Study on influencing factors in efficiency of introducing gene into human keratinocyte (KC) / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe the effect of plasmids in different size and gene transfection protocol on efficiency of introducing gene into human KC.</p><p><b>METHODS</b>Four plasmids in different size, inclu-ding pSUPER-enhanced green fluorescent protein (EGFP), pEGFP-N2, pHSER-green fluorescent protein (GFP) and ploxP-EGFP, were transfected into immortal human KC line (HaCaT) and human embryo kid-ney cell line (293FT) separately following transfection protocols of liposome (LTP), cation polymerizer (CPTP), electroporation combined with nucleus transfection agent (ETP) and lentivirus. 293FT was used as control. GFP expression was observed under inverted fluorescence microscope. The transfection efficiency (TE) was calculated.</p><p><b>RESULTS</b>(1) The four plasmids could be introduced into HaCaT (TE, 1.0%-3.3%) and 293FT (TE, 80.0%-84.7% ) following LTP. (2) The four plasmids could also be introduced into HaCaT (TE, 1.0%-3.7% ) and 293FT (TE, 81.3%-86.7% ) following CPTP. (3) Two shorter plasmids (pSUPER-EGFP and pEGFP-N2) could be introduced into HaCaT by ETP with higher TE than the othr two longer plasmids (pHSER-GFP and ploxP-EGFP), which were 22.3% and 19.0% vs. 4.0% and 3.3%, respectively. (4) pHSER-GFP packaged by lentivirus could be introduced into HaCaT with the TE reaching 97.0%, which surpassed the above three protocols.</p><p><b>CONCLUSIONS</b>It is difficult to introduce exogenous gene into human KC by LTP or CPTP; TE of lentivirus transfection protocol apparently surpasses</p>

Clone screening and interference efficiency of seed cells with CCL20 gene knockdown for tissue-engineered skin / 中华外科杂志

<p><b>OBJECTIVE</b>To screen stable cell clones of CCL20 gene knockdown and assess their interference effects, recombinant lentivirus vectors with CCL20 gene specific shRNA were applied to infect human immortal keratinocyte line (HaCaT).</p><p><b>METHODS</b>The three pHSER-CCL20-shRNA-GFP vectors (pHCG-1 and pHCG-2 were CCL20 gene specific, and pHCG-3 was used as mismatch control) have been previously constructed. The virus packaging cell line 293FT was transfected with these vectors by using CaCl2 methods to produce lentiviral particles. After the viral titers of these three harvested cell supernatants were determined by flow cytometry, HaCaT cells were transfected by these viruses and screened under the pressure of G418. The CCL20 mRNA from HaCaT cell clones and the CCL20 protein levels in the supernatants of HaCaT cell clones were detected by Real-time RT-PCR and ELISA, respectively.</p><p><b>RESULTS</b>The titers of three lentiviruses were 7.08 x 10(5) transduced units (TU)/ml, 1.88 x 10(5) TU /ml and 2.08 x 10(5) TU/ml, respectively. Two HaCaT cell clones from each lentiviral vectors were obtained after G418 screening for 5 - 8 weeks. Four CCL20 gene specific clones showed stable interference effect in both Real-time RT-PCR and ELISA. The mRNA expression and protein level of CCL20 gene specific clones were down regulated significantly.</p><p><b>CONCLUSIONS</b>The four human immortal keratinocyte clones with long term CCL20 gene knockdown have been screened by recombinant lentivirus vectors with CCL20 gene specific shRNA. These clones might be served as seed cells for novel tissue-engineered skin with lower rejection.</p>