CELL-CELL INTERACTION IN CALF AND HUMAN LYMPHOCYTES TRANSFORMED BY SODIUM PERIODATE

Abstract

Publisher Summary This chapter describes the preparation of lymphocytes from calf submandibular lymph nodes by mincing in medium. In an experiment described in the chapter, human lymphocytes are purified from peripheral blood by density gradient centrifugation. Addition of supernatant media from oxidized calf cell cultures to untreated cultures did not stimulate the rate of DNA synthesis, but human supernatant media transformed human cells to the same degree as oxidation of the cells. In order to define whether membrane-associated molecules are responsible for the cell–cell stimulation in human lymphocyte cultures, human tonsils were frozen and plasma membranes are isolated by freeze-shredding and differential centrifugation. Untreated human lymphocytes were cultured with variable amounts of untreated or NaI0 4 -oxidized tonsil plasma membranes. DNA synthesis rates exceeded that of control lymphocytes alone, only when high concentrations of untreated membranes were added. Oxidized membranes do not result in stimulation of DNA synthesis. NaIO 4 induces calf lymphocyte transformation in oxidized cells themselves, independent of cell–cell interaction. NaIO 4 transforms human lymphocyte cells suspensions—largely a result of cell–cell interaction—through soluble factors.