A cytotoxic nonstructural protein, NS1, of human parvovirus B19 induces activation of interleukin-6 gene expression

Stanley Moffatt, Nobuyuki Tanaka, Kohtaro Tada, Masato Nose, Masataka Nakamura, Osamu Muraoka, Toshio Hirano, Kazuo Sugamura

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)


We examined the biological function of a nonstructural regulatory protein, NS1, of human parvovirus B19. Because of the cytotoxic activity of NS1, human hematopoietic cell lines, K562, Raji, and THP-1, were established as transfectants which produce the viral NS1 protein upon induction by using bacterial lactose repressor/operator system. NS1 was significantly produced in the three transfectant cells in an inducer dose- and time-dependent manner. Surprisingly, these three transfectants secreted an inflammatory cytokine, interleukin-6 (IL-6), in response to induction. However, no production of other related cytokines, IL-1β, IL-8, or tumor necrosis factor alpha, was seen. Moreover, NS1-primed IL-6 induction was transiently demonstrated in primary human endothelial cells. Analysis with luciferase reporter plasmids carrying IL-6 promoter mutant fragments demonstrated that NS1 effect is mediated by a NF-κB binding site in the IL-6 promoter region, strongly implying that NS1 functions as a trans-acting transcriptional activator on the IL-6 promoter. Our novel finding, IL-6 induction by NS1, supports the possible relationship between parvovirus B19 infection and polyclonal activation of B cells in rheumatoid arthritis and indicates that NS1 protein may play a significant role in the pathogenesis of some B19- associated diseases by modulating the expression of host cellular genes.

Original languageEnglish
Pages (from-to)8485-8491
Number of pages7
JournalJournal of virology
Issue number12
Publication statusPublished - 1996 Dec
Externally publishedYes

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology


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