Characterization of the binding of radioiodinated hybrid recombinant IFN-alpha A/D to murine and human lymphoid cell lines.
The hybrid recombinant human interferon (IFN) rIFN-alpha A/D was radioiodinated. Specific binding of [125I]rIFN-alpha A/D was observed with both human and murine cell lines. The binding of [125I]rIFN-alpha A/D to human Daudi cells had similar characteristics to the previously described binding of [125I]rIFN-alpha A or -alpha 2. The following lines of evidence demonstrated that [125I]rIFN-alpha A/D bound with high affinity to the same receptor on murine cells as murine IFN-alpha and -beta: (i) the binding of [125I]rIFN-alpha A/D to murine LBRM cells was inhibited to a similar extent by natural murine IFN-alpha, natural murine IFN-beta, and rIFN-A/D; (ii) the Kd (approximately 2 X 10(-10) M) obtained from both competition experiments and saturation binding experiments with [125I]rIFN-alpha A/D was comparable to the previously reported Kd for the binding of natural murine IFN-alpha and -beta to other murine cell lines; (iii) the size of the cross-linked [125I]rIFN-alpha A/D receptor complex formed on murine LBRM cells was similar to the previously reported cross-linked complex formed after binding radioiodinated natural murine IFN-beta to other murine cell lines. Due to the current lack of readily available recombinant murine IFN-alpha or -beta for radiolabeling and the previously demonstrated biological activity of rIFN-alpha A/D on murine cells, [125I]rIFN-alpha A/D should prove to be a useful reagent for further studies of murine IFN receptors.
Faltynek
C R
CR
Department of Immunopharmacology, Sterling Research Group, Malvern, PA 19355.
Princler
G L
GL
Schwabe
M
M
Shata
M T
MT
Lewis
G K
GK
Kamin-Lewis
R M
RM
D000818:Animals; D002460:Cell Line; D006801:Humans; D007370:Interferon Type I / Q000378:metabolism*; D007457:Iodine Radioisotopes; D008214:Lymphocytes / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism; D017471:Receptors, Interferon; D011994:Recombinant Proteins
D007370:Interferon Type I; D007457:Iodine Radioisotopes; D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D011994:Recombinant Proteins