Construction of C3a secrectory expression vector and tubular epithelial cell line stably expressing C3a / 医学研究生学报

ABSTRACT

[Abstract ] Objective Evidence from previous studies indicated that over-activation of C3a/C3aR axis existed in the renal tubular epithelial cells of patients with renal diseases including diabetic nephropathy .However , the pathological significance of over-ac-tivating C3a/C3aR axis still remains to be elucidated .In this study, we constructed a renal tubular epithelial cell line over-expressing C3a in a secretory manner in order to provide a cell model to investigate the pathological significance of over -activating C3a/C3aR axis under various pathological scenes . Methods We designed a synthesized C3a secretory expression unit and cloned it into the multi-clonal site of lentivirus expression vector pLenti 6.3-MCS-IRES2-EGFP.After identification by sequencing , recombinant lentivirus was packaged by using pLenti 6.3-C3a-IRES2-EGFP and packaging plas-mid in 293T cells.Then, the recombinant lentivirus was used to in-fect HK2, a cell line of human renal tubular epithelial cells .After screening in medium with blasticidin , blasticidin resistant cell clones were obtained .Real-time PCR and ELISA method were applied to analyze the expression and secretion of stable transfected cells cloned C3a and identify renal tubular epithelial cell lines with stable over-activating C3a. Results ①C3a secretory expression unit was suc-cessfully synthesized and correctly cloned into the multi-clonal site of pLenti6.3-IRES2-EGFP; ②C3a secrectory expression recombi-nant lentivirus LV-C3a was successfully packaged with a high titer of 5 ×108/mL;③HK2 Cell clones resistant for blasticidin were ob-tained;according to the analysis of Real-time PCR and ELISA, the C3a mRNA level in HK2-C3a cell lines was significantly higher than that of HK2 cells(1.0 ±0.5 vs 1321.0 ±18.0, P<0.01) and the secreted C3a level increased significantly ([0.3 ±0.2]ng/mL vs [249.0 ±37.0] ng/mL, P<0.01). Conclusion The present study successfully constructed C 3a secretory expression vector pLenti6.3-C3a-IRES2-EGFP and C3a over-expression renal tubular epithelial cell line HK 2-C3a, which is very useful in further study of the function and significance of C 3a/C3aR axis not only in renal tubular epithelial cells but also in other cell types .