The effect of N acetyl C-galactosamine and other sugars on the mitogenic activity and attachment of PHA to tonsil cells.

P HYTOHEMAGGLUTININ (PHA), an extract of the red kidney bean, agglutinates erythrocytes,’ leukocytes,’ and other types of cells.2 Lymphocytes, stimulated by PHA, show an increase in the synthesis of DNA, RNA, and protein. These metabolic changes are accompanied by cell enlargement and mitosis. Little is known about the site where PHA attaches to the cell or of the mechanism underlying its mitogenic properties. Recently the effect of simple sugars on the agglutination of erythrocytes and leukocytes by PHA was studied in this laboratory. It was found that agglutination was specifically and reversibly inhibited by N acetyl D-galactosamine ( NAGAL) in a concentration of 10-50 mg./ml.4 The present report is concerned with the effect of NAGAL on the stimulatory activity of PHA and with its attachments to lymphocytes.