Nef protein of human immunodeficiency virus and lipopolysaccharide induce expression of CD14 on human monocytes through differential utilization of interleukin-10

David Creery, Jonathan B. Angel, Susan Aucoin, William Weiss, William D. Cameron, Francisco Diaz-Mitoma, Ashok Kumar

Research output: Contribution to journalArticlepeer-review

Abstract

We investigated the expression of membrane-bound CD14 (mCD14) on monocytes and soluble CD14 (sCD14) released into the culture supernatants of peripheral blood lymphocytes (PBMC) from human immunodeficiency virus (HIV)-infected individuals. Monocytes from HIV-positive individuals exhibited both enhanced mCD14 expression and sCD14 production in the PBMC culture supernatants compared to the levels of mCD14 and sCD14 in HIV-negative individuals. This enhanced mCD14 expression and sCD14 production in HIV-infected individuals may be due to the effects of cytokines, the bacterial product lipopolysaccharide (LPS), and/or the HIV regulatory antigens Tat and Nef. Interleukin-10 (IL-10), an immunoregulatory cytokine, as well as LPS enhanced mCD14 expression and the release of sCD14 in the culture supernatants. HIV-Nef, unlike Tat, enhanced mCD14 expression on monocytes but did not induce the release of sCD14 into the culture supernatants. Studies conducted to investigate the mechanism underlying HIV-Nef-induced mCD14 expression revealed that HIV-Nef upregulated mCD14 expression via a mechanism that does not involve endogenously produced IL-10. In contrast, LPS upregulated the expression of mCD14 and increased the release of sCD14 via a mechanism that involves, at least in part, endogenously produced IL-10. Furthermore, dexamethasone, an anti-inflammatory and immunosuppressive agent, inhibited HIV-Nef-induced CD14 expression in an IL-10-independent manner. In contrast, dexamethasone inhibited IL-10-dependent LPS-induced CD14 expression by interfering with IL-10-induced signals but not by blocking IL-10 production. These results suggest that HIV-Nef and IL-10 constitute biologically important modulators of CD14 expression which may influence immunobiological responses to bacterial infections in HIV disease.

Original languageEnglish (US)
Pages (from-to)1212-1221
Number of pages10
JournalClinical and Diagnostic Laboratory Immunology
Volume9
Issue number6
DOIs
StatePublished - Nov 2002
Externally publishedYes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Clinical Biochemistry
  • Microbiology (medical)

Fingerprint Dive into the research topics of 'Nef protein of human immunodeficiency virus and lipopolysaccharide induce expression of CD14 on human monocytes through differential utilization of interleukin-10'. Together they form a unique fingerprint.

Cite this