THE EFFECTS OF HETEROLOGOUS ANTILYMPHOCYTIC ANTISERUM IN THE LATE PRENATAL AND EARLY POSTNATAL PERIOD IN MICE

Abstract

Female CBA mice were injected with heterologous antilymphocytic antiserum (ALS) or normal rabbit serum (NRS) during gestation or lactation. Their progeny grew normally and rejected skin homografts at the age of 21 clays at the same tempo as controls. Injection of ALS or NRS did not interfere with normal gestation. ALS at immunologically effective concentrations was not toxic to newborn mice. CBA mice treated with 0.05–0.15 ml of ALS within 10 days of birth and grafted on day 21 retained A strain skin homografts longer than normal (maximum, 47 days; maximum in controls, 16 clays). Mice treated with either NRS or ALS in the first 10 days of life were found to be paralysed with respect to rabbit IgG. This effect was demonstrated by following the elimination rate of a test dose of 131I rabbit IgG administered after challenge at 21 days of life in the presence of adjuvant. This persisting effect of ALS in young mice over a period of rapid growth could be due either to the persistence of ALS as such or to a modification of the progeny of cells originally exposed to it.