TOLERANCE-MEDIATED INHERITANCE OF IMMUNE RESPONSIVENESS

A marked variation in DNA synthesis is observed in lymphocyte cultures stimulated with PHA. When other variables are closely controlled part of the variation seen can be attributed to hour to hour differences in the ability of autologous serum to sustain DNA synthesis. This variation is unrelated to serum phosphorus concentration or to insulin, growth hormone, or hydrocortisone levels. In addition, under closely controlled conditions variation in DNA synthesis occurs which is attributable to changes in the lymphocytes themselves. In the prodrome of an acute gastroenteritis before any symptoms had appeared, the lymphocytc response to PHA was decreased drastically. It is not clear whether the changes seen in vitro relate to in vivo events. It is tempting to speculate, however, that the events observed in vitro reflect mechanisms for the in vivo alteration of lymphocytc reactivity in the normal individual. The hypothesis that the normal immune system is subject to such regulation is plausible, but further experiments are necessary to determine if, in fact, this is the case. It also remains to be seen whether the factors observed in the above experiments arc responsible, when greatly magnified, for the alteration of the PHA response seen in certain disease states. © 1969 S. Karger AG, Basel.