is seen with highly purified CD34+ cells, suggesting direct effect of rIP-10 on the progenitors. Combination of rIP-10 and other chemokines at inactive concentrations inhibited colony formation in a synergistic manner. rIP-10 did not affect colony formation in the absence of any growth factors or in the presence of rEPO or rGM-CSF but in absence of rSLF. The effects of IP-10 may be relevant to normal marrow function and might be harnessed to protect human hematopoietic progenitors from the cytotoxic effects of chemotherapy.

Original languageEnglish (US)
Pages (from-to)1127-1132
Number of pages6
JournalJournal of Experimental Medicine
Issue number3
StatePublished - Sep 1 1993


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

Cite this