Augmentation of Leukemic Lymphocyte

This study demonstrates that the deincorporate ‘4C-thymidine during stimficiency of phytohemagglutinin (PHA) ulation with phytohemagglutinin in cell receptors recently shown to be present culture. The present experiments serve on the leukemic lymphocyte may be as a prototype for possible in vivo ameliorated by incubating these cells modification of the leukemic lymphowith a biologically analogous material cyte surface to make this cell amenobtained from human saliva. This able to immunogenic stimuli and p0manuever, performed under controlled, tentially more susceptible to chemostandardized conditions, doubled the therapeutic agents. capacity of leukemic lymphocytes to O NE OF THE CHARACTERISTICS of the lymphocyte in chronic lymphocytic leukemia (CLL) is its failure to respond in a quantitatively normal manner 3 when exposed to phytohemagglutinin (PHA). Whereas this suboptimal in vitro reactivity was explained initially on the basis of deficiencies of intracellular organelles alone,48 the recent demonstration that the leukemic lymphocyte lacks PHA-binding receptor sites on its surface9 implied that events at the periphery of this cell might also be disturbed. Since the biochemical sequences leading to PHA-induced RNA, DNA, and protein synthesis, and ultimately mitosis are initiated at the cell membrane,’#{176}’3 defects in this structure are of critical primary importance. The purpose of this investigation was to determine whether the responses of the leukemic lymphocyte to PHA could be augmented by providing, from an external source, additional binding sites for the mitogen. This was accomplished by incubating leukemic lymphocytes with lyophilized human saliva, which contains a PHA-binding glycoprotein,’4 prior to being placed in cell culture. Such treatment doubled incorporation of ‘4C-thymidine (‘4C-Tdr) by these cells during stimulation with PHA.