Der S, Read SE, Lau AS; International Conference on AIDS.

Int Conf AIDS. 1990 Jun 20-23; 6: 343 (abstract no. 1116).

Division of Infectious Diseases, Hosp Sick Children, Toronto, Canada

IFNs are naturally occurring proteins with potent antiviral and immunomodulatory properties. High levels of an unusual acid-labile interferon (IFN) alpha present in AIDS sera have been implicated in the pathogenesis of AIDS. We are interested to determine the biological properties of the acid-labile IFN-alpha as an initial step to investigate its role in HIV infections. We have previously reported that the acid-labile IFN-alpha is capable of inducing TNF synthesis and its receptor expression. Human IFN-alpha titers in patients' sera were quantitated by a cytopathic effect protection assay on T98G cells (glioblastoma), using recombinant IFN-alpha2 (Schering) as standard. To test responsiveness of blood mononuclear cells to IFN, 2-5A synthetase activities of the cellular extracts were determined using poly r(I):r(C) coated agarose beads. We have shown that the acid-labile IFN-alpha subtype is capable of down-regulating IFN-alpha receptors and inducing 2-5A synthetase activity, similar to recombinant IFN-alpha2 or leukocyte-derived interferon (Wellferon, Burroughs Wellcome). In determining the cellular origin, it appears that B-cell subsets from blood mononuclear cells are the main source of the acid-labile IFN subtype. On the contrary, HIV infection of CD4-expressing cells, including Jurkat and CEM, produces low levels of IFN-alpha. In accord with previous reports, the IFN-alpha subtype from AIDS sera is acid-labile and can be neutralized by anti-IFN-alpha antibodies. In addition, when IFN-alpha2 or leukocyte IFN are treated with AIDS sera, the exogenous IFNs become acid-labile, similar to that of the endogenous IFN subtype found in AIDS sera. It therefore appears that the acid-lability of the IFN is dependent on the presence of an unknown factor in AIDS serum. In summary, we have determined that the IFN subtype present in AIDS has similar biological activities as leukocyte and recombinant alpha IFNs.

Publication Types:

• Meeting Abstracts

Keywords:

• Acids
• Acquired Immunodeficiency Syndrome
• Antiviral Agents
• CD4-Positive T-Lymphocytes
• HIV Infections
• Humans
• Interferon Alfa-2b
• Interferon Type I, Recombinant
• Interferon-alpha
• Interferons
• Leukocytes

Other ID:

• 40111690

UI: 102196969

From Meeting Abstracts