"Interiorization of Phytohemagglutinin during Activation of Human Killer T-Lymphocytes."

John H. Frenster, M.D.
Departments of Medicine
Stanford University and Santa Clara Valley Medical Center
San Jose, California 95128

Human T-lymphocytes can be activated by phytohemagglutinin (PHA) to the blastic killer-cell state in preparation for in-vivo immunotherapy trials in donor cancer patients (Frenster JH, Ann. N.Y. Acad. Sci. 277,
45-51, 1976). Human peripheral blood buffy coat cells (granulocytes, lymphocytes, and monocytes) were incubated from 15 minutes to 24 hours with purified tritiated PHA (³H-PHA) in-vitro, and the localization of individual ³H-PHA molecules was determined by high-resolution electron- microscopic radioautography. Granulocytes degenerated quickly in culture and could not be analyzed, but lymphocytes and monocytes underwent RNA synthesis, blastic transformation, and cell membrane activation by 24 hours of culture. Both lymphocytes and monocytes concentrated ³H-PHA from the medium, and at 15 minutes of culture, both types of cells had interiorized most of their ³H-PHA into the cytoplasm from the cell membrane, with smaller amounts already within the cell nucleus. Uptake and interiorization of ³H-PHA continued, but at 24 hours of culture, the lymphocytes had concentrated nearly all of their ³H-PHA within the cell nucleus, while the monocytes had concentrated nearly all of their ³H-PHA within the cell cytoplasm. Further culture beyond 24 hours resulted in DNA synthesis and cell mitosis of lymphocytes but not of monocytes, suggesting that nuclear interiorization of PHA may be necessary for DNA synthesis and cell division in lymphocytes. Supported in part by Research Grants CA-10174 and CA-13524 from the National Cancer Institute, by Research Grant IC-45 from the American Cancer Society, and by a Research Scholar Award from the Leukemia Society of America.
Top of Page - Matrix Cognition Home Page - Current Research - Links 

matrixcognition: "Computer-Assisted Decision-Making".