Cloning and Expression
of Human CD20 Gene on NIH-3T3 Cell
Membrane
HONG Hai-Yan*1, GUO Yan-Xiang, WANG Jia-Nan, LAI
Chun-Ning, QI Zhong-Tian1, SHEN Bei-Fen
( Institute of Basic Medical Sciences, Academy of Military Medical
Sciences, Beijing 100850, China； 1Department of Microbiology, Second
Military Medical University, Shanghai 200433, China )
Abstract CD20 is a
specific antigen expressed on normal and neoplastic B cells exclusively. Recent
researches showed that in B cell leukemia, CD20 was over-expressed. Therefore
monoclonal antibody (McAb) to CD20 may be of clinical value in diagnosis and
treatment of some leukemias and lymphomas. In this study, the full length gene
of CD20 cDNA were cloned from total RNA of Raji cells, inserted into
an eukaryotic expression vector pcDNA3.1, forming a recombinant plasmid
pcDNA3.1/CD20. NIH-3T3 cells were transfected with pcDNA3.1/CD20
and selected with G418 for the transfected cells. Alkaline phosphatase against
alkaline phosphatase assay(APAAP) experiments showed that the selected cells
could express the human CD20 onto its surface. Balb/c mice were immunized with
CD20＋ NIH-3T3 cells once three weeks for 3
shuts. Indirect immunofluorescence experiments were done with the Raji cells
and the serum of the immunized mice, and the results showed that the spleen of
the immunized mice could be used to prepare the McAb to CD20 .
Key words human CD20； gene transfection； immunization
*Corresponded author： Tel：86-21-25070267, Fax：86-21-25070265,e-mail：[email protected]