Tissue Culture of Cells Already in DNA Synthesis from Patients with Infectious Mononucleosis

1. Peripheral blood cultures from patients with infectious mononucleosiscontained approximately 50 times more cells incorporating tritiated thymidineat time 0 than normal cultures.

2. Cultures from these patients showed active cell division within thefirst 24 hours. No cell division was seen during this time in cultures of normal cells.

3. Cells dividing within the first 24 hours were identified as cells whichhad incorporated thymidine at time 0 by observation of metaphases containingtritiated thymidine.

4. Cell division ceased after 18-24 hours in the absence of phytohemagglutinin.

5. The data suggest that a population composed of immature lymphocyticcells in the circulation of patients with infectious mononucleosis is in theprocess of cell division. Proliferative capacity of peripheral blood cells cannot be studied adequately by ordinary morphologic technic.

Submitted on March 16, 1964 Accepted on November 11, 1964     

The Kinetics of Cell Proliferation in Cultures of Human Peripheral Blood

The kinetics of growth of peripheral blood cells in tissue culture are described. There was a rapid increase of cells in DNA synthesis beginning at24 hours and by 72 hours 40-45 per cent of the cells were in DNA synthesis.Mitotic rates of 1 per cent/hour were seen after 72 hours in cultures. Studieswith tritiated thymidine and colchicine indicated that these cells representtransformed lymphocytes and do not arise from the cells in DNA synthesisat time zero or from any other small population of cells.

Accepted on November 7, 1961