Acta Pharmacologica Sinica 2007 October; 28 (10): 1659-1664; doi: 10.1111/j.1745-7254.2007.00623.x

Aim: To investigate the anti-lymphoproliferative effect of the prepared recombinant chimeric human/murine anti-cluster of differentiation(CD) 71 monoclonal antibody (AbCD71), which is composed of mouse-derived, antigen-binding variable regions and human-derived constant regions.

Methods: After plasmids construction and transfection, the expression of AbCD71 in the transfectoma supernatant was determined by the sandwich ELISA. Indirect immunofluorescence assay was used to measure the antigen-binding characteristic and the percent CD71-expressed peripheral blood mononuclear cells (PBMC). The antibodies were purified from the ascites via diethylaminoethyl(DEAE)-Sephadex A-50 chromatography and then identified by SDS-PAGE. At last, inhibitory effect of AbCD71 on PHA-induced PBMC proliferation was calculated by methyl thiazolyl tetrazolium (MTT) assay.

Results: Constant domain of heavy chain (C_H) and light chain (C_L)of AbCD71 were in the human Cγ family and human Cκ family, respectively. AbCD71 could compete with its original murine mAb to bind with CD71-positive human leukemia cell line CEM cells. AbCD71 could inhibit the peripheral blood mononuclear cell proliferation induced by phytohemagglutinin (PHA) in vitro in a dose-dependent manner, especially at time-points 0 and 12 h after induction. There was no statistical difference when compared with original murine mAb.

Conclusion: The AbCD71 is a promising immunosuppressant. Our approach to blocking CD71 with the chimeric human/murine mAb provides a novel strategy for prolonging allograft survival.

Keywords: AbCD71; chimeric human/murine antibody; lymphoproliferation; transplantation rejection