Lamprey is a representative of the agnathans, the most ancient class of vertebrates. Parasitic lampreys secrete anticoagulantfrom their buccal glands and prevent blood coagulation of host fishes. We identified a buccal gland secretory protein-2(BGSP-2) from a buccal gland cDNA library of Lampetra japonica. The full-length BGSP-2 gene was cloned and the recombinantBGSP-2 protein was generated. The role of BGSP-2 on lymphocyte proliferation was studied by examining its effects onhuman T lymphocytes. We found that lamprey BGSP-2 was able to effectively block the proliferation of T cells in vitro by inducingG_1/S cell cycle arrest. Furthermore, it inhibited the proliferation of human T lymphocytes stimulated by phytohemagglutinin(PHA) at a minimum concentration of 0.1μg/ml. Our data suggest that lamprey BGSP-2 is able to block the mitosis of humanT lymphocytes at the G1/S point, and has the potential of anti-proliferative effect on PHA-activated T
Jing SUN Shuiyan YU Zhuang XUE Cenjie LIU Yu WU Xin LIU Qingwei LI
