Four normal human subjects were immunized with alligator erythrocytes. The development of in vitro lymphocyte blastogenesis and humoral antibody to these cells was followed at serial intervals after immunization. Humoral antibody was not detected in preimmunization samples of serum. Significant in vitro lymphocyte blastogenesis to alligator erythrocytes was seen with all four subjects prior to immunization. This reaction represented either a primary immune response in vitro or an example of antigenic cross reactivity. Following immunization, there was a rapid increase in the blastogenic response. This effect was noted before antibody was detected in the serum and persisted long after antibody could no longer be measured. There was, however, a correlation between antibody formation and in vitro lymphocyte blastogenesis. It is concluded that in vitro lymphocyte blastogenesis is a more sensitive index for both the development and the persistence of an immune response to a xenogeneic cell than is the measurement of humoral antibody.
ASJC Scopus subject areas