Abstract: Objective To clone human CD45 gene PTPRC and establish Hela cells overexpressing recombinant human CD45
protein. Methods The intact cDNA encoding human CD45 amplified using RT-PCR from the total RNA extracted from
peripheral blood mononuclear cells (PBMCs) of a healthy donor was cloned into pMD-18T vector. The CD45 cDNA fragment
amplified from the pMD-18T-CD45 by PCR was inserted to the coding region of the PcDNA3.1-3xflag vector, and the resultant
recombinant expression vector PcDNA3.1-3xflag-CD45 was transfected into Hela cells. The expression of CD45 in Hela cells
was detected by flow cytometry and Western blotting, and the phosphastase activity of CD45 was quantified using an alkaline
phosphatase assay kit. Results The cDNA fragment of about 3 900 bp was amplified from human PBMCs and cloned into
pMD-18T vector. The recombinant expression vector PcDNA3.1-3xflag-CD45 was constructed, whose restriction maps and
sequence were consistent with those expected. The expression of CD45 in transfected Hela cells was detected by flow
cytometry and Western blotting, and the expressed recombinant CD45 protein in Hela cells showed a phosphastase activity.
Conclusion The cDNA of human CD45 was successfully cloned and effectively expressed in Hela cells, which provides a basis
for further exploration of the functions of CD45.