Expression of biologically active human recombinant interferon alpha 2b in human breast cancer cell line Bcap-37

Human interferon alpha 2b (IFNα-2b) is a pleiotropic cytokine used to treat various viral diseases and cancers. Conventionally, recombinant human IFNα-2b used in clinics was produced by prokaryotic expression system, which always lack of enough biological activity due to limitations on proper folding and post-translational modifications, so the eukaryotic expression system are becoming prevailing method for the production of recombinant proteins. In this study, human breast cancer cell Bcap-37 was firstly used as host for the expression of human IFNα-2b, with the expression vector pIRES2-IFN-EGFP, in which IFNα-2b gene is under the control of CMV promoter. The expression of recombinant IFNα-2b was detected by Western blot and ELISA. Results showed that the concentration of the secreted recombinant IFNα-2b in culture medium was 435.7 pg/mL/24 h. Biological activity of the recombinant IFNα-2b was assayed by detecting the expression of IFN-inducible genes, including MxA, OAS, PKR, and Caspase1 through QRT-PCR. Results demonstrated that recombinant IFNα-2b possess the biological activities. Compared to non-transgenic cells, the expression levels of the aforementioned four IFN-inducible genes were increased by 18.098-, 1.843-, 2.21-, and 3.066-folds, respectively. We got to a conclusion that the human breast cancer cell Bcap-37 could express bioactive recombinant IFNα-2b.