Behavior of a cloned murine interferon alpha/beta receptor expressed in homospecific or heterospecific background.

Abstract

A murine interferon (IFN) a/(3 receptor was cloned from the IFN-sensitive L1210 cell line on the basis of its homology with the human receptor. A combination of methods that includes the screening of random-primed and oligo(dT)-primed cDNA libraries and polymerase chain reactions with a single-side specificity was used. At the amino acid level, the murine IFN-a/fi shows 46% identity with its human counterpart. Both human WISH cells presenting a low sensitivity to mouse IFN and a murine L1210 mutant subline that does not express the receptor have been stably transfected with the murine IFN-a/fB receptor. Whereas transfected human cells became sensitive to a limited number of mouse IFN-a/fi subtypes, the transfected murine L1210 mutant was found to be fully complemented and became sensitive to all mouse IFNa/(3 subtypes tested, including those that were not active on transfected human cells. These results strongly suggest that the receptor described here is implicated in the mediation of the activities of all murine IFN-ei/i3 subtypes.The interferon (IFN) a/,B family consists of not less than 20 related genes (1). In the mouse system, an IFN-a/f3 protein mixture is generally produced by cells infected by virus (2). The biological effects of these IFNs, including the inhibition of virus replication and the inhibition of cell growth, are mediated by a cell surface receptor (3, 4). In the murine system, the quantitative relationship between binding and biological activities ofIFN-a/fB has been only poorly studied; it is assumed that the general conclusions concerning the correlation between binding and activities of IFNs found in human (5-7) are also true for the murine system. A cDNA encoding a human IFN-a/,f receptor has already been cloned by an expression cloning strategy in which a mouse cell clone transfected with human DNA has been isolated on the basis of its acquired sensitivity to the human (13) and selected in medium containing G418 (GIBCO) at 1.25 mg/ml. The IFN-sensitive and -resistant mouse L1210 cell lines (9) have been recloned from the sensitive and resistant clones used by Aguet (3) and named S61 and R101, respectively. They were cultivated in RPMI 1640 medium supplemented with 10%6 fetal calf serum, transfected by the electroporation procedure (14) in a 0.4-cm diameter cuvette (300 V; 960 OF) with a Bio-Rad Gene Pulser, and selected with G418 at 1.5 mg/ml. General Methods. Standard procedures were as described (15) Howley et al. (19). Briefly, hybridization was at 420C in 1 M NaCl/0.1% Ficoll/0.1% polyvinylpyrrolidone/0.1% bovine serum albumin/5% dextran sulfate/S mM EDTA/1% SDS/25% (vol/vol) deionized formamide in 50 mM sodium phosphate (pH 7.2). Washing was at 420C in 1 M NaCl/5 mM EDTA/1% SDS/30% formamide in 50 mM sodium phosphate (pH 7.2).Abbreviations: IFN, interferon; nt, nucleotide(s).

Role of interferon alpha/beta receptor chain 1 in the structure and transmembrane signaling of the interferon alpha/beta receptor complex.

“…The mouse and bovine homologues of IFNaRl have been cloned and also confer sensitivity to the antiviral action of IFNa when transfected into nonresponsive cells (12)(13)(14). These results clearly demonstrate that the IFNaRl chain plays a central role in signal transduction through the IFNaR.…”

The soluble murine type I interferon receptor Ifnar-2 is present in serum, is independently regulated, and has both agonistic and antagonistic properties

“…11 In humans and mice, there is a single form of IFNAR-1. 12 In contrast, multiple isoforms of human IFNAR-2 have been shown to result from alternative splicing of the same gene producing huIFNAR-2a (encoding a putative soluble isoform), huIFNAR-2b (encoding a putative transmembrane receptor with a truncated cytoplasmic domain), and huIFNAR-2c (encoding a putative full-length transmembrane receptor). 13 HuIFNAR-2c reconstituted IFN signaling in the huIFNAR-2-deficient cell line (U5A), which was otherwise unresponsive to IFN, whereas huIFNAR-2b did not, indicating that the latter was a nonfunctional isoform.…”

Antiviral activities of the soluble extracellular domains of type I interferon receptors

“…1). IFNAR1 has been cloned from human (17), bovine (18,19), ovine (19,20), murine (21), and chicken cells (22). A soluble form of human (hu) IFNAR2 was first purified as an IFN-␣ binding protein from urine (IFNAR2a; ref.…”