Atypical spI interferon binds on porcine cells to a major component of type I interferon receptor.
The short porcine type I interferon (spI IFN), encoded by a gene physiologically expressed by the pig embryonic trophoblast during implantation, represents the first member of a novel family type I IFN. Binding and cross-linking experiments were carried out to characterize its cellular receptor. On porcine kidney cells, specific binding of 125I-spI IFN could be displaced significantly by spI IFN, rpIFN-alpha 1, and rhIFN-alpha 1, but not by rhIFN-alpha 2a or by rpIFN-gamma. On the other hand, all these type I IFNs but not rpIFN-gamma were capable of displacing bound 32P-hIFN-alpha A-P1 on these cells. Cross-linking data show that the specific 120 kD complex formed with these two radiolabeled ligands was displaceable by an excess of both spI IFN and rpIFN-alpha 1. These results provide primary evidence that spI IFN shares at least the major binding subunit of type I IFN receptor on porcine cells. On human WISH cells, 125I-spI IFN did not form any complex, nor did spI IFN affect cross-linking complexes of 32P-hIFN-alpha A-P1 on these cells, unlike rpIFN-alpha 1. The lack of antiviral and antiproliferative effects of spI IFN on human cells is primarily a result of its inability to recognize human type I IFN receptor.
Laboratoire de Virologie et Immunologie moleculaire INRA, Jouy-en-josas, France.
P D
PD
Niu
F
F
Lefevre
C
C
La Bonnardiere
D000818:Animals; D002460:Cell Line; D003432:Cross-Linking Reagents; D006801:Humans; D007370:Interferon Type I / Q000378:metabolism*; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D011869:Radioligand Assay; D017471:Receptors, Interferon / Q000378:metabolism*; D011994:Recombinant Proteins; D013552:Swine
D003432:Cross-Linking Reagents; D007370:Interferon Type I; D017471:Receptors, Interferon; D011994:Recombinant Proteins