Preferential utilisation of deoxycytidine by undifferentiated (peanut positive) tonsillar lymphocytes

Peanut agglutinin (PNA), a D-galactose specific lectin, agglutinated 10-18% of lymphocytes isolated from tonsils of 3- to 6-yr-old children. PNA+ cells were found to be mainly B lymphocytes showing a 9.6 times higher specific activity of DNA polymerase alpha compared to the PNA- cells. The specific activity of deoxycytidine kinase as well as the incorporation of [5-3H]deoxycytidine were also much higher in PNA+ cell fraction than in PNA- fraction (7.7-fold and 6-fold, respectively). On the other hand, thymidine kinase activity and [5-3H]deoxythymidine incorporation were only 3.6 and 3.9 times higher, respectively. The data presented here show a high degree of DNA synthesis and preferential utilisation of [5-3H]deoxycytidine for DNA synthesis in this undifferentiated B lymphocyte fraction.