Ultrastructural localization of interferon receptors on the surfaces of cultured cells and erythrocytes

Abstract

The bindings sites for interferon (IFN) on the limiting cell membranes of human and mouse fibroblasts and erythrocytes were revealed by an indirect immunoferritin technique. Mouse IFN-beta and human IFN-beta of high specific activity were used with the corresponding purified antibodies. Species-specific IFN binding was demonstrated by ferritin deposition on human erythrocytes and fibroblast membranes treated with human IFN and on mouse erythrocytes and fibroblast membranes treated with mouse IFN, but not on human erythrocytes or fibroblast membranes treated with mouse IFN. IFN binding sites on fibroblasts were located on regions of membranes between microvilli, whereas diphtheria toxin receptors were demonstrated mainly on microvilli. IFN binding altered the diphtheria toxin after IFN treatment. This reduced toxicity correlated with a decrease in the quantity of receptors for diphtheria toxin on the cell membrane. Thus, the species-specific binding of IFN appears to depend on membrane receptors in discrete regions of the limiting membrane which are present not only on functionally responsive fibroblasts but also on erythrocytes.

Corrections for mRNA extraction and sample normalization errors find increased mRNA levels may compensate for cancer haplo‐insufficiency

“…Diploid lymphocyte chromosomes were confirmed by FISH karyotyping (Allison and Nestor, ) and the SKY karyotypes of A549, DU 145, LN‐18, PC‐3, and SUIT‐2 have been published (Nestor et al, ; Bazeley et al, ). Complete SKY analyses of ≥24 karyotypes was performed, although only 13 normal BUD‐8 karyotypes were successfully examined in this previously reported diploid line (Kushnaryov et al, ). HK genes were identified by functional analyses and expression in >99% of 2,263 cell types (Bazeley et al, ), followed by selection of 520 HK genes mapping to a single locus on chromosomes 1 to 22.…”

Rat interferon enhances the expression of acetycholine receptors in rat myotubes in culture

“…Indeed, IFN has varied effects on cell growth and functions, especially in cell membranes. These include inhibition of lectin-induced capping of immunoglobulins on mouse splenocytes (Matsuyama, 1979), cytoskeleton alterations (Preble and Friedman, 1983), early increase (Kuhry et al, 1983) or decrease (Pfeffer et al, 1981) in membrane fluidity, changes in fatty acid composition (Chandrabose et al, 1981;Apostolov et Barker, 1981), inhibition of the binding of cholera toxin, of TSH (Chang et al, 1978), and of diphteria toxin (Kushnaryov et al, 1982), enhancement of major histocompatibility complex (MHC) antigens (Rosa et al, 1986), decreased exposure of oligosaccharide residues of gangliosides , etc. In this paper, we present experimental evidence that rat IFN does enhance the expression of a-Bgt binding sites on rat myotubes in culture.…”

Ultrastructural distribution of interferon receptor sites on mouse L fibroblasts grown in suspension: ganglioside blockade of ligand binding

“…Employing an indirect immunoferritin technique, we have previously shown the ultrastructural location of receptor sites of human and mouse IFN-P on cells cultured in a monolayer (26). Virtually no coated membrane areas or coated pits were revealed at 22°C on the surface of mouse L929 cells grown in monolayer; IFN receptors were distributed randomly on the membrane of these cells.…”

“…IFNs. Mouse L929 IFN-13, 3.4 x 107 IU/mg of protein, used in the majority of immunocytochemical experiments, was prepared as previously described (26). The mouse IFN that we labeled with 1251 (Biotechnologies, New Haven, Conn.) had a specific activity of 5 x 108 IU/mg of protein.…”

“…Mouse mock IFN was prepared by using cell culture fluid from uninduced L929 cells processed through identical purification steps as mouse IFN (26). No antiviral activity was detected in the mock preparations.…”