Preferential effect of γ interferon on the synthesis of HLA antigens and their mRNAs in human cells

Abstract

Interferons produce a variety of biological effects on cells. They induce resistance to virus proliferation^1,2, inhibit cell growth³, modify cell structure and differentiation^3–5, stimulate some immune functions and inhibit others⁶. However, the different interferon (IFN) species may vary in their mechanism of action and, hence, in their relative efficiency for inducing each of the effects. IFN-γ (type II) appears to show stronger immunoregulatory^7–9 and growth inhibitory effects^10–12 than antiviral effects¹³, but this conclusion has been challenged in other reports¹⁴. The aim of the present work is to compare the action of IFN-γ and other (type I) interferons on the induction of (2′–5′) oligo(A) synthetase which is probably part of the antiviral response^15,16 and the induction of the histocompatibility HLA-A,-B,-C antigens^17–19. We have shown previously that the induction of both proteins is regulated by interferons at the mRNA level^20,21, but show here that IFN-γ from stimulated human lymphocytes²² and from monkey cells transfected by cloned human IFN-γ cDNA²³ induced the HLA-A,-B,-C and β₂-microglobulin mRNAs or proteins at concentrations over 100 times lower than those needed to induce the (2′–5′)oligo(A) synthetase and the antiviral state. This difference was not found with IFN-α and -β (type I).